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WO2025217005A1 - Dispositifs de capteurs électroniques, à semiconducteur et photoniques, boîtiers, fabrication et cas d'utilisation - Google Patents

Dispositifs de capteurs électroniques, à semiconducteur et photoniques, boîtiers, fabrication et cas d'utilisation

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Publication number
WO2025217005A1
WO2025217005A1 PCT/US2025/023345 US2025023345W WO2025217005A1 WO 2025217005 A1 WO2025217005 A1 WO 2025217005A1 US 2025023345 W US2025023345 W US 2025023345W WO 2025217005 A1 WO2025217005 A1 WO 2025217005A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensor
sample
detection
molecules
detection area
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/US2025/023345
Other languages
English (en)
Inventor
John J. Daniels
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Diagmetrics Inc
Original Assignee
Diagmetrics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US18/628,747 external-priority patent/US20250314613A1/en
Priority claimed from US18/667,489 external-priority patent/US20250314614A1/en
Application filed by Diagmetrics Inc filed Critical Diagmetrics Inc
Publication of WO2025217005A1 publication Critical patent/WO2025217005A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/414—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
    • G01N27/4145—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS specially adapted for biomolecules, e.g. gate electrode with immobilised receptors
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/08—Measuring devices for evaluating the respiratory organs
    • A61B5/082—Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue
    • A61B5/14532—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue for measuring glucose, e.g. by tissue impedance measurement
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/414—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
    • G01N27/4146—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS involving nanosized elements, e.g. nanotubes, nanowires
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor

Definitions

  • the present inventions relate generally to semiconductor sensors and, more particularly, to a unique packaging structure and manufacturing process for a bare die semiconductor sensor used in diagnostic and environmental applications, where a portion of the bare die sensor must remain exposed to allow a sample to be received at a detection area of the sensor.
  • the standard packaging approach is to fully encapsulate the semiconductor die to safeguard the internal semiconductor materials and device features.
  • Traditional packaging solutions provide electrical connectivity through wire bonding that connects device features on the die with external pins or leads, which can then soldered onto a printed circuit board (PCB) or connected through a socket that is soldered on the PCB. This full encapsulation is considered essential for protecting the sensitive components from environmental factors that could compromise their integrity and functionality.
  • packaging techniques are not optimal for semiconductor sensors designed to interact with a fluid sample for the detection of various analytes. These sensors require direct exposure of certain areas or the semiconductor device to the sample while still maintaining the integrity of the electrical connections and the sensor itself. There exists a need for a packaging structure that allows the sensor to function effectively in its intended diagnostic application.
  • the present inventions also relate generally to breath-based disease diagnosis and monitoring.
  • diabetes is a global health concern that affected an estimated 536.6 million people in 2021, with projections rising to 783.2 million by 2045. It is characterized by the body’s inability to produce or properly utilize insulin, resulting in elevated blood glucose (BG) levels that can damage various organs, potentially leading to complications such as cardiovascular disease, neuropathy, and kidney failure.
  • BG blood glucose
  • the standard practice of diagnosing and monitoring diabetes frequently involves invasive techniques that require skin punctures to draw blood, causing discomfort, stress, and the risk of infection for patients who must test BG levels multiple times per day.
  • a breath-based diagnostic system that integrates sensors for measuring biomarker in the condensate of exhaled breath vapor, such as glucose in EBC sample, along with sensors for detecting breath gases, such as acetone, ketones and/or ammonia in exhaled breath.
  • breath gases such as acetone, ketones and/or ammonia in exhaled breath.
  • the invention described herein addresses these challenges by providing a packaged semiconductor sensor with a novel structure that includes an open detection area for fluid sample contact. This configuration enables the semiconductor sensor to analyze samples effectively while ensuring that the rest of the semiconductor die is adequately protected and the electrical connections are maintained.
  • a packaged semiconductor sensor includes a semiconductor die having a top surface and a bottom surface, with at least two bond pads and at least one detection area located at the top surface.
  • a support member has a top side and a bottom side, and a detection window provided as an opening in the support member from the top side to the bottom side.
  • the opening/detection window in the support member and the detection area located at the top surface of the semiconductor die define a sample well for receiving a sample to be tested by the packaged semiconductor sensor.
  • a least two conductive traces are provided on the bottom side of the support member.
  • a biosensor card assembly includes a bare die semiconductor sensor with a top surface including two or more bond pads and at least one detection area.
  • a support member has at least a corresponding number of conductive traces as the bond pads on the bare die.
  • the conductive traces are provided on at least a bottom side of the support member for connecting with the bond pads of the bare die.
  • the support member has a through-hole detection window aligning with the detection area of the bare die.
  • a conductive adhesive is provided between each bond pad of the bare die and a corresponding conductive trace of the support member.
  • the conductive epoxy provides an electrical connection between a respective bond pad and a corresponding conductive trace.
  • a sensor card assembly is configured for enhanced fluid sample analysis.
  • a sensor element is provided with a detection area and a plurality of bond pads on a top surface.
  • the support member includes a top side with integrated liquid detection features and a bottom side providing conductive traces corresponding to the bond pads.
  • a z-axis conductive adhesive is provided between each bond pad and a corresponding conductive trace for selective electrical connection in the z-axis direction.
  • a detection window on the top side of the support member is aligned with the detection area of the sensor element to form a sample well.
  • an integrated biosensor card and bare die sensor assembly for targeted biomarker detection.
  • a semiconductor die has a top surface with a least one sensor device and at least one sensor area and bond pads associated with each sensor device.
  • a support member having a bottom side with conductive traces corresponding to the bond pads supports the semiconductor die and connects the semiconductor devices of the die to a printed circuit board.
  • An accumulator in fluid communication with the sensor areas applies an electrostatic field to a fluid sample for aligning target biomarkers within a fluid sample. The accumulator facilitates enhanced detection by modulating the orientation and proximity of target biomarkers to the immobilized capture molecules at the sensor areas.
  • a packaged semiconductor sensor includes a semiconductor die having a top surface and a bottom surface, with at least two bond pads and at least one detection area located at the top surface.
  • a support member has a top side and a bottom side, and a detection window provided as an opening in the support member from the top side to the bottom side.
  • the opening/detection window in the support member and the detection area located at the top surface of the semiconductor die define a sample well for receiving a sample to be tested by the packaged semiconductor sensor.
  • a least two conductive traces are provided on the bottom side of the support member.
  • a z-axis conductive adhesive bonds and electrically connects a respective one of the bond pads to a corresponding one of the conductive traces.
  • a sealing member seals the bottom side of the support member with the top surface of the die to seal the sample well.
  • the z-axis conductive adhesive can also be used to form the sealing member.
  • the sealing member can comprise at least one of an epoxy, glue, pressure sensitive adhesive and gasket.
  • a biosensor card assembly includes a bare die semiconductor sensor with a top surface including two or more bond pads and at least one detection area.
  • a support member has at least a corresponding number of conductive traces as the bond pads on the bare die.
  • the conductive traces are provided on at least a bottom side of the support member for connecting with the bond pads of the bare die.
  • the support member has a through-hole detection window aligning with the detection area of the bare die.
  • a conductive adhesive is provided between each bond pad of the bare die and a corresponding conductive trace of the support member. The conductive epoxy provides an electrical connection between a respective bond pad and a corresponding conductive trace.
  • a sensor card assembly is configured for enhanced fluid sample analysis.
  • a sensor element is provided with a detection area and a plurality of bond pads on a top surface.
  • the support member includes a top side with integrated liquid detection features and a bottom side providing conductive traces corresponding to the bond pads.
  • a z-axis conductive adhesive is provided between each bond pad and a corresponding conductive trace for selective electrical connection in the z-axis direction.
  • a detection window on the top side of the support member is aligned with the detection area of the sensor element to form a sample well.
  • an integrated biosensor card and bare die sensor assembly for targeted biomarker detection.
  • a semiconductor die has a top surface with a least one sensor device and at least one sensor area and bond pads associated with each sensor device.
  • a support member having a bottom side with conductive traces corresponding to the bond pads supports the semiconductor die and connects the semiconductor devices of the die to a printed circuit board.
  • An accumulator in fluid communication with the sensor areas applies an electrostatic field to a fluid sample for aligning target biomarkers within a fluid sample. The accumulator facilitates enhanced detection by modulating the orientation and proximity of target biomarkers to the immobilized capture molecules at the sensor areas.
  • a method includes the steps of i) Providing a semiconductor wafer having a transparent substrate, ii) Forming device regions each includes a source, a drain and at least one channel region, iii) Forming a gate oxide layer over each channel region, iv) Forming a detection area area including a charge transfer layer over the gate oxide layer, v) Immobilizing capture molecules on the charge transfer layers, includes the steps of a) immobilizing at least a first set of activatable linker molecules and a second set of activatable linker molecules on the charge transfer layer of device region, each respective first set and second set of activatable linker molecules being activated for binding by a different corresponding first wavelength of linker-activating radiation and second wavelength of linkeractivating radiation, and b) disposing over a surface of the semiconductor substrate wafer covering the plurality of device regions a capture molecule carrier fluid containing at least a first set of activatable capture molecules and a second set of activatable capture molecules as free
  • the method also includes c) selectively irradiating through the transparent substrate a first pattern of radiation includes the first wavelength of linkeractivating radiation and the first wavelength of capture molecule-activating radiation to bind a first set of activated capture molecules to a first set of activated linker molecules.
  • the method also includes d) selectively irradiating through the transparent substrate a second pattern of radiation includes the second wavelength of linker-activating radiation and the second wavelength of capture molecule-activating radiation to bind a second set of activated capture molecules to a second set of activated linker molecules.
  • a semiconductor sensor system includes a semiconductor sensor having a source, a drain, and a substrate configured to form a two-dimensional electron gas (2DEG) within a detection area of the sensor, capture molecules immobilized within the detection area for detecting target molecules, an Exhaled Breath Condensate (EBC sample) Collector configured as a chilled thermal mass connected to the semiconductor sensor, a thermally conductive adhesive directly coupling the semiconductor sensor to the EBC sample Collector to facilitate heat transfer from the semiconductor sensor to the EBC sample Collector, and where the EBC sample Collector is configured to stabilize the temperature of the semiconductor sensor during operation, thereby reducing thermal effects that cause non-linear sensor responses and charge trapping.
  • 2DEG two-dimensional electron gas
  • EBC sample Exhaled Breath Condensate
  • a semiconductor sensor system in another aspect, includes a substrate, a detection area located on the substrate configured to include capture molecules for detecting target molecules, a source and a drain disposed on the substrate and forming part of a two-dimensional electron gas (2DEG) system for measuring electrical properties affected by interactions within the detection area, an insulator coupled to the substrate via an adhesive, configured to thermally isolate the semiconductor sensor from external thermal effects during operation, where the semiconductor sensor further includes a Device Under Test (DUT) sensor and a reference sensor, the DUT sensor being exposed to a liquid sample containing target molecules and the reference sensor being unexposed to the liquid sample to minimize thermal effects influenced by the electrical current flow from the source to the drain.
  • DUT Device Under Test
  • a sensor system in another aspect, includes a substrate equipped with a detection area, capture molecules immobilized within the detection area for binding target molecules, a source and a drain arranged on the substrate to form a flow of charges between the source and the drain dependent on the binding between the capture molecules and the target molecules, and top and bottom driving electrodes configured to apply an electric field to orient and migrate molecules within a sample towards or away from the detection area.
  • a method for fabricating a multi-biomarker detecting semiconductor sensor array includes i) Providing a semiconductor wafer having a transparent substrate. The method also includes ii) Forming and array of sensor devices each includes a source, a drain, and at least one channel region. The method also includes iii) Forming a gate oxide layer over each channel region. The method also includes iv) Forming an array of detection areas including the gate oxide layer.
  • the method also includes v) Immobilizing capture molecules on the detection areas through a multi-step process, includes a) Immobilizing a first set of activatable linker molecules on the detection area of each device region, each linker molecule being activatable by a specific wavelength of linker-activating radiation, b) Applying a first capture molecule carrier fluid over the surface of the semiconductor substrate wafer covering the plurality of device regions, the fluid containing a first set of capture molecules as free- floating activatable capture molecules, c) Selectively irradiating through the transparent substrate with a specific pattern of radiation corresponding to the activating wavelength for the first set of linker molecules, binding the first set of capture molecules to the activated linker molecules, d) Removing the first capture molecule carrier fluid and rinsing the surface to leave behind the immobilized first set of capture molecules, e) Optionally repeating steps b) through d) for subsequent sets of capture molecules, each set being provided in a new carrier fluid and activated for binding by a different corresponding wavelength
  • a method of fabricating a multi-biomarker detecting array of semiconductor sensors on a bare die includes Providing a semiconductor substrate, Forming a plurality of drain electrodes on the substrate, Depositing a drain insulation layer over the drain electrodes, Forming a plurality of source electrodes orthogonal to the drain electrodes and over the drain insulation layer, Depositing a barrier layer over the source and drain electrodes, leaving an opening for forming an array of detection areas, Defining a glass layer over the barrier layer to form sample wells at each detection area while exposing bond pads for the source and drain electrodes, and Forming a gate insulation layer over the glass layer, configuring the detection areas to function as field effect transistors with individually addressable source and drain electrodes.
  • a vertical GaN semiconductor sensor includes a N+ GaN wafer forming a substrate, a N-GaN drift layer disposed over said N+ GaN wafer, a plurality of capillary channels defined within said N-GaN drift layer, a pGaN layer disposed over said N- GaN drift layer, forming p-n junctions therewith, a drain located at a bottom portion of said N+ GaN wafer, multiple sources disposed at a top surface of said pGaN layer, a plurality of depletion layers formed at interfaces between said pGaN layer and said N-GaN drift layer, configured to control charge carrier flow based on binding events occurring at detection areas, capture molecules immobilized within said capillary channels and configured to bind target molecules, a liquid gate electrode configured to apply a gate voltage through a liquid sample disposed at said detection areas, where said sensor is configured to detect target molecules by modulation of the depletion layers and charge carrier flow in response to binding events.
  • a method for detecting molecular binding events using a Wheatstone Bridge circuit includes arranging a plurality of semiconductor sensors, each having a source and a drain, to form a Wheatstone Bridge circuit where each sensor's source-to-drain resistance serves as one of the resistors in the bridge, connecting the Wheatstone Bridge to a power source and a voltage measurement device across two output terminals, balancing the Wheatstone Bridge such that the voltage across the output terminals is zero under a baseline condition without target molecule binding, exposing the semiconductor sensors to a sample potentially containing target molecules, and detecting a voltage difference across the output terminals, the voltage difference being indicative of a molecular binding event that alters the source-to-drain resistance of at least one sensor in the bridge.
  • a breath-based diagnostic for monitoring the progression of diabetes disease includes a) an exhaled breath receiver for receiving a stream of exhaled breath from a user, b) a gas sensor for sensing a gas component from the stream of exhaled breath and generating a sensor signal dependent on at least one gas sensed from the stream of exhaled breath, c) a condensation surface in thermal communication with a chilled thermal mass for chilling a portion of the received stream of exhaled breath into a liquid exhaled breath condensate (EBC sample), d) a biomarker detector for detecting at least one biomarker in the EBC sample and generating a detector signal dependent on at least one biomarker contained in the EBC sample, and e) a microprocessor for receiving the sensor signal and detector signal as monitored biometric parameters and for comparing the monitored biometric parameters to stored initial baseline biometric data previously obtained from the user and stored in a memory connected with the microprocessor.
  • EBC sample liquid exhaled breath condensate
  • the breath-based diagnostic may also include/be configured where the initial baseline biometric data is obtained using a baseline biometric test includes at least one of Hemoglobin A1C (HbAlC), Oral Glucose Tolerance Test (OGTT), Fasting Plasma Glucose (FPG), Random Plasma Glucose (RPG), C-Peptide Test, and Continuous Glucose Monitoring (CGM).
  • HbAlC Hemoglobin A1C
  • OGTT Oral Glucose Tolerance Test
  • FPG Fasting Plasma Glucose
  • RPG Random Plasma Glucose
  • CGM Continuous Glucose Monitoring
  • the breath-based diagnostic may also include/be configured where the gas sensor senses acetone, ketones and ammonia gas components from the stream of exhaled breath and generates the sensor signal dependent on a proportion of the acetone, ketones and ammonia gas components in the stream of exhaled breath.
  • the breath-based diagnostic may also include/be configured where the microprocessor determines at least one patient-specific threshold for the monitored biometric parameters dependent on the stored baseline biometric data, where the monitored breath-based biometric parameters includes levels of glucose detected by the biomarker detector, and acetone detected by the gas sensor, where the monitored biometric parameters are dependent on physiological changes of the user in response to at least one of a therapeutic treatment and a progression of the diabetes disease, determining at least one exceeded threshold dependent on a comparison of the detected one or more monitored biometric parameters and the at least one patient-specific threshold.
  • the breath-based diagnostic may also include/be configured where the microprocessor further activates at least one action depending on the determined exceeded threshold, where the at least one action is at least one of a notification to a patient, a change in the therapeutic treatment, and a notification to at least one trusted receiver.
  • the breath-based diagnostic may also include/be configured where at least one of the notification to the patient and the notification to the trusted receiver includes suggested diagnosis and current treatment options determined through an Al-powered web crawler.
  • the breath-based diagnostic may also include/be configured where the applied treatment includes an applied electrocuetical treatment for activating muscles of the patient. [0036] The breath-based diagnostic may also include/be configured where the at least one action further includes transmitting an alert to a caregiver, modifying the therapeutic treatment, and transmitting data dependent on the physiological change, the one or more biometric parameters, the therapeutic treatment and the least one patient-specific threshold.
  • the breath-based diagnostic may also include/be configured where the step of determining the at least one patient-specific threshold includes determining from a data set of the one or more monitored biometric parameters whether the data set is acceptable for deciding that the at least one physiological change threshold has been exceeded.
  • the breath-based diagnostic may also include/be configured where the step of determining the at least one patient-specific threshold further includes applying a statistical weighting to each of the one or more monitored biometric parameters, where the statistical weighting is dependent on a predetermined value of a ranking of importance in detecting each of the at least one physiological change for said each of the one or more monitored biometric parameters relative to others of the one or more monitored biometric parameters.
  • the breath-based diagnostic may also include/be configured where the biomarker detector includes a vertical GaN semiconductor sensor includes one of an N+ or an N- GaN substrate, the other of the N+ or an N- GaN drift layer disposed over said GaN substrate, a plurality of capillary channels defined within said drift layer, a junction forming GaN layer disposed over said drift layer, forming p-n junctions therewith, one of a drain or source located at a bottom portion of said substrate, the other of the drain or source disposed at a top surface of said junction forming layer, a plurality of depletion layers formed at interfaces between said junction forming layer and said drift layer, configured to control charge carrier flow depending on binding events between a capture molecule and target molecule occurring at a detection area, where the capture molecule is immobilized within said capillary channels and is configured to bind with the target molecule, and a liquid gate electrode configured to apply a gate voltage through a liquid sample disposed at said detection areas, where said vertical GaN semiconductor sensor is
  • the breath-based diagnostic may also include/be configured where said capillary channels are configured substantially parallel to a sample flow to guide a liquid EBC sample sample to said detection areas for interaction with said capture molecules.
  • the breath-based diagnostic may also include/be configured where said capillary channels are configured substantially perpendicular the sample flow to facilitate pooling of the liquid EBC sample sample on said detection areas for interaction with said capture molecules.
  • the breath-based diagnostic may also include/be configured where the width of the depletion layers adjusts in response to an electric field change caused by said binding events, thereby modulating conductivity of said drift layer.
  • the breath-based diagnostic may also include/be configured where said sources are configured to inject charge carriers into said drift layer and said drain is configured to collect charge carriers flowing through said sensor, with said flow being indicative of the presence and concentration of said target molecules.
  • the breath-based diagnostic may also include/be configured where said junction forming layer and said drift layer form a vertical charge carrier pathway for high sensitivity in detecting the binding events.
  • the breath-based diagnostic may also include/be configured where said depletion layers operate to fully form and prevent charge carriers from moving freely across said sensor in the absence of said target molecules, thereby setting a baseline conductance state of the sensor.
  • the breath-based diagnostic may also include/be configured where said binding events between said capture molecules and said target molecules induce changes in said electric field at the interface of said junction forming layer and said N- drift layer, detected as variations in current flow between said source and said drain.
  • the breath-based diagnostic may also include the biomarker detector comprising a lateral flow assay includes: a sample pad for receiving the EBC sample sample that condenses on the condensate surface; a conjugate release pad downstream from the sample pad, where florescent-label molecules are provided, where the florescent-label molecules selectively bind with the target molecules at label-binding sites of the target molecules to form a florescent- labeled target molecule conjugate; a detection area where capture molecules are immobilized, where the capture molecules selectively bind to the target molecules at capture moleculebinding sites to capture and immobilize the fl ore scent-lab eled target molecule conjugate, whereby the detection of the at least one biomarker in the EBC sample by the biomarker detector includes emitting a florescence-triggering wavelength of radiation at the detection area and detecting a florescence emission from the florescent-labeled target molecule conjugate immobilized at the detection area.
  • the breath-based diagnostic may also include the biomarker detector comprising a hybrid semiconductor/lateral flow assay that includes: a lateral flow assay portion having a sample pad for receiving the EBC sample sample that condenses on the condensate surface, a conjugate release pad downstream from the sample pad, where florescent-label molecules are provided, where the florescent-label molecules selectively bind with the target molecules at label-binding sites of the target molecules to form a florescent-labeled target molecule conjugate; and a semiconductor sensor portion having a detection area where capture molecules are immobilized, where the capture molecules selectively bind to the target molecules at capture molecule-binding sites to capture and immobilize the florescent-labeled target molecule conjugate, whereby the detection of the at least one biomarker in the EBC sample by the biomarker detector includes a first detection performed by emitting a florescence-triggering wavelength of radiation at the detection area and detecting a florescence emission from the fl
  • a method includes the steps of i) Providing a semiconductor wafer, ii) Forming device regions includes a source, drain and a channel region, iii) Forming a detection area including a charge transfer layer over said at least one of an insulator layer and a dielectric layer, iv) Immobilizing capture molecules on the charge transfer layer, and v) After immobilizing the capture molecules separating individual semiconductor devices from the semiconductor wafer.
  • an apparatus comprises a fluid dam for controlling the accumulation and release of an exhaled breath condensate (EBC) sample in a microfluidic assembly, the fluid dam including a sample conditioning layered stack including at least one of a sample concentrator, a lysing agent, a buffer, a labeled conjugate and a capture molecule; and at least one of an electronic biosensor and a microfluidic membrane positioned downstream of the fluid dam for receiving the EBC sample after release by the fluid dam.
  • EBC exhaled breath condensate
  • FIG. 1 is a partial exploded perspective view of biosensor card components, illustrating the spatial relationship between conductive traces, z-axis conductive adhesive, and a bare die semiconductor sensor.
  • FIG. 2 illustrates a top-down view of the bare die biosensor, showing the device features on the top surface of the bare die semiconductor sensor.
  • FIG. 3 is an exploded view diagram showing the layered construction of the biosensor card showing the separate components starting from the top overlay, with a liquid detection window, followed by the top conductive traces, the detection window on the support member, and the bottom conductive traces through to the bottom overlay.
  • FIG. 4 is a top-down, layer-by-layer view of the biosensor card's material stack.
  • FIG. 5 illustrates the material composition and stack-up dimensions for an etched copper flex circuit version of the biosensor card.
  • FIG. 6 shows a top view of a bare die semiconductor sensor, showing the layout of individual source and gate connections for four sensor devices, with a common drain.
  • FIG. 7 is a cross-sectional view of a GaN biosensor, showing the layered structure with a detection well at the top surface.
  • FIG. 8 shows top and bottom views of the fully assembled biosensor card.
  • FIG. 9 illustrates a semiconductor biosensor with six individually addressable GaN HEMT (High Electron Mobility) sensor devices sharing a common gate and drain.
  • GaN HEMT High Electron Mobility
  • FIG. 10 shows an alternative semiconductor sensor design with five functional test devices and one reference device.
  • FIG. 11 is a logic flow diagram for Applied Probabilistic Analysis to determine the detecting of a target biomarker, and illustrates the operation of an exemplary method utilized by an exemplary diagnostic device and electronic medical records database.
  • FIG. 12 shows the die attachment process for a bare die semiconductor sensor to the support member.
  • FIG. 13 shows an isolated and partial assembly view of an embodiment of the biosensor card showing the arrangement of conductive traces, detection areas, sample wells, and other relevant structural features of a biosensor card assembly with four individually addressable and functionalizable sensor devices on a single bare die.
  • FIG. 14 illustrates an embodiment of a completed biosensor card with four individually addressable sensor devices.
  • FIG. 15 shows the top side and bottom side of a biosensor card with four independently functional sensor devices, each with its own sample well for targeted molecule detection within the same fluid sample.
  • FIG. 16 is an isolated view showing a bare die sensor attached to conductive traces.
  • FIG. 17 shows a biosensor card with attached sensor die, microfluidic liquid sample flow path and compressed cellulose wick, where the biosensor card assembly is electrically and mechanically connected with a printed circuit board.
  • FIG. 18 is a close up view of a bare die sensor attached to a biosensor card with the detection window of the biosensor card aligned with the detection area of the sensor.
  • FIG. 19 shows a semiconductor sensor device with an accumulator to selectively position target molecules in a fluid sample for enhanced biomarker detection.
  • FIG. 20 is a side view of a sensor for detecting target molecule in a fluid sample with a detection area for receiving the fluid sample and a top driving electrode and a bottom driving electrode where an electric potential drives the target molecule towards the capture molecules to concentrate the target molecule in a portion of the fluid sample received at the detection area.
  • FIG. 21 is a flowchart of the steps for concentrating the target molecule in a fluid sample and testing for a change in electrical characteristics of a functionalized transistor sensor.
  • FIG. 22 illustrates a graphene detection interface with nanoCLAMP capture molecules immobilized by linker molecules, with a portion of the capture molecules immobilized at a greater distance from the detection interface than another portion of the capture molecules.
  • FIG. 23 illustrates target and non-target molecules free floating in a liquid medium in the vicinity of capture molecules immobilized on a graphene detection surface.
  • FIG. 24 illustrates an electric field potential applied in the detection area and driving a target molecule and non-target molecule towards the capture molecules, where the target molecule is captured by a capture molecule extending on linker molecules at a relatively longer distance from the detection interface.
  • FIG. 25 illustrates the electric field potential removed from detection area.
  • FIG. 26 illustrates an opposite polarity electric field potential that drives the target molecule and non-target molecule away from the detection interface, where the target molecule remains tethered by the capture molecule immobilized by the relatively long linker on the detection interface.
  • FIG. 27 illustrates more target molecule and non-target molecules flowing into the detection area.
  • FIG. 28 illustrates the electric field potential applied in the detection area, driving the tethered target molecule into position to be captured by a capture molecule immobilized by a relatively shorter linker molecule, and where another target molecule is captured by another capture molecule extending on linker molecules at a relatively longer distance from the detection interface to concentrate the target molecules in a portion of the fluid sample received at the detection interface.
  • FIG. 29 shows a semiconductor sensor device fixed to a large thermal mass, such as the EBC sample Collector, through a conductive adhesive to remove internally generated heat from the sensor during operation.
  • FIG. 30 shows a semiconductor sensor device fixed to an insulator to thermally isolate the sensor during operation.
  • FIG. 31 stylistically illustrates a field of capture molecules immobilized on the detection area of a sensor device with a single molecule that is about to bind with one or more of the capture molecules.
  • FIG. 32 stylistically illustrates a target molecule binding to one or more capture molecules showing a propagation of charge effects radiating through the field of capture molecules.
  • FIG. 33 shows the formation of an array of drain conductors of a reconfigurable bare die semiconductor sensor.
  • FIG. 34 shows the formation of a drain insulation layer on the an array of drain conductors of the reconfigurable bare die semiconductor sensor.
  • FIG. 35 shows the formation of an array of source conductors at a right angle to the array of drain conductors and over the drain insulation layer of the reconfigurable bare die semiconductor sensor.
  • FIG. 36 shows a barrier layer formed over the arrays of drain and source conductors and having an opening for forming an array of detection areas.
  • FIG. 37 shows a detection area field formed over the arrays for drain and source conductors of the reconfigurable bare die semiconductor device.
  • FIG. 38 shows a pair of drain conductors and a pair of source conductors being tapped for electrical measurement of the source to drain current flow.
  • FIG. 39 illustrates the layout of a sensor array with a glass passivation layer, showcasing individually addressable detection areas, test points for electrical signal capture, and a schematic for Al-driven analysis of binding event patterns.
  • FIG. 40 illustrates a sensor array having test points for signal extraction, a measured binding event, and a liquid gate electrode.
  • FIG. 41 illustrates a sensor array with 120 individually addressable sensor devices featuring a structured layout of twelve drain electrodes.
  • FIG. 42 depicts a biosensor card featuring an integrated antenna for wireless communication, liquid detection capabilities, and a bare die biosensor array with 120 individually addressable devices customizable for either panel tests with different capture molecules or a wide area FET sensor with uniform functionalization to enhance detection sensitivity.
  • FIG. 43 illustrates bare die die biosensor having semiconductor sensor devices functionalized for FluA/FluB/SARS testing.
  • FIG. 44 illustrates an applied-field-reactive capture molecule conjugate having an applied-field-responsive end and a capture molecule end with a linker molecule providing electro-chemical properties that change at least one of a polarity and a conductivity.
  • FIG. 45 illustrates a capture molecule conjugate having a magnetically attractive end and a capture molecule conjugate end.
  • FIG. 46 shows a process for forming aligned and oriented capture molecule conjugates aligned in an aligning field on a dissolvable adhesive.
  • FIG. 47 shows a process for forming aligned and oriented capture molecule conjugates aligned in an electric field on a dissolvable adhesive.
  • FIG. 48 illustrates a bare die sensor having a detection area covered by a field of capture molecules, and a liquid sample containing specific target molecules and non-specific ions and molecules.
  • FIG. 49 illustrates electric field applying top and bottom driving electrodes applying an electric field causing the specific target molecules and non-specific ions and molecules in the liquid sample to orient and migrate in a direction depending on the positive and negative charges of the molecules and ions, where the capture molecules and target molecules are brought into the potential for a specific target molecule binding event.
  • FIG. 50 shows the applied electric field being reversed causing the molecules and ions to orient and migrate in another direction where the target molecules that bind with the capture molecules remain immobilized at the detection area.
  • FIG. 51 shows an optional step of washing away non-specific ions and molecules that are not bound to capture molecules to improve the signal caused by target molecules that remain immobilized at the detection area.
  • FIG. 52 illustrates different capture molecules for detecting different target molecules and bonding to activatable linkers.
  • FIG. 53 shows three sensors formed on a wafer having a transparent substrate, with a combination of selectively activate-able capture molecule and linker pairs.
  • FIG. 54 illustrates the steps of selectively binding a first sub-set of capture molecules to activatable linker molecules.
  • FIG. 55 illustrates illustrates the steps of selectively binding a respective second and third sub-set of capture molecules to corresponding activatable linker molecules.
  • FIG. 56 shows three sensors formed on a wafer having a transparent substrate, each respective sensor having a corresponding selectively activate-able capture molecule and linker pair immobilized on its detection area.
  • FIG. 57 illustrates an emission plate with individually addressable emitting pixels for selectively immobilizing capture molecules on respective detection areas of a biosensor array.
  • FIG. 58 shows a Wheatstone Bridge circuit concept utilizing semiconductor sensors, where each sensor's source-to-drain resistance acts as a bridge resistor, enabling the detection of molecular binding events that cause measurable changes in resistance in the S-D resistance of a DUT (device under test).
  • FIG. 59 shows a vertical GaN sensor array in its baseline state, showing the detailed arrangement of components like depletion layers, drains, gates, and sources, set up for detecting molecular interactions.
  • FIG. 60 illustrates a vertical GaN sensor system where target molecule binding to capture molecules causes changes in the depletion layer.
  • FIG. 61 depicts a vertical GaN semiconductor sensor enhanced with liquid gate electrodes, for applying a gate voltage through a liquid sample to dynamically adjust, for example, the depletion layer, and improve the detection of chemical or biological entities.
  • FIG. 62 illustrates a vertical GaN sensor with a liquid gate, showing how target molecules in a liquid sample influence the field effect at the detection areas by binding with capture molecules, and modulating electrical properties for enhanced signal detection.
  • FIG. 63 illustrates the breath based diagnostic device configured as a stand-alone medical device.
  • FIG. 64 illustrates the outer housing of the breath based diagnostic device.
  • FIG. 65 illustrates the breath based diagnostic device as a modular configuration including durable and washable components and easily handled and installed consumable components.
  • FIG. 66 is a side view showing the flow path of exhaled breath onto the condensate forming surface and the gas sensor.
  • FIG. 67 shows a biosensor card mounted and configured for use with a refreshable biosensor.
  • FIG. 68 is an exploded view of the biosensor card, collection well housing and the bottom cap of the breath diagnosis system
  • FIG. 69 shows a bare die semiconductor biosensor having bond pads and detection surfaces where the feature sizes fit the biosensor card packaging solution.
  • FIG. 70 shows a section for the biosensor card with the bare die sensor attached with the detection surfaces accessible by the liquid or gas sample through a detection window.
  • FIG. 71 illustrates a bare die biosensor with nano rod and capture molecule functionalization.
  • FIG. 72 illustrates another version of the bare die biosensor with a small gate and detection area formed close to the 2DEG (Two-Dimensional Electron Gas) heterojunction.
  • 2DEG Tewo-Dimensional Electron Gas
  • FIG. 73 shows photomicrographs of ZnO nano rods selectively patterned on a semiconductor surface.
  • FIG. 74 shows a wafer scale functionalization process.
  • FIG. 75 illustrates a process for fabricating a GaN HEMT biosensor with a nano rod detection surface and immobilized capture molecules, protected during manufacturing.
  • FIG. 76 shows a vertical GaN semiconductor cross section structure with surface area and sample flow optimizing capillary channels.
  • FIG. 77 shows the vertical GaN semiconductor when the conductance channel flows current in response to binding events between the target molecule and capture molecules.
  • FIG. 78 shows a liquid gate vertical GaN semiconductor.
  • FIG. 79 shows the conductance channel flows current in response to binding events between the target molecule and capture molecules.
  • FIG. 80 illustrates the capillary channels oriented perpendicular to the flow of the liquid sample.
  • FIG. 81 illustrates the capillary channels oriented parallel to the flow of the liquid sample.
  • FIG. 82 a biosensor configured as advanced lateral flow assay with photonic readout.
  • FIG. 83 shows a hybrid version of lateral flow assay and semiconductor biosensor.
  • FIG. 84 shows the hybrid version with capillary channels perpendicular to the liquid sample flow.
  • FIG. 85 shows a disposable/refreshable hybrid version of lateral flow assay and semiconductor biosensor.
  • FIG. 86 shows the modular biosensor/bottom cap for ease of use and cleaning.
  • FIG. 87 shows the modular biosensor/bottom cap ready to be installed into the breath based diagnostic device.
  • FIG. 88 illustrates the exhaled breath to EBC sample flow path onto the hybrid version of lateral flow assay and semiconductor biosensor.
  • FIG. 89 illustrates the construction of a vertically stacked flow-through biosensor where the exhaled breath is directed through flow channels form by the stacking of two biosensors in face-to-face arrangement to form the flow channels that bring the exhaled breath into contact with the functionalized detection surfaces of the biosensor.
  • FIG. 90 shows a horizontally stacked configuration of multiple biosensors that are positioned for multiplex testing of two or more different biomarkers from a stream of exhaled breath.
  • FIG. 91 illustrates a biosensor embodiment that enables an electroosmotic flow (EOF) for moving liquid samples, such as exhaled breath condensate (EBC sample), through the capillary channels and over the detection areas of the flow-through biosensor.
  • EEF electroosmotic flow
  • FIG. 92 shows a vertically stacked configuration of the biosensor with Peltier cooling structures formed adjacent to the semiconductor biosensor.
  • FIG. 93 shows an embodiment of a self-contained testing system where a user's exhaled breath is blown under pressure in a hollow tube and into an inlet formed from the vertically stacked biosensor structure.
  • FIG. 94 illustrates the embodiment of the self-contained testing system showing the position of the stacked biosensors within the hollow tube.
  • FIG. 95 shows the internal components of a rapid, portable and usable-anywhere breath based testing system.
  • FIG. 96 is an exploded view of the rapid, portable and anywhere breath based testing system.
  • FIG. 97 shows the outer tubular shell of the rapid, portable and anywhere breath based testing system.
  • FIG. 98 shows a holistic diabetes and weight management system that includes the breath based diagnostic device and Al-assisted algorithms.
  • FIG. 99 is a flow chart illustrating an algorithm for activating an action based on comparison of a baseline biometric versus monitored biometrics.
  • FIG. 100 illustrates a schematic block diagram of a breath-based diagnostic system for diabetes monitoring, showing the integration of gaseous and liquid sample suppliers, analyzers, condensation surface, microcontroller, memory, user interface, and communications module.
  • FIG. 101 illustrates a respirator or continuous positive airway pressure (CPAP) system integrated with an exhaled breath condensate (EBC sample) and exhaled breath biomarker testing system.
  • CPAP continuous positive airway pressure
  • FIG. 102 illustrates a dual-function face mask system designed to test both exhaled breath biomarkers and ambient air for potential health concerns or environmental exposures.
  • FIG. 103 is an exploded view of a microfluidic assembly for use with a biosensor card.
  • FIG. 104 illustrates the top side of the assembled microfluidic assembly.
  • FIG. 105 illustrates the bottom side of the assembled microfluidic assembly.
  • FIG. 106 illustrates the biosensor card showing the location of the microfluidic paper and a wick.
  • FIG. 107 illustrates the assembled microfluidic assembly mounted on a biosensor card.
  • FIG. 108 is an isolated view showing the microfluidic paper having a conjugate release pad and testing line.
  • FIG. 109 is an exploded view of a microfluidic assembly for use with a biosensor card, where the microfluidic paper has a conjugate release pad and testing line.
  • FIG. 110 shows a dissolvable adhesive placed at the entrance to the microfluidic membrane, creating a temporary sample well where exhaled breath condensate (EBC sample) accumulates on top of a plastic substrate.
  • EBC sample exhaled breath condensate
  • FIG. 111 illustrates the EBC sample sample further accumulating above the dissolvable adhesive.
  • FIG. 112 highlights the flow of EBC sample through the microfluidic strip after the adhesive fluid dam has dissolved.
  • FIG. 113 illustrates different sample accumulation (fluid dam) stacks for conditioning and controlling the flow of a sample onto a semiconductor or hybrid photonic/electronic biosensor.
  • FIG. 114 illustrates a microfluidic test assembly configured with a sample well opening covered layers such as dissolvable adhesive, conjugate release, and optional sample conditioning materials.
  • FIG. 115 depicts a layered microfluidic setup in which dissolvable adhesive prevents the sample from flowing into the microfluidic membrane and test line until sufficient exhaled breath condensate (or other liquid) has accumulated and undergone any sample conditioning (e.g., buffering, lysing).
  • sample conditioning e.g., buffering, lysing
  • the semiconductor die that includes at least one sensor device is positioned to be attached to the bottom conductive traces.
  • the sensor device can be, for example, a GaN HEMT, g-FET, or formed from other semiconductor, insulator and conductor elements that provide a biological or environmental sensor for the detection of targeted analytes.
  • the top surface of the semiconductor die includes the bond pads and the detection area.
  • the bond pads are connected to the conductive traces via a z-axis conductive adhesive, which provides both mechanical attachment and electrical continuity.
  • the z-axis conductive adhesive also provides a sealing member the seals a sample well defined by the top surface of the die and the walls of the detection window.
  • additional layers can be formed to increase the volume of the sample well.
  • the sealing member can be formed using an additional bead of a non-conductive material such as silicone.
  • the z-axis conductive adhesive allows for vertical (z-axis) electrical connection from the bond pads on the semiconductor die to the conductive traces on the support member, without shorting between conductive traces and/or bond pads.
  • the z-axis conductive adhesive has an anisotropic conductivity profile that prevents lateral electrical connectivity, providing signal transmission from the detection area while also providing a reliable electrical bond, mechanical attachment and a fluid seal, without interfering with the detection area on the top surface of the die.
  • An example of a z-axis conductive adhesive is an anisotropic conductive adhesive 125-01 A/B-187 from Creative Materials, Ayer, MA.
  • the conductive adhesive is applied, for example, using a conventional die bonder semiconductor processing equipment so that after dispensing the adhesive onto the conductive traces and a pick and place operation, the adhesive is between each bond pad of the bare die and corresponding conductive trace of the support member.
  • the packaged semiconductor sensor includes a semiconductor die having a top surface and a bottom surface, with at least two bond pads and at least one detection area located at the top surface.
  • a support member e.g., printed circuit board substrate, has a top side and a bottom side, and a detection window provided as an opening in the support member from the top side to the bottom side.
  • the opening/detection window in the support member and the detection area located at the top surface of the semiconductor die define a sample well for receiving a sample to be tested by the packaged semiconductor sensor.
  • a least two conductive traces are provided on the bottom side of the support member. Each bond pad of the bare die is aligned with and electrically connected to a respective conductive trace via the z-axis conductive epoxy without the need for wire bonding.
  • a z-axis conductive adhesive bonds and electrically connects a respective one of the bond pads to a corresponding one of the conductive traces.
  • a sealing member seals the bottom side of the support member with the top surface of the die to seal the sample well.
  • the z-axis conductive adhesive can also be used to form the sealing member.
  • the sealing member can comprise at least one of an epoxy, glue, pressure sensitive adhesive and gasket.
  • the detection window/opening and the detection area collectively define a sample well for receiving a fluid sample to be analyzed.
  • a sealing member can integrated or formed separately with the z-axis conductive epoxy that seals the sample well.
  • the sealing member can be composed of the z-axis conductive epoxy, and/or the sealing member can be composed of a non-conductive adhesive that seals the detection area and detection window to form the sample well and provide a barrier to protect the z-axis conductive adhesive from contacting a fluid disposed in the sample well.
  • FIG. 2 shows a top-down view of a semiconductor biosensor, detailing the surface features integral to the functionality as a sensor including features at the top surface that are involved in the detection of specific analytes.
  • An exemplary embodiment comprises a bond pad 202, a gate 204, a die 206, a drain 208, a source 210, and a top side 212.
  • the detection area a key functional part of the biosensor where the capture molecules are immobilized for selective binding and detection of target molecule present in a fluid sample.
  • the capture molecules at the detection area interact with the fluid sample directly and therefore the detection area at the top surface of the packaged semiconductor sensor must remain open for receiving the sample.
  • bond pads Surrounding the detection area are bond pads, which are small, conductive areas on the top surface of the bare die. Each bond pad is positioned to interface with corresponding conductive traces on the support member to provide the transmission of changes in electrical signals resulting from the detection events (capture molecule/target molecule binding) that occurs at or near the detection area the top surface of the die.
  • the sensor devices on the bare die includes gate, source and drain features connected with the bond pads. The layout of the bare die features are selected to enable the electrical connections to the conductive traces via the z-axis conductive adhesive while ensuring the detection area remains unobstructed for sample interaction.
  • inventive biosensor card configuration is adaptable to any sensor, not just the semiconductor FET type sensor illustrated, that includes the bond pad and detection area arrangement similar to that shown herein.
  • FIG. 3 shows an exploded view of the layered structure of the biosensor card, providing a detailed illustration of each layer and its respective components as they would be assembled in the manufacturing process.
  • An exemplary embodiment includes a bare die window 302 formed in support member 322 of the biosensor card 304, a bottom overlay 306, a bottom side 308, a conductive trace 310, a detection window 312, liquid detection features 314, a liquid detection window 316, an opening 318, a top overlay 320, a top side 324, a z-axis conductive adhesive 326, and a bare die 328.
  • a top overlay is the uppermost layer of the biosensor card. Directly beneath the top overlay are the conductive traces that include liquid detection features, in this exemplary embodiment the conductive traces are etched copper on a flexible substrate material such as Kapton. At least one liquid detection feature is integrated into the top surface of the support member to monitor the presence of a fluid sample.
  • a detection window is formed as an opening within the support member.
  • the detection window aligns with the detection area of the semiconductor die, enabling the fluid sample to contact the biosensor's detection region.
  • the bottom side of the support member has another set of conductive traces. These traces on the bottom side provide electrical connections to the corresponding bond pads on the semiconductor die.
  • the first layer is the top overlay, which functions as a protective cover for the underlying components.
  • This overlay features a liquid detection window that allows the liquid sample to reach the liquid detection features.
  • the liquid detection features are used for determining the flow of the a liquid sample before and after the sample is received by the detection area of the biosensor.
  • the top conductive traces are shown below the top overlay.
  • the conductive traces can be etched copper or printed conductive ink and provide the electrical pathways on the flexible substrate support member to provide electrical connectivity to the sensor elements.
  • the support member layer includes a detection window, an aperture that is aligned with the detection area on the semiconductor die and defines along with the detection area the sample well where the fluid sample is collected and analyzed.
  • the support member provides a platform onto which the semiconductor die will be attached.
  • the support member includes bottom conductive traces on its reverse side, which are in turn connected to external electronic circuitry and provide a means for electrical signals to be read out from the sensor.
  • a bottom overlay protects the bottom side of the biosensor card, completing the assembly.
  • the bottom overlay includes a bare die window that provides an opening to the bottom conductive traces for connecting with the bond pad of the bare die via the z-axis conductive adhesive.
  • FIG. 4 shows a layered breakdown of the biosensor card, depicted in a top-down view.
  • This drawing illustrates each component of the material stack to indicate the layout and individual function of the layers that form the complete biosensor card.
  • An exemplary embodiment comprises a conductive trace 402, a bottom overlay 404, a bare die window 406, a detection window 408, a liquid detection features 410, an opening 412, a support member 414, a top overlay 416, a liquid detection window 418, and a top side 420.
  • the topmost layer shown is the top overlay, which acts as the protective outer covering of the biosensor card. It features a predefined liquid detection window that corresponds to the location of the underlying liquid detection features.
  • the liquid detection features are formed on the top side and operative to indicate a fluid sample presence and flow characteristics.
  • top overlay Below the top overlay is the layer of top conductive traces that form the liquid detection features.
  • the support member has the conductive traces formed thereon either by a subtractive process, such as etching copper foil, or by an additive process, such as screen printing conductive silver ink.
  • the support member also include the detection window that aligns with the detection area on the semiconductor die, allowing the biosensor to interact with the test sample.
  • Beneath the support member, bottom conductive traces connect the die sensor devices features with an external electronic circuit.
  • the bottom overlay protects and insulates the bottom conductive traces and includes the bare die window for connecting the bare die with the conductive traces.
  • the support member can be one of a flex circuit having an etched metal pattern forming the conductive traces, a plastic substrate having printed conductive ink forming the conductive traces, and rigid circuit board having at least one of etched metal and printed conductive ink forming the conductive traces.
  • FIG. 5 shows the material stack-up for a biosensor card, specifically designed in this exemplary embodiment as an etched copper flex circuit.
  • This drawing illustrates the various layers and their respective thicknesses for forming the biosensor card using conventional and well-known manufacturing processing and materials.
  • the materials and thickness as for example only, other constructions can also be used.
  • a polyester (PET) or other suitable plastic substrate may be used with screen printed conductive ink forming the conductive traces.
  • PET polyester
  • This plastic substrate embodiment may be particularly advantageous since the additive manufacturing process will be lower cost and have less environmental impact that the use of an etched copper flex circuit construction.
  • the die attach process can be done at relatively lower temperatures, for example, using a UV curable z-axis conductive adhesive or tape, making the lower cost plastic substrate with screen printed conductive ink an attractive alternative to etch copper on Kapton.
  • the stack-up begins with the top overlay or coverlay, a protective layer measuring 25 micrometers (pm) in thickness that protects the underlying circuitry.
  • a layer of overlay adhesive of the same thickness secures the top overlay to the base copper layer and the support member.
  • the base copper layer which is 18 pm thick, forms the conductive pathways for the circuit and includes additional thickness from plating, ensuring robust electrical connections.
  • a 25 pm thick adhesiveless polyimide layer forms the substrate of the support member.
  • Another etched copper layer of 18 pm plus plating forms the bottom conductive traces.
  • an additional overlay adhesive and a bottom overlay layer each 25 pm thick, help to encapsulate and protect the entire assembly.
  • a stiffener with adhesive is incorporated at the edge of the biosensor card, contributing to a total ZIF connector end thickness of 311 pm.
  • FIG. 6 shows a detailed top view of a multi-sensor GaN biosensor device with four individually addressable sensor elements, each with its own source and gate connections and sharing a common drain.
  • the drawing illustrates the design and layout of the sensor's ohmic features that form the bond pads on the top surface of the bare die.
  • An exemplary embodiment comprises a conductive trace 602, a detection area 604, a bond pad 606, and a die 608.
  • the type of sensor that will work with the biosensor card construction is not limited to semiconductor transistors.
  • the sensor could be as simple as two conductors with a detection surface between them and a charge transport or other conductive or semiconductive layer formed on the detection surface where target molecules that are present in a sample in contact with the detection surface cause a detectable change in the electrical characteristics between the two conductors.
  • a graphene or graphene oxide charge transport layer can be functionalized and act as a variable resistor where the variation is caused by the presence of target molecules that influence the conduction through the charge transport layer.
  • the detection area is formed at the central region of the die, but could be formed at other locations and the die could also include other electronic features connected with features of the sensor devices. For example, resistor, capacitors, transistors and other semiconductor electronic devices can be provided directly on the die and/or provided as discrete electronic devices provided on a printed circuit board connected with the sensor devices through the biosensor card. Capture molecules are immobilized at the detection area that are specific to the target analyte(s). The detection area is positioned to be in direct contact with the sample in the detection well.
  • the bare die Surrounding the detection area, the bare die includes various bond pads, which serve as the terminals for electrical connectivity. The bond pads are connected via the z-axis conductive adhesive to the conductive traces and form the electrical pathways for signal detection.
  • FIG. 7 provides a cross-sectional representation of a Gallium Nitride (GaN) biosensor, illustrating the essential components and their arrangement within the device.
  • An exemplary embodiment comprises capture molecules 702, a sample well 704, a drain 706, a source 708, a detection area 710, and a 2DEG 712.
  • the substrate of an experimental wafer used to successfully build the exemplary embodiment was made from Silicon Carbide (SiC) wafer, the primary functional layer of the GaN is formed.
  • Other wafer substrates are available for GaN HEMT fabrication, such as sapphire and Si.
  • the GaN layer has the advantage of wide bandgap properties that facilitate high electron mobility and contribute to the sensor's sensitivity and response time.
  • a two-dimensional electron gas (2DEG) channel forms at the heterojunction interface with the AlGaN Layer.
  • the 2DEG is a thin layer of mobile electrons that is highly sensitive to changes in electric fields and charge density.
  • AlGaN Aluminum Gallium Nitride
  • the Aluminum Gallium Nitride (AlGaN) layer works in conjunction with the underlying GaN to create the 2DEG heterojunction channel.
  • the material properties of AlGaN, including its adjustable bandgap and electron mobility, can be finely tuned during manufacturing to optimize the sensor's performance for an intended use-case.
  • the detection area is formed at the surface of AlGaN Layer (or a cap layer, such as GaN or Au may be provided This detection area is where capture molecules are immobilized.
  • the capture molecules are designed to selectively bind to specific analytes, initiating a change in the electrical properties of the 2DEG below, which can then be measured and translated into a detectable signal indicating the presence of the target substances.
  • a detection well is provided. This well is where the sample containing potential target molecules interacts with the capture molecules.
  • the GaN HEMT sensor can be improved through the systematic optimization of features formed at the wafer level balanced with materials and processes in the fabrication of the functionalized sensor devices of the die attached to the biosensor card connected with the reader electronics PCB.
  • thinning the AlGaN Layer in a GaN HEMT sensor has the potential to increase the sensor's sensitivity, as it brings the detection area — where the capture molecule/target molecule binding occurs — closer to the 2DEG.
  • the proximity can enhance the perturbation effect of the bound molecules on the 2DEG, potentially leading to a stronger modulation of the channel's conductivity when a target molecule binds to a capture molecule.
  • the thickness of the AlGaN Layer in a GaN HEMT (High Electron Mobility Transistor) device is an important design parameter.
  • a thinner AlGaN Layer can indeed bring the detection area closer to the 2DEG, potentially increasing the sensor's sensitivity, but it can also introduce several challenges.
  • the AlGaN Layer typically ranges from a few nanometers to tens of nanometers.
  • the optimal thickness is often a result of empirical optimization and depends on the specific application. For biosensing, it might be thinned to just above the critical thickness that prevents the introduction of dislocations and other crystal defects.
  • a thinner AlGaN Layer can alter the electrical properties of the HEMT structure. It can affect the 2DEG density and the device's threshold voltage. These properties should remain within certain limits to maintain the operational integrity, so part of the systematic improvement of the bare die structure can include a design of experiments aimed at the optimization of the AlGaN Layer, and may include an insulator stack comprising different materials that provide the best balance of fabrication costs, biosensor sensitivity and device robustness to withstand all the fabrication processes, shelf life considerations and test performance.
  • FIG. 8 illustrates the fully assembled biosensor card as viewed from both the top and bottom perspectives.
  • the top view photo shows the liquid detection features formed from the top conductive traces.
  • the liquid detection features are useful for determining the flow of the liquid sample just before and after the sample passes over the biosensor.
  • the bare die semiconductor sensor is shown mechanically fixed on the biosensor card and electrically connected to the bottom conductive traces via a z-axis conductive adhesive. This anisotropic adhesive material provides a reliable bond that maintains the electrical integrity of the connection while allowing for electrical conduction only in the vertical (z-axis).
  • FIG. 9 shows an alternative design of a semiconductor biosensor die with an array of six Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) devices.
  • GaN Gallium Nitride
  • HEMT High Electron Mobility Transistor
  • An exemplary embodiment comprises a bond pad 902, a detection area 904, a drain 906, and a source 908. That is, the sensor devices each have its own source electrode, while sharing a common gate and drain. This configuration that facilitates the parallel and/or serial readout of test results for multiple biomarkers. This shared structure also reduces the complexity of the biosensor card and enhances the die's compactness, an important consideration since die cost is typically relatable to die size.
  • Each source bond pad connects the individual sensor devices, and is linked to a separate detection area for each sensor device.
  • These separately addressable detection areas are functionalized with unique capture molecules to enable the detection of various biomarkers, or the same capture molecule can be provided and an average reading from each addressable sensor device taken as the test output.
  • This multi-sensor approach allows for a broad spectrum of diagnostic capabilities, such as simultaneous testing for different viral proteins or pathogens.
  • This sensor array can be used to effectively analyze complex biological samples, identifying the presence of multiple biomarkers with high specificity and sensitivity. For instance, each sensor device could be functionalized to detect distinct biomarkers associated with various diseases or conditions, offering a comprehensive diagnostic tool within a single semiconductor die.
  • FIG. 10 shows a multi-sensor biosensor die with five test sensors and one reference sensor, all integrated onto a single bare die.
  • Each test sensor device can be uniquely functionalized to detect a specific biomarker.
  • An exemplary embodiment comprises a bond pad 1002, a die 1004, a detection area 1006, a drain 1008, a gate 1010, and a source 1012.
  • CM1 Capture Molecule 1
  • CM5 Capture Molecule 1
  • SARS-CoV-2 N and S proteins a capture molecules that are selected for their high affinity to particular biomarkers, allowing the sensors to identify and measure the presence of multiple analytes such as the SARS-CoV-2 N and S proteins, Flu A and B antigens, and the Respiratory Syncytial Virus (RSV).
  • RSV Respiratory Syncytial Virus
  • the reference sensor device labeled ‘Ref ’ can be used to normalize the test readings and account for environmental variables like temperature and humidity that could affect sensor performance. It is functionalized with a capture molecule that exhibits representative electrical characteristics similar to the other sensors. This feature enables the reference sensor to act as a control point, maintaining the reliability of the biosensor's output by providing a consistent baseline for comparison.
  • a comparator circuit may be used to contrast the signal from the reference sensor with that of each test sensor. This comparison helps to ensure that any signal variations are attributable to the presence of the target biomarker, rather than extraneous environmental factors.
  • FIG. 11 is a logic flow diagram for Applied Probabilistic Analysis to determine the detection of a target biomarker, and illustrates the operation of an exemplary method, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments.
  • applied probabilistic analysis can be used to improve the predictive model of an individual’s infection status and in the aggregate, help to refine the testing results thresholds for an objective quantitative or qualitative testing system.
  • a method is provided for the applied probabilistic analysis to the test results for two or more biomarkers to determine pathogen exposure.
  • Host-generated biomarkers resulting from the immune response of the patient can be combined with virus biomarkers such N- or S- proteins of the SARS-CoV-2 virus.
  • Biomarker 1 is first tested for (step one), Biomarker2 is then tested for (step two).
  • BiomarkerN can be tested for where N can be any number of multiple biomarkers tested using the inventive testing system. If no target biomarker is detected (step three) then a Negative Test report is generated (step four). If any target biomarker is detected (step three) then probabilistic analysis may be performed depending simply on the detected presence (yes/no) or quantitative analysis (e.g., concentration) of the one or more detected biomarkers (step five). The probabilistic analysis can be performed using an updated probability model where probabilistic multipliers for the tested-for biomarkers are determined for a population.
  • the probabilistic multipliers for the tested-for biomarkers can be determined from confirmed cases occurring during the earlier outbreak.
  • a threshold can be determined for the results of the probabilistic analysis based on the probabilistic multipliers obtained from the confirmed cases and help to improve the accuracy of the testing system.
  • a threshold voltage for considering a test result as positive can be adjusted based on the probabilistic analysis of previously tested and confirmed positive cases. Over time, the accuracy and confidence of positive and negative determinations is improved based on the history of confirmed cases and obtained threshold voltages. As the database of tested cases grows, the overall testing regimen with interconnected communication, sharing and analysis of tests results is used to automatically improve the accuracy and confidence of future tests.
  • step six e.g., low concentration of a particular target biomarker, or the presence of just one weak biomarker indicating likely infection
  • a Maybe Test report is generated (step seven).
  • the ability to detect a possible infection that isn't necessarily confirmed positive could be important during an early stage of a new pandemic or regional outbreak since it is important to identify possible infections and remove the possibly infected individuals from unnecessary contact with others until their infection status can be confirm.
  • a threshold e.g., high concentration of a particular target biomarker, or the presence of two or more biomarkers indicating likely infection
  • a Positive Test report is generated (step eight).
  • the Test Report is then transmitted (step nine) (e.g., in a manner described herein or other suitable transmission mechanism including verbal, digital, written or other communication transmission that adds to the accumulated database of test results).
  • the logic flow is implemented by a non-limiting embodiment of an apparatus, comprising at least one Processor; and at least one Memory including computer program code, the at least one Memory and the computer program code configured to, with the at least one Processor, cause the apparatus to perform at least the following: detecting one or more biometric parameters using a droplet harvesting structure for converting breath vapor to a fluid droplet for forming a fluid sample and a testing system having a biomarker testing zone for receiving the fluid sample and detecting the biometric parameter, where the biometric parameters are dependent on at least one physiological change to a patient in response to a concerning condition such as a virus infection; receiving the one or more biometric parameters and applying probabilistic analysis to determine if at least one physiological change threshold has been exceeded dependent on the probabilistic analysis of the one or more biometric parameters; and activating an action depending on the determined exceeded physiological change.
  • a biosensor testing device having one or more biometric detectors each for detecting biomarkers as one or more biometric parameters.
  • the biometric parameters are dependent on at least one physiological change to a patient or test subject, such as the production of immune response chemicals, the presence in the body of an active or deactivated virus or virus component, antibodies, antigens, virus RNA, or other biomarker inducing change (including an immune response or viral load count).
  • a microprocessor receives the one or more biometric parameters and determines if at least one physiological change threshold has been exceeded depending on the one or more biometric parameters.
  • An activation circuit activates an action depending on the determined physiological change. The action includes at least one of transmitting an alert, modifying a therapeutic treatment, and transmitting data dependent on at least one physiological change, the one or more biometric parameters, and therapeutic treatment.
  • a mask-based diagnostic platform may utilize the components described herein, and can also be used to monitor the progression of a disease in a patient, for example, a hospitalized patient that is going through the disease progression of Covid- 19, recovering from a heart attack, organ injury, cancer, etc.
  • the at least one physiological change can also be in response to an applied therapeutic treatment that causes a change in the condition of the patient to enable the monitoring of the body’s response to an applied therapeutic.
  • the action can include transmitting an alert, modifying a therapeutic treatment, and transmitting data dependent on at least one of the at least one physiological change, the one or more biometric parameters, and therapeutic treatment.
  • the microprocessor can analyze the one or more biometric parameters using probabilistic analysis comprising determining from a data set of the one or more biometric parameters whether the data set is acceptable for deciding that the at least one physiological change threshold has been exceeded.
  • the probabilistic analysis can further comprise applying a statistical weighting to each of the one or more biometric parameters, where the statistical weighting is dependent on a predetermined value of a ranking of importance in detecting each of the at least one physiological change for said each of the one or more biometric parameters relative to others of the one or more biometric parameters.
  • the MDB system can utilize the logic flow diagram for Applied Probabilistic Analysis in conjunction with an Al-agent that can perform the analysis of the collected biomarker data.
  • the Al-agent can be designed to analyze the aggregated data from a remote server to identify patterns and trends in the data, and determine if a threshold has been exceeded for the at least one physiological change.
  • the Al-agent can also determine if any target biomarker has been detected and perform the probabilistic analysis using an updated probability model.
  • the Al-agent can apply a statistical weighting to each of the biometric parameters, which can help to determine the ranking of importance in detecting each of the at least one physiological change for said each of the one or more biometric parameters relative to others of the one or more biometric parameters. This can further help to improve the accuracy and confidence of positive and negative determinations.
  • the Al-agent can provide feedback based on the identified patterns and trends in the data and the results of the probabilistic analysis. This feedback can be used to improve the efficacy of the remote patient monitoring system by implementing the feedback to optimize at least one hardware, software, and networking component of the remote patient monitoring system.
  • Bayesian network is a probabilistic graphical model that represents a set of variables and their conditional dependencies using a directed acyclic graph. Bayesian networks can be used to model the probability distribution over the biomarkers and other variables, allowing for the calculation of conditional probabilities and the updating of the probability distribution as new data is collected.
  • Other Al algorithms that can be used for biomarker data analysis include support vector machines (SVMs), random forests, and deep learning neural networks.
  • FIG. 12 shows the detailed procedure for attaching a bare die semiconductor sensor to a support member (e.g., printed circuit board substrate).
  • the bare die is attached to the support member so that the detection window in the support member aligns with the detection areas on the sensor devices.
  • An exemplary embodiment comprises a mask 1202, a top surface 1204, a bond pad 1206, a detection area 1208, a z-axis conductive adhesive 1210, a non-conductive adhesive 1212, a liquid detection window 1214, and a support member 1216.
  • a z-axis conductive epoxy bead is applied around the edges of the bare die.
  • the conductive epoxy serves multiple purposes: it secures the bare die to the support member; provides electrical connectivity between the die and the conductive traces on the support member; and seals the sample well defined the by the top surface of the bare die and the walls of the detection window in the support member.
  • the sample well can include additional layers, such a patterned plastic or an external well structure to hold a volume of a liquid sample as a pool in contact with the detection well.
  • a barrier bead of a non-conductive adhesive can be provided that prevents the z-axis conductive epoxy from being exposed to solvents and other materials or processes that could degrade the z-axis conductive adhesive.
  • This non- conductive adhesive may be beneficial depending on the post-die attach processing of the biosensor card.
  • Conventional solder paste and reflow process can be used for the electrical connections between the bond pads and the traces, with the bead of non-conductive adhesive provided to seal the detection well.
  • the non- conductive adhesive could be provided as a barrier to prevent exposure of the z-axis conductive adhesive to the solvent.
  • a gasket may be pick and placed and held in place by the z-axis conductive adhesive bond or the gasket may have a better bond strength to give more flexibility to the choice of z-axis conductive material.
  • the bare die is placed onto the epoxy bead and the epoxy is cured. Pressure can be applied during curing to ensure good physical contact and the formation of a robust electrical and mechanical bond between the die and the support member.
  • a protection layer can also applied on the sensor, leaving the detection areas and bond pads open.
  • This protection layer can be formed from cooperating hydrophobic and hydrophilic structures. For example, at the wafer level or in materials adjacent to the die (e.g., on the biosensor card). During the die attach process, the bare die is placed onto the support member so that the detection window in the support member aligns with the detection area of the sensor devices. The views shown in FIG.
  • the support member is held on a work holder and z-axis conductive epoxy bead is formed at the bare die window of the support member, then the bare die is pick and placed onto the z-axis conductive epoxy bead and pressure applied to ensure a good electrical contact, mechanical attachment and seal.
  • the applied pressure may be held during a snap or UV curing process.
  • the z-axis conductive adhesive comprises at least one of an anisotropically conductive epoxy, anisotropically conductive glue, and anisotropically conductive pressure sensitive adhesive film.
  • the conductive adhesive provides at least one of an electrical connection and mechanical attachment, and the respective bond pad and corresponding conductive trace is electrically connected by the z-axis conductive adhesive without causing short circuits between adjacent or other bond pads and conductive traces.
  • the sealing member can be a silicone adhesive or sealing material that forms a barrier between the sample well and the z-axis conductive adhesive.
  • FIG. 13 shows an isolated view of the packaged semiconductor sensor where a bare die semiconductor sensor device is attached to an flex circuit biosensor card using a z-axis conductive adhesive.
  • the view shows an isolated and partial assembly of the biosensor card showing the arrangement of conductive traces, detection areas, sample wells, and other relevant structural features of a biosensor card assembly with four individually addressable and functionalizable sensor devices on a single bare die.
  • the exemplary embodiment comprises a conductive trace 1302, a detection area 1304, a detection window 1306, and a die 1308.
  • Conductive traces are patterned on the substrate of the biosensor card to provide electrical pathways to enable signal detection and transmission from the sensor elements to a data processing unit, e.g., reader electronics provided on a printed circuit board. Individually addressable detection areas and individually accessible sample wells are provided so that a fluid sample can be tested for different target analytes by each of the four individually addressable sensor devices.
  • a data processing unit e.g., reader electronics provided on a printed circuit board.
  • Individually addressable detection areas and individually accessible sample wells are provided so that a fluid sample can be tested for different target analytes by each of the four individually addressable sensor devices.
  • FIG. 14 shows an embodiment of a completed biosensor card with four individually addressable sensor devices. Each sensor is equipped with its own sample well, allowing for the detection of distinct target molecule from the same fluid sample. The detection areas of each of the sensor devices can be individually functionalized to perform multiplexed testing within a compact and integrated system. This configuration allows for simultaneous and selective analysis of various biomarkers in the same fluid sample.
  • the drawing shows a biosensor card 1402, a conductive trace 1404, a detection window 1406, liquid detection features 1408, and a sample well 1410.
  • the completed biosensor card is a multi-sensor platform where each sensor device has an individually assessable sample well.
  • the detection windows visible in the center of the photo, receive the fluid sample.
  • the biosensor card includes liquid detection features that are used to determine the flow of the liquid sample before and after the detection areas.
  • This biosensor card allows for the simultaneous analysis of different target molecules within a single fluid sample by using four independently addressable sensor devices. Each of these sensor devices can be individually functionalized to detect specific biomarkers enabling multiplexed testing capabilities for scenarios where multiple assays need to be performed concurrently, such as in comprehensive medical diagnostics or complex environmental analyses.
  • the biosensor card assembly includes a bare die semiconductor sensor with a top surface including two or more bond pads and at least one detection area.
  • a support member has at least a corresponding number of conductive traces as the bond pads on the bare die.
  • the conductive traces are provided on at least a bottom side of the support member for connecting with the bond pads of the bare die.
  • the support member has a through-hole detection window aligning with the detection area of the bare die.
  • a conductive adhesive is provided between each bond pad of the bare die and a corresponding conductive trace of the support member.
  • the conductive epoxy provides an electrical connection between a respective bond pad and a corresponding conductive trace.
  • FIG. 15 presents a detailed schematic of a biosensor card, showing various integral components and their arrangement for multiplexed biomarker detection.
  • the biosensor card has a top side and a bottom side, and a detection window.
  • the detection window through-hole through-hole is aligned with individually accessible sample wells situated on the top side of the biosensor card.
  • An embodiment comprises a biosensor card 1502, a bottom side 1504, a conductive trace 1506, and a detection window 1508.
  • Each sensor device is independently addressable, enabling the biosensor card to analyze distinct target molecules concurrently within a single fluid sample. This capacity for individual functionalization of the sensor devices allows for an analysis of multiple biomarkers.
  • the support member can be fabricated from a flexible or rigid substrate material and the conductive traces are formed on the substrate through at least one of an additive manufacturing process (e.g., screen printed conductive ink) and a subtractive manufacturing process (e.g., etched copper).
  • FIG. 16 shows an exemplary layout of a biosensor card with conductive traces leading to distinct sensor devices.
  • the exemplary embodiment comprises a bond pad 1602, conductive traces 1604, a detection window 1606, a die 1608, gates 1610, a detection area 1612, and one or more semiconductor sensor devices 1614 fabricated on the same bare die.
  • This layout enables multiplexing testing where different sensor devices on the same biosensor card can be selectively activated and read, allowing for complex diagnostic assays to be performed in parallel.
  • the addressable detection wells are arranged to correspond with the detection areas, and each well is configured for analyzing specific target molecule from a fluid sample introduced through the detection window.
  • the conductive traces are patterned for independent electrical addressing of each sensor device, enabling the simultaneous and separate analysis of multiple biomarkers.
  • This layout enables multiplexing capability, where different sensor areas on the same card can be selectively activated and read, allowing for complex diagnostic assays to be performed in parallel.
  • Such a configuration is key for high-throughput screening and real-time monitoring of diverse biological samples, indicating the card's potential utility in advanced medical diagnostics, environmental sensing, and bioanalytical systems.
  • FIG. 17 shows an embodiment of the biosensor card interfaced with a printed circuit board (PCB) through a zero insertion force (ZIF) connector.
  • the biosensor card include microfluidic channels comprising a filter paper, guiding a fluid sample along a defined path. Initially, the sample encounters a liquid detection feature just before flowing through the filter paper and over the detection area and then a second liquid detection feature that is encountered after flowing over the detection area.
  • the sample flows over the detection wells where the sample interacts with the detection area of the biosensor. As the sample exits the detection wells, it passes over the second liquid detection feature.
  • the compressed cellulose sponge adjacent to the microfluidic channels serves as a reservoir or wicking material to facilitate the capillary action that drives the sample through the microfluidic system without the need for external pumps.
  • the PCB which the biosensor card connects to via the ZIF connector, provide electronic components to transduce the sensor signals into readable data.
  • the ZIF connector facilitates quick-release engagement with the electronic reader and data processing unit via a mechanical and electrical connector interface, allowing for rapid interchangeability of the biosensor card and reuse of the reader electronics for many tests.
  • FIG. 18 shows a close-up image of a portion of a biosensor card, specifically focusing on the components for sample detection.
  • a detection window an open area that allows a fluid sample to interact with the sensor’s detection area.
  • the detection area functionalized with specific reagents or biological elements such as capture molecules, is the active site where the target molecules within the sample are captured for signal detection and analysis.
  • the detection well Surrounding the detection area is the detection well, which contains the fluid sample and ensure that it remains over the detection area for a sufficient period to enable the sensor to detect the target molecule if present in the sample.
  • the detection window facilitates the introduction of the sample, the detection well serves to confine the sample over the detection area for analysis, and the detection area itself contains the elements for the biochemical interaction or reaction that leads to the detection of specific biomolecules.
  • FIG. 19 shows an electrostatic control system for use with a semiconductor sensor to enhance the detection and analysis of target molecules in a fluid sample.
  • Driving electrodes create a controlled electrostatic field across the sample flow path.
  • the electrostatic field modulates the motion and orientation of charged particles and polar molecules within the sample.
  • the electrostatic field can be controlled at various locations along the sample flow path so that when the sample flow passes over the detection area, the target molecule are better positioned for binding with the immobilized capture molecules.
  • An exemplary embodiment comprises an accumulator 1902, capture molecules 1904, a detection area 1906, a die 1908, driving electrodes 1210, a flow path 1914, and a target molecule 1916.
  • An integrated biosensor card and bare die sensor assembly is provided for targeted biomarker detection.
  • a semiconductor die has a top surface with a least one sensor device and at least one sensor area and bond pads associated with each sensor device.
  • a support member having a bottom side with conductive traces corresponding to the bond pads supports the semiconductor die and connects the semiconductor devices of the die to a printed circuit board.
  • An accumulator in fluid communication with the sensor areas applies an electrostatic field to a fluid sample for aligning target biomarkers within a fluid sample.
  • the accumulator can be provided on the biosensor card and/or in the flow path of the liquid sample, and facilitates enhanced detection by modulating the orientation and proximity of target biomarkers to the immobilized capture molecules at the sensor areas.
  • a semiconductor sensor such as a graphene field effect transistor sensor, has optimized sensitivity that is related to the Debye screening length and the distance and orientation of the capture molecule binding sites from the detection surface.
  • an accumulator can be provided in the flow path of the liquid sample before the sample reaches the detection area.
  • An electrostatic field selectively concentrates and orients the target molecules in the sample volume adjacent to the detection area.
  • the signal applied to the conductor of the accumulator can be controlled so that the momentum of the polar molecules is altered to favor the movement of the binding site of the target molecule towards the capture molecules immobilized at the detection area.
  • the electrostatic field selectively controls the orientation and movement of target molecule and concentrates them in the direction of the capture molecules immobilized on the detection area.
  • the applied electrostatic driving force induces rotational movements in polar molecules, positioning them for binding and contributing the captured charges at that detection surface to influence the flow of electrons as a detected signal.
  • the immobilized capture molecule can also be a polar molecule.
  • the electrostatic field orients the capture molecule and the applied signal can be control so that the orientation is optimized for the binding interaction with the target molecule.
  • the flow path can include hydrophobic and hydrophilic structures formed at the wafer level that control the flow and volume of the fluid sample to improve the wetting of the detection area and form a pool of the flowing liquid sample.
  • This flow path layer can be formed from cooperating hydrophobic and hydrophilic structures to control the direction and rate of the liquid sample flow. For example, at the wafer level or in materials adjacent to the die (e.g., on the biosensor card), microfabricated, screen printed or otherwise formed or applied pattern of surface energy features can be made.
  • An accumulator applies an electrostatic field to the fluid sample passing between two insulated conductors. The electrostatic field can be applied in pulses or patterns to give momentum to a polar molecule to cause rotation. For example, an on/off DC (direct current) pulse can be tuned to maximize the separation of the polar target molecule from the other ions and polar constituents in the sample.
  • hydrophobic and hydrophilic patterns at the wafer level enables the control of the sample fluid flow using surface modifications that alter the wetting properties of specific areas on the die. These surface properties are can be controlled at the microscale for directing and confining fluid samples to targeted areas, such as the detection zones in a biosensor.
  • the hydrophobic and hydrophilic patterns can be fabricated by selectively applying these layers through stencil printing or microcontact printing. Plasma treatments can also be used to modify surface energy. For example, exposing the detection surface to an oxygen plasma can make it more hydrophilic, while a fluorocarbon plasma can make it more hydrophobic.
  • the hydrophilic/hydrophobic patterns can converge the liquid sample flow path to the detection area and a pattern of more and less hydrophobic/hydrophobic regions on the detection area can control the density of capture molecules immobilized during the functionalization process.
  • the pattern can be made to facilitate wetting active regions of the detection area.
  • Hydrophobic boundaries can also be designed around the detection area to create a microwell or pool where the sample can accumulate.
  • a fine grid of hydrophilic boundaries on the detection area can also control both the density and uniformity of the immobilized capture molecules, as well as utilize the surface tension of the fluid sample to draw the sample into contact with hydrophobic detection area active regions bounded by the hydrophilic grid.
  • Hydrophobic boundaries can control the size of the pool to determine the volume of the sample that interacts with the sensor to enable quantitative analysis.
  • standardized wetting and pooling can lead to more consistent sample volumes and sensor interactions, improving the reproducibility of the sensor's readings.
  • the accumulator is provided in fluid communication with the sensor areas, the accumulator applies an electrostatic field to the fluid sample for aligning target biomarkers within a fluid sample.
  • the accumulator facilitates enhanced detection by modulating the orientation and proximity of target biomarkers to the sensor areas.
  • GaN HEMT Gallium Nitride High Electron Mobility Transistor
  • GaN surfaces can be modified with hydrophobic and hydrophilic patterns to control fluid flow much easier than forming patterns of graphene at the microscale.
  • the robustness of GaN allows for a variety of surface treatments that can create these patterns without compromising the integrity of the sensor.
  • the functionalization of the GaN detection area to immobilize capture molecules can benefit from hydrophilic/hydrophobic patterning. For instance, a hydrophilic grid can attract the sample and promote even distribution across the active area, improving signal-to-noise ratios in the sensor output.
  • the fine-tuning of pool sizes via hydrophobic boundaries around GaN detection areas can facilitate precise quantitative analysis by controlling the volume of the sample interacting with the sensor.
  • the GaN sensor’ s stability under various environmental conditions allows for such features to be implemented with high reproducibility.
  • GaN technology is compatible with standard semiconductor microfabrication techniques. Microfabricated patterns for controlling sample flow at the wafer level can be implemented on GaN devices using conventional etching, photolithography, or newer methods like direct laser writing.
  • At least one of hydrophilic and hydrophobic patterns are formed on at least one of the top side of the biosensor card and the top surface of the bare die control flow and positioning of the fluid sample over the detection area.
  • the hydrophilic and hydrophobic patterns are arranged to create microchannels that direct the fluid sample towards the detection area.
  • the hydrophobic patterns are located around a periphery of the detection area to contain the fluid sample.
  • a microstructured surface on the detection area can includes a combination of hydrophilic and hydrophobic regions designed to modulate sample volume and fluid dynamics for optimizing surface wetting properties of the detection area.
  • the fluid transfer mechanism conducts a portion of the fluid sample containing relatively less target molecule through the SAP which selectively absorbs water and ions and leaves behind larger molecules, such as a target protein molecules.
  • the wick absorbs the water and ions from the SAP leaving another portion of the fluid sample containing relatively more target molecule flowing towards the capture molecules at the detection area of the sensor device.
  • FIG. 21 is a flowchart of the steps for concentrating the target molecule in a fluid sample and testing for a change in electrical characteristics of a functionalized transistor sensor.
  • a method for detecting a target molecule from a fluid sample comprises the steps of: receiving the fluid sample comprising the target molecule at a microfluidic channel; transferring the fluid sample from the microfluidic channel to a detection interface of a sensor device, the sensor device comprising a detection area for receiving the fluid sample with the detection interface functionalized with capture molecules, a top driving electrode and a bottom driving electrode defining a gap there between, and a fluid conductor disposed in the gap for conducting the fluid sample through the gap, wherein an electric potential applied to the top and the bottom driving electrode drives the target molecule towards the capture molecules as shown, for example, in FIG.
  • the sensor comprising, for example, a field effect transistor having a gate disposed in electrical communication with the detection interface that is functionalized with the capture molecules, and a source and drain on either side of the gate, or some other semiconductor device feature arrangement where the conduction of charges is affected by the presence of target molecules in a tested sample (see, for example, FIG. 2).
  • a field effect transistor having a gate disposed in electrical communication with the detection interface that is functionalized with the capture molecules, and a source and drain on either side of the gate, or some other semiconductor device feature arrangement where the conduction of charges is affected by the presence of target molecules in a tested sample (see, for example, FIG. 2).
  • At least a portion of at least one of the top and the bottom electrode can be disposed at or in electrical or electrostatic communication with the detection area.
  • a gate, source or drain electrode of the sensor may comprise, for example, the top driving electrode and the sensor device substrate or other conductive member comprise the bottom driving electrode so that an electrostatic field is applied through the liquid sample that causes molecules and ions to orient and or move in response to the applied electrostatic field.
  • the arrangement of conductors and features described herein are illustrative of possible variations. Various arrangements of the conductors are possible with the aim of establishing a controllable electrical field that causes a change in orientation and location of the molecules and ions present in the sample material being tested.
  • the electrodes and conductive members of the system can be driven with applied electrical signals intermittently and selectively for applying an AC, DC or other waveform of electric potentials for driving the target molecule and for taking a test reading of a change in an electrical characteristic at or between any of the source, drain and gate, or other conductive member of the system.
  • the system is used to detect a target molecule contained in a liquid exhaled breath condensate (EBC sample) biosample
  • EBC sample sample is received at the microfluidics or fluid transfer mechanism of the system (step two).
  • a voltage is applied to a driving electrode grid that supports the SAP beads, or other top and bottom electrode configuration where an electrostatic field is created in the detection interface (step three).
  • the applied voltage drives the polar target molecule and ions in the EBC sample sample towards and away from the capture molecules at the detection interface of the biosensor depending on the applied polarity and the particular charge distribution of the molecules and ions in the EBC sample sample.
  • the aim is to concentrate the target molecule in a portion of the fluid sample received at the detection interface, with excess water absorbed by SAP and/or the wick.
  • the target molecule in the tested EBC sample sample are captured by the capture molecules immobilized at the detection interface causing a detectable change, for example, in the flow of current from the source to the drain of the sensor device.
  • the electric potential for driving the target molecule is stopped (step five).
  • a test reading is taken of a change in an electrical characteristic caused by the captured target molecule affecting the electron charge mobility or surface charge characteristic at the detection surface interface.
  • the electric potential for driving the target molecule can be applied intermittently with taking a test reading of a change in an electrical characteristic at the source/drain/gate electrodes of the transistor biosensor (step six).
  • Alternative electrode and biosensors configurations can also be used, including printed electrodes with nanoparticle, nanotube, metal, semiconductor and/or organic detecting interface materials. If the change in electrical characteristics is greater than a threshold value (step seven) then a positive test is reported (step eight) and the tested ended (step nine). If the change is less than the threshold value (step seven) then it is determined if it is time to end the test (step ten). For example, the test can be ended after a given period of time or a given amount of fluid sample is tested.
  • step ten If it is not time to end the test (step ten) then the process flow returns to receiving more of the collected EBC sample sample at the microfluidic (step two). If it is time to end the test (step ten) and the change in electrical characteristics has not exceeded the threshold (step seven), then a negative test is reported (step eleven) and the test is ended (step nine).
  • FIG. 22 shows a monolayer of graphene of an electrolyte-gated graphene field-effect transistor.
  • the graphene layer is functionalized with nanoCLAMP capture molecules through a pyrene linker, where two or more nanoCLAMP capture molecules are binding to different binding sites of a target molecule.
  • the testing unit provided in a mask-based diagnostic system may comprise a g-FET biosensor having a detection interface comprising a graphene layer functionalized with capture molecules.
  • a mask-based syndromic testing device including sensor devices can be designed to bind to biomarkers of FluA, FluB, SARS N-protein (more conserved, slower to mutate protein across SARS viruses) and S-protein (faster to mutate, main cause of the SARS-CoV-2 variants).
  • a GaN HEMT sensor (or other sensor device) can include the capture molecules immobilized on a detection area that provides a detectable signal when one or more binding events between target and capture molecules occurs.
  • FIG. 23 illustrates a graphene detection interface with nanoCLAMP capture molecules immobilized on the graphene surface by linker molecules, with a portion of the capture molecules immobilized at a greater distance by a longer link than other capture molecules immobilized on the detection interface with shorter linkers. Also shown is a non-target protein, the target protein, and nanoCLAMPs.
  • the target and non-target molecules are free floating in a liquid sample medium, such as EBC sample, blood, serum, saliva, urine, sweat, interstitial fluid, tears, sputum, lavage, etc.
  • FIG. 24 illustrates an electric field potential applied in the detection area that drives a target molecule and non-target molecule towards the capture molecules where the target molecule is captured by a capture molecule extending on linker molecules a relatively longer distance from the detection.
  • FIG. 25 illustrates the electric field potential removed from detection area.
  • a portion of the capture molecules is immobilized on the detection interface at a greater distance than another portion immobilized on the detection interface.
  • a target molecule As a target molecule is driven towards the detection interface, it may encounter a capture molecule that is tethered at a relatively longer stand-off distance and get captured and thus immobilized and then also tethered to the detection interface.
  • FIG. 26 illustrates an opposite polarity electric field potential that drives the target molecule and non-target molecule away from the detection interface.
  • the target molecule remains tethered by the capture molecule that is immobilized by the relatively longer linker on the detection interface.
  • the non-target molecules and ions contained in the fluid sample along with the target molecule that are not captured are driven further away from the detection interface by the opposite polarity electric field.
  • the driving circuit reverses polarity of the applied electric potential to cyclically drive non-target molecules from the detection area (making room for another target molecule to migrate towards the detection interface) while target molecules captured by capture molecules immobilized on the detection interface are retained in the detection area.
  • the molecules and ions that are of opposite polarity as the target molecule will be driven away from the capture molecules when the target molecule are driven towards the capture molecule, and vice-versa.
  • the net effect is that the binding opportunity for target and capture molecules increases through the application of the applied electric field and once the binding occurs the target molecules are tethered to the detection detection interface (e.g., graphene surface in the case of a gFET sensor).
  • FIG. 27 illustrates additional target molecule molecules and non-target molecules flowing into the detection area, or otherwise being brought into proximity with the capture molecules where the applied electric field can selectively tether additional target molecule and increase the detectable signal.
  • This cycle of reversing electric field polarity can be used to concentrate the target molecules in a portion of the fluid sample received at the detection interface.
  • Some target molecules may get captured directly at the shorter standoff distance capture molecules, or through a pumping action of cycling the polarity of the applied electric field, the target molecules over time become more prevalent and captured by the capture molecules at the detection interface while the non-target molecules and ions present at the detection interface are reduced.
  • the resulting different capture molecule standoff distances from the detection surface produce different sensor-to-antigen binding site distances with the capture molecules that bind to the target molecule contributing a stronger signal response of the detection circuit.
  • This sensor system is designed to enhance molecular detection by utilizing both physical arrangement and electric fields to manipulate and measure molecules within a sample.
  • the sensor includes a source and a drain on the substrate that create a pathway for charges to flow, which is influenced by the binding events between the capture and target molecules. This change in charge flow is an indicator of molecular binding.
  • the system employs top and bottom driving electrodes. These electrodes generate an electric field that orients and directs the movement of molecules within the sample, guiding them towards or away from the detection area. This arrangement not only increases the likelihood of target molecules binding with their corresponding capture molecules but also aids in the removal of non-specific ions and molecules. A washing process can be used to clear the detection area of these non-specific molecules or ions, enhancing the signal from the bound target molecules.
  • An aspect of the system is to adjust the electric field dynamically through a feedback mechanism that responds to real-time data on target molecule binding. This allows for precise control over molecular interactions at the detection site.
  • the system can also reverse the polarity of the electric field cyclically, effectively repelling non-target molecules and preventing them from interfering with the detection process. This feature is particularly useful in complex samples from sources like exhaled breath condensate, blood, or urine, where numerous non-target molecules may be present.
  • FIG. 29 shows a semiconductor sensor device fixed to a large thermal mass, such as a the EBC sample Collector, through a conductive adhesive to remove internally generated heat from the sensor during operation.
  • the drawing shows a capture molecules 2908, a source 2910, a drain 2912, a substrate 2914, a 2DEG 2916, a detection area 2918, an EBC sample Collector 2920, and a thermally conductive adhesive 2922.
  • the Exhaled Breath Condensate (EBC sample) Collector of a mask-based diagnostic is used to convert exhaled breath vapor into exhaled breath condensate.
  • the EBC sample Collector provides a large, chilled thermal mass to enhance the performance of the sensor used in a mask-based diagnostic system. For example, phenomenons of the Kink Effect and Trapped Charges can be utilized with the EBC sample Collector thermal mass to improve sensor functionality.
  • the Kink Effect refers to a sudden increase in drain current at a certain voltage. This phenomenon typically occurs due to impact ionization and the subsequent trapping of charges at or near the drain region. For a GaN sensor embedded in a diagnostic mask, the Kink Effect could cause non-linear changes in sensor response as the device heats up during operation. Normally, this would be undesirable as it introduces unpredictability in sensor readings.
  • the EBC Collector as a heatsink, the temperature rise in the sensor can be minimized. This stable thermal environment can suppress the Kink Effect by reducing the chances of impact ionization, which is more pronounced at higher temperatures. Keeping the sensor at a lower and more stable temperature via the chilled EBC Collector can help maintain the electrical characteristics of the sensor to provide more consistent and predictable measurements.
  • the thermal mass of the EBC sample Collector is frozen water.
  • the thermal conductivity of ice at 0°C is approximately 2.2 W/mK.
  • the EBC sample Collector comprises a thermal mass of frozen water and super abosorbent gel also having a thermal conductivity of approximately 2.2 W/mK, which facilitates efficient heat transfer from the semiconductor sensor to the EBC sample Collector, thereby minimizing thermal gradients and enhancing sensor stability.
  • thermal conductivity of ice (2.2 W/mK) is not as high as metals, it is sufficient to effectively dissipate heat generated by the sensor during operation, especially since the surface of the EBC sample Collector that the bare die sensor is attached to can be made of a highly thermally conductive material such aluminum or a moderately conductive material such as Teflon.
  • a chilled thermal mass helps to remove heat from the sensor, preventing local overheating and maintaining a more uniform temperature distribution across the sensor.
  • the ability to maintain a stable temperature reduces the likelihood of thermal effects such as the Kink Effect and charge trapping.
  • the EBC Collector helps suppress impact ionization and/or other effects that would otherwise lead to non-linear changes in the sensor response as the device heats up. This stability can help obtain precision and reliability of the sensor device, and reproducibility when considered wafer to wafer, device to device, test to test.
  • a stable thermal environment provided by the chilled EBC sample Collector also minimizes the conditions that lead to charge trapping within the semiconductor material. Charge trapping often results in threshold voltage shifts and can degrade the sensor’s performance over time. By maintaining a cooler temperature, the EBC sample Collector reduces charge mobility, thereby decreasing the likelihood of these detrimental effects.
  • the semiconductor sensor system consists of a semiconductor sensor with a source, a drain, and a substrate and a two-dimensional electron gas (2DEG) at a heterojunction below a detection area.
  • This detection area has immobilized capture molecules that are specifically designed to detect particular target molecules.
  • An exmobiment of the diagnostic system includes an Exhaled Breath Condensate (EBC sample) Collector, which includes a chilled thermal mass to condense exhaled breath vapor into exhaled breath condensate.
  • the EBC sample Collector can be thermally connected to the semiconductor sensor through a thermally conductive adhesive. This enhances heat transfer from the sensor to the EBC sample Collector.
  • the stable temperature environment provided by the EBC sample Collector helps to mitigate thermal effects that typically induce non-linear responses and charge trapping in the sensor.
  • FIG. 30 shows a semiconductor sensor device fixed to an insulator to thermally isolate the sensor during operation.
  • the drawing shows a capture molecules 3008, a source 3010, a drain 3012, a substrate 3014, a 2DEG 3016, a detection area 3018, an adhesive 3024, and an insulator 3026.
  • the sensor configuration shown in FIG. 30 provides a highly stable environment for sensitive measurements where the thermal effects caused by functioning of the sensor are maximized. In this case, instead of sinking away the generated heat (as described above), the internally generated heat is maintained in the sensor bulk by thermally isolating the sensor.
  • the system can include both a Device Under Test (DUT) sensor and a reference sensor, both devices thermally isolated so that the thermal effects during operation are enhanced.
  • the DUT sensor is exposed to a liquid sample containing target molecules, while the reference sensor remains unexposed. This configuration allows for comparative analysis, where the reference sensor serves as a baseline to account for any potential non-target related changes in the sensor’s environment or in its own material properties.
  • the semiconductor sensor system includes a substrate with a detection area containing capture molecules for detecting target molecules.
  • the detection process leverages on a two- dimensional electron gas (2DEG) formed between a source and a drain, and measures electrical properties influenced by molecular interactions within the detection area.
  • 2DEG two- dimensional electron gas
  • the sensor can include an insulator bonded to the substrate using an adhesive. This insulating setup thermally isolates the sensor.
  • the sensor system features a dual-sensor setup comprising a Device Under Test (DUT) sensor and a reference sensor.
  • the DUT sensor is exposed to a liquid sample containing target molecules, whereas the reference sensor remains unexposed, and is used to determine how to compensate for thermal variations caused by electrical current flow from the source to the drain.
  • the system can include a temperature monitor for real-time feedback on the sensor's temperature.
  • FIG. 31 stylistically illustrates a field of capture molecules immobilized on the detection area of a sensor device, with a single molecule poised to bind with one or more of these capture molecules.
  • the drawing shows a target molecule (3108), capture molecules (3110), and a die (3112).
  • Previous research has described a phenomenon where an electrostatic change from a single antibody binding event propagates through closely arranged capturing antibodies on a sensor's gate surface. See, for example, Macchia E, Torricelli F, Caputo M, Sarcina L, Scandurra C, Bollella P, Catacchio M, Piscitelli M, Di Franco C, Scamarcio G, Torsi L.
  • the sensor's gate surface (detection area) is densely packed with capturing antibodies (capture molecules), this dense packing allows the field of the capture molecules to electrostatically influence each other.
  • the surface chemistry at the detection area can be designed so that the immobilized capture molecules retain their orientation and packing density.
  • electrostatic forces between charged groups on the antibodies can transmit changes in electrostatic potential through the layer
  • the binding event may cause physical movements or conformational changes in the bound antibody that could mechanically influence adjacent antibodies
  • antibodies have dipole moments where the alteration in the orientation or environment of one antibody’s dipole upon binding can influence the dipoles of neighboring antibodies.
  • This propagated electrostatic change alters the overall electronic characteristics of the gate surface, specifically affecting its capacitance and conductance. These changes can then be amplified and detected as the output signal of the sensor device.
  • the ability to detect a change initiated by a single molecular binding event could tremendously enhance the sensor's sensitivity. Instead of requiring multiple binding events across the sensor surface to generate a detectable signal, the propagation effect means that a single event can lead to a measurable change, pushing the limits of detection down to the single-molecule level.
  • This mechanism would enable ultra-sensitive detection capabilities necessary for applications requiring the identification of very low concentrations of biomarkers, such as in early-stage disease diagnosis or in environmental monitoring where the target molecules may be present in trace amounts.
  • FIG. 32 stylistically illustrates a target molecule binding to one or more capture molecules, demonstrating the propagation of charge effects through the field of capture molecules on a sensor's surface.
  • the drawing shows capture molecules (3204), a die (3206), and a visualization (arrows) of the propagation of the binding event (3208).
  • binding events can enhance or restrict charge transfer between molecules. This influence may result from the creation or disruption of conjugation pathways, affecting the molecular layer's overall conductivity.
  • the field effect induced by the binding event significantly affects the conductivity between the source and drain of a transistor.
  • the change in surface potential at the sensor interface, caused by the binding event modulates the transistor channel's current flow. This modulation might directly result from the propagated charge effects.
  • Binding events can also alter the capacitive properties of the sensor surface. Detecting changes in capacitance indicates the occurrence and magnitude of binding events, providing an indication of the binding events and the propagation of charge effects through the capture molecule field.
  • a pattern of drain electrodes 3304 is formed on the surface of a suitable semiconductor substrate, such as a sapphire wafer with a pattern of GaN HEMT device features.
  • FIG. 34 shows the formation of a drain insulation layer on the an array of drain conductors of the reconfigurable bare die semiconductor sensor.
  • a pattern of drain insulation 3404 is formed over at least of portion of the array of drain conductors. The drain insulation allows for a subsequent formation of conductors that cross over the drain conductors, where drain insulation prevents shorting between the formed patterns of conductors.
  • FIG. 35 shows the formation of an array of source conductors at a right angle to the array of drain conductors and over the drain insulation layer of the reconfigurable bare die semiconductor sensor.
  • the source electrodes 3504 are formed in a pattern that intersects the drain conductors with the drain insulation preventing shorting between the formed patterns of conductors.
  • FIG. 36 shows a barrier layer formed over the arrays of drain and source conductors and having an opening for forming an array of detection areas.
  • a layer of glass 3604 is formed so that a detection area 3606 is left exposed that defines a sample well for each sensor device.
  • the glass layer passivates the features formed on the wafer and leaves the samples well (detection area) and bond pad 3608 for the conductors exposed.
  • Other semiconductor sensor features such as a gate insulator, can be formed to complete the fabrication of an array of semiconductor sensors.
  • the different functionality of the conductors e g., source, drain, gate
  • the intersecting conductor structure shown may form the source and gate conductors instead of the drain and source conductors as described, and the drain conductor can be provided on the backside of the GaN device substrate (see, for example, FIG. 59).
  • FIG. 37 shows a detection area field formed over the arrays for drain and source conductors of the reconfigurable bare die semiconductor device.
  • the sensor array include a layer of gate insulation 3704 that is formed over the glass layer shown in FIG. 36 or otherwise so that the detection areas 3706 have an insulator as necessary to form a field effect transistor with the individually addressable source electrodes 3710 and drain electrodes 3708 so that an x-y scanning scheme can be used to address individual or gangs of electrodes.
  • FIG. 38 shows a pair of drain conductors and a pair of source conductors being tapped for electrical measurement of the source to drain current flow.
  • the electrical characteristics of the detection areas measured at test points 3804 will be indicative of measured binding events 3806 that occur at a number of detection areas as illustrated.
  • the signal at the measured test points may be considered to have a gradient of signal strength that depends on the location of the binding event and the proximity to drain and source electrodes. This enables the possibility of obtaining a significant amount data by scanning and measuring the individually addressable electrodes over time. This data can be analyzed by Al-agents to discern patterns of useful information that indicate improved test results, improvement to the test device structure, hardware and software, better patient outcomes and lower costs.
  • FIG. 39 shows a construction of the array of sensor devices with a glass passivation layer defining individually addressable detection areas between the grid of source and drain electrodes.
  • Test points 3904 are tapped to obtain an electrical signal that is indicative of binding events occurring at detection areas that have at least one edge adjacent to a tapped test point.
  • a complex pattern of the binding events may result which can be provided as data for Al-analysis.
  • contrived samples of a target molecule can be used to create a training database of measurements so that unsupervised learning algorithms can analyze the complex patterns and improve the sensor’s detection accuracy over time.
  • FIG. 40 shows test points 4008, a measured binding event 4010, and a liquid gate electrode 4012.
  • the liquid gate uses a liquid sample that covers the detection areas of the sensor array.
  • a gate voltage applied through the liquid gate electrode to the drain electrode enables the measurement of the source-to-drain current, which varies based on both the applied gate voltage and charges influenced by binding events. These events induce a field effect that modifies the source-to-drain current flow.
  • the presence or absence of a target molecule in the sample can be ascertained.
  • the system is calibrated by comparing source-to-drain currents at specific gate voltages, using AI- analysis to discriminate and categorize different known concentrations of a target molecule based on distinct current change patterns, where all detection surfaces are functionalized with the same capture molecule. This approach enhances detection accuracy and specificity.
  • the method for fabricating a multi-biomarker detecting array of semiconductor sensors on a bare die involves several steps to construct and optimize the sensor's functionality.
  • a semiconductor substrate is provided and a plurality of drain electrodes are formed, over which a drain insulation layer is deposited to prevent electrical shorting.
  • Source electrodes are then formed orthogonal to the drain electrodes and positioned over the drain insulation layer.
  • a barrier layer is subsequently deposited over both the source and drain electrodes, patterned to leave openings that define an array of detection areas.
  • a patterned glass layer is defined over the barrier layer, forming sample wells at each detection area and leaving the bond pads for the source and drain electrodes exposed for electrical connections for signal readout.
  • a gate insulation layer is formed to configure the detection areas as field effect transistors with individually addressable source and drain electrodes.
  • a liquid gate electrode may be formed over the detection areas to facilitate the measurement of source-to-drain currents that are modified by binding events within the detection areas. Pairs of source and drain conductors can be tapped for electrical measurement. This can enable the analysis of binding events based on a gradient of signal strength, which is dependent on the proximity of the binding events to the source and drain electrodes. This configuration enables the detection of minute changes in conductivity caused by molecular interactions within the detection areas along with the ability to detect multiple biomarkers in a single sample. Note that the sequence and layers may be altered depending on the desired performance and use-case of the multi-biomarker detecting array.
  • the bare die biosensor array 4212 may consist of 120 individually addressable biosensor devices, for example. These devices can be specifically tailored for diverse diagnostic purposes with each sensor can be functionalized with one or more different capture molecules, allowing a panel of sensors to test for a variety of target analytes simultaneously. This capability makes it particularly valuable in settings where multiplex testing is required, such as detecting multiple pathogens or biomarkers from a single sample.
  • the sensors can be uniformly functionalized with the same capture molecule across the entire array, forming an addressable wide-area field-effect transistor (FET) sensor with optimizable surface area available for detecting binding events, enhancing the detection of low-concentration target molecules in the sample.
  • FET field-effect transistor
  • the SARS biomarkers include both the SARS N- protein and S- protein.
  • Each charge transfer layer of the different gFETs has a different type of capture molecule (e.g., capture molecule or detecting FluA biomarker).
  • the capture molecules are immobilized at the detection area of each corresponding gFET.
  • a liquid gate electrode , a drain electrode, and a source electrode provide electrical conduction to the semiconductor features that form the different biosensor ganged on semiconductor bare die, where one or more of these biosensor can be functionalized at the processed wafer level.
  • the present invention is designed as a modular system of subassemblies, each module can be separately completed and tested to ensure their functionality before being integrated into the diagnostic system.
  • This modular approach facilitates rapid reconfiguration of the diagnostic system to respond to new pathogen threats, new disease use-cases and rapid implementation of improvements developed by engineers with Al-assisted improvement guidance.
  • the packaged biosensor can have multiple biosensors on a single bare die, and each sensor can be individually functionalized with a different capture molecule. This allows for the creation of a syndromic biosensor that can test for multiple biomarkers of the same disease (e.g., S and N proteins and even RNA of SARS-CoV-2 virus) and/or different diseases (e.g., SARS, Flu-A, Flu-B).
  • FIG. 45 illustrates a capture molecule conjugate having a magnetically reactive end (magnetic reactive particle 4502) and a capture molecule conjugate having an electric field reactive end (field reactive particle 4504).
  • FIG. 46 shows a process for forming aligned and oriented capture molecule conjugates aligned in a magnetic field on a dissolvable adhesive or lateral flow assay membrane or other support structure.
  • An aligning field 4602 is used to orient and drive the capture molecule conjugates towards the adhesive or membrane.
  • FIG. 47 shows a process for forming aligned and oriented capture molecule molecule conjugates aligned in an electric field on a dissolvable adhesive or lateral flow assay membrane or other support structure.
  • the drawing shows a magnetic field plate 4702 and an aligning field 4704.
  • an array of applied-field-reactive capture molecule conjugates is made by providing a dissolvable adhesive film or other support film or structure, on a substrate, membrane, liner, or free standing.
  • a carrier fluid that is a non-solvent for the dissolvable adhesive film has randomly dispersed applied-field-reactive capture molecule conjugates.
  • An aligning field is applied to the carrier fluid for assembling the applied- field-reactive capture molecule conjugates onto the dissolvable adhesive film.
  • the carrier fluid is removed (evaporated, dip or spin coating) leaving the assembled applied-field-reactive capture molecule conjugates fixed on the support film.
  • FIG. 48 illustrates a bare die sensor having a detection area covered by a field of capture molecules, and a liquid sample containing specific target molecules and non-specific ions and molecules.
  • the drawing shows a bare die 4806, a capture molecules 4808, a target molecule 4810, a non-target molecule 4812, an ion 4814, a bottom driving electrode 4816, and a top driving electrode 4818.
  • FIG. 49 illustrates electric field applying top and bottom driving electrodes applying an electric field causing the specific target molecules and non-specific ions and molecules in the liquid sample to orient and migrate in a direction depending on the positive and negative charges of the molecules and ions, where the capture molecules and target molecules are brought into the potential for a specific binding event.
  • the drawing shows a top driving electrode 4904, a non-target molecule 4906, a bottom driving electrode 4908, a capture molecules 4910, an ion 4912, and a target molecule 4914.
  • FIG. 50 shows the applied electric field being reversed causing the molecules and ions to orient and migrate in another direction where the target molecules that bind with the capture molecules remain immobilized at the detection area.
  • the drawing shows a capture molecules 5004, a target molecule 5006, a non-target molecule 5008, an ion 5010, a bottom driving electrode 5012, and a top driving electrode 5014.
  • FIG. 51 shows an optional step of washing away non-specific ions and molecules that are not bound to capture molecules to improve the signal caused by target molecules that remain immobilized at the detection area.
  • the drawing shows a bare die 5104, a capture molecules 5106, a target molecule 5108, a top driving electrode 5110, and a bottom driving electrode 5112.
  • FIG. 52 illustrates different capture molecules for detecting different target molecules and bond to activatable linkers.
  • an unactivated linker is selectively activate by patterned radiation to bind different capture molecules to functionalize different sensor devices formed on a semiconductor wafer.
  • the capture molecules include two or more different types (e.g., capture moleculel , capture molecule2, and capture molecule3). Each capture molecule selectively binds with a different target molecule (respectively, target moleculel, target molecule2, target molecule3).
  • the detection interface of different sensor devices on the same wafer can be functionalized with a distinct capture molecule that can be used to detect the presence of a class of biomarkers.
  • the N- protein within the viral envelope of these virus is usually preserved from variant to variant, while the S- protein will mutate and become a variant or sub-variant of a predecessor variant or original viral strain.
  • the N- protein biomarker can then be considered a class of biomarker that is detectable for many different strains of SARS.
  • the same detection interface of a semiconductor sensor can be functionalized with multiple capture molecules.
  • a screening test can be used where a detected change in signal output caused by capturing at least one type of biomarker indicates a potential health condition.
  • One or more electronic biosensor interface can be functionalized with two or more types of capture molecules that selectively bind to a respective one of these six identified biomarkers.
  • Gastro-intestinal lavage obtained during a colonoscopy can be used as a biosample that is tested.
  • a screening test for pancreatic testing can use a change in the signal output from the biosensor that exceeds a predetermined threshold as an indication that the test subject may have pancreatic cancer and should be tested further.
  • the detection interface of six adjacent semiconductor sensors can be functionalized with a respective capture molecule that selectively binds with one corresponding biomarker. Probabilistic analysis of the signal out from each sensor can be used to determine if the test subject should undergo additional testing for pancreatic cancer.
  • FIG. 53 shows selectively binding a first sub-set of capture molecules to activatable linker molecules.
  • the drawing shows a capture moleculel 5304, a capture molecule2 5306, a capture molecule3 5308, a sensori 5310, a sensor2 5312, a sensor3 5314, a liquid medium 5316, a linkerl 5318, a linker2 5320, and a linker3 5322.
  • each sensor device includes a source, a drain and at least one channel region. At least one of an insulator layer and a dielectric layer is formed over each channel region and a detection area including a charge transfer layer is formed adjacent or near to at least one of an insulator layer and dielectric layer. That is, the sensor devices can have a range of device configurations and material layers, including sensor constructions known as g-FETs (graphene field effect transistors), GaN HEMT, and vertical GaN, etc., as a few examples of known semiconductor device constructions.
  • g-FETs graphene field effect transistors
  • GaN HEMT gallium HEMT
  • vertical GaN etc.
  • the g-FET sensor performance parameters include, for example: the dain current, ID, the trans-conductance, gm, the channel conductance, gD, the threshold voltage, VT, the gate stack reliability, and the gate direct tunneling current density, JDT. Most of these parameters are influenced by the gate dielectric capacitance, Cdi, channel mobility, Ich, metal-semiconductor work function difference, /MS, gate stack charge density, Qgsc, interface trap density, Dit, and bulk dielectric trap density, Dbt, cf. (see, for example, High Permittivity Gate Dielectric Materials, Samares Kar, DOI 10.1007/978-3-642-36535-5)
  • the gate stack capacitance influences many important aspects of the field effect transistor sensor.
  • the insulator/dielectric layer can be a multilayered stack with a high-k material core, including at least one of HfO2, La2O3, HfSiO, HfAlO, HfNO, HfSiON, ErTiO5, SrTiO3, LaScO3, LaA103, GdScO3, LaLuO3, La2Hf2O7, Gd2O3, La2SiO5, SrHfO3.
  • An unactivated linker is incubated and immobilized on the charge transfer layers of the g-FETs.
  • Capture molecules are selectively immobilized on the charge transfer layers of the g- FETs. Different types of capture molecules can be immobilized on the different g-FETs using selective photo-activation of the unactivated linker molecules.
  • the activatable linker molecules are first immobilized on the charge transfer layers (or detection area) through an incubation step as described herein.
  • a capture molecule carrier fluid containing the capture molecules as free-floating capture molecules is disposed over a top surface of the semiconductor substrate wafer covering the plurality of device regions.
  • spin and/or dip coating can be used to form a thin film of the carrier fluid as a liquid medium containing a first type of free- floating capture molecules (capture moleculel) on the surface of the wafer (step one).
  • a first type of free- floating capture molecules capture moleculel
  • the activatable linker molecules Prior to activation the activatable linker molecules are relatively less receptive to binding to the free- floating capture molecules.
  • the chemistry that causes the capture molecule to bind to the linker molecule can be initiated by a selective process, such as patterned photo-radiation.
  • the photo-radiation can be irradiated using an emission plate through a transparent substrate and used to selectively activate the activatable linker molecules to form activated linkers immobilized at some of the charge transfer layers or detection areas (step two).
  • FIG. 54 illustrates the steps of selectively binding a first sub-set of capture molecules to activatable linker molecules.
  • the drawing shows a transparent substrate 5404, an emitting pixel 5406, a transparent substrate 5408, an emission plate 5410, and a sensori 5412.
  • FIG. 55 illustrates illustrates the steps of selectively binding a respective second and third sub-set of capture molecules to corresponding activatable linker molecules.
  • the drawing shows a capture moleculel 5502, a linkerl 5504, an emission plate 5506, an emitting pixel 5508, a linker2 5510, and a linker3 5512.
  • the described method involves fabricating a multi-biomarker detecting semiconductor sensor array on a wafer with a transparent substrate, such as quartz or sapphire.
  • the process includes forming an array of sensor devices, each comprising a source, a drain, and at least one channel region, over which a gate oxide layer is formed. An array of detection areas is established on top of the gate oxide layer.
  • FIG. 58 shows a Wheatstone Bridge circuit concept utilizing semiconductor sensors, where each sensor's source-to-drain resistance acts as a bridge resistor, enabling the detection of molecular binding events that cause measurable changes in resistance in the S-D resistance of a DUT (device under test).
  • the drawing shows an arrangement of individual semiconductor sensors to form a Wheatstone Bridge.
  • a Wheatstone Bridge is a fundamental electrical circuit used to measure very small changes in resistance. It operates on the principle of balancing two legs of a bridge circuit, one leg of which includes the component to be measured.
  • a typical Wheatstone Bridge consists of four resistors arranged in a diamond shape. These four resistors include three resistors of known value and fourth resistor whose value is to be determined or monitored.
  • a Wheatstone Bridge circuit is used for the detection of molecular binding events using semiconductor sensors, each equipped with a source and a drain. Each sensor’s source-to-drain resistance acts as a resistor within the bridge. The Wheatstone Bridge is then connected to a power source and a voltage measurement device across two output terminals. Initially, the bridge is balanced with no voltage difference across the terminals under baseline conditions, where no target molecules are bound to the sensors.
  • molecular binding events alter the source-to-drain resistance of one or more sensors. This change disrupts the balance of the bridge, resulting in a measurable voltage difference across the output terminals. This voltage difference is indicative of molecular binding events.
  • the resistance values of the known resistors within the bridge are adjusted, and the bridge can be calibrated under various baseline conditions to account for environmental or sensor variations.
  • the molecular binding involves interactions between capture molecules, which are immobilized on the sensors, and target molecules within the sample.
  • This Wheatstone Bridge configuration may include three resistors with known resistances and a variable resistor (i.e., the source to drain resistance of the DUT) that dynamically changes due to molecular binding events, allowing precise measurements of these interactions.
  • FIG. 59 illustrates a semiconductor sensor device configuration that utilize a vertical GaN semiconductor architecture.
  • a vertical GaN (Gallium Nitride) semiconductor architecture refers to a design where the electron flow (current) is perpendicular to the surface of the wafer. Unlike lateral structures where devices are fabricated side by side on the surface of the semiconductor substrate, vertical architectures stack the components such as source, drain, and gate vertically. This configuration allows for devices that can handle higher power and voltage levels due to the ability to spread heat more efficiently and use the bulk of the material for current conduction. Vertical GaN structures are particularly advantageous in power electronics, enabling compact, efficient, and high-performance devices suitable for applications like power conversion systems, electric vehicles, and renewable energy technologies.
  • the sensor drawing shows capillary channels 5908, capture molecules 5910, depletion layers 5912, a drain 5914, gates 5916, an N-GaN drift layer 5918, a N+GaN wafer 5920, sources 5922, termination edges 5924, capture molecules 5926, and pGaN layer 5928.
  • the depletion layers extend through the semiconductor bulk and pinch off current from flowing vertically between the sources and the drain.
  • the vertical GaN (Gallium Nitride) semiconductor sensor array is designed for sensing applications.
  • Depletion Layers 5912 extend from pGaN 5928 layers where charge carriers are absent. Modulating these depletion layers controls the flow of electricity through the sensor. The width and properties of the depletion layers are altered by the presence of target molecules, affecting the overall electrical characteristics of the sensor.
  • the drain 5914 is located at the base of the sensor structure and collects electrons that flow down through the device.
  • An N- GaN drift layer 5918 is the region where charge carriers mainly move and is made of n-type GaN to create a pathway with a controlled level of electron density that can be optimized to detect a change in the field effect caused by binding events occurring between capture molecules and target molecules at the detection areas of the sensor devices.
  • An N+ GaN wafer 5920 serves as the substrate for the sensor, providing a highly conductive layer that supports the overall structure and enhances the device's electrical properties.
  • Capillary channels 5908 are formed within the sensor, to receive the flow of a liquid sample so that a large detection area with immobilized capture molecules can bind with target molecules contained in the fluid sample.
  • the capture molecules 5910 are immobilized on the detection areas of the sensor devices and are designed to bind specifically with the target analytes. The binding events between these molecules and the targets initiate changes in the sensor's electrical properties.
  • Gates 5916 can control the flow of carriers in the N-GaN drift layer. By applying different voltages to these gates, the electric field across the sensor can be precisely modulated, altering the conductivity of the N-GaN drift layer to provide a detectable response to the binding events.
  • Sources 5922 are the entry points for electrons into the sensor device and inject carriers into the N-GaN drift layer. Termination edges 5924 define the physical boundaries of the sensor elements, helping to isolate the electrical activity within each sensor and prevent crosstalk between adjacent devices.
  • the pGaN layers 5928 are a p-type GaN layer that works in conjunction with the N-GaN drift layer to form a p-n junction. These p-n junctions provide a diode action within the sensor devices.
  • FIG. 60 shows the change in the depletion layer resulting from binding events between the target molecules and the capture molecules.
  • the drawing shows a drain 6006, capture molecules 6008, a depletion layer 6010, a gate 6014, an N-GaN drift layer 6016, a N+GaN wafer 6018, a capillary channels 6020, a pGaN 6022, a source 6026, a charge conduction 6028, and a termination edge 6030.
  • the binding events cause a field effect change in the depletion layer and opens the charge conduction path allowing more electrons to flow vertically between the sources and the drain.
  • FIGS. 59 and 60 The operation of the vertical GaN sensor structure depicted in FIGS. 59 and 60 involves detecting the presence of target molecules through their binding to capture molecules. This detection mechanism relies on changes in the electrical properties of the sensor, particularly within the depletion layer, as a result of molecular binding events.
  • the sensor As a starting condition, there is no liquid sample or target molecules present (FIG. 59).
  • the sensor is in a baseline state without any target molecules bound to the capture molecules.
  • the depletion layers around the pGaN and N-GaN junction are fully formed and prevent charge carriers from moving freely across the sensor, effectively increasing the sensor’s Source to Drain resistance.
  • a voltage applied to the gates controls the width of the depletion layers, setting the baseline conductance across the sensor. The gate voltage can be set so that no significant current flows through the sensor as the conductance is mainly blocked by the depletion layers.
  • target molecules present in the environment or liquid sample interact and bind with the capture molecules 6008 located within the capillary channels 6020. These channels direct the liquid sample with the target molecules to the active sensor areas.
  • the binding of target molecules to the capture molecules introduces a local field effect. This effect alters the electric field at the interface of the pGaN 6022 and the depletion layers 6010.
  • the local field effect caused by the binding modulates the width of the depletion layers 6010 and allows more charge carriers to flow through the sensor, in the vertical direction from the source 6026 to the drain 6006.
  • the reduction in the depletion layer width opens up a conduction path 6028 for charge carriers with an increase in current flow between the source 6026 and the drain 6006, which can be measured as a decrease in the overall resistance of the sensor (e.g., in conjunction with the Wheatstone Bridge arrangement shown in FIG. 58.
  • the increase in current flow correlates to the presence of target molecules.
  • the amount of current change provides quantitative information about the concentration of target molecules bound to the capture molecules.
  • the changes in current are processed and translated into a measurable signal, indicating the presence and possibly the concentration of target molecules.
  • the vertical GaN sensor structure utilizes the change in electrical properties caused by molecular binding events to detect the presence of specific target molecules. This process leverages the vertical architecture of the sensor to effectively modulate charge carrier flow and sensitivity, enhancing the sensor's performance in detecting molecular interactions.
  • FIG. 61 is similar to FIG. 59 but includes one or more liquid gate electrodes that allow a gate voltage to be applied through a liquid sample disposed at the detection area of the sensor device.
  • the drawing shows a capillary channels 6106, a capture molecule 6108, a depletion layer 6110, a drain 6112, a liquid gate electrode 6114, an N-GaN drift layer 6116, a N+GaN wafer 6118, a pGaN 6120, a source 6122, and a termination edge 6124.
  • FIG. 61 shows a vertical Gallium Nitride (GaN) semiconductor sensor structure designed for enhanced detection of chemical or biological targets through a liquid gate electrode.
  • Capillary channels 6106 are provided to facilitate the movement of liquid samples towards the sensor’s detection area.
  • Capture molecules 6108 are immobilized on the detection area of the sensor devices, the walls of the capillary channels. These molecules specifically bind to target molecules present in the liquid sample and result in detectable changes in the sensor's electrical properties.
  • a depletion Layer 6110 region forms around the junctions within the sensor where charge carriers are depleted when no external influence is applied. The binding of target molecules to the capture molecules affects this layer through a field effect that changes the sensor’s source to drain conductivity.
  • the drain 6112 is positioned at the bottom of the device, the drain collects carriers that flow through the device and a drain bond pad, along with the bond pads of the sources, are the test points for the measurement of changes in electrical current as a result of binding events.
  • the liquid gate electrode 6114 is used along with the vertical GaN structure where the liquid gate electrode allows for the application of a gate voltage applied through the liquid sample. This approach enables real-time modulation of the electrical characteristics of the depletion layer based on the chemical composition of the sample and can be used for applying an electrical field that drives target molecules towards the capture molecules and helps clear ions and non-specific molecules (non-target molecules) from the detection area.
  • the vertical GaN structure includes an N-GaN drift layer 6116, which is typically a lightly doped layer that supports the vertical movement of charge carriers from the source to the drain.
  • An N+ GaN Wafer 6118 provides a highly conductive pathway for charge carriers.
  • a pGaN layer 6120 is formed and works along with the N-GaN drift layer to create a p-n junction with a conduction channel that varies depending on the field effect caused by the binding events between the capture and the target molecules.
  • Sources 6122 inject carriers into the N- GaN drift layer and a termination edges 6124 define the physical boundary of the sensor element.
  • the liquid gate electrode provides dynamic control of the sensor’s response by applying a voltage across the liquid sample itself.
  • FIG. 62 illustrates the vertical GaN with liquid gate sensor when a liquid sample that contains target molecules is applied to the detection areas of the sensors.
  • Target molecules in a liquid sample influence the sensor's detection areas by binding with capture molecules, modulating electrical properties for enhanced signal detection.
  • the illustrated drawing shows target molecules 6206, capillary channels 6208, capture molecules 6210, a depletion layer 6212, a drain 6214, a liquid gate electrode 6216, an EBC sample 6218, an N-GaN drift layer 6220, a N+GaN wafer 6222, charge conduction 6224, pGaN 6226, and a termination edge 6228.
  • the sensor incorporates a liquid gate electrode which can apply and dynamically adjust a gate voltage through the liquid sample.
  • the binding events between capture molecules and target molecules induce changes in the electric field at the pGaN and N-GaN interface, which are detected as variations in current flow between the source and the drain, providing a quantifiable measure of molecular presence.
  • An aspect of the invention pertains to a non-invasive breath-based diagnostic system designed for at-home monitoring of a disease or health concern, such as diabetes and weight loss monitoring.
  • the embodiment shown in FIG. 63 includes an exhaled breath inlet 6312 and a display interface 6314.
  • the system measures glucose in exhaled breath condensate (EBC sample), along with acetone, and/or other ketones and/or ammonia levels in exhaled breath, to provide a comprehensive metabolic profile.
  • EBC sample exhaled breath condensate
  • FIG. 63 illustrates a standalone configuration of the breath-based diagnostic device, including an exhaled breath inlet and display interface. The device receives and processes exhaled breath for diagnostic analysis.
  • the compact, self-contained design allows for portability and ease of use.
  • initial baseline biometric data related to a disease or health concern are stored in a memory.
  • the initial baseline biometric data can be obtained in a clinical setting using a relatively more precise or data rich baseline biometric test(s).
  • the initial baseline biometrics are stored in a memory, for example, of a smartphone user-interface or a user's personal account stored on a cloud server.
  • the baseline biometrics are available so that patient-specific monitoring and treatment adjustments can be done with greater utility based on real-time or accumulated data compared with more complete data.
  • These baseline tests can include well-established clinical procedures and the one or more test performed, for example, by a professional healthcare provider to establish a patient’s baseline biometrics related to a particular disease or concerning health condition, such as diabetes.
  • the Hemoglobin A1C (HbAlC) Test reflects the average blood glucose levels over the past two to three months, by measuring the percentage of glycated hemoglobin (the fraction of red blood cells that have glucose attached). This is considered a precision test because HbAlC incorporates long-term glucose concentration and more random fluctuations in daily blood sugar do not impact the results. Typically, this test is used to diagnose pre-diabetes and diabetes, as well as in the long-term monitoring of diabetic patients.
  • the HbAlC result is an example of a reliable clinically-derived baseline for determining the patient's initial glucose levels and metabolic state.
  • This baseline data is stored in the system’s memory and is used to establish patient-specific thresholds for monitored biomarkers, such as glucose levels in exhaled breath condensate (EBC sample) or acetone detected in the exhaled breath stream.
  • EBC sample exhaled breath condensate
  • acetone detected in the exhaled breath stream.
  • Oral Glucose Tolerance Test assesses the body’s ability to handle a glucose load in real time. This is often considered the “gold standard” for diagnosing Type 2 diabetes and gestational diabetes, as it captures how efficiently insulin responds to a known challenge. After fasting overnight, a patient ingests a measured glucose solution. Blood glucose levels are then measured at specified intervals — typically at fasting baseline, then at 1 hour and 2 hours. Typically, this test is used for individuals with borderline or equivocal results on other tests and to screen for gestational diabetes during pregnancy.
  • the Oral Glucose Tolerance Test is a clinical baseline test that measures the body’s ability to process glucose by tracking blood glucose levels at specific intervals after a glucose-rich drink. This test provides detailed information about a patient’s glucose metabolism and insulin response, and is an example of a clinically-derived baseline that can be used for precision medicine based on an understanding of the individual patient's metabolic state.
  • OGTT results are used to establish patient-specific thresholds for biomarkers like glucose in exhaled breath condensate (EBC sample) and acetone levels in the breath. By comparing real-time monitored biometrics against these thresholds, the system can detect changes in glucose regulation, such as worsening insulin resistance or improving glucose control. This enables timely interventions, tailored recommendations, and proactive management of diabetes, ultimately leading to better patient outcomes.
  • CGM Continuous Glucose Monitoring
  • CGM systems are becoming increasingly accurate for monitoring daily variations in glucose and can be correlated with labbased tests for better diabetes management. They offer real-time insights, which is different from single-point measurements. These tests are primarily used by people with diabetes (especially Type 1) for real-time glucose management rather than official diagnosis.
  • OGTT Oral Glucose Tolerance Test
  • FIG. 65 shows the modular configuration of the breath-based diagnostic system, illustrating the washable durable components and disposable consumable parts.
  • the drawing shows a user interface 6504, washable durable components 6506, disposable consumable parts 6508, and a condensation surface 6510.
  • This modular setup allows for efficient disassembly, facilitating the replacement of re-useable components such as the condensation surface along with disposable or refreshable biomarker detection modules. By separating reusable and singleuse elements, this design reduces operational costs and enhances user compliance while maintaining accuracy and reliability in diabetes monitoring.
  • FIG. 66 is a side view of the system illustrating the flow path of exhaled breath through the condensate surface and gas sensor and shows the integration of the condensation and gas-sensing subsystems.
  • the drawing shows washable durable components 6604, disposable consumable parts 6606, a condensation surface 6608, a biomarker detection module 6610, a mouth piece 6612, a gas sensor 6614, and an EBC sample condensation 6616. This configuration allows for efficient sample capture and analysis.
  • the flow path of exhaled breath starts with the user blowing in through the mouth piece and passes over the gas sensor and EBC sample condensation subsystems.
  • the EBC sample condensation module includes a chilled thermal mass that can be chilled by placing in a freezer, or can use an endothermic reaction, or electronic cooling such as a Peltier cooler.
  • the exhaled breath impinges on the condensation surface, where the moist breath vapor is cooled to form a liquid sample of exhaled breath condensate (EBC).
  • EBC exhaled breath condensate
  • the same breath stream passes over the gas sensor, which detects volatile biomarkers such as acetone, ketones and ammonia.
  • the EBC is analyzed by the biomarker detector for glucose levels, enabling the simultaneous detection of important biomarkers for tracking the progression of diabetes and weight loss. This streamlined configuration enables efficient sample collection, rapid analysis, and precise diagnostic outputs for diabetes and weight loss management.
  • FIG. 67 shows the biomarker detection module mounted and ready for use within the diagnostic device.
  • This module of the module-based diagnostic drawing shows a biosensor card 6704 removably held in the biomarker detection module 6706.
  • This module enables a low cost, reusable or refreshable biosensor module, for example, that connects a bare die sensor with a printed circuit board and/or supports a disposable lateral flow assay (LFA) type test strip of a photonic LFA.
  • the biosensor card is configured to support reusable or refreshable biosensors for the detection of biomarkers in exhaled breath condensate (EBC sample) or other sample types, including other liquids and other gases.
  • EBC sample exhaled breath condensate
  • the biosensor card enables easy reuse or exchange of the EBC sample biomarker detector for example, for glucose and other analytes in EBC sample so that a multiple biomarker system, which may include a gas sensor for ketones, acetone, and ammonia detection, is provided.
  • a multiple biomarker system which may include a gas sensor for ketones, acetone, and ammonia detection
  • these particular biomarkers are relevant for monitoring diabetes and weight loss progression, the system is also adaptable for monitoring breath based biomarkers for other diseases and health conditions including viral and bacterial infections, cardiac monitoring, acute kidney disease, asthma, COPD, cancer screening, and tuberculosis, to name a few.
  • the modular design allows for easy installation and replacement, enabling a very user- friendly integration with the housing, electronics, EBC sample collection and other elements of the breath based diagnostic device.
  • the device includes modular components for sample input, signal processing, and electrical connections to the microprocessor for power and data transmission and analysis.
  • This embodiment of the biosensor card is designed to utilize semiconductor, LFA or hybrid biosensors for the precise detection of target biomarkers, for example but not limited to, leveraging the features of the vertical GaN semiconductor sensors or hybrid lateral flow assays described herein.
  • the configuration of the biosensor card facilitates real-time monitoring at-home or in a clinical setting with very easy capture of the biometric data during each testing session, along with user-friendly transmission of the data via bluetooth or wifi connection to a remote cloud server for data aggregation from many users or directly to a trusted received, such as the patient's family caregiver or remotely located healthcare provider.
  • the washable or disposable components of the diagnostic device enabled enhanced hygiene and user compliance, making it suitable for both clinical and at-home use.
  • a refreshable biosensor module can be provided that can be used multiple times by refreshing the detection surface of the sensor devices.
  • a refreshing solution and process can be used to dissociate glucose from GOx as a practical and effective way to reuse a ZnO nano rod biosensor.
  • Refreshing Solution for ZnO/GOx As part of the at-home cleaning or a more controlled factory refresh of the biosensor, a refreshing solution can be used to break the bond between the capture molecule (GOx) and the target molecule (glucose) while minimizing damage to the ZnO nanorod layer or denaturing the GOx detection molecules. This approach allows the biosensor to reset for subsequent measurements while maintaining the integrity and activity of the ZnO nano rod/GOx interface.
  • the refreshing solution disrupts the binding between glucose (target molecule) and GOx (capture molecule) while limiting any affect on the ZnO nano rods or the immobilized GOx.
  • One or more of the following processes can be used for refreshing the detection surface - Competitive Binding Agents, where a solution containing high concentrations of non-reactive glucose analogs (e.g., galactose or mannose) competitively bind to GOx, displacing residual glucose. pH Shifts, since GOx-glucose interactions are pH-sensitive, a mild, reversible pH adjustment (e.g., using a buffered solution) can be used to temporarily weaken the glucose binding to reduce damage to the enzyme or ZnO layer.
  • non-reactive glucose analogs e.g., galactose or mannose
  • Ionic Strength Changes where increasing ionic strength (e.g., using NaCl or KC1 solutions) can reduce electrostatic interactions between glucose and GOx, facilitating the detachment of glucose.
  • a controlled concentration of non-denaturing surfactants e.g., Tween-20 or Triton X-100
  • Tween-20 or Triton X-100 can help disrupt non-covalent interactions between glucose and GOx without overly compromising the ZnO nanorod structure or GOx activity.
  • the refreshing process may comprise one or more of the following steps: 1) Application of Refreshing Solution, where the refreshing solution is introduced to the detection surface, targeting the glucose bound to GOx.
  • the solution can be allowed to interact for a specific time to facilitate complete dissociation of glucose from GOx.
  • PBS phosphate-buffered saline
  • the refreshing solution limits damaging or denaturing the GOx, allowing for multiple cycles of use.
  • the refreshing process is designed to be quick with the solution designed to be minimally destructive to the ZnO Nanorod layer and to selectively target the glucose-GOx bond, to leave the detection surface sufficiently intact for the next measurement.
  • an initial test of the biosensor may be used to determine if a new biosensor card module is needed of if a calibration step would enable re-use in a subsequent EBC sample glucose test.
  • An example of the refreshing solution can include a composition of 10 mM phosphate buffer (pH ⁇ 7.5), 100 mM NaCl (ionic strength adjustment), and 0.1% Tween-20 (gentle surfactant).
  • an amount of the refreshing solution is applied to the detection surface. For example, about 100-300 pL of the solution to the sensor surface can be deposited into the test well or the biosensor card dipped into an ultrasonic bath of the solution for a set period. The solution is then rinsed away with a buffer solution or plain water. In a laboratory or factory setting, a known glucose standard or other calibration check can be used to confirm the sensor is refreshed and functional.
  • the biosensor card may be part of a subscription service that includes shipping back and forth to exchange new or factory-refreshed biosensor cards for used ones.
  • FIG. 68 is an exploded view of the biosensor card assembly, showing the structural components and arrangement optimized for at-home ease-of-use without assistance for effective diagnostic performance.
  • the drawing shows a top housing 6804, a collection well 6806, a biosensor card 6808, a bottom housing 6810, and a bottom cap 6812.
  • the assembly includes multiple modular layers designed for easy assembly of the biosensor card in a housing.
  • the biosensor card top housing includes a collection well, which directs the EBC sample sample to pool onto the detection surface of the sensor device.
  • a microfluidic channel such as filter paper, capillary flow structure, microfluidic membrane, or the like, can be provided to present a flow of the EBC sample over the detection surface to allow the target molecules in the EBC sample to flow over the detection surface and allow for the binding of target molecules to the immobilized capture molecules.
  • the biosensor card is a printed circuit board that has the sensor die attached for electrical connection with reader electronics.
  • the biosensor card is held in a bottom housing that mates with a bottom cap that fits into the outer housing of the stand-alone diagnostic device.
  • the bottom cap can include reader electronics and the electrical interface to connect with the conductive traces of the biosensor card.
  • the biosensor card is configured to be used with an edge card connector for connecting to cabling or directly to a printed circuit board containing the reader and/or bluetooth/wifi communication electronics.
  • FIG. 69 shows a bare die semiconductor biosensor having bond pads and detection surfaces configured and dimensioned for the unique biosensor card packaging solution.
  • the bare die 6902 includes bond pads 6906 a detection area 6904.
  • the bond pads connect the active device features, such as source, drain and gate, to the conductive traces of the biosensor card.
  • FIG. 70 shows a section for the biosensor card with the bare die sensor attached with the detection surfaces accessible by the liquid or gas sample through a detection window.
  • the biosensor card 7002 includes a detection window 7004 for providing access to a detection area 7006 of the biosensor sensor.
  • the bare die sensor is connected by bond pads to the conductive traces 7008 and in turn connect the active device features, such as source, drain and gate, to the reader electronics.
  • FIG. 71 illustrates a bare die biosensor with nano rod and capture molecule functionalization.
  • the drawing shows a source 7102, a drain 7104, a gate 7106, a GaN layer 7108, an Al GaN Layer 7110, a 2DEG (Two-Dimensional Electron Gas) 7112, a passivation layer 7114, a nano rod 7116, a bioreceptors 7118, a substrate 7120, and a detection area 7122.
  • the bioreceptor such as an H1N1 aptamer
  • the aptamer is designed with high specificity to the H1N1 target protein of the flu A virus, and is immobilized on the nano rods through a chemical modification such as a 5' thiol group and a linker molecule.
  • the aptamer binds specifically to the target protein. This binding event induces a change in the local surface charge on the ZnO nanorods due to the electrostatic characteristics of the protein-aptamer interaction.
  • the change in surface charge alters the electric field near the nano rods, which in turn modifies the field effect in the GaN HEMT structure.
  • This change in the electric field impacts the two-dimensional electron gas (2DEG) layer at the AlGaN/GaN interface, resulting in an increase or decrease in the conductivity between the source and drain electrodes of the biosensor.
  • the degree of this conductivity change is proportional to the concentration of the H1N1 target protein in the sample, allowing for sensitive and specific detection. This mechanism provides real-time, label-free monitoring of the binding events, making it an efficient approach for detecting biomarkers such as the H1N1 target protein in breath-based diagnostics.
  • the process begins with surface preparation of the ZnO nano rods.
  • the ZnO nano rods are cleaned and activated using a mild oxygen plasma treatment or chemical cleaning to remove contaminants and expose hydroxyl (-OH) groups on the surface.
  • the surface is functionalized using a linker molecule, such as (3- Mercaptopropyl)trimethoxysilane (MPTS), which contains a thiol-reactive silane group.
  • MPTS (3- Mercaptopropyl)trimethoxysilane
  • the MPTS is applied to the ZnO surface and incubated at an appropriate temperature and humidity to ensure covalent attachment through silane bonding, forming a stable thiol-functionalized ZnO surface.
  • the H1N1 aptamer with the 5’ thiol modification is introduced to the surface.
  • the thiol (-SH) group on the aptamer readily forms a covalent bond with the thiol groups of the MPTS layer through disulfide bonding or direct thiol-metal interactions.
  • the immobilization process is optimized by adjusting factors such as pH, ionic strength, and incubation time designed to optimize the aptamer binding while maintaining its structural integrity, orientation and binding affinity for the H1N1 Hemagglutinin (HA) protein.
  • the senor is rinsed with a blocking buffer (such as bovine serum albumin or mercaptoethanol) to prevent non-specific binding and stabilize the aptamer layer.
  • a blocking buffer such as bovine serum albumin or mercaptoethanol
  • the functionalized ZnO nanorod surface is then ready for H1N1 detection, where the aptamer specifically binds to the HA protein present in exhaled breath condensate (EBC sample) of a flu infected test subject. This binding event modulates the electrical properties of the GaN HEMT, leading to a measurable signal that enables real-time, high-sensitivity virus detection.
  • the substrate for the biosensor plays a critical role in the biosensor bare die performance and manufacturability, and various materials can be chosen based on the specific application.
  • Sapphire (AI2O3) is an option due to its high thermal conductivity, electrical insulation, and stability, making it suitable for high sensitivity biosensors like GaN HEMTs.
  • sapphire is expensive and brittle, which can complicate manufacturing.
  • Silicon carbide (SiC) offers exceptional thermal conductivity and robustness, making it suitable for demanding environments, but it is also costlier and less widely available than silicon.
  • Silicon (Si) is the most affordable and scalable option, benefiting from established CMOS manufacturing processes, though it has lower thermal conductivity and durability compared to sapphire or SiC.
  • Gallium nitride can be used as both a substrate and an active layer, offering high electron mobility and excellent thermal properties for high-performance biosensors, though it is more expensive.
  • Quartz substrates provide outstanding optical properties and stability, making them suitable for hybrid biosensors that combine optical and electronic detection, but they require additional layers for electrical conductivity.
  • Polymer substrates, such as PDMS or Kapton, are flexible and biocompatible, enabling wearable biosensors, but they have limited thermal and electrical performance. The choice of substrate depends on the intended application, with SiC and sapphire being good choices for high- sensitivity applications, silicon for scalable and cost-effective production, and quartz or polymer for specialized optical or wearable devices. These materials support a range of biosensor technologies, including GaN HEMTs, MOSFETs, and hybrid systems, enabling the detection of molecular binding events in applications like exhaled breath condensate-based diabetes monitoring.
  • FIG. 72 illustrates another version of the bare die biosensor with a small gate and detection area formed close to the 2DEG (Two-Dimensional Electron Gas).
  • the drawing shows a gate 7202, a source 7204, a drain 7206, a detection area 7208, a nano rod 7210, and a bioreceptors 7212.
  • the substrate supports a GaN layer adjacent to an AlGaN Layer possibly with a thin GaN cap just a few nanometers in thickness, that forms the active region of the device.
  • a portion of the top surface of the AlGaN/GaN structure is exposed and divided into two functional regions: the gate and the detection area.
  • the gate is a metallic layer, such as Ni/Au, that partially covers the exposed AlGaN surface.
  • This gate modulates the flow of charge carriers within the two-dimensional electron gas (2DEG) layer located at the AlGaN/GaN interface. This modulation controls the electrical conductivity between the source and the drain, which is the basis for the sensor’s operation.
  • the detection area is the remaining exposed surface between the source and drain. This region is functionalized with ZnO nanorods, which provide a high surface area for immobilizing bioreceptors, such as aptamers, antibodies, or other biomolecules. These nanorods are specifically grown and positioned in this detection area to facilitate interaction with target molecules, such as biomarkers in exhaled breath condensate (EBC sample).
  • EBC sample exhaled breath condensate
  • This design leverages the distinct functionalities of the gate and detection area, with the gate providing baseline control and the detection area enabling biochemical interaction and signal transduction.
  • the integration of ZnO nanorods and bioreceptors within the detection area enhances sensitivity and ensures the biosensor’s capability for real-time, label-free biomolecule detection.
  • FIG. 73 shows photomicrographs of ZnO nano rods selectively patterned on a semiconductor surface.
  • ZnO nano rods can be selectively grown in specific regions using lithographically defined templates or masks, making the growth process fit very well with the semiconductor processes for forming the GaN HEMT structure and providing a basis for wafer-level functionalization of the biosensor die, at least for the nano rod layer.
  • the immobilization of the capture molecule on the nano rods could also be done prior to dicing the wafer.
  • This selective growth capability and the tenacity of the ZnO nano rod layer on the GaN detection surface allows for scalable and precise functionalization without affecting non-active regions and enables wafer-level functionalization at the detection area of the ZnO nano rod layer.
  • the surface chemistry of ZnO is also well-suited for covalent or non-covalent immobilization of biomolecules, such as glucose oxidase, other capture and probe molecules including nano bodies, nanoCLAMPs, aptamers, antibodies, or DNA.
  • Hydrothermal synthesis is a cost-effective and scalable method for growing ZnO nano rods on the detection areas of GaN biosensor dies.
  • the process begins with preparing the GaN wafer by cleaning its surface to remove contaminants and applying a photoresist layer to define the specific detection areas using photolithography. After exposing the detection regions, a thin ZnO seed layer is deposited on these areas to provide nucleation sites for nano rod growth, while the remaining regions remain protected by the photoresist.
  • a growth solution is then prepared by dissolving a zinc salt, such as zinc nitrate, and a hydroxide source, such as hexamethylenetetramine (HMTA), in water.
  • a zinc salt such as zinc nitrate
  • a hydroxide source such as hexamethylenetetramine (HMTA)
  • HMTA hexamethylenetetramine
  • the pH of the solution is adjusted to optimize the growth conditions, typically between pH 10 and pH 12.
  • Optional additives, such as polyethylene glycol (PEG) may be included to control the size and alignment of the nano rods.
  • PEG polyethylene glycol
  • the patterned GaN die or wafer is immersed in this solution, and the setup is heated to around 70-95°C for several hours. During this time, ZnO nano rods grow vertically on the seed layer, forming aligned structures along their natural crystallographic axis.
  • the die is rinsed with deionized water to remove any residual solution and dried.
  • the remaining photoresist is stripped to leave ZnO nano rods only on the detection areas.
  • the nano rods can then be functionalized with bioreceptor molecules, such as glucose oxidase or aptamers, to enable specific biomarker detection.
  • bioreceptor molecules such as glucose oxidase or aptamers
  • ZnO nano rods offer a significant advantage for the biosensor by dramatically increasing the capacity for immobilizing capture molecules.
  • ZnO nano rods have a high surface-to-volume ratio due to their vertical alignment and nanoscale dimensions, which creates more available binding sites compared to a flat detection surface. This increased surface area enables a greater density of capture molecules, such as enzymes, aptamers, antibodies, or other biomolecules, to be immobilized.
  • This enhanced capacity for immobilization improves the sensitivity of the biosensor in several ways.
  • a higher density of capture molecules increases the likelihood of interactions with target molecules, such as glucose or acetone in exhaled breath and exhaled breath condensate (EBC sample). This increases the detectable signal, allowing the biosensor to identify even low concentrations of biomarkers.
  • target molecules such as glucose or acetone in exhaled breath and exhaled breath condensate (EBC sample).
  • EBC sample exhaled breath and exhaled breath condensate
  • the uniform distribution of nanorods ensures that the capture molecules are evenly spaced, reducing steric hindrance and improving the efficiency of target binding.
  • the nano structured surface facilitates more efficient charge transfer to the underlying GaN HEMT detection layer, enhancing the signal-to-noise ratio and providing more reliable measurements.
  • nanorods there are several types of nanorods that can be used for functionalizing the detection surface of the described GaN or other types of biosensors, each type of nano rod has advantages and disadvantages.
  • ZnO nano rods are a good choice due to their high biocompatibility, strong piezoelectric properties, cost-effective hydrothermal growth process, and stability in aqueous environments. However, they can degrade in extreme pH conditions and have moderate conductivity. Titanium dioxide (TiCh) nano rods are chemically stable and resistant to degradation, with photocatalytic properties that could enhance sensing. However, their conductivity is lower, and they require additional surface modifications to attach biomolecules effectively.
  • Silicon (Si) nano rods offer high conductivity and precise fabrication, making them a good choice for integration with semiconductor systems, but they are more expensive to produce and need protective passivation layers.
  • Gold (Au) nano rods provide excellent biocompatibility and strong plasmonic properties for optical detection, but their high cost and mechanical fragility make them less practical for large-scale use.
  • Aluminum oxide (AI2O3) nano rods are inert, stable, and biocompatible, but their poor electrical conductivity limits their applications in electrical signal-based biosensors.
  • Gallium nitride (GaN) nanorods have excellent electrical conductivity, strong piezoelectric properties, and are highly robust, making them a good choice for integration with GaN-based biosensors.
  • GaN gallium nitride
  • MBE molecular beam epitaxy
  • Carbon nanotubes (CNTs) offer extremely high surface area and superior conductivity, but their synthesis is costly, and they require significant processing to ensure proper alignment and biocompatibility.
  • Iron oxide (FesC ) nano rod 7210rods provide unique magnetic properties and biocompatibility, which can enable novel sensing mechanisms, but they are prone to oxidation and have moderate conductivity.
  • Each type of nano rod offers unique advantages depending on the application, such as sensitivity, cost, and environmental stability.
  • FIG. 74 shows a wafer scale functionalization process.
  • the drawing shows an AlGaN Layer 7402, a GaN layer 7404, a substrate 7406, a source 7408, a gate 7410, a drain 7412, a detection area 7414, a nano rod 7416, a bioreceptors 7418, a passivation layer 7420, a kerf 7422, and a protection layer 7424.
  • FIG. 74 illustrates the sequential steps involved in fabricating a semiconductor biosensor, as described in the flow chart of FIG. 75.
  • the method enables the efficient manufacture of biosensors with immobilized capture molecules for detecting specific target analytes.
  • a semiconductor substrate wafer (7402) is provided.
  • the substrate wafer consists of layers such as a base semiconductor layer (7404) and functional device layers (7406).
  • a plurality of semiconductor device regions (7410, 7412) is defined. Each region comprises at least a source region, a drain region, and a channel region between them.
  • Step Two a detection area (7414) is formed over the channel region.
  • This detection area provides the surface for immobilizing capture molecules.
  • nano rod structures can be formed to increase the surface area and improve sensitivity.
  • Capture molecules (7416) such as aptamers or antibodies, are immobilized on the detection area. This process involves a functionalization step to create stable bonds between the detection surface and the capture molecules. The immobilization ensures specificity to the target analyte.
  • the individual semiconductor devices (7422) are separated from the wafer. This separation occurs after the immobilization step.
  • the separated devices may include protective layers (7424) that can be removed during final assembly or activation, ensuring that each device retains its functionalized detection area intact. The process facilitates the waferlevel precision in manufacturing and preserves the integrity of the detection area for optimal biosensor performance.
  • FIG. 75 illustrates a process for fabricating a GaN HEMT biosensor with a nano rod detection surface and immobilized capture molecules, protected during manufacturing steps including dicing.
  • the process begins with a semiconductor substrate wafer, such as sapphire, SiC, or Si, which serves as the handle or foundation for the biosensor.
  • a semiconductor substrate wafer such as sapphire, SiC, or Si
  • the source, drain, and channel regions of the GaN HEMT are created, forming with the 2DEG, the electrical pathway for the test signal electron flow.
  • the detection area is then formed over the channel, and nano structures such as ZnO nano rods grown on the detection area to significantly increase the surface area at the detection area creating advantages for biomolecule immobilization and target molecule detection.
  • Capture molecules such as antibodies, aptamers, nano bodies, nanoCLAMPs or enzymes, can also be immobilized onto the nano rods using chemical or covalent bonding, linker molecules, etc., to enable highly selective detection of target biomarkers.
  • a temporary protection layer such as a polymer or resist, is applied over the detection surface.
  • the resist layer is chosen so that subsequent removal after dicing and/or other manufacturing processing steps, and/or for an extended shelf-life, leaves the detection area still functionalized for detecting the target molecule.
  • the wafer is diced into individual biosensor devices while the protection layer is in place to minimize mechanical damage or contamination. After the protection layer is removed, the detection surface is exposed for further functionalization steps or for analyte testing.
  • FIG. 76 is a cross-sectional view of an embodiment of a vertical GaN semiconductor biosensor, showing capillary channels designed to optimize the surface area and sample flow, with significantly enhanced surface area for immobilized detection molecules through the use of ZnO nano rods. This structure improves the interaction between biomarkers and detection molecules.
  • ZnO nano rods are used to functionalize a GaN HEMT biosensor to provide several significant advantages, especially for biosensing applications like glucose detection in exhaled breath condensate (EBC sample). These advantages are obtained from the inherent material properties of ZnO, and compatibility with GaN-based semiconductor sensor devices.
  • ZnO nano rods provide a high surface-to-volume ratio due to their high aspect ratio, which significantly improves the packing density of functionalization sites for biomolecules like glucose oxidase (GOx). This increased surface area significantly improves sensitivity by enabling more target-analyte interactions.
  • ZnO nano rods and the nano rods growth process are well-matched for wafer-level functionalization on the GaN detection surface. This growth process can carried out in the control conditions of an evaporation chamber or spin coating or other nano rod growth chambers and process. The growth of the nano rod at the detection areas can be done at the wafer-level without inducing significant stress or defects, preserving the performance of the underlying HEMT structure.
  • ZnO nano rods can amplify the biosensor’s response by creating stronger interactions with target molecules, such as glucose in EBC. The nano rods facilitate more efficient charge transfer to the GaN HEMT channel, enhancing the signal-to-noise ratio.
  • ZnO nano rods also exhibit strong piezoelectric effects, which can enhance the sensor’s transduction mechanism.
  • the piezoelectric nature can improve the detection of binding events at the detection surface, increasing the sensor’s ability to convert biochemical interactions into measurable electrical signals.
  • ZnO is inherently biocompatible, making it a good material for biosensing applications that require interactions with biomolecules or biological samples. This property allows for reliable functionalization with capture molecules such as enzymes, nano bodies, aptamers, nanoCLAMPs or antibodies.
  • ZnO is optically transparent, which can be advantageous for hybrid biosensors incorporating both electrical and optical detection mechanisms. This property enables complementary detection modes (e.g., fluorescence and electrical signals) for greater reliability and confidence in a detected test result.
  • ZnO nano rods exhibit good stability in aqueous environments, making them suitable for applications involving liquid-phase detection, such as EBC sample samples. This stability in water is particularly suited for EBC sample which is a relatively clean, mostly water, biosample.
  • the vertical GaN (Gallium Nitride) semiconductor architecture refers to a design where the electron flow (current) is perpendicular to the surface of the wafer. Unlike lateral structures where devices are fabricated side by side on the surface of the semiconductor substrate, vertical architectures stack the components such as source, drain, and gate vertically. This configuration allows for devices that can handle higher power and voltage levels due to the ability to spread heat more efficiently and use the bulk of the material for current conduction. Vertical GaN structures are particularly advantageous in power electronics, enabling compact, efficient, and high-performance devices suitable for applications like power conversion systems, electric vehicles, and renewable energy technologies.
  • the vertical GaN structure can also have the advantages of smaller size, lowing cost and improving the detection capabilities of the sensor.
  • the vertical GaN sensor bare die comprises capillary channels 7608, with nano rods functionalized with capture molecules 7610 disposed in the capillary channels, depletion layer 1512, a drain 7614, gates 7616, sources 7618, an N-GaN drift layer 7620, a N+GaN GaN wafer 7622, and pGaN layer 7624.
  • the depletion layers extend through the semiconductor bulk and pinch off current from flowing vertically between the sources and the drain.
  • the vertical GaN (Gallium Nitride) semiconductor sensor array is designed for advanced sensing applications.
  • Depletion Layers that extend from pGaN layer formed around the sensor elements where charge carriers are absent for controlling the flow of current through the device. The width and properties of these layers are altered by the presence of target molecules, affecting the overall electrical characteristics of the sensor.
  • the drain is located at the base of the sensor structure and collects electrons that flow down through the device.
  • An N-GaN drift layer is the region where charge carriers mainly move and is made of n-type GaN to create a pathway with a controlled level of electron density that can be optimized to detect a change in the field effect caused by binding events occurring between capture molecules and target molecules at the detection array of the sensor devices.
  • An N+ GaN wafer serves as the substrate for the sensor, providing a highly conductive layer that supports the overall structure and enhances the device's electrical properties.
  • Capillary channels are formed within the sensor, these channels allow the flow of a liquid sample so that a large detection area with immobilized capture molecules can bind with target molecules contained in the fluid sample.
  • the capture molecules are immobilized on the detection areas of the sensor devices and are designed to bind specifically with the target analytes. The binding events between these molecules and the targets initiate changes in the sensor's electrical properties.
  • Gates can be provide to control the flow of carriers in the N-GaN drift layer.
  • Sources are the entry points for electrons into the sensor device and inject carriers into the N-GaN drift layer. Termination edges define the physical boundaries of the sensor elements, helping to isolate the electrical activity within each sensor and prevent cross-talk between adjacent devices.
  • the pGaN layers are a p-type GaN layer that works in conjunction with the N-GaN drift layer to form a p-n junction. These p-n junctions provide a diode action within the sensor devices.
  • FIG. 77 shows the vertical GaN semiconductor in operation, where current flows through the conductance channel in response to biomarker binding events.
  • the electrical characteristics shift based on these binding interactions and this shift is amplified by reader electronics and used as the test signal to determine the presence or absence of a target molecule, typically based on exceeding a threshold change from baseline reading to tested sample reading.
  • This mechanism provides real-time, direct-to-electrical signal output for biomarker detection.
  • FIG. 78 illustrates a liquid gate version of the vertical GaN semiconductor biosensor.
  • liquid samples are utilized to modulate the applied gate voltage, enabling biochemical detection through interactions at the detection area.
  • the system includes a liquid gate electrode 7804, a capture molecule 7806, and a depletion layer 7808.
  • the vertical GaN structure comprises a source region located at the top, a drain region positioned at the bottom, and an N-GaN drift layer that facilitates a vertical charge carrier pathway.
  • a depletion layer created at the interface between the p-GaN layer and the drift layer, acts as a modulating layer for charge carrier flow in response to changes induced by biochemical events.
  • the liquid gate introduces the gate voltage via the liquid sample, which flows over the detection area functionalized with capture molecules.
  • capture molecules are designed to specifically bind with target molecules, such as biomarkers or proteins present in the liquid sample.
  • target molecules such as biomarkers or proteins present in the liquid sample.
  • target molecules bind to the capture molecules, they induce localized electric field changes near the detection surface. These changes alter the width of the depletion layer, thereby affecting the flow of charge carriers between the source and drain regions.
  • This modulation in charge carrier flow is translated into a measurable electrical signal, directly correlating to the concentration or presence of the target molecules.
  • the liquid gate provides a stable and uniform electric field across the liquid sample and detection area, enhancing the sensitivity and reliability of the measurement.
  • the vertical design of the GaN semiconductor is particularly suited for detecting low-concentration analytes in liquid samples due to its high sensitivity to surface charge changes.
  • the liquid sample serves as both the medium for biochemical interaction and the pathway for the applied gate voltage.
  • This dual function allows for a simplified design and improved signal fidelity.
  • the design is optimized for high sensitivity and stability, making it effective for applications requiring precise detection of biomarkers in liquid-phase samples.
  • FIG. 79 shows the binding events at the capillary channels of the vertical GaN semiconductor, showing capture molecules interacting with target molecules. The resulting modulation of the conductance channel is illustrated.
  • the drawing shows a target analyte 7904, a liquid gate electrode 7906, and a depletion layer 7908.
  • the liquid gate configuration of a vertical GaN semiconductor biosensor modulates the gate voltage via a liquid sample.
  • the vertical GaN sensor comprises a liquid gate that allows the application of a gate voltage through the liquid sample itself.
  • the structure includes a source region positioned at the top and a drain region at the bottom, with an N-GaN drift layer in between, forming a vertical charge carrier pathway.
  • the liquid gate introduces the gate voltage through the liquid sample, which flows over the detection area.
  • This detection area is functionalized with capture molecules, enabling the specific binding of target molecules, such as proteins or biomarkers.
  • target molecules such as proteins or biomarkers.
  • As target molecules bind to the capture molecules changes in the local electric field occur due to the binding events. These changes affect the depletion layer width, thereby modulating the flow of charge carriers between the source and the drain. This modulation results in a measurable change in the electrical signal, correlating to the concentration or presence of the target molecule.
  • the liquid gate may provide a more uniform and stable electric field through the liquid medium to the detection area and the surface charges that modulate the field effect creating a detectable change for a given applied gate voltage, or sweep of applied gate voltage, in current flow between the source and the drain.
  • the vertical design may provide a high sensitivity to surface charge changes, making it ideal for detecting low-concentration analytes in liquid samples.
  • FIG. 80 illustrates a system of capillary channels designed to enhance the interaction between a liquid sample, such as exhaled breath condensate (EBC sample), and the detection surface.
  • the channels are oriented perpendicular to the direction of the liquid sample flow, creating a dynamic environment that facilitates pooling and turbulence at the detection areas. This configuration may improve the probability of target molecule binding events, especially when the concentration of the target molecule in the EBC sample is low.
  • the capillary channels disrupt the laminar flow of the sample, increasing mixing and enhancing the interaction between the target molecules in the liquid and the immobilized capture molecules on the detection surface.
  • This turbulent flow minimizes the formation of stagnant layers near the detection areas, ensuring that a greater proportion of the liquid sample is exposed to the active binding sites.
  • the resulting pooling effect allows for prolonged contact time, giving low-concentration target molecules more opportunities to interact with the detection surface.
  • This design is particularly advantageous for biomarker detection in EBC sample, where target molecules like glucose, ketones, or acetone may be present in minute quantities.
  • the capillary channels are oriented and configured to optimize the balance between flow dynamics and sample retention.
  • FIG. 81 illustrates capillary channels oriented parallel to the flow of the liquid sample, such as exhaled breath condensate (EBC sample). This orientation is designed to facilitate smooth and controlled continuous flow of the sample over the detection area, facilitating an efficient interaction between the target molecules in the EBC sample and the immobilized capture molecules on the detection surface.
  • the continuous flow configuration enhances sample turnover, which can increase the probability of target molecule binding events, particularly in scenarios where the concentration of the target molecule is low.
  • the parallel arrangement of capillary channels minimizes flow disruptions, providing a uniform and steady stream of liquid across the detection surface through the capillary flow phenomenon. This flow pattern ensures that fresh portions of the sample are consistently delivered to the detection area, replenishing the target molecules available for binding. This continuous flow prevents the stagnation of liquid, maximizing the efficiency of the biomolecule capture process.
  • FIG. 82 shows a biosensor configuration based on advanced lateral flow assay with photonic readout.
  • the design integrates fluorescent label detection for target molecules.
  • the lateral flow assay (LFA) biosensor has a fluorescent photonic readout system designed for detecting low concentrations of target molecules, such as glucose, in exhaled breath condensate (EBC sample).
  • EBC sample exhaled breath condensate
  • the process begins at the sample pad, where the EBC sample sample is applied.
  • the sample then moves to the conjugate release pad, which contains fluorescent-labeled conjugates that bind with the target molecule or analyte and form an analyte/florescent-labed antibody complexes.
  • the sample reaches two detection zones: the test line and the control line.
  • immobilized capture molecules bind to the analyte/fluorescent-labeled antibody complexes, creating the accumulation of fl orescent tags to form a detectable signal.
  • unbound fluorescent-labeled antibodies are captured, verifying that the assay is functioning correctly. Any remaining sample components and excess reagents are absorbed by the adsorbent pad, ensuring consistent flow and preventing back flow.
  • a UV emission source excites the fluorescent labels accumulated at the test and control lines, and the emitted fluorescence is measured using a photonic readout system.
  • This system provides a highly sensitive and accurate signal corresponding to the concentration of the target molecule in the EBC sample.
  • the integration of fluorescence detection enhances sensitivity, enabling the detection of low-abundance analytes. This design enables rapid, reliable, and scalable analysis, making it a good choice for non-invasive diagnostics to monitor metabolic conditions such as diabetes.
  • FIG. 83 shows a hybrid biosensor combining lateral flow assay and semiconductor biosensors.
  • the system uses both fluorescence detection and electrical property changes to detect the same biomarker, providing an enhanced dataset pertaining to the detection and concentration of the biomarker in the fluid sample.
  • the label in addition to or instead of the fluorescence molecule or nanoparticle, can include an ionic or other molecular structure that can include charge enhancing component to change the charge confirmation of the capture/target complex and enhance the affect of the binding event on the field effect or other detectable change in an electrical characteristic between two or more test points, e.g., the source and the drain.
  • FIG. 84 shows the hybrid biosensor with capillary channels oriented perpendicular to the liquid flow. This layout promotes pooling and facilitates interaction of target molecules with capture molecules at the detection surface, increasing the interaction time, turn over of the liquid sample at the detection area surface, and increases the opportunity for target molecules to bind with capture molecules.
  • the perpendicular orientation of the capillary channels creates areas of enhanced turbulence, facilitating more effective exposure of the target molecules in the sample to come into binding contact and optimizing the binding efficiency of the biomolecules at the detection surface.
  • the capillary channels can be etched or micro-machined at the detection surface of a GaN HEMT field effect transistor, or can be built up separately from the sensor die or built up from additional layers and etching processes at the wafer level.
  • the capillary channels direct the EBC flow and when composed of the detection areas for example, in the vertical GaN sensor structure or a conventional horizontal sensor die, provide more surface area for the detection surface.
  • the perpendicular alignment encourages localized sample retention and turbulence at the detection area interface with the sample, facilitating improved biomarker binding opportunities.
  • the detection surface is functionalized with capture molecules (e.g., glucose oxidase or aptamers) immobilized on ZnO nanorods or other suitable substrates. These capture molecules selectively bind with target analytes such as glucose present in the EBC sample.
  • capture molecules e.g., glucose oxidase or aptamers
  • This hybrid system combines the benefits of lateral flow assay (LFA) techniques, such as straightforward handling and optical fluorescence readouts, with the high sensitivity and specificity of semiconductor biosensors, such as GaN-based HEMT structures.
  • LFA lateral flow assay
  • semiconductor biosensors such as GaN-based HEMT structures.
  • the perpendicular flow configuration optimizes both optical and electrical signal detection by maximizing the binding events at the detection surface.
  • the hybrid photonic lateral flow assay (LFA) and semiconductor biosensor system combines two powerful detection methods to enhance the performance and reliability of diagnostics.
  • the photonic LFA provides high sensitivity through fluorescence or colorimetric signals, while the semiconductor biosensor, for example, using ZnO nanorods and GaN HEMT technology, detects small electrical changes with high precision.
  • these technical approaches improve sensitivity by cross-verifying results and detecting low-abundance biomarkers in complex samples like exhaled breath condensate (EBC sample).
  • EBC sample exhaled breath condensate
  • the system offers superior specificity by reducing false positives, as the semiconductor biosensor can confirm optical signals from the photonic LFA. This dual approach also provides redundancy, ensuring reliable results even if one modality is affected by noise or interference.
  • EBC sample exhaled breath condensate
  • LFA lateral flow assay
  • a wick-based fluidics system uses absorbent materials, such as hydrophilic sponges or paper, to maintain a steady flow by drawing excess liquid through the device.
  • absorbent materials such as hydrophilic sponges or paper
  • a combination of techniques can be employed, such as capillary action with vacuum assistance or gravity with wick-based fluidics.
  • This hybrid approach optimizes fluid control and enables efficient sample processing, suitable especially for multiplexed or multi-step assays described herein.
  • the choice of fluidic method depends on the specific requirements of the LFA or biosensor component, such as cost, complexity, and desired level of precision.
  • the modular system of the breath based diagnostic has a flexible design that can accomodate a variety of configurations depending on specific requirements for cost, precision, time and easy-of-use.
  • the hybrid system expands the range of detectable biomarker concentrations by combining the LFA's broad screening capability with the semiconductor biosensor's precise and possible quantitative detection. It is robust in challenging environments, with each modality compensating for the other's weaknesses, such as optical interference or electronic noise.
  • the LFA structure is user-friendly and disposable, and can include visually interpretable results, while the photonic LFA and semiconductor biosensor results in a direct-to-electrical test signal that is well suited for automated readouts. Together, they provide real-time, multiplexable detection for multiple biomarkers, supporting both rapid screening and detailed monitoring.
  • this system is cost-effective and scalable, leveraging the affordability of LFAs with the durability and accuracy of semiconductor biosensors.
  • the hybrid design supports advanced statistical analyses and machine learning, reducing uncertainty and improving diagnostic accuracy.
  • the perpendicular capillary arrangement allows for efficient sample utilization by channeling the EBC sample sample from the condensation surface and directly to the collection well and onto the active detection area.
  • the target molecules in the EBC sample sample Prior to being received by the detection area, the target molecules in the EBC sample sample can be concentrated, for example, by selectively drawing away water and ions using a super absorbent polymer.
  • the perpendicular channels improve the signal strength for both electrical and optical readouts.
  • the biosensor supports easy replacement or refreshing of the detection layer for sustained use. This embodiment is particularly well-suited for at-home, real-time, non-invasive monitoring of diabetes-related biomarkers.
  • FIG. 85 shows a disposable or refreshable hybrid biosensor system.
  • the configuration allows for single-use or easily replaced sensor components to balance cost-effectiveness and performance.
  • the drawing shows a biomarker detection module 8504, capillary channels 8506, a conjugate release pad 8508, a sample pad 8510, a wick 8512, and hydrophobic surfaces 8514.
  • FIG. 85 depicts a disposable or refreshable hybrid biosensor system optimized for cost-effective and high-performance usage.
  • This system includes the biomarker detection module (8504), which incorporates capillary channels (8506) designed to enhance the sample flow and interaction with the detection surfaces.
  • the conjugate release pad (8508) facilitates the controlled release of reagents that interact with the biomarker in the sample.
  • the sample pad (8510) is positioned to receive and initiate the flow of exhaled breath condensate (EBC sample) or liquid samples into the capillary channels.
  • the wick (8512) ensures the continuous movement of fluids through the system, aiding in efficient sample processing and test completion.
  • Hydrophobic surfaces (8514) are strategically included to direct and confine liquid samples, minimizing sample loss and ensuring precise delivery to the detection areas. This configuration allows for either single-use or easily replaced components, making it adaptable for clinical and at-home applications.
  • FIG. 86 shows the modular biosensor and bottom cap designed for ease of cleaning and replacement. This modular approach simplifies device maintenance and supports both clinical and at-home usage scenarios.
  • the drawing shows a bottom cap 8604, a bare die 8606, a microfluidic assembly 8608, and a biosensor card 8610.
  • FIG. 86 illustrates the modular construction of the biosensor and its corresponding bottom cap, which is designed to simplify maintenance and enable easy cleaning or replacement of biomarker detection components.
  • the bottom cap (8604) securely houses the bare die (8606), and a microfluidic assembly (8608) is integrated with the bare die to facilitate the precise flow of EBC sample or liquid samples onto the detection surfaces.
  • the biosensor card (8610) incorporates the necessary electronic and detection components and is replaceable or refreshable. This modular approach enhances usability for both clinical professionals and individual users by facilitating component swaps and routine cleaning, ensuring reliable performance and long-term durability.
  • FIG. 87 illustrate the modular biosensor and bottom cap shown installed and ready for use within the diagnostic system.
  • the bottom cap can include a battery and electronics for both the photonic LFA and semiconductor biosensors.
  • FIG. 88 illustrates the flow path of exhaled breath as it is directed onto the hybrid biosensor.
  • the device channels the exhaled breath into a condensation system that converts a portion of the exhaled breath into EBC sample.
  • This EBC sample is then guided onto the lateral flow assay and semiconductor biosensor for analysis.
  • the system leverages the strengths of both detection methods: the lateral flow assay for visual or photonic readout and the semiconductor biosensor for high-sensitivity electrical measurements.
  • the design highlights the integration of exhaled breath handling with hybrid detection technologies, supporting precise biomarker analysis in a compact form factor. This embodiment is well-suited for real-time, frequent monitoring in both clinical and at-home environments.
  • FIG. 89 illustrates a pass-through biosensor system designed to efficiently direct exhaled breath or liquid samples through defined flow channels.
  • the drawing shows capillary channels (8908) and flow channels (8910) integrated into a flow-through biosensor (8914). These channels are configured and dimensioned for direct and controlled interaction between the sample and the functionalized detection surfaces.
  • the flow channels formed by aligning and stacking biosensor components, provide a controlled pathway for sample flow.
  • the capillary channels are etched or otherwise fabricated for enhancing the flow liquid or gaseous samples while maintaining close contact with the biosensor surface for improved detection capability.
  • the pass-through design is particularly suited for applications requiring real-time analysis of biomarkers in exhaled breath or exhaled breath condensate (EBC sample).
  • EBC sample exhaled breath or exhaled breath condensate
  • the configuration allows simultaneous testing of multiple analytes by functionalizing different regions of the biosensor with capture molecules specific to various target molecules. This enhances the biosensor’s versatility and adaptability for multiplex diagnostics.
  • FIG. 90 shows a horizontally stacked configuration of multiple biosensors, enabling multiplex testing of different biomarkers from a shared stream of exhaled breath or EBC sample.
  • the drawing shows a bare die 9006, a flow channels 9008, and a flow-through biosensor 9010.
  • the stacked biosensors are arranged linearly, allowing each biosensor to perform a distinct detection task.
  • This modular arrangement facilitates the simultaneous analysis of various biomarkers, such as breath gases (e.g., acetone, ammonia) or EBC sample components (e.g., glucose, lactate, ketones, proteins).
  • the design leverages electroosmotic flow (EOF) to move liquid samples through microfluidic channels.
  • Conductive surfaces within the biosensor structure support EOF, which is achieved by applying an electric field to drive liquid movement. This technique ensures precise and uniform sample flow across the detection areas, enhancing the interaction between the sample and the functionalized detection surfaces.
  • EOF is advantageous due to its plug-like flow profile, which minimizes shear stress on biomolecules and ensures consistent sample delivery without mechanical pumps. This integration of EOF simplifies the biosensor system, reduces mechanical complexity, and improves reliability, making the stacked biosensor system a robust solution for multiplexed diagnostics.
  • FIG. 91 illustrates an advanced implementation of the flow-through biosensor system, incorporating Electroosmotic flow structures (9104) for precise liquid handling.
  • the biosensor structure (9106) includes flow channels (9108) that guide the liquid sample over the detection surfaces in a controlled manner. This embodiment showcases the integration of EOF into the biosensor system to achieve enhanced precision in sample delivery and biomarker detection.
  • Electroosmotic flow structures utilize an applied electric field to move liquid samples efficiently through the microfluidic system. This method allows fine-tuning of the flow rate by adjusting the voltage, enabling precise control over sample delivery.
  • the EOF mechanism eliminates the need for mechanical pumps, simplifying the device design and reducing the risk of mechanical failure.
  • the uniform plug-like flow created by EOF ensures even exposure of the sample to the detection surfaces, maximizing the biosensor’s sensitivity and reliability.
  • the modularity of the biosensor design allows for scalability, enabling the addition of multiple biosensor layers to expand diagnostic capabilities. This flexibility supports customization based on specific clinical or diagnostic requirements.
  • the biosensor system is compatible with real-time data collection and analysis, facilitated by a central control unit connected to a user interface or smartphone for seamless diagnostic reporting. This integration of advanced flow control and multiplex testing capabilities positions the biosensor system as a versatile and efficient diagnostic tool for clinical and at-home applications.
  • FIG. 92 illustrates a vertically stacked configuration of a biosensor system, which integrates Peltier cooling structures to enable precise thermal management of the bare die .
  • the drawing shows a thermal management 9202, a Peltier cooling structures 9204, a vertical GaN semiconductor biosensor 9206, and a capillary channels 9208.
  • the biosensor assembly is designed for applications requiring temperature stabilization to improve the accuracy and sensitivity of biomarker detection in liquid or gas-phase samples.
  • the stacked configuration consists of alternating layers of thermal management heat sink/absorber (9202) and reversable Peltier cooling structure (9204), forming a compact and modular assembly.
  • Each functional layer incorporates semiconductor biosensors (9206), which may include nano structures such as ZnO nano rods or similar features for immobilizing capture molecules. These capture molecules interact with target analytes to generate detectable changes in the biosensor signal.
  • semiconductor biosensors (9206), which may include nano structures such as ZnO nano rods or similar features for immobilizing capture molecules. These capture molecules interact with target analytes to generate detectable changes in the biosensor signal.
  • the modular design facilitates multiplex testing of multiple biomarkers, as each layer can be functionalized differently for specific analytes.
  • Peltier cooling structures are positioned adjacent to the biosensor layers, ensuring localized temperature control at each detection area. These thermoelectric cooling units operate by transferring heat from one side of the device to the other when an electric current is applied, effectively cooling the detection surface. This cooling capability is critical for applications requiring stable thermal conditions, such as the condensation of exhaled breath condensate (EBC sample) or maintaining biomolecule activity during detection processes.
  • EBC sample exhaled breath condensate
  • the configuration allows for efficient heat dissipation and uniform cooling across all biosensor layers, improving signal stability and reducing noise caused by temperature fluctuations.
  • the compact design also ensures high scalability, as additional layers can be added vertically to increase the system's capacity for multiplex testing.
  • the vertically stacked biosensor system integrated with Peltier cooling structures, provides an innovative solution for enhancing the performance and reliability of diagnostic devices, especially those relying on precise temperature control for sensitive biomarker detection.
  • the detection area can be operated or refreshed using applied heat.
  • the Peltier cooling structures can be operated in reverse and apply heat to the bare die.
  • the detection area when functionalized to detect ammonia, the detection area includes a layer of iridium oxide. Heat applied to the bare die will facilitate driving off the ammonia making the sensor ready for the next detection.
  • FIG. 93 illustrates an embodiment of a self-contained testing system designed to analyze a user’s exhaled breath for diagnostic purposes.
  • the system includes a hollow tubular housing (9302) that directs the user's exhaled breath under pressure towards an inlet (9304) formed as part of the vertically stacked biosensor structure.
  • the hollow tube serves as both a conduit for breath delivery and an enclosure for maintaining the environmental stability of the testing system.
  • the vertically stacked biosensor structure (9208) is positioned within the tubular housing to optimize the interaction between the exhaled breath and the biosensor's detection surfaces.
  • the biosensors are configured for the detection of target analytes in either the gaseous phase or in exhaled breath condensate (EBC sample) that forms as the breath cools upon contact with the sensor.
  • EBC sample exhaled breath condensate
  • the stacked biosensor design allows for multiplexed detection of multiple biomarkers, leveraging the high sensitivity and selectivity of functionalized nanostructures such as ZnO nanorods.
  • the directed airflow ensures consistent sample delivery to the biosensor inlet.
  • the pressure of the exhaled breath promotes the interaction between the target molecules and the capture molecules immobilized on the sensor's surface. Additionally, the stacked biosensor configuration allows for simultaneous detection of several biomarkers, increasing the diagnostic capability of the device.
  • FIG. 94 illustrates an embodiment of a self-contained testing system where the stacked biosensor structure is positioned within a hollow tube (9402).
  • the hollow tube acts as both a housing and a conduit for directing the flow of exhaled breath toward the biosensors for analysis.
  • the biosensor assembly shown centrally located within the tube, consists of a vertically stacked configuration designed to detect multiple biomarkers simultaneously, providing multiplexed diagnostic capability.
  • the hollow tube (9402) is constructed to channel the user's exhaled breath efficiently, ensuring a consistent and controlled flow across the detection surfaces of the biosensors.
  • the placement of the biosensors within the tube allows for optimal interaction between the exhaled breath and the functionalized detection surfaces.
  • the biosensors are configured to analyze both gas-phase biomarkers, such as ketones and ammonia, and liquid-phase biomarkers, such as glucose and proteins, in exhaled breath condensate (EBC sample) that forms as the breath cools.
  • EBC sample exhaled breath condensate
  • the stacked biosensor structure within the tube enables enhanced functionality through parallel testing of multiple biomarkers, including breath gases and liquid EBC sample and is configurable for many use-cases such as diabetes monitoring, respiratory infection detection, and metabolic analysis.
  • FIG. 95 illustrates an embodiment of a rapid, portable, and easy-to-use breath-based testing system.
  • the system is designed to facilitate noninvasive diagnostic testing in various settings, including at-home, clinical, and at remote or resource-limited regions.
  • a compact housing (9502) contains the core diagnostic components of the system. Inside the housing, a removable test cartridge (9506) is positioned. This cartridge provides a removable and easily handled interface for analyzing exhaled breath samples.
  • the test cartridge incorporates integrated biosensors and associated microfluidic structures for collecting and analyzing exhaled breath condensate (EBC sample) or gas-phase biomarkers.
  • EBC sample exhaled breath condensate
  • gas-phase biomarkers gas-phase biomarkers
  • the diagnostic biosensor array (9508), integrated within the cartridge, can include capabilities for specific biomarkers present in exhaled breath.
  • these biomarkers can include glucose, acetone, ammonia, ketones, or proteins, depending on the application.
  • FIG. 96 is an exploded view illustrating the components of a rapid, portable, and versatile breath-based testing system, highlighting its modular design for ease of assembly, maintenance, and operation.
  • the drawing shows a reader electronics 9602, a biosensor card 9604, a bare die 9606, and a Peltier cooling structures 9608.
  • the biosensor card 9604 is a replaceable cartridge that can incorporate the biosensors, microfluidic channels, and functionalized detection areas for analyzing biomarkers in exhaled breath or exhaled breath condensate (EBC sample).
  • the cartridge is removable and replaceable, allowing users to switch between different assays or to maintain system hygiene.
  • the bare die (9606) is attached to the biosensor card using an electrical connection between the bond pads and the conductive traces that also forms a seal to contain the liquid biosample in a collection well.
  • Peltier cooling structures 9608 are provided to cool or heat the detection area.
  • FIG. 97 illustrates the outer tubular shell (9704) of the rapid, portable, and anywhere breath-based testing system, designed to house and protect the internal diagnostic components while facilitating efficient breath sample collection and analysis.
  • the drawing shows a hollow tube 9704, a Peltier cooling structures 9708, a bare die 9710, and a biosensor card 9712.
  • FIG. 98 shows a configuration of a diabetes and weight management system, incorporating the diagnostic device, Al algorithms, and notifications and treatment options. It includes electroceutical and pharmaceutical treatment modalities, as well as data aggregation for Al-assisted personalized care and product/system improvements.
  • FIG. 98 illustrates the system’s ability to integrate diagnostics with actionable insights for disease management.
  • the inventive, non-invasive breath-based diagnostic system described herein is designed for at-home monitoring of diabetes, but with modifications, such as those contemplated herein, the system can be configured for many use-cases for diagnostics, remote patient monitoring, and provides the necessary link between the doctor, patient, and treatment options.
  • the system measures glucose in exhaled breath condensate (EBC sample), along with acetone, ketones and ammonia levels in exhaled breath, providing a metabolic profile.
  • EBC sample exhaled breath condensate
  • acetone, ketones and ammonia levels in exhaled breath providing a metabolic profile.
  • the breath diagnostic device uses a smartphone application serving as the user interface.
  • the app not only displays real-time data but also relays information to a secure cloud platform, enabling continuous engagement between patients and healthcare providers (HCPs).
  • HCPs healthcare providers
  • the system incorporates advanced tracking and analytics, alerting users and their HCPs to concerning trends, such as sudden spikes in ammonia levels, which may indicate potential health complications.
  • a user-friendly dashboard allows patients to monitor their progress, view trends over time, and receive personalized guidance on diet and exercise. Simultaneously, healthcare providers can access an aggregated dashboard to monitor multiple patients, enabling proactive and tailored care. Additionally, aggregate anonymized data from many users contributes to the use of Al-agents to assist in improving diagnostic accuracy and patient outcomes.
  • FIG. 98 illustrates a holistic system architecture for a breath-based diagnostic and disease management system designed to monitor and manage diabetes progression.
  • the system integrates multiple components, including at-clinic baseline testing, remote monitoring devices, Al-driven data aggregation, and personalized therapeutic interventions. As shown, there is an overlaping interaction between clinical, diagnostic, and therapeutic components for the management system, with a holistic approach to improving outcomes for diabetes patients through noninvasive, data-driven monitoring and personalized care.
  • At-Clinic Testing for Baseline Data The process begins with baseline biometric data collection at a clinical setting, utilizing conventional diagnostic tests such as Hemoglobin A1C (HbAlC), Oral Glucose Tolerance Test (OGTT), or Continuous Glucose Monitoring (CGM). These baseline metrics establish individualized patient thresholds, which are later used for comparison with remote biometric data gathered by the system.
  • HbAlC Hemoglobin A1C
  • OGTT Oral Glucose Tolerance Test
  • CGM Continuous Glucose Monitoring
  • the breath-based diagnostic device shown on the right, captures exhaled breath to measure biomarkers such as glucose, acetone, and ammonia.
  • the diagnostic device includes a gas sensor for volatile components, a condensation surface for generating exhaled breath condensate (EBC sample), and a biomarker detector for precise quantification of target molecules.
  • EBC sample exhaled breath condensate
  • biomarker detector for precise quantification of target molecules.
  • the collected biometrics are processed by an onboard microprocessor and transmitted wirelessly to a cloudbased server.
  • the center hub of the system includes a cloud-base service that includes data aggregation and Al-powered analysis hub.
  • This hub integrates biometric data from the remote devices used at-home by many users monitoring their diabetes, with stored baseline metrics, applying statistical algorithms and machine learning models to detect trends, anomalies, and exceeding threshold.
  • the Al agents provide real-time insights and generate recommendations tailored to each user’s physiological changes and therapeutic response.
  • Electroceutical Treatment includes wearable muscle stimulation garments designed to activate muscles and improve glucose metabolism in diabetic patients.
  • Pharmaceutical Treatment administers or recommends appropriate medications, such as insulin or oral hypoglycemic agent.
  • Behavioral Adjustments Tailored guidance is sent to a mobile application for the user to modify their diet, exercise, or other lifestyle factors.
  • Notifications and Alerts The mobile device on the top right represents the patientfacing application, which provides real-time updates, progress tracking, and alerts.
  • a separate channel (depicted on the left) sends notifications and updates to caregivers or healthcare providers, enabling them to monitor the patient’s condition remotely and adjust treatment plans proactively.
  • System Workflow The system operates in a continuous loop, where updated biometrics from the diagnostic device are compared to baseline thresholds, and the Al agents trigger alerts or therapeutic adjustments if deviations are detected. This integration of diagnostic tools, data analytics, and personalized treatment creates a closed-loop diabetes management system.
  • HbAlC Hemoglobin A1C
  • EBC sample EBC sample glucose levels
  • acetone and ketone levels reflect fat metabolism and the presence of ketosis.
  • Significant deviations from the HbAlC baseline may indicate issues like poor glucose control, early signs of ketosis, or potential complications like diabetic ketoacidosis.
  • This dynamic comparison helps identify patterns and trends, enabling timely interventions such as adjusting diet, medication, electroceutical or other treatments. By providing more personalized and proactive monitoring, this approach can improve patient outcomes by preventing complications, optimizing therapy, and supporting better long-term diabetes management.
  • the systems and methods described herein can be utilized as a more holistic approach for improving patient outcomes in progressive diseases, such as diabetes and for lifestyle dependent self-improvement, such weight loss monitoring where data can be used to set baselines and track realizable goals.
  • the systems and methods include collecting chemical biomarker data, such as glucose, acetone, and ketones, and non-chemical biometric data, such as weight, activity levels, and heart rate, from individual patients using a breath-based diagnostic system and biometric sensors.
  • the data is transmitted wirelessly to a remote server, where it is aggregated with similar data from other patients.
  • An artificial intelligence (Al) agent analyzes the aggregated data to identify patterns and trends in glucose regulation, fat metabolism, and weight loss efficiency.
  • the Al uses unsupervised machine learning to cluster patients with similar biomarker and biometric profiles, enabling the identification of common factors affecting diabetes progression and weight management.
  • a Large Language Model technique, or similar probabilistic analysis, such as Principal component analysis (PCA) is applied to reduce the dimensionality of the data and refine the clusters, uncovering second-order patterns that provide deeper insights into patient behavior and response to treatments.
  • PCA Principal component analysis
  • the Al Based on these insights, the Al generates personalized feedback and recommendations, such as adjustments to dietary or therapeutic interventions, and transmits this feedback to the patient or healthcare provider.
  • the system further uses this analyzed data to improve its own performance, implementing feedback to enhance hardware, software, and network components.
  • This iterative process enables the breath-based diagnostic system to deliver increasingly accurate and effective monitoring, improving both individual outcomes and population-wide insights into diabetes and weight loss management.
  • the system supports proactive, personalized care that optimizes metabolism, insulin management, and overall health.
  • FIG. 99 is a flow chart illustrating an algorithm for activating an action based on comparison of a baseline biometric versus monitored biometrics.
  • the flow chart depicts the operation of the inventive breath-based diagnostic system for monitoring the progression of diabetes.
  • Step One obtain Baseline Biometric: The system begins by collecting baseline biometric data from a user, obtained through traditional clinical tests such as Hemoglobin A1C (HbAlC), Oral Glucose Tolerance Test (OGTT), or Continuous Glucose Monitoring (CGM).
  • Step Two Store Baseline Biometric: This baseline data is stored in a memory accessible to the system’s microprocessor, establishing individualized thresholds for comparison.
  • Step Three The microprocessor uses the stored baseline data to calculate patient-specific thresholds for monitored biometric parameters, including glucose, acetone, and ammonia levels detected in exhaled breath.
  • Step Four Detect Monitored Biometrics: The system employs a gas sensor to analyze volatile compounds (acetone, ammonia) and a biomarker detector to measure glucose and other biomarkers in exhaled breath condensate (EBC sample). These measurements represent the user’s current monitored biometrics.
  • Step Five The monitored biometric parameters are compared against the calculated patient-specific thresholds. The microprocessor determines if any thresholds have been exceeded, which could indicate physiological changes due to diabetes progression or treatment response.
  • Step Six (Activate Action): If a threshold is exceeded, the system activates at least one action, such as notifying the patient, recommending a therapeutic adjustment (e.g., pharmaceutical or electroceutical treatment), or alerting a caregiver. Additionally, an AI- powered component may provide personalized treatment suggestions or diagnostic insights based on the detected biometrics.
  • a therapeutic adjustment e.g., pharmaceutical or electroceutical treatment
  • an AI- powered component may provide personalized treatment suggestions or diagnostic insights based on the detected biometrics.
  • the flow chart illustrates how the system integrates baseline data, ongoing monitoring, and automated decision-making to support diabetes management through noninvasive breath analysis.
  • the flow chart in FIG. 99 illustrates how the system leverages baseline biometrics and daily monitoring to manage diabetes effectively using breath-based diagnostics.
  • the system collects baseline biometric data, such as HbAlC, OGTT, or CGM results, in a clinical setting and stores this data to establish patient-specific thresholds for biomarkers like glucose, acetone, and ketones.
  • the system measures these monitored biomarkers through breath analysis, using sensors for volatile compounds like acetone and ketones and a biomarker detector for glucose in exhaled breath condensate (EBC sample).
  • the monitored biometrics are then compared against the individualized thresholds derived from the baseline. If the system detects that any threshold has been exceeded, it activates an appropriate action, such as notifying the user, recommending a treatment adjustment, or alerting a caregiver.
  • An Al agent receives the individual patient's data and may provide personalized insights or suggestions to optimize treatment. This process allows for dynamic and proactive diabetes management, supporting better patient outcomes by identifying changes in glucose control or metabolic state early and enabling timely interventions.
  • FIG. 100 depicts a block diagram of a breath-based diagnostic system designed for monitoring the progression of diabetes.
  • the system is structured to integrate multiple components for processing both gaseous and liquid samples derived from a user’s exhaled breath, enabling comprehensive analysis of biomarkers indicative of metabolic health.
  • the Gaseous Sample Supplier provides a stream of exhaled breath from the user, which is directed into the Gaseous Sample Tester.
  • This component includes a gas sensor configured to detect volatile biomarkers, such as acetone and ammonia, and to generate corresponding sensor signals. These signals represent the concentration of the gaseous biomarkers in the exhaled breath.
  • the exhaled breath stream then passes to a Condensation Surface in thermal communication with a Chiller, which cools the breath stream to condense a portion of it into liquid exhaled breath condensate (EBC sample).
  • EBC sample liquid exhaled breath condensate
  • the condensed EBC sample serves as the liquid sample for further biomarker analysis.
  • the condensed liquid sample is directed to the Liquid Sample Tester, which incorporates a biomarker detector.
  • This detector analyzes the EBC sample to identify key biomarkers, such as glucose or other diabetes-related analytes, and generates a detector signal dependent on the presence and concentration of these biomarkers.
  • the Microcontroller receives the sensor signals from both the Gaseous Sample Tester and the Liquid Sample Tester. It processes these monitored biometric parameters and compares them to stored baseline biometric data, which is retrieved from a connected Memory.
  • the baseline data is established during a clinical setting and is used to create individualized thresholds for monitoring the patient’s health over time.
  • the User Interface provides an accessible platform for the user or caregiver to view diagnostic results and receive alerts or recommendations based on the analysis. Additionally, a Communications Module enables wireless transmission of data to remote servers or healthcare providers for further analysis and long-term monitoring.
  • This biomarker detection system allows for precise, multi-modal analysis of diabetes- related biomarkers in exhaled breath, facilitating early detection of metabolic changes and supporting improved patient outcomes.
  • FIG. 101 illustrates a respirator or continuous positive airway pressure (CPAP) system integrated with an exhaled breath condensate (EBC sample) and exhaled breath biomarker testing system.
  • the drawing shows a fresh air inlet 10102, a testing system 10104, and a mask 10106.
  • the system includes a mask that delivers and collects airflow from the user, connected to a Y-connector that splits airflow into inspiratory and expiratory paths.
  • the inspiratory path includes a flexible breathing tube, an inspiratory unidirectional valve, a fresh gas inlet, and an absorber to remove CO2 or other waste gases, ensuring clean airflow to the user.
  • the expiratory path includes an expiratory unidirectional valve, a reservoir for managing exhaled breath, and an adjustable pressure limiting (APL) valve to regulate pressure.
  • the EBC sample Testing System collects exhaled breath and converts a portion of it into EBC sample, allowing for biomarker analysis.
  • This system enables real-time, non-invasive monitoring of biomarkers such as glucose, acetone, and ammonia, providing insights into metabolic and respiratory health. It is particularly suited for use during sleep or in unconscious states, such as coma patients, as it continuously collects and analyzes breath data without requiring active participation from the user.
  • This integration of diagnostic capabilities into a respirator or CPAP system offers a practical solution for monitoring health conditions like diabetes, metabolic disorders, and respiratory issues.
  • a breath-based testing system integrated into a CPAP or respirator leverages the extended duration of breathing while the body is at rest to continuously collect and analyze exhaled breath condensate (EBC sample) and breath gases.
  • EBC sample exhaled breath condensate
  • This setup allows for prolonged, uninterrupted monitoring of biomarkers, such as glucose, acetone, ammonia, or lactate, providing a detailed profile of metabolic and physiological changes during restful states.
  • biomarkers such as glucose, acetone, ammonia, or lactate
  • These nighttime biomarker levels can then be compared with measurements taken during active periods of the day to identify variations caused by activity, stress, or metabolic changes.
  • Such comparisons offer valuable insights into the user’s overall health, optimizing management of conditions like diabetes, weight loss, or sleep-related disorders.
  • This approach also supports long-term trend analysis, aiding in personalized treatment plans and better health outcomes.
  • the breath-based diagnostic system provides a non-invasive method for monitoring and diagnosing various health conditions by analyzing biomarkers in exhaled breath condensate (EBC sample) and breath gases. This system enables frequent and convenient health monitoring, with specific use-cases tailored to individual needs.
  • EBC sample exhaled breath condensate
  • the device measures glucose levels in EBC sample, allowing users to monitor glycemic control without the need for invasive blood sampling. Additionally, the system analyzes breath gases such as acetone and ammonia, which are indicative of ketone production and protein metabolism. These measurements can aid in the detection of complications like diabetic ketoacidosis (DKA) and provide data to optimize treatment plans based on trends compared with clinical baseline metrics.
  • DKA diabetic ketoacidosis
  • the system measures biomarkers like acetone and lactate to track fat metabolism and exercise efficiency. Elevated acetone levels in the breath reflect increased fat burning, while lactate in EBC sample indicates anaerobic activity during physical exertion. By monitoring these biomarkers daily, users can adjust their diet and exercise regimens to achieve and maintain desired weight-loss goals.
  • VOCs volatile organic compounds
  • COPD chronic obstructive pulmonary disease
  • biomarkers such as nitric oxide (NO) in the gas phase or hydrogen peroxide in EBC sample, provide insights into airway inflammation and oxidative stress, enabling proactive management and early intervention.
  • NO nitric oxide
  • the system also supports fitness and recovery monitoring by tracking lactate and carbon dioxide levels. Lactate levels in EBC sample indicate anaerobic thresholds and muscle fatigue, while carbon dioxide concentrations reflect respiratory efficiency. These measurements allow athletes and active individuals to optimize training intensity, recovery periods, and overall performance.
  • infectious disease detection the system identifies specific proteins, metabolites, and VOCs linked to viral or bacterial infections, including influenza and COVID-19. Frequent testing of these biomarkers facilitates early detection, monitoring of disease progression, and evaluation of treatment effectiveness.
  • the system extends to liver and kidney health by measuring ammonia and urea levels, biomarkers that indicate liver function and renal health, respectively. Regular tracking of these indicators helps identify early signs of liver or kidney dysfunction and supports timely medical intervention.
  • the system detects VOCs and proteins in EBC sample that serve as biomarkers for specific cancers, such as lung cancer.
  • VOCs and proteins in EBC sample that serve as biomarkers for specific cancers, such as lung cancer.
  • the system analyzes acetone and carbon dioxide levels, providing information on metabolic activity and respiratory efficiency that correlate with heart health. These measurements allow users to monitor the effects of lifestyle changes and medication on cardiovascular function.
  • the system also facilitates hydration and nutrition monitoring by analyzing the composition of EBC sample for biomarkers indicative of hydration status and nutritional deficiencies. This capability is especially useful for athletes and individuals with specialized dietary requirements, enabling precise adjustments to maintain optimal health.
  • FIG. 102 illustrates a dual-function face mask system designed to test both exhaled breath biomarkers and ambient air for potential health concerns or environmental exposures.
  • the drawing shows a mask 10206, an air flow passage and ambient air testing system 10208, a testing system 10210, a wireless transmitter 10212, and a smartphone 10214.
  • the mask includes two distinct testing modalities integrated into its structure. The first modality involves an air flow passage and ambient air testing system, which actively draws in surrounding air under pressure. The ambient air passes over a biosensor incorporated within the mask, allowing for the detection and analysis of airborne chemical markers, such as environmental toxins, pathogens, or harmful pollutants.
  • the second modality utilizes a breath-based testing system positioned within the mask to analyze the user’s exhaled breath and exhaled breath condensate (EBC sample).
  • EBC sample exhaled breath and exhaled breath condensate
  • This system is configured to detect specific biomarkers in the exhaled breath, such as glucose, acetone, or ammonia, which can indicate metabolic changes, infections, or other health concerns.
  • the confined volume within the mask provides a positive and negative pressure depending on whether the users is breathing in or out, and enables collection and analysis of both exhaled breath and ambient air.
  • the mask includes a wireless transmitter (indicated as "tx") that communicates the testing results to a connected user interface, such as a smartphone.
  • tx a wireless transmitter
  • This user interface provides real-time feedback on the user's health status and environmental exposures, enabling timely interventions.
  • This dual-modality system offers a comprehensive solution for monitoring personal health and environmental conditions, making it particularly valuable for individuals in high-risk or medically sensitive environments.
  • FIG. 103 is an exploded view of a microfluidic assembly (10318) for use with a biosensor card.
  • the assembly includes a plastic substrate (10302), microfluidic paper (10304), a wick (10306), a fluid dam (10308), a superabsorbent polymer (SAP) element (10310), a sample through-hole (10314), a detection window (10316), and a sample receiving stack (10320).
  • the sample receiving stack (10320) form a fluid dam (10308) that accumulates a fluid sample before permitting it to rush through the sample through-hole (10314) and onto a lateral flow assay (LFA) microfluidic paper (10304).
  • LFA lateral flow assay
  • a conjugate release pad can also be integrated with or near the microfluidic paper (10304), enabling release of a fluorescent label — for example, Estapor® Europium Microspheres (Millipore, Mo).
  • the fluorescent label is bound to a capture molecule, such as an antibody, that specifically binds to a target biomarker in the sample.
  • the microfluidic assembly (10318) may be mounted above or integrated with a biosensor card, which can include a hybrid photonic-electronic detection system.
  • a biosensor card which can include a hybrid photonic-electronic detection system.
  • an LED or other suitable excitation source illuminates the portion of the microfluidic paper (10304) where the labeled conjugates accumulate, and a photodetector on or near the biosensor card captures the resulting fluorescence signal.
  • the substrate (10302) and microfluidic paper (10304) are selected to be transparent or semi-transparent to both the excitation (e.g., UV or near-UV) wavelength and the corresponding emission wavelength of the fluorescent label (e.g., around 613 nm in the case of europium).
  • the fluorescent emission has a large Stokes Shift and is at a significantly longer wavelength (around 610-620 nm) than its excitation (typically -340-380 nm), which reduces background signal and simplifies optical filtering through the detection window (10316) and received by the photodetector.
  • the fluid flows from the fluid dam (10308) through the sample through-hole (10314), it travels along the microfluidic paper (10304) by capillary action (or other microfluidic means).
  • the fluorescently tagged conjugates i.e., europium beads/antibody bound to the analyte
  • the capture molecules bind and immobilize the labeled conjugates, leading to a higher local concentration of fluorescent microparticles. This accumulation may be viewed visually under UV illumination or more typically sensed by a fluorescent photodiode or other optical detector integrated in or on the biosensor card.
  • An inventive embodiment incorporates features of both a photonics and electronic biosensor.
  • a stimulation wave length is emitted, for example, by a UV or near-UV LED through the detection window (10316) and through the wet microfluidic paper (10304) to impinge on the captured target molecules accumluated at the detection surface of the semiconductor biosensor.
  • Emitted light from the europium labels passes through the wet microfluidic paper, through the detection window and is then detected by a photosensor (e.g., photodiode, photomultiplier, or CMOS sensor).
  • a photosensor e.g., photodiode, photomultiplier, or CMOS sensor
  • the captured target molecules at a bare-die sensor region provide a second or parallel detection mechanism. This allows an electrical readout (e.g., measuring a change in impedance or surface potential) in addition to the fluorescent signal, creating a “hybrid” approach that can enhance sensitivity and/or provide additional confirmatory data.
  • an electrical readout e.g., measuring a change in impedance or surface potential
  • the optical path can be optimized by selecting the right fibers, the construction, thickness and optical properties of the microfluidic paper when wet.
  • dyes can be provided that selectively block the wave lengths that reduce the signal/noise at the output of the photodetector.
  • the microfluidic assembly substrate can be made from plastic, paper, or other suitable material the can be formed for providing a sample through-hole for passing a fluid sample from a fluid dam.
  • the fluid dam allows a fluid sample to accumulate before flowing through the sample through-hole.
  • the fluid dam can be formed from a sample receiving stack which may include a dissolvable adhesive or barrier pull tab that prevents the sample from flowing through the sample through-hole until enough sample has accumulated so that a rush of the fluid sample is received by a type of lateral flow assay including microfluidic paper and the conjugate release pad.
  • a layer of SAP powder on the sticky top surface of the dissolvable adhesive can be formulated to selectively concentrate the target molecule in the EBC sample or other fluid sample.
  • the construction of the fluid can be designed to tend towards optimization of the accumulation of a visual or florescent label at the test line.
  • the accumulation of the florescent label occurs through the action of the LFA where the rush of fluid sample through the sample through-hole is received by the microfluidic paper.
  • Other fluid moving structures and components are possible including small pumps, capilliary tubes or channels, EOF pumps, etc.
  • the microfluidic paper has cost and fabrication advantages but is provided here by way of example.
  • the microfluidic or sample moving structure can be optimized towards transparency of the UV wave length and the florescence wave length at the test line and also act as a filter for unwanted wavelengths.
  • the optical properties when wet with the fluid sample can be optimized towards a filter that is selectively tuned to pass the stimulating UV and the florescence wave lengths from the stimulated accumulated florescent labels so that the received signal-to-noise at the photo detector is maximized.
  • a conventional LFA assay has capture molecules immobilized on the surface of the microfluidic membrane at the area of the test line.
  • the capture molecules can be immobilized on at the detection of a bare die sensor attached to the biosensor card. This forms a version of the hybrid photonic and electronic biosensor system described herein.
  • FIG. 104 illustrates an assembled microfluidic assembly (10408) integrated on a plastic substrate (10402).
  • the substrate can be formed from polycarbonate, polystyrene, polyethylene terephthalate (PET), or other polymers capable of providing mechanical support, chemical resistance, and compatibility with microfluidic elements.
  • PET polyethylene terephthalate
  • This substrate can also include any necessary channels, through-holes, or adhesive layers for forming a microfluidic assembly (10408) for flowing a fluid sample, such as EBC sample, over a detection area of a hybrid LFA assay and electronic sensor.
  • the detection window (10404) is an aperture or transparent region in the top layer of the microfluidic assembly, aligned with a test line that is located adjacent to the detection area of a bare die sensor attached to a biosensor.
  • the detection window can be a open through-hole or formed from a material chosen to optimize transmission at specific wavelengths (e.g., UV for excitation or visible/near-infrared for emission), depending on the chosen detection modality.
  • the SAP can absorb and retain many times its own weight in liquid, providing a passive mechanism to remove surplus sample.
  • the microfluidic assembly (10408) includes all fluid handling layers and components (e.g., microfluidic channels, pads, conjugate release materials) with elements that can be provided on the plastic substrate and/or the biosensor card.
  • the assembly includes a lateral flow membrane, paper-based channels (microfluidic paper), or alternative microfluidic structures that direct sample fluid from the inlet region (initial point of sample reception) toward a test line or detection zone under the detection window (10404).
  • the assembly can be designed to create a control flow, mixing, and/or incubation times so that captured biomolecules (e.g., LAM antibodies) can bind to the target molecules (e.g., LAM protein).
  • the detection window (10404) aligns with a photonic detector mounted above and/or electronic sensor mounted on the biosensor card below the plastic substrate (10402), allowing the sample to be excited and/or read out by optical means or to interface with electrical detection elements (e g., a bare-die sensor).
  • the SAP (10406) in such embodiments helps maintain stable fluidic conditions by removing unneeded fluid. Consequently, the user or automated system can read an optical and/or electrical signal to determine the presence or concentration of a target analyte with minimal background interference.
  • FIG. 105 presents a bottom-side view of an assembled microfluidic assembly (10508).
  • This non-limiting embodiment includes plastic substrate (10502) that serves as the primary support structure, while a wick (10504) and microfluidic paper (10506) are shown, indicating how fluids flow and are managed for directing the flow of sample onto the test line or detection area of a hybrid photonic/electronic biosensor.
  • the plastic substrate (10502) can be formed from thermoplastic materials (e.g., PET, polycarbonate) chosen for their dimensional stability, manufacturability, and compatibility with fluid reagents.
  • the substrate can include cutouts, channels, or adhesive layers that bond the microfluidic components (10506, 10504) into the microfluidic assembly.
  • the microfluidic paper (10506) is a porous membrane or paper strip that provides for the capillary-driven flow of the fluid sample and includes regions for sample application, reagent or conjugate release, and capture/test lines.
  • the membrane is positioned so that fluid traveling from the top side (or from an inlet region) wicks toward the detection area for analyte detection.
  • the wick (10504) is a higher-capacity absorbent strip or pad that helps draw the fluid through the microfluidic paper (10506) and accumulate waste or excess sample.
  • the wick maintains a consistent fluid flow across the test region by preventing backflow and creating a gentle capillary pull.
  • the wick can be made from a single material component or from a combination of SAP, cellulose or other fibrous materials that can hold large volumes of liquid relative to their size.
  • the microfluidic assembly (10508) includes an integrated stack of materials including substrate (10502), microfluidic paper (10506), wick (10504), and any additional sealing, flow
  • I l l control or structural layers This assembly is designed so that fluid introduced on the top side flows through designated channels or pads, encounters detection chemistries, and finally reaches the wick (10504) on the bottom, which collects spent fluid to complete the assay.
  • the sample once the sample enters from the top or is directed via a sample through-hole, it travels through or along the microfluidic paper (10506). After interacting with specific test or capture regions, the fluid is drawn into the wick (10504) by capillary action. This ensures one-way flow and prevents back-migration of the sample, maintaining assay integrity.
  • FIG. 106 is an isolated view showing the biosensor card and the location of the microfluidic paper and wick.
  • the drawing shows a biosensor card 10602, a wick 10604, a microfluidic paper 10606, and a liquid detection features 10608. These components can be provided on the plastic substrate of the microfluidic assembly, or manufactured as part of the biosensor card with an attached bare die sensor.
  • liquid detection features (10608) are also provided for indicating or verifying sample flow in real time.
  • the liquid detection features shown comprises parallel conductors that are shorted when the liquid sample is present between the conductors.
  • a fluid sample e.g., exhaled breath condensate or a liquid clinical specimen
  • FIG. 107 shows an assembled microfluidic assembly (10710) affixed atop a biosensor card (10704).
  • the plastic substrate (10702) provides the primary support for various fluidic and sensor components.
  • a detection window (10706) is visible, through which optical, electronic, or hybrid detection may occur.
  • a fluid dam (10708), which helps regulate flow into the microfluidic channels or paper so that a slow accumulation of EBC sample, for example, forming on the condensation surface of an EBC sample Collector is a presented to the LFA components of the microfluidic assembly with a enough initially applied sample volume for the proper interaction and flow of reagents, sample, capture molecules, labels, etc., through the LFA assembly.
  • a biosensor support is provided by the biosensor card (10704) and has an attached bare die semiconductor sensor (as shown herein, for example, at FIG. 18) having a top surface configured as a detection area for receiving a liquid sample.
  • the liquid sample is accessible to the detection area through a sample through-hole formed in the biosensor support.
  • the microfluidic assembly (10710) is integrated atop this support, and includes a microfluidic membrane (microfluidic paper shown in FIG. 108) that has both a conjugate release pad for holding a fluorescent-labeled reagent selective to an analyte and a detection region aligned with the sensor’s detection area.
  • a photonic detection element and the semiconductor sensor are operably positioned so that when the labeled analyte complex accumulates at the detection region, its presence can be measured by at least one of an optical or electrical signal.
  • FIG. 108 provides an isolated view of the microfluidic paper (10802). This particular illustration highlights two critical regions for the hybrid photonic/electronic biosensor: a conjugate release pad (10806) and a test line (10804). Together, these elements enable a classic lateral flow assay or other microfluidic-based diagnostic procedure with the features of both visual or photonic readout and electronic or semiconductor biosensor readout.
  • microfluidic paper (10802) can be used as a porous or fibrous strip (often nitrocellulose or other membrane) that provides capillary action to transport the fluid sample enabling target molecules to bind to and reaction with reagents and capture molecules at the multiple functional zones for sample loading, conjugate release, and test/control line detection.
  • microfluidic paper or other fluid flow components are chosen for example with a uniform pore structure, wicking speed, and compatibility with biochemical reagents (e.g., capture antibodies) to form the fundamental “strip” design for lateral flow assays. Additional lines (e.g., control lines) or extended sections (e.g., wicking pads) can be included.
  • FIG. 108 illustrates the use of LFA techniques, such as controlled sample flow through or over a conjugate release pad (10806) and test line (10804) to provide for an assay with sensitivity, specificity, and ease of use for a broad range of diagnostic applications.
  • the conjugate release pad (10806) is positioned upstream of the test line (10804), this pad has labeled conjugates — such as fluorescent, colormetrics, or chemiluminescent microparticles bound to antibodies/aptamers.
  • conjugates such as fluorescent, colormetrics, or chemiluminescent microparticles bound to antibodies/aptamers.
  • the fluid sample first encounters this pad, it hydrates the conjugate, forming a conjugate complex with the antibody or capture molecule binding with the target molecule and carrying the conjugate complex forward in solution with the sample matrix (e.g., EBC sample, blood, urine, sweat, tears, saliva, etc.).
  • the sample matrix e.g., EBC sample, blood, urine, sweat, tears, saliva, etc.
  • Europium microspheres or other fluorescent tags are conjugated to the capture molecule that bind with specificity and selectivity to the target molecules in the sample.
  • a test line (10804) is a location on the microfluidic paper (10802) where capture molecules (e.g., antibodies) are immobilized to hold the conjugate complex for detection.
  • the capture molecules can be immobilized on detection area of a bare die sensor attached to the biosensor card.
  • the conjugate-analyte complexes migrate the location of the immobilized capture molecules, they become captured (e.g., by sandwich, competition, or other known binding mechanisms) by the immobilized molecules, forming a visible or fluorescent band (depending on the chosen detection chemistry) and in the hybrid photonic/electronic biosensor changing the electrical characteristics between two conductors of the electronic biosensor.
  • a fluid sample (blood, saliva, exhaled breath condensate, etc.) flows onto the microfluidic paper (10802).
  • conjugate release pad As the sample reaches the conjugate release pad (10806), fluorescent or colored labels conjugated to a capture molecule are put into the stream of the fluid sample migrating throught the microfludic assembly towards the wick.
  • Binding at Test Line The labeled complexes continue migrating along the membrane until they reach the test line (10804), where another set of capture molecules bind to and hold the labeled complexes for accumulation.
  • Readout At the test line, the accumulation of labeled conjugates-complexes produces a signal that can be visually observed or instrumentally measured (e.g., via UV excitation and photodiode detection if fluorescent labels are used, and electronic readout from the conductors of the bare die sensor connected to the trace lines of the biosensor card).
  • FIG. 109 is an exploded view of a microfluidic assembly for use with a biosensor card, where the microfluidic paper has a conjugate release pad and testing line.
  • the drawing shows a wick 10902, a fluid dam 10904, SAP 10906, a plastic substrate 10908, a sample through-hole 10910, a microfluidic paper 10912, a test line 10914, a conjugate release pad 10916, and a wick 10918.
  • the fluid dam holds back the accumulation of the biosample until a saturation or trigger, allows the fluid to pass through the sample through-hole (10910), creating a controlled “rush” of sample onto the microfluidic paper (10912).
  • the fluid dam can be formed from a dissolvable adhesive, mechanical stop, or partial enclosure around the sample inlet area.
  • SAP (10906) provided at the fluid dam holds the accumulated sample and selectively absorbs water, ions and other non-target materials in the fluid sample to concentration the target molecule. Once the fluid dam releases the accumulated sample it flows onto or into the microfluidic paper (10912), initiating lateral flow over to the conjugate release pad (10916) and the test line (10914).
  • the microfluidic assembly 10910 can be placed atop or integrated with a biosensor card. Fluid introduced at the fluid dam (10904) eventually passes through the sample through- hole (10910) and microfluidic paper (10912). The labeled conjugates released by the conjugate release pad (10916) interact with the target analytes in the sample and bind at the test line (10914) and or detection area of a biosensor die attached to the biosensor card. The accumulated labeled conjugates optically and/or electronically enable a measurable response. [0592] Note that the optical reader elements can be incorporated on or along side the bare die semiconductor sensor. For example, the emission at UV or near UV for the photonic readout can be provided by a GaN LED structure.
  • a microfluidic assembly is depicted in an exploded view for use with a biosensor card that includes a bare die semiconductor sensor (not shown) having a detection area, and at least one photonic detection element aligned with that sensor.
  • the assembly features a fluid dam (10904) on a plastic substrate (10908), where the fluid dam holds back the accumulating biosample — via a dissolvable adhesive or mechanical barrier — until saturation or a triggering event.
  • a superabsorbent polymer (SAP 10906) at the fluid dam helps concentrate the target molecule by selectively absorbing water and other non-target materials.
  • the SAP also holds the fluid sample in place in contact with the dissolvable adhesive to that the liquid sample, e.g., EBC sample which is mostly water) can accumulate in contact with and dissolve the adhesive. Once enough sample accumulates, it is released in a controlled rush through a sample through-hole (10910) and onto the microfluidic paper (10912), initiating lateral flow that passes over a conjugate release pad (10916) and then toward a test line (10914).
  • the liquid sample e.g., EBC sample which is mostly water
  • a wick can draw excess fluid away, maintaining consistent flow across the detection area of the semiconductor sensor where immobilized capture molecules bind with a florescent-labeled conjugate complex that is formed when a capture molecule (e.g., an antibody) binds to the a target molecule.
  • a capture molecule e.g., an antibody
  • the sample interacts with the fluorescent-labeled reagent from the conjugate release pad (10916), labeled analyte complexes are formed and migrate to the test line (10914) and/or a detection region aligned with the bare die sensor’s detection area.
  • This arrangement allows the analyte’s presence to be measured by at least one of an optical or electrical signal (e.g., through the photonic detection element), since the labeled complexes accumulate in the detection region where the biosensor card can read changes in fluorescence or other signal modalities.
  • an optical or electrical signal e.g., through the photonic detection element
  • a very efficient photonic/electronics sensor can be provided as a single GaN die that includes three integrated elements, a HEMT sensor, a GaN-based photoemitter, and a GaN photodetector, all cooperatively detecting the same analyte bound at a detection area:
  • GaN electronic sensor change in field-effect
  • An example HEMT sensor for electrical detection is the GaN/AlGaN transistor as described here, other HEMT, semiconductor or non-semiconductor constructions are also possible, but scalability of the GaN HEMT sensor may be more practical.
  • the sensor in any case, in this non-limiting embodiment, includes a gate or channel region exposed at the detection area.
  • Capture molecules are immobilized on this exposed gate or channel surface.
  • analyte molecules bind to the capture molecules, forming a fluorescently labeled conjugate complex (the label can be attached to a secondary reagent that also binds the analyte).
  • the HEMT detects subtle changes in electrical characteristics (like threshold voltage or drain current) resulting from this binding event. Essentially, the presence of the conjugate complex modifies charge distribution at the gate, revealing an electrical signature by modulating the field effect at the 2DGAS at the HEMT heterojunction.
  • a GaN LED or laser diode can be formed as a radiation emitter.
  • the radiation emitter is designed or tuned to emit electromagnetic radiation at a wavelength suitable for exciting the fluorescent label.
  • the photoemitter shines light onto the detection area where the fluorescent conjugate complexes are held because of the capture molecule binding events.
  • GaN Photodetector fluorescence readout
  • a GaN-based photodiode or photoconductor can also be fabricated on the same wafer, and arranged so it can detect the emitted fluorescence from the labeled conjugates.
  • conjugate complexes at the detection area are excited by the LED’s light, they emit a specific wavelength (fluorescent emission).
  • the photodetector tuned to this emission wavelength, picks up the resulting photon signal. Its output indicates how many fluorescent labels — and thus how much analyte — have bound.
  • the analyte is effectively measured two ways: (1) electrically through the HEMT’s gate modulation, and (2) photonically through fluorescence excitation/emission.
  • This dual-mode approach can enhance reliability (confirming binding events by both an electrical signature and a fluorescent optical signal) and reduce overall device size by eliminating external optical elements. It is particularly advantageous for point-of-care diagnostics, where a compact and robust sensor that crossverifies results in real time can significantly improve accuracy and user confidence.
  • FIG. 110 shows a dissolvable adhesive acting as a fluid dam to control the flow of EBC sample onto a microfluidic membrane, creating a temporary sample well where exhaled breath condensate (EBC sample) accumulates on top of a plastic substrate.
  • the drawing shows a plastic substrate 11002, a dissolvable adhesive 11006, an EBC sample 11008, a microfluidic membrane 11010, a conjugate release pad 11012, a photonic emitter/detector pair 11014, a test line 11016, a wick 11018, and a sample through-hole 11020.
  • EBC sample exhaled breath condensate
  • the dissolvable adhesive (11006) serves as a temporary fluid dam on the plastic substrate (11002), preventing the sample from advancing until enough liquid is collected. Once the adhesive dissolves, the fluid moves through a sample through-hole (11020) and onto the microfluidic membrane (11010), which carries it over the conjugate release pad (11012). There, fluorescent labels bind with the target analyte before reaching the test line (11016), where a photonic emitter/detector pair (11014) interrogates the resulting signal. A wick (11018) at the terminal end of the microfluidic membrane draws away excess fluid.
  • FIG. I l l illustrates the EBC sample further accumulating above the dissolvable adhesive. The drawing shows an EBC sample 11102, a dissolvable adhesive 11104, and a sample through-hole 11106.
  • FIG. 112 highlights the flow of EBC sample through the microfluidic strip after the adhesive fluid dam has dissolved.
  • the drawing shows an EBC sample 11202, a microfluidic membrane 11206, a conjugate release layer 11208, a test line 11210, a photonic emitter/detector pair 11212, a plastic substrate 11214, a wick 1 1216, and a sample through-hole 11218.
  • FIG. 13 depicts three different sample accumulation stacks placed above a semiconductor or hybrid photonic/electronic biosensor, each incorporating a dissolvable adhesive to temporarily block sample flow.
  • the adhesive prevents liquid from passing into the sample well until enough fluid has accumulated for sample conditioning or additional treatments (e.g., pH adjustment, lysing, buffering, or conjugate release).
  • sample conditioning or additional treatments e.g., pH adjustment, lysing, buffering, or conjugate release.
  • the now-conditioned sample travels through a sample- through hole into the sample well, where it contacts the biosensor (either purely semiconductor or a photonic/electronic hybrid), enabling improved analyte detection.
  • the various layers such as conjugate release, SAP for concentration, or specialized electrodes — can be stacked as needed to facilitate targeted pre-treatment before the fluid reaches the detection area.
  • the drawing shows a bare die 11302, a biosensor card 11304, a plastic substrate 11306, a dissolvable adhesive 11308, a sample well 11310, a sample through-hole 11312, a conjugate relase layer 11314, a sample conditioning layer 11316, a driving electrodes 11318, a sample conditioning layer 11320, and a detection area 11324.
  • a labeled conjugate (antibody, aptamer, or other capture molecule with a fluorescent or colored label) can be incorporated directly into the dissolvable adhesive layer.
  • the adhesive is water-soluble (e.g., made of sugars, certain polysaccharides, or other water-soluble polymers) and dissolves as the fluid sample accumulates.
  • the labeled conjugate can be embedded into the adhesive matrix, once the adhesive have been in contacts with enough liquid sample for enough time, it dissolves and releases both the conjugate and the analytecontaining fluid sample
  • An adhesive formula can both serve as a fluid dam and help stabilize the labeled conjugate over the product’s shelf life.
  • Buffer components can be at appropriate ionic strengths to maintain pH and ionic conditions to protect the conjugate’s structure.
  • Trehalose or other sugars can also help preserve protein folding and minimize aggregation.
  • Polyols e.g., glycerol
  • stabilizers like BSA bovine serum albumin
  • the adhesive matrix may be formulated to limit moisture ingress from the environment until actual use.
  • the water-soluble polymers can be formulated to form a relatively impermeable film when dry, to preserve the conjugate.
  • a desiccant or humidity modifiers can be added into the adhesive itself or the packaging to further reduce moisture exposure pre-use.
  • Materials added to the adhesive or other layers of the sample conditioning layered stack such as the labeled conjugate can also be encapsulated in microspheres or layered in pockets within the polymer adhesive matrix to protect from unfavorable conditions until the device is activated (i.e., the user EBC sample dissolves the adhesive).
  • FIG. 114 illustrates a microfluidic test assembly configured with a sample well beneath layers that include dissolvable adhesive, conjugate release, and optional sample conditioning materials.
  • exhaled breath condensate or another fluid sample
  • any needed conditioning e g., buffering or lysing
  • the fluid flows through the microfluidic channel toward the test line, with an emitter and detector positioned to measure fluorescent signals produced by bound analyte-conjugate complexes at or near the test line.
  • a wick at the far end draws away excess fluid, ensuring consistent flow and reliable detection.
  • the drawing shows a plastic substrate 11402, a microfluidic assembly 11404, a sample conditioning layer 11406, a dissolvable adhesive 1 1408, a sample through-hole 11412, a microfluidic membrane 11414, a conjugate release pad 11416, a test line 11418, a photonic emitter/detector pair 11420, a wick 11422, and a conjugate release layer 11124.
  • the layered microfluidic assembly includes a fluid dam that may comprise a water proof sheet material pull tab and/or a dissolvable adhesive to prevent the sample from flowing into the microfluidic membrane and test line until sufficient exhaled breath condensate (or other liquid) has accumulated and undergone any sample conditioning (e.g., buffering, lysing). Once the adhesive dissolves, the sample travels across the conjugate release region, picking up fluorescent labels that bind to the target analyte. A detection window over the test line allows an emitter and detector to measure the resulting fluorescence, while a wick at the far end draws fluid through, ensuring consistent flow and reliable signal readout.
  • a fluid dam may comprise a water proof sheet material pull tab and/or a dissolvable adhesive to prevent the sample from flowing into the microfluidic membrane and test line until sufficient exhaled breath condensate (or other liquid) has accumulated and undergone any sample conditioning (e.g., buffering, lysing).
  • sample conditioning e.g.,
  • FIG. 115 is an exploded view showing the material layers of a microfluidic assembly with a sample accumulating fluid dam and sample conditioning layers that can include a conjugate release layer that allows the sample to mix with the labeled conjugate to form a label conjugate complex.
  • the drawing shows a sample conditioning layer 11502, a SAP 11504, a conjugate relase layer 11506, a dissolvable adhesive 11508, a plastic substrate 11512, a sample through- hole 11514, a detection window 11516, a spacer 11518, a microfluidic paper 11520, a wick 11522, and a bottom substrate 11524.
  • the sample conditioning layer (11502) and SAP (11504) help treat and/or concentrate the sample, while a conjugate release layer (11506) adds a visible or florescent labeled conjugate including a capture molecule (e g., anitbody, aptamer, nanobody, etc.) for binding with a target molecule.
  • the dissolvable adhesive (11508) acts as a temporary fluid dam, preventing flow until enough sample has accumulated.
  • a plastic substrate (11512) with a sample through-hole (11514) and detection window (11516) is spaced (11518) above the microfluidic paper (11520), which drives fluid toward the wick (11522) for controlled flow.
  • the assembly includes a bottom substrate (11524).
  • the sample conditioning layered stack may comprises the dissolvable adhesive formulated with at least one stabilizer (selected from sugars, polyols, or proteins) and buffer components that preserve the labeled conjugate’s activity and maintain ionic conditions suitable for detecting an analyte when the fluid dam dissolves.
  • the labeled conjugate and other sample conditioning materials can be encapsulated in microspheres or layered within the polymer adhesive matrix, thereby creating a relatively impermeable barrier to moisture prior to use, and releasing the sample conditioning materials, such as the labeled conjugate upon contact with sufficient exhaled breath condensate for an extended mixing period before flow proceeds to the microfluidic membrane or detection area.

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Abstract

La présente invention concerne une nouvelle structure d'encapsulation pour un capteur à semiconducteur à puce nue, spécifiquement conçue pour des applications de diagnostic dans lesquelles un contact direct d'échantillon de fluide avec la zone de détection du capteur est nécessaire. Le capteur à semiconducteur encapsulé comprend une puce en semiconducteur ayant une surface supérieure présentant des plots de liaison et une zone de détection, et une surface inférieure. Un élément de support ayant un côté supérieur, un côté inférieur et une fenêtre de détection forme un puits d'échantillon pour recevoir un échantillon de fluide lorsqu'il est aligné avec la zone de détection. Un adhésif conducteur d'axe Z connecte électriquement des plots de connexion à des traces conductrices sur l'élément de support. Un élément d'étanchéité scelle le puits d'échantillon, préservant la fonctionnalité du capteur tout en permettant l'exposition de la zone de détection à l'échantillon.
PCT/US2025/023345 2024-04-07 2025-04-05 Dispositifs de capteurs électroniques, à semiconducteur et photoniques, boîtiers, fabrication et cas d'utilisation Pending WO2025217005A1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
US18/628,747 2024-04-07
US18/628,747 US20250314613A1 (en) 2024-04-07 2024-04-07 Packaged semiconductor sensor with an open detection surface and sealed detection well
US18/667,489 US20250314614A1 (en) 2024-04-07 2024-05-17 Semiconductor sensor devices, packaging, fabrication and use-cases
US18/667,489 2024-05-17
US202563743608P 2025-01-09 2025-01-09
US63/743,608 2025-01-09
US202563752849P 2025-02-02 2025-02-02
US63/752,849 2025-02-02

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US20230296558A1 (en) * 2020-07-14 2023-09-21 Grolltex, Inc. Hydrogel-based packaging of 2d materials-based biosensor devices for analyte detection and diagnostics
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US20050112544A1 (en) * 2002-12-20 2005-05-26 Xiao Xu Impedance based devices and methods for use in assays
US20080269075A1 (en) * 2004-07-20 2008-10-30 Umedik Inc. Method and Device to Optimize Analyte and Antibody Substrate Binding by Least Energy Adsorption
US20110036913A1 (en) * 2009-08-17 2011-02-17 Nxp B.V. Electrochemical sensor
US20170102358A1 (en) * 2014-12-18 2017-04-13 Agilome, Inc. Chemically-sensitive field effect transistors, systems, and methods for manufacturing and using the same
US20210325279A1 (en) * 2020-04-19 2021-10-21 John J. Daniels Mask-Based Testing System for Detecting Biomarkers in Exhaled Breath Condensate, Aerosols and Gases
US20230296558A1 (en) * 2020-07-14 2023-09-21 Grolltex, Inc. Hydrogel-based packaging of 2d materials-based biosensor devices for analyte detection and diagnostics
US20230333038A1 (en) * 2022-04-17 2023-10-19 Diagmetrics, Inc. Mask-based diagnostic device and wafer-level functionalization of a packaged semiconductor biosensor

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