JP6414407B2 - Raman spectroscopic device and electronic device - Google Patents

Description

  The present invention relates to a measurement method, a Raman spectroscopic device, and an electronic apparatus.

  In recent years, demand for medical diagnosis, food inspection, and the like has been increasing, and development of a small and high-speed sensing technology has been demanded. Various types of sensors, including electrochemical techniques, have been studied. However, surface plasmon resonance (SPR) is used because it can be integrated, is low-cost, and does not choose the measurement environment. There is growing interest in sensors. For example, there is known one that detects the presence or absence of substance adsorption, such as the presence or absence of antigen adsorption in an antigen-antibody reaction, using SPR generated on a metal thin film provided on the surface of a total reflection prism. This technique senses the presence of a molecule to be detected by detecting that the extinction wavelength by SPR shifts before and after the adsorption of the molecule to be detected.

As one of high-sensitivity spectroscopic techniques for detecting a low concentration of molecules, attention is focused on surface enhanced Raman scattering (SERS) using SPR. The SERS, a phenomenon that the Raman scattering light at the metal surface having an uneven structure of nanometer scale is 10 ^doubled to 10 ⁴ times enhanced. When a molecule such as a laser is irradiated with excitation light having a single wavelength, light having a wavelength slightly shifted from the wavelength of the excitation light by the vibration energy of the molecule (Raman scattered light) is scattered. When the scattered light is spectrally processed, a spectrum (fingerprint spectrum) unique to the molecular species is obtained. By analyzing the shape of this fingerprint spectrum, it becomes possible to identify the molecule.

  For example, Patent Documents 1 and 2 and Non-Patent Document 1 describe sensor chips using SERS as described above.

Special table 2007-538264 gazette JP 2008-14933 A OPTICS EXPRESS, Vol. 17, no. 20, 2009, 17234-17241

  Here, when the target substance to be detected is adsorbed to the metal nanoparticle (metal microstructure) of the sensor chip (electric field enhancing element), depending on the refractive index of the target substance, localized surface plasmon resonance (LSPR: It is known that the resonance wavelength of Localized Surface Plasmon Resonance shifts. For this reason, the SERS enhancement strength increases or decreases depending on the amount of the target substance adsorbed on the metal microstructure or its refractive index. Therefore, the techniques described in Patent Documents 1 and 2 and Non-Patent Document 1 may not be able to accurately quantify the target substance.

One of the objects according to some embodiments of the present invention is to provide a measurement method capable of accurately quantifying a target substance. Another object of some embodiments of the present invention is to provide a Raman spectroscopic device capable of accurately quantifying a target substance. Another object of some embodiments of the present invention is to provide an electronic apparatus including the above-described Raman spectroscopic device.

The measurement method according to the present invention includes:
Irradiating the electric field enhancing element with white light to obtain a first reflection spectrum;
Exposing a target substance to the surface of the electric field enhancing element;
Irradiating the electric field enhancing element exposed to the target substance with the white light to obtain a second reflection spectrum;
Obtaining a shift amount of a resonance wavelength of surface plasmon resonance before and after exposing the target substance to the electric field enhancing element based on the first reflection spectrum and the second reflection spectrum;
Irradiating the electric field enhancing element with laser light to obtain a Raman spectrum;
Obtaining a peak intensity of a peak caused by the target substance based on the Raman spectrum;
Quantifying the target substance based on the shift amount and the peak intensity;
including.

  In the measurement method according to the present invention, the amount of electric field enhancement in the electric field enhancement element after exposure of the target substance is taken into account by determining the amount of shift in the resonance wavelength of surface plasmon resonance before and after exposure of the target substance to the electric field enhancement element. Thus, the target substance can be quantified. Thereby, in the measuring method according to the present invention, the target substance can be accurately quantified.

In the measurement method according to the present invention,
The step of quantifying the target substance comprises:
Based on the shift amount, the electric field enhancement element after the target substance is exposed to the square of the electric field enhancement intensity at the wavelength of the laser light and the electric field at the wavelength of the Raman scattered light caused by the target substance. Find the product E _i ² × E _s ² of the square of the enhancement and
Based on the following formula (1), the number N of molecules of the target substance may be obtained.
However, in Formula (1),
I _SERS is the peak intensity,
I ₀ is the intensity of the laser beam,
C is a constant.

  In the measurement method according to the present invention, the target substance can be accurately quantified.

The measurement method according to the present invention includes:
Irradiating an electric field enhancing element with a first laser beam having a wavelength that changes with time to obtain a first reflection spectrum;
Exposing a target substance to the surface of the electric field enhancing element;
Irradiating the electric field enhancing element exposed to the target substance with the first laser light to obtain a second reflection spectrum;
Obtaining a shift amount of a resonance wavelength of surface plasmon resonance before and after exposing the target substance to the electric field enhancing element based on the first reflection spectrum and the second reflection spectrum;
Irradiating the electric field enhancing element with a second laser beam whose wavelength does not change with time, and acquiring a Raman spectrum;
Obtaining a peak intensity of a peak caused by the target substance based on the Raman spectrum;
Quantifying the target substance based on the shift amount and the peak intensity;
including.

  In the measurement method according to the present invention, the amount of electric field enhancement in the electric field enhancement element after exposure of the target substance is taken into account by determining the amount of shift in the resonance wavelength of surface plasmon resonance before and after exposure of the target substance to the electric field enhancement element. Thus, the target substance can be quantified. Thereby, in the measuring method according to the present invention, the target substance can be accurately quantified.

In the measurement method according to the present invention,
The step of quantifying the target substance comprises:
Based on the shift amount, the electric field enhancement element after the target substance is exposed to the square of the electric field enhancement intensity at the wavelength of the second laser light and the wavelength of the Raman scattered light caused by the target substance. Find the product of the square of the electric field enhancement of E _i ² × E _s ² ,
Based on the following formula (1), the number N of molecules of the target substance may be obtained.
However, in Formula (1),
I _SERS is the peak intensity,
I ₀ is the intensity of the second laser beam,
C is a constant.

  In the measurement method according to the present invention, the target substance can be accurately quantified.

The Raman spectroscopic device according to the present invention is:
An electric field enhancing element to which the target substance is exposed;
A light source that emits white light or laser light;
A photodetector for detecting light emitted by the electric field enhancement element when the electric field enhancement element is irradiated with the white light or the laser beam;
Based on the detection result of the photodetector when the electric field enhancing element is irradiated with the white light, a reflection spectrum acquisition unit that acquires a reflection spectrum;
Based on the reflection spectrum, a shift amount calculation unit for obtaining a shift amount of a resonance wavelength of surface plasmon resonance before and after the target substance is exposed to the electric field enhancing element;
Based on the detection result of the photodetector when the electric field enhancing element is irradiated with the laser light, a Raman spectrum acquisition unit that acquires a Raman spectrum;
A peak intensity calculation unit for obtaining a peak intensity of a peak due to the target substance based on the Raman spectrum; a quantification unit for quantifying the target substance based on the shift amount and the peak intensity;
including.

  In the Raman spectroscopic device according to the present invention, the electric field enhancement intensity in the electric field enhancement element after the target substance is exposed is obtained by determining the shift amount of the resonance wavelength of the surface plasmon resonance before and after the target substance is exposed to the electric field enhancement element. In consideration, the target substance can be quantified. Thereby, in the Raman spectroscopic device according to the present invention, the target substance can be accurately quantified.

In the Raman spectroscopic device according to the present invention,
The light source is
A first light emitting element for generating the white light;
A second light emitting element for generating the laser beam;
You may have.

  In the Raman spectroscopic device according to the present invention, the light source can irradiate the electric field enhancing element with white light or laser light.

In the Raman spectroscopic device according to the present invention,
The quantitative unit is
Based on the shift amount, the electric field enhancement element after the target substance is exposed to the square of the electric field enhancement intensity at the wavelength of the laser light and the electric field at the wavelength of the Raman scattered light caused by the target substance. Find the product E _i ² × E _s ² of the square of the enhancement and
The number N of molecules of the target substance may be obtained based on the following formula (1).
However, in Formula (1),
I _SERS is the peak intensity,
I ₀ is the intensity of the laser beam,
C is a constant.

  The Raman spectroscopic device according to the present invention can accurately quantify the target substance.

The Raman spectroscopic device according to the present invention is:
An electric field enhancing element to which the target substance is exposed;
A tunable laser light source that irradiates a first laser beam whose wavelength changes with time or a second laser beam whose wavelength does not change with time;
A photodetector for detecting light emitted by the electric field enhancement element when the electric field enhancement element is irradiated with the first laser light or the second laser light;
A reflection spectrum acquisition unit for acquiring a reflection spectrum based on a detection result of the photodetector when the electric field enhancement element is irradiated with the first laser beam;
Based on the reflection spectrum, a shift amount calculation unit for obtaining a shift amount of a resonance wavelength of surface plasmon resonance before and after the target substance is exposed to the electric field enhancing element;
A Raman spectrum acquisition unit that acquires a Raman spectrum based on a detection result of the photodetector when the second laser beam is irradiated onto the electric field enhancement element;
A peak intensity calculation unit for obtaining a peak intensity of a peak due to the target substance based on the Raman spectrum; a quantification unit for quantifying the target substance based on the shift amount and the peak intensity;
including.

  In the Raman spectroscopic device according to the present invention, the number of light emitting elements can be reduced.

In the Raman spectroscopic device according to the present invention,
The quantitative unit is
Based on the shift amount, the electric field enhancement element after the target substance is exposed to the square of the electric field enhancement intensity at the wavelength of the second laser light and the wavelength of the Raman scattered light caused by the target substance. Find the product of the square of the electric field enhancement of E _i ² × E _s ² ,
The number N of molecules of the target substance may be obtained based on the following formula (1).
However, in Formula (1),
I _SERS is the peak intensity,
I ₀ is the intensity of the second laser beam,
C is a constant.

  The Raman spectroscopic device according to the present invention can accurately quantify the target substance.

In the Raman spectroscopic device according to the present invention,
A storage unit that stores information on the correlation between the shift amount and the product may be included.

In the Raman spectroscopic device according to the present invention, the quantification unit stores the shift amount of the resonance wavelength of the surface plasmon resonance and the product E _i ² × E _s stored in the storage unit before and after exposing the target substance to the electric field enhancement element. ² can be used to quantify the target substance.

In the Raman spectroscopic device according to the present invention,
A correlation information acquisition unit that acquires information on the correlation between the shift amount and the product from an external storage device may be included.

In the Raman spectroscopic device according to the present invention, the quantification unit obtains the resonance wavelength shift amount of the surface plasmon resonance before and after the target substance is exposed to the electric field enhancement element and the product E _i ² × acquired by the correlation information acquisition unit. The target substance can be quantified using information on the correlation with E _s ² .

The electronic device according to the present invention is
A Raman spectroscopic device according to the present invention;
A computing unit that computes health and medical information based on detection information from the photodetector;
A storage unit for storing the health care information;
A display unit for displaying the health care information;
including.

  Since such an electronic device includes the Raman spectroscopic device according to the present invention, highly accurate medical information can be provided.

The functional block diagram of the Raman spectroscopy apparatus which concerns on this embodiment. The top view which shows typically the electric field enhancement element of the Raman spectroscopy apparatus which concerns on this embodiment. Sectional drawing which shows typically the electric field enhancing element of the Raman spectroscopic device which concerns on this embodiment. The graph which shows the reflectance with respect to a wavelength, and the electric field enhancement intensity in an electric field enhancement element. Raman spectrum of pyridine. Graph illustrating the shift amount of the resonance wavelength of surface plasmon resonance of the before and after exposing the target substance to the electric field amplification elements, a product E _i ² × E _s ^2, a correlation. Graph illustrating the shift amount of the resonance wavelength of surface plasmon resonance of the before and after exposing the target substance to the electric field enhancement device, and the electric field strength E _i, a correlation. Graph illustrating the shift amount of the resonance wavelength of surface plasmon resonance of the before and after exposing the target substance to the electric field enhancement device, and the electric field strength E _s, the correlation. The flowchart for demonstrating the measuring method which concerns on this embodiment. The functional block diagram of the Raman spectroscopy apparatus which concerns on the 1st modification of this embodiment. The functional block diagram of the Raman spectroscopy apparatus which concerns on the 2nd modification of this embodiment. The figure for demonstrating the specific structure of the Raman spectroscopy apparatus which concerns on this embodiment. 1 is a diagram schematically illustrating an electronic apparatus according to an embodiment. The graph which shows the relationship between the density _| concentration of pyridine, and intensity _| strength I _SERS . The graph which shows peak intensity | strength I _SERS of the Raman shift 1014cm < ^-1 > resulting from a pyridine. The graph which calculated | required the molecular number N of a pyridine.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. Raman Spectroscopic Device First, a Raman spectroscopic device according to this embodiment will be described with reference to the drawings. FIG. 1 is a functional block diagram of a Raman spectroscopic device 100 according to this embodiment. As shown in FIG. 1, the Raman spectroscopic device 100 includes a light source 10, an electric field enhancement element 20, a photodetector 30, a filter 40, an operation unit 50, a display unit 52, a storage unit 54, and a storage medium. 56 and a processing unit 60.

The light source 10 irradiates the electric field enhancing element 20 with white light L1 or laser light L2. The light source 10 includes a first light emitting element 12 that generates white light L1 and a second light emitting element 14 that generates laser light L2. The first light emitting element 12 is, for example, a white LED (Light
Emitting Diode). White light is, for example, light having a plurality of different wavelengths. The second light emitting element 14 is, for example, a semiconductor laser or a gas laser, and the first light L1 is laser light. The wavelength of the first light L1 is, for example, not less than 350 nm and not more than 1000 mn, and specifically 633 nm. In the illustrated example, the lights L1 and L2 enter the electric field enhancing element 20 through the half mirror 2.

  Lights L <b> 1 and L <b> 2 are incident on the electric field enhancing element 20. The electric field enhancing element 20 receives the lights L1 and L2 and emits light. The light emitted from the electric field enhancing element 20 is scattered light and includes, for example, reflected light reflected by the electric field enhancing element 20. Here, FIG. 2 is a plan view schematically showing the electric field enhancing element 20. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2 schematically showing the electric field enhancing element 20. As shown in FIGS. 2 and 3, the electric field enhancing element 20 includes a substrate 22 and a metal microstructure 24.

  The substrate 22 is, for example, a glass substrate, a silicon substrate, or a resin substrate. Although not shown, a metal layer provided on the substrate 22 and a dielectric layer provided on the metal layer are disposed between the substrate 22 and the metal microstructure 24. Good.

  The metal microstructure 24 is provided on the substrate 22. The shape of the metal microstructure 24 is not particularly limited, and examples thereof include a columnar shape, a particle shape, a prism, a sphere, and a spheroid. In the example shown in FIG. 3, the planar shape of the metal microstructure 24 is a circle. In a plan view, the size (for example, the diameter) of the metal microstructure 24 is equal to or less than the wavelength of the laser beam L2 irradiated to the electric field enhancing element 20. Specifically, the size of the metal microstructure 24 is not less than 10 nm and not more than 1 μm, and preferably not less than 40 nm and not more than 700 nm. The thickness of the metal microstructure 24 is, for example, not less than 1 nm and not more than 500 nm, preferably not less than 10 nm and not more than 100 nm.

For example, a plurality of metal microstructures 24 are provided. The number of metal microstructures 24 is not particularly limited. In the illustrated example, the shapes of the plurality of metal microstructures 24 are the same as each other, but may be different from each other. In the illustrated example, the plurality of metal microstructures 24 are provided periodically, but may not be provided periodically. The distance between the adjacent metal microstructures 24 is, for example, 1 nm or more and 500 nm or less.

  The material of the metal microstructure 24 is gold, silver, aluminum, or copper. Gold, silver, aluminum, and copper are metals that have a small imaginary part of dielectric constant in the ultraviolet to visible light region, and can enhance the electric field enhancement effect.

  The metal microstructure 24 is formed by, for example, a patterning method after forming a thin film by a vacuum deposition method, a sputtering method, or the like, a microcontact printing method, a nanoimprinting method, or the like.

  The metal microstructure 24 generates surface plasmon resonance (SPR) when irradiated with light. Specifically, the metal microstructure 24 generates localized plasmon resonance (LSPR). LSPR is a phenomenon in which, when light is incident on a metal structure having a wavelength equal to or less than the wavelength of light, free electrons existing in the metal collectively vibrate due to the electric field component of the light and induce a localized electric field outside. This localized electric field can enhance Raman scattered light. The enhancement of Raman scattered light by the electric field induced by SPR is referred to as an electric field enhancement effect. The intensity of Raman scattered light (SERS light) enhanced by SPR is proportional to the fourth power of the electric field enhanced by SPR.

  A sample (for example, a gas sample) containing a target substance to be detected is exposed to the metal microstructure 24. As a result, the target substance is adsorbed on the metal microstructure 24. The target substance is, for example, pyridine, aniline, toluene, ethyl alcohol, or methyl alcohol.

  When the electric field enhancing element 20 is irradiated with the laser light L2 in a state where the target substance is adsorbed on the metal microstructure 24, Rayleigh scattered light having the same wavelength as the laser light L2 and Raman scattered light having a wavelength different from the laser light L2. Occurs. The energy of the Raman scattered light corresponds to a specific vibration energy corresponding to the structure of the target substance. Therefore, the target substance can be specified by obtaining the Raman shift that is the difference between the wave number (frequency) of the Raman scattered light and the wave number of the laser light L2. Furthermore, the concentration of the target substance can be known from the Raman shift and the intensity.

  As shown in FIG. 1, the photodetector 30 detects light emitted from the electric field enhancement element 20 when the electric field enhancement element 20 is irradiated with white light L <b> 1 or laser light L <b> 2. That is, the photodetector 30 detects the light emitted by the electric field enhancing element 20 when the electric field enhancing element 20 is irradiated with the white light L1 or the laser light L2. In the illustrated example, two photodetectors 30 are provided. One light detector (first light detector) 30a detects light emitted by the electric field enhancing element 20 when the electric field enhancing element 20 is irradiated with the white light L1. The other photodetector (second photodetector) 30b detects light emitted by the electric field enhancing element 20 when the electric field enhancing element 20 is irradiated with the laser light L2. The photodetector 30 may include a CCD (Charge Coupled Device), a photomultiplier tube, a photodiode, an imaging plate, and the like.

For example, the filter 40 is provided between the electric field enhancing element 20 and the second photodetector 30b. When the electric field enhancing element 20 is irradiated with the laser light L2, the light emitted by the electric field enhancing element 20 enters the filter 40 before entering the second photodetector 30b. The second photodetector 30b detects the light that has passed through the filter 40. The filter 40 is, for example, a band stop filter. The filter 40 can remove Rayleigh scattered light having the same wavelength as the laser light L2. As shown in FIG. 1, the filter 40 is not provided between the electric field enhancing element 20 and the first photodetector 30a.

  The operation unit 50 performs a process of acquiring an operation signal corresponding to the operation by the user and sending the signal to the processing unit 60. The operation unit 50 is, for example, a button, a key, a touch panel display, a microphone, or the like.

  The display unit 52 displays the processing result of the processing unit 60 based on the display signal input from the processing unit 60. For example, the display unit 52 displays the processing result of the processing unit 60 in characters. The display unit 52 is, for example, an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube), a touch panel type display, or the like.

  The storage unit 54 stores programs, data, and the like for the processing unit 60 to perform various types of calculation processing and control processing. The storage unit 54 is further used as a work area of the processing unit 60. The operation signal input from the operation unit 50, the program and data read from the storage medium, and the calculation results executed by the processing unit 60 according to various programs. Etc. are temporarily stored. A database 55 is stored in the storage unit 54.

  In the database 55, data related to the target substance to be analyzed is registered. Specifically, the database 55 includes data for specifying (qualifying) the target substance from the Raman shift, and data for specifying (quantifying) the concentration of the target substance from the intensity of the Raman spectrum. Is registered.

  The processing unit 60 performs various types of calculation processing in accordance with programs stored in the storage unit 54 and programs stored in a storage medium. In the present embodiment, the processing unit 60 executes a program stored in the storage unit 54 to thereby obtain a reflection spectrum acquisition unit 61, a shift amount calculation unit 62, a Raman spectrum acquisition unit 63, and a peak intensity calculation unit. 64, a quantification unit 65, and a correlation information acquisition unit 66. The function of the processing unit 60 can be realized by hardware such as various processors (CPU, DSP, etc.), ASIC (gate array, etc.), and programs. Note that at least a part of the processing unit 60 may be realized by hardware (a dedicated circuit).

  The reflection spectrum acquisition unit 61 acquires a reflection spectrum (reflectance spectrum) based on the detection result of the first photodetector 30a when the electric field enhancing element 20 is irradiated with the white light L1. Specifically, the reflection spectrum acquisition unit 61 receives the signal output from the first photodetector 30a and acquires the reflection spectrum. The reflection spectrum acquisition unit 61 acquires, for example, a first reflection spectrum before the target substance is exposed to the electric field enhancement element 20, and then acquires a second reflection spectrum after the target substance is exposed to the electric field enhancement element 20. get.

  Here, FIG. 4 shows the result of the simulation showing the reflectance (reflection spectrum) with respect to the wavelength and the electric field enhancement intensity in the electric field enhancement element. As a simulation, an FDTD simulation was used. As the reflectance, a ratio between the intensity of light incident on the electric field enhancing element and the intensity of light reflected from the electric field enhancing element was obtained. As the electric field enhancement intensity, the ratio between the electric field of the incident light and the maximum value of the electric field induced on the surface of the metal microstructure by SPR was obtained.

In FIG. 4, the reflectance and electric field enhancement intensity before the target substance is exposed to the electric field enhancing element (before the target substance is adsorbed to the metal microstructure), and the target substance having a refractive index n of 1.3 are applied to the electric field enhancing element. Reflectivity and electric field enhancement intensity after exposure to the target (after the target substance is adsorbed to the metal microstructure), and reflectivity and electric field enhancement after the target substance having a refractive index n of 1.47 is exposed to the electric field enhancement element Degree. In the electric field enhancing element used in the simulation, the material of the metal microstructure was gold, the size of the metal microstructure in plan view was 96 nm, and the thickness of the metal microstructure was 30 nm.

  As shown in FIG. 4, the reflection spectrum is expressed as a wavelength on the horizontal axis and a reflectance on the vertical axis. The reflection spectrum has an absorption region as shown in FIG. The absorption region is a region where the reflection spectrum changes due to light absorption by SPR (specifically, LSPR), and specifically, a region where the reflectance of the reflection spectrum falls. In other words, when LSPR is generated by the irradiation of excitation light (incident light), absorption due to resonance occurs, the reflectance decreases, and an absorption region appears. The wavelength at the minimum point of the absorption region (the point at which the reflectance is minimum) is called the resonance wavelength of surface plasmon resonance. Since the electric field enhancement is stronger as the reflectance value is closer to zero, the reflectance can be used as an index of the electric field enhancement by SPR.

  Based on the reflection spectrum acquired by the reflection spectrum acquisition unit 61, the shift amount calculation unit 62 is a surface plasmon resonance resonance wavelength (hereinafter simply referred to as “resonance wavelength”) before and after the target substance is exposed to the electric field enhancement element 20. Shift amount Δλ (hereinafter also simply referred to as “shift amount Δλ”). Specifically, the shift amount calculation unit 62 reads the wavelength at which the reflectance is minimized from the first reflection spectrum acquired by the reflection spectrum acquisition unit 61, and the first amount before the target substance is exposed to the electric field enhancement element 20. One resonance wavelength is acquired. Further, the shift amount calculation unit 62 reads the wavelength at which the reflectance is minimized from the second reflection spectrum acquired by the reflection spectrum acquisition unit 61, and the second resonance wavelength after the target substance is exposed to the electric field enhancement element 20. To get. Then, the shift amount Δλ of the resonance wavelength is obtained from the difference between the first resonance wavelength and the second resonance wavelength. As shown in FIG. 4, when the target substance is exposed to the electric field enhancing element, the resonance wavelength shifts to the long wavelength side. For example, when a target substance having a refractive index n = 1.3 is exposed, the shift amount of the resonance wavelength is Δλ1, and when a target substance having a refractive index n = 1.47 is exposed, the shift amount of the resonance wavelength. Is Δλ2, which is larger than Δλ1.

  The first resonance wavelength before the target substance is exposed may be stored in the storage unit 54 in advance. Then, the shift amount calculation unit 62 uses the second resonance wavelength after the target substance acquired from the second reflection spectrum is exposed and the first resonance wavelength stored in the storage unit 54 in advance to use the resonance wavelength. May be obtained.

  The Raman spectrum acquisition unit 63 acquires a Raman spectrum based on the detection result of the second photodetector 30b when the electric field enhancing element 20 is irradiated with the laser light L2. Specifically, the Raman spectrum acquisition unit 63 receives a signal output from the second photodetector 30b when the electric field enhancing element 20 after the target substance is exposed to the laser beam L2, and receives the signal. Acquire a Raman spectrum. For example, the Raman spectrum acquisition unit 63 acquires a Raman spectrum after the shift amount is calculated by the shift amount calculation unit 62.

  Here, FIG. 5 is a Raman spectrum (SERS spectrum) of pyridine as a target substance. In the experiment for obtaining the Raman spectrum shown in FIG. 5, the material of the metal microstructure of the electric field enhancement element is gold, the size of the metal microstructure in plan view is 96 nm, and the thickness of the metal microstructure is 30 nm. As shown in FIG. 5, the Raman spectrum is expressed as a Raman shift on the horizontal axis and the intensity (SERS intensity) on the vertical axis.

  Based on the Raman spectrum acquired by the Raman spectrum acquisition unit 63, the peak intensity calculation unit 64 obtains the peak intensity of the peak due to the target substance. Hereinafter, the processing of the peak intensity calculation unit 64 will be specifically described.

First, the peak intensity calculation unit 64 acquires the maximum intensity I _MAX between the first ranges S1. The first range S1 is preset according to the target substance and is stored in the storage unit 54.
When the user selects pyridine as the substance displayed on the display unit 52 via the operation unit 50, for example, the first range S1 is 1008 cm ^{−1 to} 1016 cm ⁻¹ .

Next, the peak intensity calculation unit 64 obtains the average intensity of the baseline around the Raman shift (for example, 1014 cm ^{−1 in} the case of pyridine) where the intensity is I _MAX . Specifically, the peak intensity calculation unit 64 acquires the average intensity of the second range S2 and the average intensity of the third range S3, and calculates the average intensity I _AVE of both values. The Raman shift in the second range S2 is smaller than the Raman shift in the first range S1, and the Raman shift in the third range S3 is larger than the Raman shift in the first range S1. The second range S2 and the third range S3 are set in advance according to the target substance, and are stored in the storage unit 54. When the user selects pyridine, for example, the second range S2 is 950 cm ^{−1 to} 980 cm ⁻¹ , and the third range S3 is 1050 cm ^{−1 to} 1080 cm ⁻¹ .

Next, the peak intensity calculator 64 subtracts the baseline average intensity I _AVE from the intensity I _MAX to obtain the peak intensity I _SERS of the peak caused by the target substance.

In the above example, the peak intensity I _SERS was obtained by subtracting the baseline average intensity I _AVE from the intensity I _MAX , but the peak intensity calculation unit 64 is based on the intensity I _MAX and the baseline average intensity I _AVE . Then, the peak area of the peak caused by the target substance (for example, the area of the hatched region shown in FIG. 5) may be obtained, and the peak area may be used as the peak intensity I _SERS . The peak area is determined using, for example, the half width method.

The quantification unit 65 quantifies the target substance based on the shift amount Δλ obtained by the shift amount calculation unit 62 and the peak intensity I _SERS obtained by the peak intensity calculation unit 64. Hereinafter, the process of the fixed_quantity | quantitative_assay part 65 is demonstrated concretely.

First, based on the shift amount Δλ obtained by the shift amount calculation unit 62, the quantification unit 65 squares the electric field enhancement intensity E _i at the wavelength of the laser light L2 in the electric field enhancement element 20 after the target substance is exposed. When obtains the square and the degree of electric field enhancement E _s of the wavelength of the Raman scattered light due to the target substance, the product E _i ² × E _s ^2. For example, as illustrated in FIG. 6, the storage unit 54 stores information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² . With reference to the information, the shift amount calculation unit 62 can obtain the product E _i ² × E _s ² from the shift amount Δλ.

Information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² is information specific to the target substance. When the user selects, for example, pyridine as the substance displayed on the display unit 52 via the operation unit 50, the quantification unit 65 uses the shift amount Δλ corresponding to pyridine (according to the selected substance) and the product E _i. from ² × information correlated with the _E ^{s 2,} determining the product _E ^{i 2} × _E ^{s 2.}

Here, a procedure for acquiring information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² stored in the storage unit 54 will be described. First, as shown in FIG. 4, for example, the concentration (refractive index) of the target substance is changed to obtain the reflectance and the electric field enhancement with respect to the wavelength. Next, the shift amount Δλ of the resonance wavelength is obtained from the obtained reflectance. Next, as shown in FIG. 7, the relationship between the obtained shift amount Δλ and the electric field enhancement intensity E _i at the wavelength incident on the electric field enhancing element 20 (the wavelength of the laser light L2, for example, 633 nm) is obtained by simulation. . Next, as shown in FIG. 8, the obtained shift amount Δλ and the electric field enhancement Es at the wavelength of Raman scattered light caused by the target substance (for example, 676 nm caused by Raman shift 1014 cm ⁻¹ in the case of pyridine), Is obtained by simulation. Then, it is possible from the electric field enhancement E _i and the electric field enhancement E _s, as shown in FIG. 6, to acquire the information of the correlation between the shift amount Δλ and product E _i ² × E _s ^2. In FIG. 4, wavelengths 633 nm and 676 nm are indicated by broken lines.

Note that the information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² is a value unique to the electric field enhancing element 20. Therefore, for example, when the electric field enhancement element 20 is consumed and replaced with a new electric field enhancement element 20, information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² is acquired for the new electric field enhancement element 20. It is preferable to correct it.

  Next, the quantification unit 65 obtains the number of molecules of the target substance (for example, the number of molecules adsorbed on the hot site) N based on the following formula (1).

However, in the formula (1), E _i is the degree of electric field enhancement at the wavelength of the laser beam L2, E _s is the wavelength of the Raman scattered light due to the target substance, I _SERS is an peak intensity , I ₀ is the intensity of the laser beam L2, and C is a constant.

In the formula (1), the peak intensity I _SERS is obtained by the peak intensity calculator 64. The product E _i ² × E _s ² is obtained by the quantification unit 65. I ₀ is stored in the storage unit 54 in advance, for example. C is a proportionality constant determined by the detection sensitivity of the Raman spectroscopic device 100 and the ease of scattering of the Raman scattered light per target substance. C can be obtained from the slope of a calibration curve indicating the relationship between the number of molecules N and the peak intensity I _SERS , with I ₀ being constant. Further, C is based on the following formula (2), and constant I _0, can also be determined and molecular number N, from the slope of the calibration curve showing the relationship between the Raman scattering intensity I _Raman.

  As described above, the quantification unit 65 can quantitate the target substance.

In the above description, the example in which the correlation information (see FIG. 6) between the shift amount Δλ and the product E _i ² × E _s ² is stored in the storage unit 54 has been described. In the storage unit 54, information on the correlation between the shift amount Δλ and the electric field enhancement E _i (see FIG. 7) and information on the correlation between the shift amount Δλ and the electric field enhancement E _s (see FIG. 8). ) May be stored. In this case, the quantification section 65 refers to the information of the correlation between the shift amount Δλ and degree of electric field enhancement E _i, determine the degree of electric field enhancement E _i, the information of the correlation between the shift amount Δλ and degree of electric field enhancement E _s Referring to determine the degree of electric field enhancement E _s. And based on Formula (1), a target substance can be quantified.

The correlation information acquisition unit 66 acquires information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² from an external storage device. The correlation information acquisition unit 66 may acquire correlation information between the shift amount Δλ and the product E _i ² × E _s ² from an external storage device via a network, or may store external information via a storage medium. You may acquire from an apparatus. In this case, information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² may not be stored in the storage unit 54.

  The Raman spectroscopic device 100 has the following features, for example.

In the Raman spectroscopic device 100, based on the reflection spectrum acquired by the reflection spectrum acquisition unit 61, a shift amount calculation for obtaining a shift amount Δλ of the resonance wavelength of surface plasmon resonance before and after the target substance is exposed to the electric field enhancing element 20. Unit 62, peak intensity calculation unit 64 for obtaining peak intensity I _SERS of the peak due to the target substance based on the Raman spectrum acquired by Raman spectrum acquisition unit 63, and shift amount obtained by shift amount calculation unit 62 And a quantification unit 65 that quantifies the target substance based on Δλ and the peak intensity I _SERS obtained by the peak intensity calculation unit 64. Therefore, the Raman spectrometer 100, by determining the shift amount [Delta] [lambda], the electric field enhancement E _i in an electric field enhancement device 20 after exposure of the target _substance, in consideration of the E _s, can be quantified target substance. Thereby, in the Raman spectroscopic device 100, the target substance can be accurately quantified. That is, the Raman spectroscopic device 100 can quantify the target substance with high accuracy.

Here, the peak of the electric field enhancement intensity shifts according to the refractive index around the metal microstructure, that is, the concentration of the target substance and the number of molecules (see, for example, FIG. 4). Therefore, the target substance may not be accurately quantified without considering the electric field enhancement intensity in the electric field enhancing element after the target substance is exposed. In Raman spectroscopy apparatus 100, the electric field enhancement E _i, the variation of E _s is corrected, it is possible to accurately quantify the target substance.

  In the Raman spectroscopic device 100, the light source 10 includes a first light emitting element 12 that generates white light L1 and a second light emitting element 14 that generates laser light L2. Therefore, the light source 10 can irradiate the electric field enhancing element 20 with the white light L1 or the laser light L2.

The Raman spectroscopic device 100 includes a storage unit 54 that stores information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² . Therefore, the quantification unit 65 can quantitate the target substance using information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² stored in the storage unit 54.

The Raman spectroscopic device 100 includes a correlation information acquisition unit 66 that acquires information on the correlation between the shift amount Δλ and the product E _i ² × E _s ² from an external storage device. Therefore, the quantification unit 65 can quantitate the target substance using the correlation information between the shift amount Δλ and the product E _i ² × E _s ² acquired by the correlation information acquisition unit 66.

The electric field enhancing element has a high Q factor (Quality Factor). The Q value of resonance is a value obtained by the following formula (3), which indicates the sharpness of resonance, and indicates the height of the light confinement effect. Here, ω ₀ , ω ₁ , and ω ₂ are the frequency at the resonance peak, the frequency at which the resonance energy is half the peak at the low energy side of the resonance peak, and the resonance energy at the peak at the high energy side of the resonance peak, respectively. The frequency which becomes a half value is shown (that is, ω ₂ −ω ₁ is a half value width).

The resonance Q value is a dimensionless number representing the state of vibration based on SPR. When light of a certain wavelength is irradiated onto the metal microstructure, electronic vibration is induced on the other surface of the metal microstructure based on SPR. However, this electronic vibration is attenuated by collision between electrons or scattering of electrons and phonons. By changing this attenuation term, the Q value changes. In general, after the vibration is started, if the vibration continues for a long time, the Q value is said to be high. The higher the Q value, the stronger the localized electric field induced by electronic vibration. Therefore, it can be said that the electric field enhancing element is suitable for SERS. On the other hand, the higher the Q value, the stronger the wavelength dependency, suggesting that the intensity increases greatly when the wavelength shifts. Therefore, the electric field enhancing element 20 of the Raman spectroscopic device 100 tends to increase or decrease greatly when the wavelength shifts. As described above, the electric field enhancing element E _i in the electric field enhancing element 20 after the target substance is exposed as described above. , taking into account the E _s, is possible to quantify the target substance, it is particularly effective.

2. Measurement Method Next, a measurement method according to the present embodiment will be described with reference to the drawings. FIG. 9 is a flowchart for explaining the measurement method according to the present embodiment. Hereinafter, a measurement method using the Raman spectroscopic device 100 will be described as a measurement method according to the present embodiment.

  For example, when the user requests a process for quantifying the target substance via the operation unit 50, the processing unit 60 receives the operation signal from the operation unit 50 and starts the process. For example, the user inputs the type of the target substance when requesting the processing.

  First, the processing unit 60 performs a process for acquiring the first reflection spectrum (step S102). Specifically, the processing unit 60 receives an operation signal from the operation unit 50 and outputs a signal for irradiating the first light emitting element 12 with the white light L1. The first light emitting element 12 receives the signal from the processing unit 60 and irradiates the electric field enhancing element 20 with the white light L1. The first photodetector 30 a detects light emitted from the electric field enhancing element 20. The reflection spectrum acquisition unit 61 acquires the first reflection spectrum from the intensity of the light detected by the first photodetector 30a. Thereafter, the processing unit 60 outputs a signal for displaying the first reflection spectrum on the display unit 52, for example.

  Next, the user exposes the target substance to the surface of the electric field enhancing element 20 (step S104). Specifically, the user operates the suction mechanism (see “4. Specific Configuration of Raman Spectrometer” described later) provided in the flow path passing near the surface of the electric field enhancing element 20 to enhance the electric field. A target substance is exposed to the surface of the element 20.

  Next, the process part 60 performs the process for acquiring a 2nd reflection spectrum (step S106). Specifically, the processing unit 60 receives an operation signal from the operation unit 50 and outputs a signal for irradiating the first light emitting element 12 with the white light L1. The first light emitting element 12 receives the signal from the processing unit 60 and irradiates the electric field enhancing element 20 to which the target substance is exposed with the white light L1. The first photodetector 30a detects light emitted from the electric field enhancing element 20 to which the target substance is exposed. The reflection spectrum acquisition unit 61 acquires a second reflection spectrum from the intensity of light detected by the first photodetector 30a. Thereafter, the processing unit 60 outputs a signal for displaying the second reflection spectrum on the display unit 52, for example.

  Next, the shift amount calculation unit 62 shifts the resonance wavelength of the SPR before and after exposing the target substance to the electric field enhancing element 20 based on the first reflection spectrum and the second reflection spectrum acquired by the reflection spectrum acquisition unit 61. An amount Δλ is obtained (step S108). Thereafter, the processing unit 60 outputs, for example, a signal for displaying the shift amount Δλ on the display unit 52.

  Next, the processing unit 60 performs a process for acquiring a Raman spectrum (step S110). Specifically, the processing unit 60 receives an operation signal from the operation unit 50 and outputs a signal for irradiating the second light emitting element 14 with the laser light L2. The second light emitting element 14 receives the signal from the processing unit 60 and irradiates the electric field enhancing element 20 with the laser light L2. The second photodetector 30b detects the light emitted from the electric field enhancing element 20. The Raman spectrum acquisition unit 63 acquires a Raman spectrum from the intensity of light detected by the second photodetector 30b. Thereafter, the processing unit 60 outputs a signal for displaying a Raman spectrum on the display unit 52, for example.

Next, the peak intensity calculation unit 64 obtains the peak intensity I _SERS of the peak caused by the target substance based on the Raman spectrum acquired by the Raman spectrum acquisition unit 63 (step S112). Thereafter, the processing unit 60 outputs a signal for displaying the peak intensity I _SERS on the display unit 52, for example.

Next, the quantification unit 65 quantifies the target substance based on the shift amount Δλ obtained by the shift amount calculation unit 62 and the peak intensity I _SERS obtained by the peak intensity calculation unit 64 (step S114). Specifically, the quantification unit 65 obtains a product E _i ² × E _s ² based on the shift amount Δλ, and obtains the number N of molecules of the target substance based on the above formula (1). Then, the processing unit 60 outputs a signal for displaying the number N of molecules of the target substance on the display unit 52, and ends the processing.

  Although not shown, steps S110 and S112 may be performed before steps S106 and S108.

  The measurement method according to the present embodiment has the following features, for example.

In the measurement method according to the present embodiment, the step of irradiating the electric field enhancing element 20 with the white light L1 to acquire the first reflection spectrum, the step of exposing the target substance to the surface of the electric field enhancing element 20, and the target substance Irradiating the electric field enhancing element 20 exposed to the white light L1 to obtain the second reflection spectrum, and exposing the target substance to the electric field enhancing element 20 based on the first reflection spectrum and the second reflection spectrum. The step of obtaining the shift amount Δλ before and after, the step of irradiating the electric field enhancing element 20 with the laser light L2 to acquire the Raman spectrum, and the peak intensity I _SERS of the peak caused by the target substance based on the Raman spectrum And a step of quantifying the target substance based on the shift amount Δλ and the peak intensity I _SERS . Therefore, in the measuring method according to the present embodiment, by determining the shift amount [Delta] [lambda], the electric field enhancement E _i in an electric field enhancement device 20 after exposure of the target _substance, in consideration of the E _s, quantitating the target substance Can do. Thereby, in the measuring method according to the present embodiment, the target substance can be accurately quantified.

3. 3. Modification of Raman spectroscopic device 3.1. First Modification Next, a Raman spectroscopic device according to a first modification of the present embodiment will be described with reference to the drawings. FIG. 10 is a functional block diagram of a Raman spectroscopic device 200 according to a first modification of the present embodiment. Hereinafter, in the Raman spectroscopic device 200, members having the same functions as the constituent members of the Raman spectroscopic device 100 described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the Raman spectroscopic device 100 described above, as shown in FIG. 1, two photodetectors 30 are provided. On the other hand, in the Raman spectroscopic device 200, as shown in FIG. 10, one photodetector 30 is provided.

  In the Raman spectroscopic device 200, by providing two half mirrors 2, light emitted from the electric field enhancing element 20 when irradiated with the white light L1 and from the electric field enhancing element 20 when irradiated with the laser light L2. The emitted light can be detected by a single photodetector.

  In the Raman spectroscopic device 200, when the white light L1 is emitted from the light source 10, the filter 40 is disposed so as not to be positioned between the electric field enhancing element 20 and the photodetector 30, and the laser light L2 is emitted from the light source 10. When this is done, the filter 40 is placed between the electric field enhancement element 20 and the photodetector 30. In the example shown in FIG. 10, a state in which the filter 40 is located between the electric field enhancing element 20 and the photodetector 30 is illustrated.

The movement of the position of the filter 40 may be manually performed by the user when the laser light L2 is emitted from the light source 10, or a drive unit for moving the filter 40 is provided, and the drive from the processing unit 60 is performed. The filter 40 may be moved by outputting a signal. The filter 40 is always located between the electric field enhancing element 20 and the photodetector 30, transmits white light L1, and functions as a band stop filter only when irradiated with the laser light L2. May be.

  In the Raman spectroscopic device 200, the reflection spectrum acquisition unit 61 acquires a reflection spectrum based on the detection result of the photodetector 30 when the electric field enhancing element 20 is irradiated with the white light L1. The Raman spectrum acquisition unit 63 acquires a reflection spectrum based on the detection result of the photodetector 30 when the electric field enhancing element 20 is irradiated with the laser light L2.

  In the Raman spectroscopic device 200, one photodetector 30 is provided. Therefore, in the Raman spectroscopic device 200, the number of photodetectors 30 can be reduced as compared with the Raman spectroscopic device 100.

3.2. Second Modified Example Next, a Raman spectroscopic device according to a second modified example of the present embodiment will be described with reference to the drawings. FIG. 11 is a functional block diagram of a Raman spectroscopic device 300 according to a second modification of the present embodiment. Hereinafter, in the Raman spectroscopic device 300, members having the same functions as the constituent members of the Raman spectroscopic devices 100 and 200 described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the Raman spectroscopic device 100 described above, as shown in FIG. 1, the light source 10 has the first light emitting element 12 that generates the white light L1 and the second light emitting element 14 that generates the laser light L2. . On the other hand, in the Raman spectroscopic device 300, the light source 10 is a wavelength tunable laser light source and irradiates the first laser light L1 whose wavelength changes with time or the second laser light L2 whose wavelength does not change with time. . Specifically, the wavelength tunable laser light source 10 includes a third light emitting element 16 that irradiates the first laser light L1 or the second laser light L2.

In the Raman spectroscopic device 300, as in the Raman spectroscopic device 200, one photodetector 30 is provided. The reflection spectrum acquisition unit 61 acquires a reflection spectrum based on the detection result of the photodetector 30 when the electric field enhancing element 20 is irradiated with the first laser light L1. The Raman spectrum is acquired based on the detection result of the photodetector 30 when the second laser beam L2 is irradiated onto the electric field enhancing element 20. Based on the shift amount Δλ, the quantification unit 65 squares the electric field enhancement E _i at the wavelength of the second laser light L2 in the electric field enhancement element 20 after exposing the target substance, and the Raman caused by the target substance. square and of the electric field enhancement E _s at the wavelength of the scattered light, the product E _i ² × E _s ² calculated based on the equation (1), determine the number of molecules N of the target substance. In this case, in the above formula (1), I ₀ is the intensity of the second laser beam L2.

  In the Raman spectroscopic device 300, when acquiring the reflection spectrum, for example, the processing unit 60 receives an operation signal from the operation unit 50 and irradiates the first laser beam L1 to the third light emitting element 16. Is output. When acquiring the Raman spectrum, for example, the processing unit 60 receives an operation signal from the operation unit 50 and outputs a signal for irradiating the second laser beam L2 to the third light emitting element 16.

  The Raman spectroscopic device 300 includes the tunable laser light source 10 that irradiates the first laser light L1 whose wavelength changes with time or the second laser light L2 whose wavelength does not change with time. Therefore, in the Raman spectroscopic device 300, it is not necessary to provide two light emitting elements as in the Raman spectroscopic device 100, and the number of light emitting elements can be reduced.

4). Specific Configuration of Raman Spectroscopic Device Next, a specific configuration of the Raman spectroscopic device according to the present embodiment will be described with reference to the drawings. Hereinafter, a specific configuration of the Raman spectroscopic device 100 will be described as a specific configuration of the detection apparatus according to the present embodiment. FIG. 12 is a diagram for explaining a specific configuration of the Raman spectroscopic device 100.

  As shown in FIG. 12, the Raman spectroscopic device 100 includes a gas sample holding unit 120, a detection unit 130, a control unit 140, and a casing 150 that houses the detection unit 130 and the control unit 140.

  The gas sample holding unit 120 includes an electric field enhancing element 20, a cover 122 that covers the electric field enhancing element 20, a suction channel 124, and a discharge channel 126. The detection unit 130 includes a light source 10, lenses 4 a, 4 b, 4 c, 4 d, a half mirror 2, a photodetector 30, and a filter 40. The control unit 140 includes, for example, an operation unit 50, a display unit 52, a storage unit 54, and a processing unit 60. As shown in FIG. 12, the control unit 140 may be electrically connected to a connection unit 146 for connecting to the outside.

  In the Raman spectroscopic device 100, when the suction mechanism 127 provided in the discharge channel 126 is operated, the inside of the suction channel 124 and the discharge channel 126 becomes negative pressure, and the gas sample containing the target substance from the suction port 123. Is sucked. The suction port 123 is provided with a dust removal filter 125, which can remove relatively large dust, some water vapor, and the like. The gas sample passes through the suction channel 124 and the discharge channel 126 and is discharged from the discharge port 128. The gas sample contacts the electric field enhancing element 20 when passing through such a path.

  The shape of the suction flow path 124 and the discharge flow path 126 is such that light from the outside does not enter the electric field enhancing element 20. Thereby, since the light which becomes noise other than a Raman scattered light does not enter, the S / N ratio of a signal can be improved. The material constituting the flow paths 124 and 126 is, for example, a material or color that hardly reflects light.

  The shape of the suction channel 124 and the discharge channel 126 is such that the fluid resistance to the gas sample is reduced. Thereby, highly sensitive detection becomes possible. For example, retention of the gas sample at the corners can be eliminated by making the shapes of the channels 124 and 126 as smooth as possible by eliminating the corners. As the suction mechanism 127, for example, a fan motor or a pump having a static pressure and an air volume corresponding to the flow path resistance is used.

  In the Raman spectroscopic device 100, the light emitted from the light source 10 is collected by the lens 4a, and then enters the electric field enhancing element 20 via the half mirror 2 and the lens 4b. The light emitted from the electric field enhancing element 20 reaches the photodetector 30 through the lens 4b, the half mirror 2, and the lenses 4c and 4d. The light emitted from the electric field enhancement element 20 by being irradiated with the laser light L2 passes through the filter 40 and reaches the photodetector 30 (specifically, the second photodetector 30b).

  The light reaching the light detector 30 is received by the light receiving element 34 via the spectroscope 32 of the light detector 30. The spectroscope 32 is formed of, for example, an etalon using Fabry-Perot resonance, and the pass wavelength band can be made variable. For example, a photodiode is used as the light receiving element 34.

5. Next, an electronic device 400 according to the present embodiment will be described with reference to the drawings. FIG.
FIG. 3 is a diagram schematically illustrating the electronic apparatus 400 according to the present embodiment. The electronic apparatus 400 can include a Raman spectroscopic device according to the present invention. Hereinafter, an example including the Raman spectroscopic device 100 as a Raman spectroscopic device according to the present invention will be described.

  As shown in FIG. 13, the electronic device 400 includes a Raman spectroscopic device 100, a calculation unit 410 that calculates health information based on detection information from the photodetector 30, and a storage unit 420 that stores health information. A display unit 430 for displaying health and medical information.

  The calculation unit 410 is, for example, a personal computer or a personal digital assistant (PDA), and receives detection information (signals or the like) transmitted from the photodetector 30. The calculation unit 410 calculates health care information based on the detection information from the photodetector 30. The calculated health and medical information is stored in the storage unit 420.

  The storage unit 420 is, for example, a semiconductor memory, a hard disk drive, or the like, and may be configured integrally with the calculation unit 410. The health care information stored in the storage unit 420 is sent to the display unit 430.

  The display unit 430 includes, for example, a display board (liquid crystal monitor or the like), a printer, a light emitter, a speaker, and the like. The display unit 430 displays or issues information based on the health care information calculated by the calculation unit 410 so that the user can recognize the contents.

  The health information includes the presence or amount of at least one biological substance selected from bacteria, viruses, proteins, nucleic acids, and antigens / antibodies, or at least one compound selected from inorganic molecules and organic molecules. Information about can be included.

  The electronic apparatus 400 includes the Raman spectroscopic device 100. Therefore, the electronic device 400 can provide highly accurate health care information.

6). Experimental Example An experimental example is shown below to describe the present invention more specifically. The present invention is not limited by the following experimental examples.

6.1. First Experimental Example In a gas sample containing pyridine as a target substance, the concentration of pyridine was varied, and the Raman shift intensity I _SERS caused by pyridine was examined. In this experiment, I _SERS was calculated using the following formula (4).

However, in Formula (4), N is the number of pyridine molecules, and E (λ _in ) is the electric field enhancement factor at the wavelength of laser light (incident light for obtaining a Raman spectrum) in the electric field enhancement element. E (λ _scat ) is the electric field enhancement intensity at the wavelength of Raman scattered light caused by pyridine in the electric field enhancing element, and I ₀ is the wavelength of the laser beam. In this experiment, the material of the metal microstructure of the electric field enhancement element was gold, the size of the metal microstructure in plan view was 96 nm, and the thickness of the metal microstructure was 30 nm.

FIG. 14 is a graph showing the relationship between the concentration of pyridine and the intensity I _SERS . Specifically, FIG. 14 is a plot (uncorrected) obtained by substituting the electric field enhancement before exposure of pyridine to the electric field enhancement element as the electric field enhancement E (λ _in ) and E (λ _scat ). As in the Raman spectroscopic device 100, a plot obtained by irradiating the electric field enhancing element with white light to obtain the resonance wavelength shift amount Δλ and substituting the electric field enhancement after exposure of pyridine from the shift amount Δλ (correction) A).

As shown in FIG. 14, it was found that with correction, the linearity was better than without correction, and the relationship of I _SERS against density could be plotted appropriately.

6.2. Second Experimental Example The intensity I _{SERS of the} Raman shift caused by pyridine was examined by changing the refractive index of the carrier gas carrying pyridine as the target substance. The number N of pyridine molecules was constant, and the refractive index n1 of the carrier gas G1 was smaller than the refractive index n2 of the carrier gas G2 (n1 <n2). Carrier gases G1 and G2 containing pyridine were exposed to an electric field enhancement element, and the electric field enhancement element was irradiated with white light as in the Raman spectroscopic device 100 to determine the resonance wavelength shift amount Δλ. When the carrier gas G1 was used, the shift amount was Δλ = 17 nm. When carrier gas G2 was used, the shift amount was Δλ = 37 nm. The material, size, and thickness of the metal microstructure of the electric field enhancing element used in this experimental example are the same as those of the electric field enhancing element used in the first experimental example.

  The electric field enhancement at the wavelength of the laser beam (incident light for acquiring the Raman spectrum) and the electric field enhancement at the wavelength of the Raman scattered light caused by pyridine are respectively determined according to the shift amount Δλ by FDTD simulation. FIG. 7 and FIG. 8 described above.

As in the Raman spectroscopic device 100, the electric field enhancing element to which the carrier gases G1 and G2 were exposed was irradiated with laser light to obtain a Raman spectrum, and the peak intensity I _SERS was obtained. FIG. 15 is a graph showing the peak intensity I _SERS at a Raman shift of 1014 cm ⁻¹ due to pyridine.

FIG. 16 is a graph obtained by dividing the peak intensity I _SERS of FIG. 15 by the product E (λ _in ) ² × E (λ _scat ) ² shown in the above formula (4) to determine the number N of pyridine molecules. In FIG. 16, “with correction” is obtained by substituting the product E (λ _in ) ² × E (λ _scat ) ² after exposure of pyridine from the shift amount Δλ obtained as described above. Without correction, the shift amount Δλ is not taken into account, and the product E (λ _in ) ² × E (λ _scat ) ² before pyridine is exposed is substituted.

As shown in FIG. 16, although the number of pyridine molecules is constant, in the case of no correction, due to the difference in peak intensity I _SERS , the carrier gas G1 has a pyridine molecule number N compared to the carrier gas G2. The result that there was much is obtained. On the other hand, in the case of correction, it was found that the difference in the number of molecules N between the carrier gas G1 and the carrier gas G2 was small, and the number of molecules N was almost the same.

  The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

2 ... half mirror, 4a, 4b, 4c, 4d ... lens, 10 ... light source, 12 ... first light emitting element, 14 ... second light emitting element, 16 ... third light emitting element, 20 ... electric field enhancing element, 22 ... substrate, 24 ... Metal microstructure, 30 ... Photo detector, 30a ... First photo detector, 30b ... Second photo detector, 32 ... Spectroscope, 34 ... Light receiving element, 40 ... Filter, 50 ... Operation unit, 52 ... Display unit 54 ... Storage unit 55 ... Database 60 ... Processing unit 61 ... Reflection spectrum acquisition unit 62 ... Shift amount calculation unit 63 ... Raman spectrum acquisition unit 64 ... Peak intensity calculation unit 65 ... Determination unit 66 ... correlation information acquisition unit, 100 ... Raman spectroscopic device, 120 ... gas sample holding unit, 122 ... cover, 123 ... suction port, 124 ... suction channel, 125 ... dust removal filter, 126 ... discharge channel, 127 ... suction mechanism , 128 ... Outlet, 130 ... detector, 140 ... controller, 146 ... connection section, 150 ... housing, 200, 300 ... Raman spectrometer, 400 ... electronic device, 410 ... operation unit, 420 ... storage unit, 430 ... display unit

Claims (12)

An electric field enhancing element to which the target substance is exposed;
A light source that emits white light and laser light;
A photodetector for detecting light emitted by the electric field enhancing element when the electric field enhancing element is irradiated with the white light and the laser light;
Based on the detection result of the photodetector when the electric field enhancing element is irradiated with the white light, a reflection spectrum acquisition unit that acquires a reflection spectrum;
Based on the reflection spectrum, a shift amount calculation unit for obtaining a shift amount of a resonance wavelength of surface plasmon resonance before and after the target substance is exposed to the electric field enhancing element;
Based on the detection result of the photodetector when the electric field enhancing element is irradiated with the laser light, a Raman spectrum acquisition unit that acquires a Raman spectrum;
Based on the Raman spectrum, a peak intensity calculation unit for obtaining a peak intensity of a peak caused by the target substance;
A quantification unit for quantifying the target substance based on the shift amount and the peak intensity;
Including a Raman spectroscopic apparatus. In claim 1,
The light source is
A first light emitting element for generating the white light;
A second light emitting element for generating the laser beam;
A Raman spectroscopic apparatus. In claim 1 or 2,
The quantitative unit is
Based on the shift amount, the electric field enhancement element after the target substance is exposed to the square of the electric field enhancement intensity at the wavelength of the laser light and the electric field at the wavelength of the Raman scattered light caused by the target substance. Find the product E _i ² × E _s ² of the square of the enhancement and
A Raman spectroscopic device for obtaining the number N of molecules of the target substance based on the following formula (1).
However, in Formula (1),
I _SERS is the peak intensity,
I ₀ is the intensity of the laser beam,
C is a constant. An electric field enhancing element to which the target substance is exposed;
A wavelength-tunable laser light source first laser beam, and the wavelength irradiates the second laser light does not change temporally wavelength changes with time,
A photodetector for detecting light emitted by the electric field enhancement element when the electric field enhancement element is irradiated with the first laser light and the second laser light;
A reflection spectrum acquisition unit for acquiring a reflection spectrum based on a detection result of the photodetector when the electric field enhancement element is irradiated with the first laser beam;
Based on the reflection spectrum, a shift amount calculation unit for obtaining a shift amount of a resonance wavelength of surface plasmon resonance before and after the target substance is exposed to the electric field enhancing element;
A Raman spectrum acquisition unit that acquires a Raman spectrum based on a detection result of the photodetector when the second laser beam is irradiated onto the electric field enhancement element;
Based on the Raman spectrum, a peak intensity calculation unit for obtaining a peak intensity of a peak caused by the target substance;
A quantification unit for quantifying the target substance based on the shift amount and the peak intensity;
Including a Raman spectroscopic apparatus. In claim 4,
The quantitative unit is
Based on the shift amount, the electric field enhancement element after the target substance is exposed to the square of the electric field enhancement intensity at the wavelength of the second laser light and the wavelength of the Raman scattered light caused by the target substance. Find the product of the square of the electric field enhancement of E _i ² × E _s ² ,
A Raman spectroscopic device for obtaining the number N of molecules of the target substance based on the following formula (1).
However, in Formula (1),
I _SERS is the peak intensity,
I ₀ is the intensity of the second laser beam,
C is a constant. In claim 3 or 5,
A Raman spectroscopic apparatus including a storage unit that stores information on a correlation between the shift amount and the product. In claim 3 or 5,
A Raman spectroscopic device including a correlation information acquisition unit that acquires information of correlation between the shift amount and the product from an external storage device. The Raman spectroscopic apparatus according to any one of claims 1 to 3 ,
A Raman spectroscopic apparatus, further comprising a half mirror that guides light emitted from the light source to the electric field enhancement element and guides light emitted from the electric field enhancement element to the photodetector. The Raman spectroscopic apparatus according to claim 8,
A Raman spectroscopic device comprising a plurality of the half mirrors. The Raman spectroscopic device according to any one of claims 1 to 9,
The Raman spectroscopic apparatus further comprising an optical filter that excludes Rayleigh scattered light from the light emitted from the electric field enhancing element. The Raman spectroscopic device according to any one of claims 1 to 10,
A computing unit that computes health and medical information based on detection information from the photodetector;
A storage unit for storing the health care information;
A display unit for displaying the health care information;
Including electronic equipment. The electronic device according to claim 11,
The health care information includes the presence or absence or amount of at least one compound selected from bacteria, viruses, proteins, nucleic acids, and antigens / antibodies, or at least one compound selected from inorganic molecules and organic molecules. Electronic equipment, including information about.