WO2016085126A1 - Ion-sensitive field effect transistor biosensor combined with nanoprobe - Google Patents

Abstract

An ion-sensitive field effect transistor (ISFET) biosensor comprises an ISFET and a disposable sensor, wherein the disposable sensor has a nanoprobe coupled thereto, and by combining a capacitance coupling phenomenon occurring in the ISFET and a nanoprobe technology, provided is a biosensor platform capable of performing simple diagnosis by directly using a clinical sample without using a PBS buffer solution, unlike a conventional biosensor platform using the PBS buffer solution.

Description

 【Specification】

 [Name of invention]

 Nano probe fusion ion sensing field effect transistor biosensor

 Technical Field

 Ion-sensing field effect transistor

A biosensor is provided.

 Background technology.

 Infectious viral and cancer diseases that are now deadly to humanity are considered a big problem that adds to the burden of public health care (Persaud, D. et al. Absence of Detectable HIV-1 Viremia after Treatment Cessation in an Infant.New Engl.J. Med., 369, ppl 828-1835, 2013; Leroy, EM et al., Fruit bats as reservoirs of Ebola virus.Nature, 438, pp 575-576, 2005). The future point-of-care (POC) system provides a diagnosis system that can be immediately diagnosed in the field, enabling early diagnosis of various diseases and preventing outbreaks of infectious diseases. Among various diagnostic platforms, transistor-based biosensors are transducers that can obtain electrical signals from biomarkers. Therefore, optical-based diagnostic systems that currently require large analytical equipment and laboratory analysis are required for electrical signals. As it can be converted into a miniaturization system using transistors, biosensors using transistors are the next generation POC diagnostic system.

Is spotlighted as a flat product (HJ Jang et al., Electrical Signaling of Enzyme-Linked Immunosorbent Assays with an. Ion-Sensitive Field-Effect Transistor, Biosens. Bioelectron, 64, p P 318-323, 2015).

 Biosensors using transistors can quickly diagnose diseases, diagnose various diseases at once, and have very high sensitivity. High sensitivity

Various nanomaterials such as carbon nanotubes, nanowires, and graphene may be used to make transistor biosensors. Nanomaterials can have a one-dimensional or two-dimensional structure, which can secure a large surface area, and thus may be useful for collecting bio signals (Zheng, GF et al., Multiplexed electrical detection of cancer markers with nanowire sensor arrays. Biotechno. 23, ppl 294-1301, 2005). As a result, an antidote platform is currently being developed that can quantify biomarkers down to attomolar level. However, despite the high sensing characteristics of transistors, biosensors using transistors have not been commercialized to the extent that they can be applied to clinical samples to date. Because, firstly, the high concentration clinical sample induces a short debye length to the biosensor using the transistor, so the biosensor using the transistor has a low sensitivity in the clinical sample. In addition, since clinical samples have various biomolecules that can induce nonspecific reactions,

It can be difficult to provide a stable platform for the biosensor. Second, biosensors using transistors can be used to

Because the sensor reacts sensitively to changes in the isoelectric point, the pH of the clinical phase sample must be constant so that the biosensor using the transistor can obtain a constant sensitivity. However, in practice, since the pH of the clinical sample varies greatly depending on the condition of the patient, the biosensor using the transistor may not be able to detect the biomarker of the clinical sample with certain sensing characteristics. In order to control this issue, the biosensor surface is typically used with biomarkers and transistors in clinical samples.

The receptor is first reacted, and the reaction is detected with a conventional phosphate buffered salin (PBS) buffer solution. At this time, the PBS buffer solution should be distilled at a constant concentration in order to avoid the detour and maintain a constant pH. Since this series of preparations requires complex sample preparation in a laboratory environment, current transistor-based biosensors can be difficult to match POC diagnostic systems.

 Unlike nanomaterial-based biosensors, even though planar ion-sensing field effect transistors (ISFETs) are already commercially available as handheld pH sensors, ISFETs It may be difficult to implement an antigen antibody sensor because it has a low sensitivity. However, in 2010, Mark-Jan Spijkman increased the sensitivity of ISFETs by applying a lower electrode to an existing ISFET, suggesting a dual gated ISFET (Mark-Jan Spijkman et al., Dual-Gate Organic Field-Effect Transistors as Potentiometric Sensors in Aqueous Solution, Adv.Funct. Mater., 20, pp898-905, 2010). Power outages in upper and lower electrodes

Using capacitive coupling, the dual gate ISFETs present a sensor platform that goes beyond Nemst's limit detection. But dual gate ISFETs PBS buffer solutions must still be used, and diagnostic systems for detecting biomarkers in clinical samples such as serum, blood, urine, saliva, and other high concentration buffer solutions have not yet been implemented.

 [Detailed Description of the Invention]

 [Technical problem]

 One embodiment of the present invention is to reduce the device occurs in clinical samples and to perform a highly sensitive diagnosis of disease. One embodiment of the present invention is to constantly control the pH of the clinical sample and to obtain a constant detection characteristics.

 One embodiment of the present invention is a novel biosensor platform that has a sensitivity exceeding the Nernst reaction and does not use PBS buffer solution and can be directly, low-cost, rapid, simple and precisely diagnosed in clinical samples. to provide a biosensor platform).

 In addition to the above object, embodiments according to the present invention can be used to achieve other objects not specifically mentioned.

 [Technical Solution]

 An ion-sensitive field effect transistor (ISFET) biosensor according to an embodiment of the present invention is a lower gate electrode, a lower insulating layer positioned on the lower gate electrode, a source and a drain disposed on the lower insulating layer and spaced apart from each other. A channel layer on the lower insulating layer and between the source and the drain, an upper insulating layer on the source and drain channels and the channel layer, an upper gate electrode on the upper insulating layer, and a replaceable type on the upper gate electrode

A nanoprobe coupled to a disposable sensor and a replaceable sensor, wherein the receptor comprises at least one of an antibody, cell, or DNA functionalized, and the negatively or positively charged nanoprobe is coupled to the receptor, and the nano Sensitivity of the biomarker is amplified by capacitive coupling of the electrons of the probe and the channel layer.

The upper insulating film and the equivalent oxide film thickness are thinner than the equivalent oxide film thickness of the lower insulating film, and the channel layer may have a thickness of 10 nm or less in which electrostatic coupling occurs. The nanoprobe may comprise metal nanoparticles. Where the metal nanoparticles are It may be gold.

 The nanoprobe may comprise a quantum dot.

 The nanoprobe may include a hybrid nanoprobe combining ferritin and a plurality of metal nanoprobes.

 The biosensor can diagnose at least one disease of hepatitis B, bird flu, hand and foot disease, pancreatic cancer, prostate cancer, cervical cancer, or liver cancer.

 The biosensor may be used as at least one of a cell-based sensor, an antigen antibody sensor, or a DNA sensor.

 【Effects of the Invention】

 An embodiment of the present invention can reduce the device occurring in the clinical sample and perform a highly sensitive diagnosis of disease,

Low cost, fast, simple, straight from the clinical sample without the use of PBS buffer solution, with constant control of the pH of the clinical sample, constant detection characteristics, and sensitivity beyond the Nernst reaction We can provide a new biosensor platform for precision diagnosis.

 [Brief Description of Drawings]

 1 is a schematic diagram of a sensor flat coupled to a transistor sensor and nanoprobe. Figure 2 is a schematic diagram showing the amplification mechanism appearing in the combination of the sensor and the gold nanoparticle probe according to an embodiment of the present invention.

 3A and 3B illustrate nanoprobe fusion according to an embodiment of the present invention.

A schematic diagram showing a simple procedure for using a transistor.

 4 is a graph illustrating a sensitivity amplification evaluation result of a biosensor in which a dual gate ISFET of Example 1 and a replaceable sensor of Example 2 are combined.

 5 shows the hepatitis B virus detection sensitivity of the biosensor in which the dual gate ISFET of Example 1 and the replaceable sensor of Example 3 are combined with the single gate of Comparative Example 1;

This is a graph comparing the sensitivity of sensing in ISFET in PBS buffer solution environment.

 6 is a graph comparing the hepatitis B virus detection sensitivity of the single-gate ISFET sensor of Comparative Example 1 and the hepatitis B virus detection sensitivity according to the concentration of the PBS buffer solution of the biosensors combined with Examples 1 and 3 .

Figure 7 is a biosensor PBS buffer solution of Example 1 and Example 3 combined It is a graph showing the change of the transfer characteristic in concentration.

 8 is a graph comparing the hepatitis B virus detection sensitivity according to the concentration of PBS buffer solution of the biosensor of Example 4.

 9 is not using the biosensor and nano-probe of Example 5

A graph comparing the detection characteristics of hepatitis B virus in serum of biosensors. [Form to carry out invention]

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily practice the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. Also, a known technique is well known that concrete _o description thereof will be omitted.

 In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. When a part such as a layer, film, area, plate, etc. is "on top" of another part, this includes not only being "on top of" the Daron part, but also having another part in between. Other parts "directly above" mean no other part in the middle, whereas layers, membranes, areas, plates, etc. are "below" when other parts are "underneath". This includes not only cases but also other parts in between. On the other hand, when one part is "just below" another part, it means that there is no other part in the middle.

 Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding the other components unless otherwise stated.

 Ion sense field effect transistor according to an embodiment of the present invention

Biosensors include ISFETs and replaceable sensors, which are combined with nanoprobes. Unlike conventional biosensor platforms using PBS buffer solution, which combines electrostatic coupling phenomenon and nanoprobe technology in ISFET, simple diagnosis can be made by directly using clinical samples without dispersing PBS buffer solution. A biosensor platform may be provided. For example, transducers and nanoprobes can be combined to provide a platform to detect biomarkers directly in clinical samples, instead of using PBS buffer solutions, minimizing the procedure of the detection system.

 The combination of charge supplied from the nanoprobe and the double gate ISFET that amplifies it directly eliminates the PBS buffer solution used in conventional sensing systems and directly in clinical sample environments such as serum, blood, urine, saliva, and high concentration buffer solutions. Diagnostic platforms that can detect various biomarkers can be provided. For example, nanoprobes can greatly amplify biological signals and provide additional charge.

The charge applied to the surface of the nanoprobe is caused by the electrostatic coupling phenomenon with the ISFET.

As amplified, it is possible to quantify the biomarkers at the attomomolar level in clinical samples. Strong positive charge or ^"negative charge of a nano-probe, in the detection system

It may have a greater impact than the change of the isoeletric point due to the biomarker binding. A series of processes that receive additional charge from the nanoprobe and amplify it from the transistor can overcome the divide in clinical samples and effectively control the changing pH.

 In addition, the small surface potential voltage difference generated by the pluggable replacement sensor is the threshold of the lower field transistor due to the supercapacitive coupling occurring in the double gate field effect transistor including the ultra thin channel layer of about 10 nm or less. The voltage change can be greatly amplified. Require high process costs

Transistors can be used continuously, and low cost sensors can be used as replacements for transistors.

 Unlike conventional ISFET-based antigenic antibody sensors, a new biosensor platform can be provided. Accordingly, high-sensitivity diagnosis can be made for diseases such as pancreatic cancer, prostate cancer, and viral diseases. A precision early screening platform can be provided.

 1 is a schematic diagram of a sensor flat coupled to a transistor sensor and nanoprobe. Nanoprobe 52 is coupled to dual gate ISFET 120. Positive charges are induced from the nanoprobe 52 having a strong negative charge, and positive charges are caused by the electrostatic coupling phenomenon.

Amplified by ISFET 120.

Referring to FIG. 1, the ISFET biosensor 100 includes a lower gate electrode 101 and a lower portion. A lower insulating film 102 positioned on the gate electrode 101, a source 103 and a drain 104 positioned on the lower insulating film 102 and spaced apart from each other, a source 103 and a drain 104 positioned on the lower insulating film 102. ) Between the channel layer 105, the source 103, the drain 104, and the channel layer 105 positioned between the upper insulating film 106 and the upper gate electrode 107 positioned above the upper insulating film 106. ) May be included.

 The replaceable sensor 130 may be a structure that is connected to the upper gate electrode 107 of the ISFET biosensor 100 through electrical connection in a replaceable form.

The replaceable sensor 130 may be a plug type and may be coupled to a transistor device. For example, the replaceable sensor 130 is located on the metal electrode 108 connected to the upper gate electrode 107, and positioned above the metal electrode 108 to detect the silver.

The sensing film 109 may be included. Through this, the replaceable sensor 130 and the ISFET 120 are separated, so that the ISFET 120 requiring high process cost is continuously used, and the low cost replaceable sensor 130 is separated from the ISFET 120. Can be used as a replacement. The receptor 51 is coupled to the replaceable sensor 130, and at least one of an antibody, cell, or DNA may be functionalized. The biomarker may comprise at least one of an antigen, a cell, or a DNA.

 Nanoprobe 52 is coupled to receptor 51 and has a negative or positive charge. Sensitivity of the biomarker is amplified by capacitive coupling of electrons of the nanoprobe 52 and the channel layer 105.

 Nanoprobe 52 includes metal nanoparticles. For example, the metal nanoparticles may be gold. When gold is used as the metal nanoparticles, there is an effect of supplying an additional charge.

 Nanoprobe 52 includes a quantum dot. When using quantum dots, it can play an additional role of supplying charge like gold nanoparticles, and can also play a bio-imaging role at the same time.

 Nanoprobe 52 includes ferritinol. Through the hybrid bonding structure of ferritin and metal nanoparticles, a larger signal can be obtained by receiving an additional charge as compared with using a single metal nanoparticle.

The small surface potential voltage difference that occurs in the replaceable sensor 130 is due to the supercapacitive coupling that occurs in the ISFET 120 including the ultra-thin channel layer, resulting in a lower electric field. The threshold voltage change of the transistor can be greatly amplified. Here, the amplification factor may be determined by the thickness of the lower insulating film, the thickness of the channel layer, the thickness of the insulating film of the upper gate, and the like. The thicker the lower insulating film 102 and the thinner the upper insulating film 106 and the channel layer 105 are, the larger the amplification factor can be.

 The channel layer 105 may be an ultra thin layer, for example, may be about 10 nm or less in thickness. Within the range of the thickness of the channel layer 105, due to the strong electric field of the lower gate electrode 101 induced in the ultra-thin film, supercapacitive coupling that can be controlled under all conditions up to the upper interface occurs. Through this, the electrons and holes induced in the upper gate interface can be completely controlled, and the leakage current can be blocked. In addition, by allowing a stable amplification factor, it is possible to improve linear reaction, hysteresis, drift phenomenon, etc. according to the surface potential, and to maintain the electrostatic coupling of the upper and lower gates. In addition, within the range of the thickness of the channel layer 105, including the ultra-thin channel layer 105

The ISFET 120 allows for a large amplification factor compared to the conventional double gate thin film transistor, and can also increase the ρΗ sensing power. For example, it may have a pH sensitivity of about 59 mV / pH or more. In addition, within the range of the thickness of the channel layer 105, the ISFET 120 including the ultra-thin channel layer 105 can also improve the stability of the existing double gate ISFET. The variable amplification factor seen in the thick channel layer, coupled with the leakage current component induced at the upper interface, can increase the deterioration of the device due to ion damage. On the other hand, the ISFET 120 including the ultra-thin channel layer 105 whose leakage current is controlled while allowing a constant amplification factor can minimize the effect of ion damage on the sensing film 109. Further, in the conventional conventional double gate ISFET, when the lower insulating film 102 becomes excessively thick, a phenomenon occurs in which the lower electric field does not control all the channel regions, but the electrostatic coupling of the upper and lower gates is weakened. According to one embodiment, by including the ultra-thin channel layer 105, it is possible to maintain the electrostatic coupling and obtain a large amplification factor. The upper and lower gates and the electrostatic coupling phenomenon occur only when the upper channel interface is completely depleted. In the conventional sensor, the entire length of the lower gate does not control the upper channel so that the amplification does not occur. The channel layer 105 may include at least one of an oxide semiconductor, an organic semiconductor, polycrystalline silicon, or single crystal silicon. When the channel layer 105 includes at least one of an oxide semiconductor, an organic semiconductor, polycrystalline silicon, or monocrystalline silicon, Bottom gate electrostatic coupling occurs and high sensitivity sensors can be fabricated, providing a transparent and flexible sensor. In this case, an amplified sensitivity characteristic of about 59 mV / pH or more can be obtained.

 The channel layer 105 is not limited in width or length, and may utilize an electrostatic coupling phenomenon using the upper and lower gate electrodes 101 and 107 in the double gate structure. The equivalent oxide thickness of the upper insulating film 106 may be thinner than the thickness of the equivalent oxide film of the lower insulating film 102. For example, the top

The thickness of the insulating film 106 may be about 25 nm or less, and the thickness of the lower insulating film 102 may be about 100 nm or more. The equivalent oxide film thickness of the upper insulating film 106 is lower

When less than the thickness of the equivalent oxide film of the insulating film 102, it is possible to cause a sensitivity amplification phenomenon of about 59 mV / pH or more using the electrostatic coupling.

 The upper insulating layer 106, the lower insulating layer 102, or the sensing layer 109 of the replaceable sensor 130 may include at least one of Si02, Hf02, A1203, Ta205, Zr02, or Ti02. In addition, the upper insulating film 106, the lower insulating film 102, or the sensing film 109 of the replaceable sensor 130 may have a single, double, and triple stacked structure. Through this, by increasing the physical thickness, and by reducing the equivalent oxide film thickness of the upper insulating film 106, it is possible to amplify the sensitivity and to prevent the degradation of the leakage current.

 The ISFET biosensor 100 may diagnose a disease with at least one of hepatitis B, avian influenza, hand and foot disease, pancreatic cancer, prostate cancer, cervical cancer, or liver cancer.

 The ISFET biosensor 100 may be used as at least one of a cell-based sensor, an antigen antibody sensor, or a DNA sensor.

 Figure 2 is a schematic diagram showing the amplification mechanism appearing in the combination of the sensor and the gold nanoparticle probe according to an embodiment of the present invention. Referring to FIG. 2, it can be seen that the nanoprobe fusion transistor sensor system can reduce the detour and the pH can be kept constant in clinical samples. Nanoprobes have a strong negative charge. Strong negative charges are surrounded by positive charges in the solution, and positive charges are applied near the surface and the deviance of the sensor.

 3A and 3B illustrate nanoprobe fusion according to an embodiment of the present invention.

A schematic diagram showing a simple procedure for using a transistor. 3A and 3B, a simple procedure of using a nanoprobe fusion transistor is shown. The serum sample containing the biomarker and the nanoprobe are mixed and injected into the nanoprobe fusion transistor. The detection system can then be completed with a simple procedure to plug in a replacement sensor.

 Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are merely examples of the present invention, and the present invention is not limited to the following Examples.

 Example 1 Fabrication of Dual Gate ISFETs

 The substrate is made of a silicon-on-insulator (SOI) in the (100) direction having a resistivity of about 10 to 20 Qcm, and the thickness of silicon, the lower gate electrode, is about 107 nm, and the buried Si02 oxide film, the lower insulating film, is about 700 Prepare the substrate in nm. Standard RCA. After cleaning, about 2.38 wt%

The upper silicon is etched with a tetramethylammonium hydroxide (TMAH) solution and the channel region is formed using photolithography. The length and width of the formed channels are about 20 and 20, respectively. And the thickness of the channel layer formed is about 4.3 nm. Subsequently, η-type polycrystalline silicon is deposited using CVD equipment to form a source and a drain. Thereafter, an upper insulating film is formed on the source and the drain by oxidizing silicon dioxide having a thickness of about 23 nm. Then, about 150 nm thick A1 thin film layer is deposited using an E-beam evaporator to form the upper gate electrode. Next, a double gate ISFET is fabricated by performing heat treatment in a gas atmosphere containing about 450 ° C. and N2 and H2 to eliminate defects and improve the interface state.

 Comparative Example 1: Single Gate ISFET Fabrication

 A single gate ISFET was fabricated in the same manner as in Example 1 except that the lower gate electrode was omitted in Example 1.

 Example 2: Replacement Sensor Manufacturing

The substrate uses p-type silicon in the (100) direction in which about 300 nm of Si0 ₂ is grown. After standard RCA cleaning, an electron evaporator is used to deposit Ti to a thickness of about 100 nm, which serves as a metal electrode to convey the electrical potential change of the sensor surface. Thereafter, a Sn02 film, which is a sensing film, is deposited to a thickness of about 45 nm on the Ti layer by using an RF sputter. At this time, RF power is about 50W. After that, a flow rate of about 20 sccm The sputtering process is carried out in an Ar gas atmosphere having a rate) and a pressure of about 3 mtorr. Subsequently, a chamber is made of polydimethylsiloxane (PDMS) for injection of the ρΗ solution and attached to the upper part of the sensing film to manufacture a replaceable sensor.

 H characteristic evaluation

 In order to evaluate the pH sensing characteristics of the biosensor combined with the dual gate ISFET and the replaceable sensor, the following experiment was performed. The replaceable sensor of Example 2 was inserted into the double gate ISFET of Example 1, and the replaceable The Ag / AgCl reference electrode is grounded to the upper electrode of the sensor. Inject pH solution into replaceable sensor, double gate

A bias is applied to the bottom electrode of the ISFET. PH sensitivity is measured by injecting a pH buffer solution into the replaceable sensor.

 4 is a graph illustrating a sensitivity amplification evaluation result of a biosensor in which a dual gate ISFET of Example 1 and a replaceable sensor of Example 2 are combined. Referring to Figure 4,

Through the linkage technology of the ISFET sensor, the transfer characteristic that caused the pH amplification is shown. Here, the ρΗ amplification size may be determined by the thickness of the lower insulating film, the thickness of the channel layer, and the thickness of the upper insulating film.

 Example 3: Replaceable Sensor with Receptor

 In order to fix the hepatitis B antibody on the surface of the detection sensor of the replaceable sensor prepared in Example 2, and form a ΟΗ group using 02 plasma on the surface of the first detection membrane ᅳ Then, the surface of the detection membrane is diluted in ethanol Reaction with 5% of (3-aminopropyl) trimethoxysilane for about an hour to form an amino group on the surface of the sensing membrane, and about 1 M of succinic

Inject succinic anhydride to react at about 37 ^° C for about 4 hours to form carboxyl groups on the surface of the sensing membrane. Next, the surface of the sensing film was prepared with about 0.4 M of N-Hydroxysuccinimide and about 0.1 M.

Ethyl (dimethylaminopropyl) carbodiimide ((ethyl (dimethylaminopropyl)

carbodiimide) for about 15 minutes.

 Characterization of Hepatitis B Virus Sensitivity

The hepatitis B antibody prepared in Example 3 was injected with a hepatitis B antigen diluted in PBS buffer solution into a functionalized replacement sensor, and the bottom of the double gate ISFET of Example 1 coupled to the replacement sensor of Example 3 By biasing the electrodes The measurement results are shown in FIGS. 5 to 7.

 5 shows the hepatitis B virus detection sensitivity of the biosensor in which the dual gate ISFET of Example 1 and the replaceable sensor of Example 3 are combined with the single gate of Comparative Example 1;

This is a graph comparing the sensitivity of sensing in ISFET in PBS buffer solution environment. Referring to FIG. 5, the biosensors in which Example 1 and Example 3 are combined show about 81.7 times surface potential amplification compared to the single gate ISFET of Comparative Example 1.

 6 is a graph comparing the hepatitis B virus detection sensitivity of the single-gate ISFET sensor of Comparative Example 1 and the hepatitis B virus detection sensitivity according to the concentration of the PBS buffer solution of the biosensors combined with Examples 1 and 3 . Referring to Figure 6, by using a biosensor combined with Example 1 and Example 3, hepatitis B virus detection characteristics using a PBS buffer solution widely used in the past is compared. As the concentration of the PBS buffer solution dilutes, the larger the bye-bye, more biological signals can be detected.

 Figure 7 is a graph showing the change in delivery characteristics in the concentration of PBS buffer solution of the biosensors of Example 1 and Example 3 combined. Referring to FIG. 7, as the concentration of the PBS buffer solution is diluted, transfer characteristics of the PBS buffer solution toward the acid appear. Since the sensor is sensitive to changes in the isoelectric point of the biomarker detected on the surface, the pH of the clinical sample must be constant to obtain a constant sensitivity. 6 and 7 show that transistor-based biosensors can be sensitive to the conditions of the PBS buffer solution. This may be an obstacle to the clinical application of transistor-based biosensors.

 Example 4 Nanoprobe Binding Biosensors in PBS Buffer Solution

 Dilute any hepatitis B virus by concentration in PBS buffer solution.

The nanoprobe containing 3 nM of gold nanoparticles prepared was reacted for 30 minutes with a biomarker-diluted solution, and the mixture was added to the sensing film of the replaceable sensor of Example 3 coupled to the double gate ISFET of Example 1. After the minute reaction, the result of measuring the sensitivity is shown in FIG. 8.

8 is a graph comparing the hepatitis B virus detection sensitivity according to the concentration of PBS buffer solution of the biosensor of Example 4. Referring to FIG. 8. The gold nanoparticle probe fusion transistor platform also exhibits characteristics of hepatitis B virus detection. Biosensors with no nanoparticles bound (biosensors combined with Examples 1 and 3, 0.001 dilution of PBS buffer solution) were also simultaneously compared. In the nanoprobe fusion transistor, it can be seen that Β hepatitis sensitivity is constantly amplified regardless of the PBS buffer solution conditions.

 Here, when comparing the amplified size of Figure 8 and the signal of Figure 6, it can be seen that the charge of the nano-probe is greater than the change in the isoelectric point of the biomarker. Nanoprobes not only amplify the signal significantly, but also show that they can effectively control the changing ρΗ in clinical samples. According to the dichroic ISFET sensor using nanoprobe, various preparations appearing in the existing sensor platform requiring the reaction of the biomarker of the clinical sample and the use of PBS buffer solution can be omitted, and the biomarker is directly detected in the clinical sample. can do.

 Example 5: Nanoprobe Binding Biosensors in Serum

 Hepatitis B virus is mixed in serum purchased from Sigma Aldrich. After 30 minutes of reaction, the nanoprobe containing 3 ηΜ gold nanoparticles prepared and the serum containing the biomarker were reacted, and the mixture was added to the detection film of the replaceable sensor of Example 3, which was bound to the double gate ISFET of Example 1, for 30 minutes. After the reaction, the result of measuring the sensitivity is shown in FIG. 9.

 9 is not using the biosensor and nano-probe of Example 5

This is a graph comparing the detection characteristics of hepatitis B virus in serum of biosensor.

Biosensors not using nanoprobes are prepared in the same manner as in Example 5 except that nanoprobes are not used. Referring to FIG. 9, a characteristic of detecting hepatitis Β in real serum is shown by using a nanoprobe fusion transistor. In five or more experiments, hepatitis B biomarkers of serum solutions used in place of PBS buffer solutions were effectively detected and nanoprobes were not included.

Compared to the biosensor, the sensitivity is about twice as large.

 Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims

[Range of request]  [Claim 1]  Lower gate electrode,  A lower insulating layer on the lower gate electrode,  A source and a drain disposed on the lower insulating film and spaced apart from each other, a channel layer located on the lower insulating film and positioned between the source and the drain;  An upper insulating layer on the source, the drain, and the channel layer, an upper gate electrode on the upper insulating layer,  A replaceable sensor positioned above the upper gate electrode, and  A receptor coupled to the replaceable sensor, wherein at least one of an antibody, cell, or DNA is functionalized;  An ion sensing field effect in which a nano probe having a negative charge or a positive charge is coupled to the receptor, and the sensitivity of a biomarker is amplified by capacitive coupling of electrons of the nanoprobe and the channel layer. Ion-sensitive field effect transistor (ISFET) biosensor.  [Claim 2]  In claim 1,  The equivalent oxide film thickness of the upper insulating film is thinner than the equivalent oxide film thickness of the lower insulating film, the ion sensing field effect transistor biosensor having the channel layer o having a thickness of 10 nm or less in which the electrostatic coupling occurs.  [Claim 3]  In claim 1,  The nano probe is an ion-sensing field effect transistor biosensor comprising metal nanoparticles.  [Claim 4]  In crab 3, The metal nanoparticle is a gold ion sensing field effect transistor biosensor 바이오 [Claim 5]  In paragraph 1,  The nanoprobe comprises a quantum dot (quantum dot) is a sensing field effect transistor biosensor.  [Claim 6]  In claim 1,  The nano probe is an ion-sensing field effect transistor biosensor comprising a hybrid nano probe combined with ferritin (ferritin) and a plurality of metal nano probes. [Claim 7]  In crab 1  The biosensor may diagnose at least one disease of hepatitis B, bird flu, hand and foot disease, pancreatic cancer, prostate cancer, cervical cancer, or liver cancer,  An ion sensing field effect transistor biosensor that is used as at least one of a cell-based sensor, an antigen antibody sensor, or a DNA sensor.