JP2016008866A - Sensor element, analyzer and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor element easily usable in the maximally close state to a designed structure by suppressing a structure change of a metal fine structure layer during storage.SOLUTION: A sensor element includes a substrate provided with a metal fine structure layer on one principal surface, and a cover provided on one principal surface of the substrate, and forming a cavity for storing the metal fine structure layer. When a pressure in the cavity is below a pressure out of the cavity, the cover is adsorbed onto the substrate, and when the pressure in the cavity is higher than the pressure out of the cavity, the cover is separated from the substrate.

Description

  The present invention relates to a sensor element, an analyzer, and an electronic device.

  In recent years, with respect to material sensing technology, demand for medical diagnosis, food inspection, and the like is increasing, and development of a small and high-speed sensing technology is required. 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 detection target molecule by detecting that the extinction wavelength by SPR shifts before and after the adsorption of the detection target molecule.

Further, as one of high-sensitivity spectroscopic techniques for detecting a low concentration substance, attention is focused on surface enhanced Raman scattering (SERS) using SPR. SERS is a phenomenon in which Raman scattered light is enhanced 10 ² to 10 ¹⁴ times on the surface of a nanometer-scale metal. When the target substance is adsorbed on this surface and irradiated with excitation light such as a laser, light with a wavelength slightly shifted from the wavelength of the excitation light (Raman scattered light) by the vibration energy of the substance (molecule) Is scattered. When this scattered light is spectrally processed, a spectrum (fingerprint spectrum) unique to the type of substance (molecular species) is obtained. By analyzing the position and shape of this fingerprint spectrum, it becomes possible to identify a substance with extremely high sensitivity. Thus, in SERS, strong scattered light can be observed by adsorbing a target substance on the surface of an electric field enhancing element having a nanometer-scale metal surface.

  For example, Patent Document 1 discloses a sample measuring device in which a plurality of electric field enhancing elements are arranged in a circle on a turntable in order to deal with a large number of samples. In such a device, an attempt is made to perform efficient measurement in a short time by driving (turning) the electric field intensifying element, which is in contact with a number of samples, to the position where the Raman scattering measurement is performed by driving the turntable. Has been.

JP 2013-007614 A

  The electric field enhancing element on the surface of which nanometer-scale metal (metal microstructure) is arranged has a structure such as the size, arrangement, and shape of the metal microstructure of the metal microstructure layer according to the target substance and measurement conditions. Designed, thereby providing a sensitive SERS measurement of the target substance.

However, when the structure of the metal microstructure layer is different from the structure designed according to the target substance and measurement conditions, it is not possible to perform good SERS measurement on the target substance that is the basis of the design. difficult. Furthermore, it has been found that the structure of the metal microstructure layer changes with storage and measurement. Specifically, the metal microstructure layer gradually or rapidly changes from a structure at the time of manufacture to a different structure depending on environmental conditions such as humidity, temperature, and composition of the exposed gas. Therefore, it may be difficult to measure the target substance with high sensitivity as designed, depending on the storage environment and usage situation of the electric field enhancing element.

  One of the objects according to some aspects of the present invention is to provide a sensor element that can be easily used in a state as close as possible to the designed structure, in which the change in the structure of the metal microstructure layer during storage is suppressed. It is to provide. Another object of some embodiments of the present invention is to provide an analyzer and electronic apparatus that can measure a target substance with high sensitivity using such a sensor element.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

  One aspect of the sensor element according to the present invention includes a substrate provided with a metal microstructure layer on one main surface, and a cavity provided on the one main surface of the substrate and accommodating the metal microstructure layer. Forming a cover, and when the pressure inside the cavity is less than the pressure outside the cavity, the cover adsorbs to the substrate, and when the pressure inside the cavity is equal to or higher than the pressure outside the cavity, The substrate and the cover are separated.

  In such a sensor element, since the metal microstructure layer is accommodated in the cavity and the metal microstructure layer is not exposed to the atmosphere outside the cavity, the change in the structure of the metal microstructure layer during storage is suppressed. Further, by reducing the pressure outside the cavity, the cover can be easily removed, and can be easily used in a state as close as possible to the designed structure.

  In the sensor element according to the present invention, the substrate and the cover may be separated when the pressure outside the cavity drops below the pressure inside the cavity.

  Such a sensor element can be easily used for measurement with a good metal microstructure layer.

  In the sensor element according to the present invention, when the pressure outside the cavity drops below the pressure inside the cavity in a state where the sensor element is installed in such an arrangement that the cover falls due to the action of gravity, The cover may be dropped from the substrate and separated.

  One aspect of the analyzer according to the present invention includes the above-described sensor element, a measurement cell that houses the sensor element, a decompression unit that decompresses the inside of the measurement cell, and a light source that irradiates the metal microstructure layer with excitation light. And a light detector that detects light emitted from the metal microstructure layer, and when the sensor element is installed in the measurement cell and the inside of the measurement cell is decompressed by the decompression means, The cover falls from the substrate and separates.

  Such an analyzer includes a sensor element in which a metal microstructure layer is accommodated in a cavity and the metal microstructure layer is not exposed to an atmosphere outside the cavity, and the cover of the sensor element can be easily removed during use. . This makes it possible to measure the target substance with high sensitivity.

  In the analyzer according to the present invention, a plurality of the sensor elements may be accommodated in the measurement cell, and the pressures of the cavities of the plurality of sensor elements may be different from each other.

  If it does in this way, each sensor element can be used for a measurement one by one by adjusting the pressure of a measurement cell. Further, before the measurement, the measurement cell is not opened, and a metal microstructure layer close to a plurality of designed structures can be easily used for the measurement.

  In the analysis apparatus according to the present invention, the sensor element is arranged in a first arrangement for separating the cover from the sensor element, and a second arrangement for irradiating the metal microstructure layer of the sensor element with the excitation light. You may have the switching mechanism switched to.

  In this way, it is possible to form a positional relationship in which no cover exists in the optical path between the light source, the metal microstructure layer, and the photodetector. Thereby, a measurement can be performed more easily.

  One aspect of the electronic apparatus according to the present invention includes the above-described analyzer, a calculation unit that calculates health and medical information based on detection information from the photodetector, a storage unit that stores the health and medical information, A display unit for displaying health care information.

  According to such an electronic device, the target substance can be easily detected with high sensitivity, and highly accurate health care information can be provided.

The schematic diagram of the cross section of the principal part of the sensor element which concerns on embodiment. The schematic diagram of the cross section of the principal part of the sensor element which concerns on embodiment. The schematic diagram of the cross section of the principal part of the sensor element which concerns on embodiment. The schematic diagram of the cross section of the principal part of the electric field enhancement element which concerns on embodiment. The schematic diagram which looked at the principal part of the electric field enhancement element which concerns on embodiment planarly. The graph which shows the result of having investigated the relationship between the lifetime of a metal microstructure layer, and humidity. The SEM observation result of a metal microstructure layer. The schematic diagram of the principal part of the analyzer which concerns on embodiment. The schematic diagram which looked at the principal part of the element holder which concerns on a modification planarly. The schematic diagram of the cross section of the principal part of the element holder which concerns on a modification. The schematic diagram of the principal part of the analyzer which concerns on embodiment. 1 is a diagram schematically illustrating an electronic apparatus according to an embodiment.

  Several embodiments of the present invention will be described below. Embodiment described below demonstrates an example of this invention. The present invention is not limited to the following embodiments, and includes various modified embodiments that are implemented within a range that does not change the gist of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

1. Sensor Element A sensor element 100 according to this embodiment, which is an embodiment of the present invention, is provided with a substrate 10, a metal microstructure layer 20 provided on the substrate 10, and a metal microstructure layer 20 provided on the substrate 10. And a cover 40 that forms a cavity 30 that accommodates. Hereinafter, it demonstrates, referring drawings. FIG. 1 is a schematic diagram of a cross section of a main part of the sensor element 100 of the present embodiment. FIG. 2 is a diagram schematically illustrating the separation of the substrate 10 and the cover 40 of the sensor element 100 of the present embodiment. FIG. 3 is a diagram schematically showing how a target substance is measured by the sensor element 100 of the present embodiment.

1.1. Substrate The sensor element 100 has a substrate 10. The substrate 10 is not particularly limited as long as it has a plate shape having a front surface and a back surface. Further, the substrate 10 may be a flat plate-like shape having a shape along a plane, a plate-like shape having a shape along a curved surface, or a shape obtained by combining these shapes. Examples of the substrate 10 include a glass substrate, a silicon substrate, a resin substrate, a metal plate, and the like, and may be a laminate of a plurality of layers made of different materials. The substrate 10 has a surface on the side where a metal microstructure layer 20 described later is disposed. That is, the metal microstructure layer 20 is provided on one main surface of the substrate 10. In this specification, the surface of the substrate 10 on the side where the metal microstructure layer 20 is disposed may be referred to as a “sensor surface” or “one main surface”.

  The shape of the sensor surface of the substrate 10 is not particularly limited as long as the cavity 30 can be formed by the cover 40 described later, and may be a flat surface, a curved surface, or a combination surface thereof. In the example of FIGS. 1 to 3, the substrate 10 has a flat plate shape and the sensor surface has a planar shape.

  The metal microstructure layer 20 may be directly formed on the substrate 10. In this case, it becomes the structure containing the board | substrate 10 and the metal microstructure layer 20, and it can be considered that the electric field enhancement element 50 is comprised. In this case, the material of the sensor surface of the substrate 10 is preferably a dielectric. Meanwhile, the metal microstructure layer 20 is provided by forming the metal microstructure layer 20 on another substrate (for example, an element substrate 51 described later) and the like and placing the other substrate on the substrate 10. Also good. In this case, the electric field enhancing element 50 is configured by a configuration including another substrate and the metal microstructure layer 20 formed on the other substrate, and the electric field enhancing element 50 is disposed on the substrate 10. Thus, it can be considered that the metal microstructure layer 20 is provided on one main surface of the substrate 10.

  The substrate 10 functions as a base (support) for the sensor element 100. The size of the substrate 10 is not particularly limited, but is at least larger than the size of the metal microstructure layer 20. Accordingly, since the user can handle the sensor element 100 (the metal microstructure layer 20) by handling the substrate 10, the operability of the sensor element 100 is improved by the substrate 10.

  The material of the substrate 10 may be optically transparent or opaque. 1 to 3, when the substrate 10 is made of an optically transparent material and the metal microstructure layer 20 is directly formed on the sensor surface of the substrate 10, the sensor surface Since the metal microstructure layer 20 can be optically exposed from the opposite surface (back surface), excitation light is applied to the metal microstructure layer 20 from the back surface side, and Raman scattered light or the like is irradiated from the back surface side. It can be observed (see FIG. 3). Thereby, the freedom degree of arrangement | positioning of the measurement cell of an apparatus which uses the sensor element 100, or the structure (light source etc.) of an optical system can be raised, for example. Further, when the material of the substrate 10 is transparent, the metal microstructure layer 20 in the cavity 30 can be observed from the substrate 10 side in a state where a cover 40 described later is an opaque material and is in close contact with the substrate 10. For example, the reflectance of the metal microstructure layer 20 can be measured while maintaining the airtightness of the cavity 30, and the quality can be checked. When the substrate 10 is made of an optically opaque material, a layer of an optically opaque material (such as a metal layer 52 described later) is provided between the substrate 10 and the metal microstructure layer 20, or the substrate 10 includes an optically opaque layer such as a metal layer, the excitation light is irradiated onto the metal microstructure layer 20 from the sensor surface side, and Raman scattered light or the like can be observed from the sensor surface side. it can.

  The substrate 10 is deformed even if the cavity 30 formed when the cover 40 (described later) is placed in close contact with each other is depressurized and subjected to stress due to a differential pressure from the pressure outside the cavity 30 (for example, atmospheric pressure). The structure and material are selected so that the strength is sufficient to prevent damage. Further, the substrate 10 may be provided with appropriate recesses, through holes, and the like.

1.2. Cover and Cavity The sensor element 100 has a cover 40. The cover 40 is disposed in contact with the sensor surface (one main surface) of the substrate 10. When the cover 40 is disposed in contact with the substrate 10, the cavity 30 is formed by the substrate 10 and the cover 40. The shape of the cavity 30 is arbitrary as long as the metal microstructure layer 20 can be disposed inside. In the example of FIGS. 1 to 3, a cover 40 formed in a cup shape is placed in contact with the flat substrate 10, and a cavity 30 is formed inside. Although not shown, a recess (depression) may be formed on the sensor surface of the substrate 10, and a flat cover 40 may be disposed so as to cover the recess. In this case as well, the metal microstructure layer 20 is accommodated therein. A cavity 30 can be formed. In the illustrated example, the entire cover 40 is formed with a curved surface (part of the shape of the surface of the spheroid), but the shape of the cover 40 is not limited to this, and the cover 40 may be formed with a flat surface. Alternatively, the shape may be a combination of a plane and a curved surface, such as a part of a cylindrical shape. Further, if the entire cover 40 is formed in a curved surface and has a shape with no corners (for example, a hemispherical shape or a dome shape), stress concentration due to a pressing force caused by a pressure difference between the inside and outside of the cavity 30 is alleviated. Is more preferable because it is difficult to collapse.

  Since the metal microstructure layer 20 is desirably easily adsorbed with the target substance, the sensor surface of the substrate 10 is formed in a flat plate shape as shown in the figure, or a convex portion or the like is provided on the substrate 10 to provide the metal microstructure layer 20. It is more desirable that the protrusion protrudes from the sensor surface of the substrate 10.

  The cover 40 can form a sealed cavity 30 together with the substrate 10. The cover 40 may have a joining member 42 such as packing in order to make the airtightness of the cavity 30 better. In the example of FIGS. 1 to 3, packing is provided as a joining member 42 at a portion of the cover 40 that contacts the substrate 10. In this example, the joining member 42 is integrally provided on the cover 40 side, but may be provided integrally on the substrate 10 side, or may be provided on both. When the bonding member 42 is provided, the bonding member 42 is formed of a material (soft material such as adhesiveness) that does not impair the detachability of the substrate 10 and the cover 40. Examples of the joining member 42 include gaskets made of various resin packings, metals, ceramics, and the like.

  The cavity 30 formed when the cover 40 is disposed in contact with the substrate 10 can have a pressure inside thereof lower than a pressure outside the cavity 30. Thereby, a differential pressure (pressure difference) is generated inside and outside the cavity 30, and a pressing force that allows the substrate 10 and the cover 40 to adhere to each other can be obtained.

  As described above, the function of the cover 40 is to form the cavity 30 that accommodates the metal microstructure layer 20. However, the cover 40 allows the metal microstructure layer 20 to come into contact with an external gas such as the atmosphere or the outside. It is possible to prevent mechanical contact with the member.

  Although it does not specifically limit as a material of the cover 40, Glass, a silicon | silicone, resin, a metal etc. are mentioned, The laminated body and mixture of the layer from which several materials differ may be sufficient. When a metal is adopted as the material of the cover 40, for example, SUS or aluminum may be used. Further, when the material of the cover 40 is transparent, the metal microstructure layer 20 in the cavity 30 can be observed in a state where the cover 40 is in close contact with the substrate 10, for example, the reflectance of the metal microstructure layer 20, etc. Can be measured with the cavity 30 maintained, and quality can be checked.

  The cover 40 is deformed or damaged even when the cavity 30 formed when the cover 40 is disposed in close contact with the substrate 10 is depressurized and subjected to stress due to a pressure difference from the pressure outside the cavity 30 (for example, atmospheric pressure). The structure and material are selected so that the strength does not occur. For example, the cover 40 has a hemispherical shape with a diameter of about 0.1 cm to 5 cm and a thickness of about 0.05 mm to 25 mm.

1.3. Attaching / detaching the cover The cover 40 can be disposed in contact with the substrate 10, and can be brought into close contact with one main surface of the substrate 10 by making the internal pressure of the cavity 30 lower than the external pressure. For example, in a space where the pressure is reduced to a pressure lower than the atmospheric pressure, the cover 40 is placed on the substrate 10, and the pressure in the external space is returned to the atmospheric pressure, so that the pressure inside the cavity 30 is less than the external pressure. Can be formed. Further, for example, when the external pressure of the cavity 30 is lowered while being placed on the substrate 10, the gas in the cavity 30 is exhausted from the gap between the substrate 10 and the cover 40, and the pressure in the cavity 30 is also reduced. it can. After that, if the external pressure of the cavity 30 is returned, a state in which the pressure inside the cavity 30 is less than the external pressure can be formed. In the latter example, the weight of the cover 40 and the joining member 42 can be adjusted appropriately.

  When the pressure inside the cavity 30 is smaller than the outside pressure, and the cover 40 is arranged in a posture such that the cover 40 is positioned away from the substrate 10 by gravity, the cover 10 is fixed. If the pressing force due to the pressure difference between the inside and outside of the cavity 30 is larger than the force that drops due to its own weight, the cover 40 does not fall. On the other hand, when the pressure inside the cavity 30 is the same as or larger than the external pressure, the cover 40 is positioned in a direction away from the substrate 10 by gravity in a state where the substrate 10 is fixed. In the case where the cover 40 is arranged in a proper posture, the cover 40 falls due to the weight of the cover 40 as shown in FIG. The weight (self-weight) of the cover 40 is not particularly limited, but is set in consideration of the balance with the pressing force generated by the pressure difference inside and outside the cavity 30.

  As the force used for separating the cover 40 from the substrate 10, in addition to the above-described gravity, a magnetic force, a centrifugal force, and the like can be given if they are not contacted, and a mechanical force can be given if they are contacted. When the cover 40 is adsorbed to the substrate 10 in a state where the pressure inside the cavity 30 is smaller than the outside pressure, the pressure outside the cavity 30 is reduced so that the pressure inside the cavity 30 is outside the pressure. The cover 40 is separated from the substrate 10 without performing mechanical operation by applying gravity, magnetic force, centrifugal force or the like to the cover 40 as appropriate so that the pressure is equal to or greater than the external pressure. The metal microstructure layer 20 can be exposed.

  Note that when the cover 40 is separated, the pressure outside the cavity 30 is set to be the same as or lower than the pressure inside the cavity 30. The pressure is higher than the maximum degree of vacuum (minimum pressure) that can be reached in the measurement cell 210. When the cover 40 is adsorbed, the pressure in the cavity 30 is not particularly limited and can be set as appropriate as long as the pressure satisfies such a condition.

1.4. Metal Microstructure Layer The sensor element 100 according to the present embodiment includes a metal microstructure layer 20. The metal microstructure layer 20 may be formed directly on the substrate 10 or may be formed through another configuration such as a dielectric layer included in the substrate 10. Moreover, the metal microstructure layer 20 may be provided on the dielectric of the substrate 10 or an appropriate chip (element substrate 51 or the like). That is, the metal microstructure layer 20 is provided on one main surface of the substrate 10.

  The position where the metal microstructure layer 20 is arranged in the cavity 30 is not particularly limited, but when the cover 40 is separated, the metal microstructure layer 20 is arranged so that the cover 40 does not contact the metal microstructure layer 20. Is preferred.

  Hereinafter, an aspect in which the metal microstructure layer 20 is provided in the electric field enhancement element 50 and the metal field microstructure element 20 is disposed in the cavity 30 by providing the electric field enhancement element 50 on the substrate 10 will be described.

The electric field enhancing element 50 is not particularly limited as long as it can generate surface plasmon resonance (SPR) on the surface to which the target substance is adsorbed and irradiated with excitation light. An example of such a surface is a metal microstructure layer 20, for example, a surface in which metal nanoparticles are randomly or regularly arranged, and excitation light is emitted in a state where a target substance is adsorbed on the surface. When irradiated, a mode in which light (Raman scattered light) having a wavelength shifted from the wavelength of the excitation light is scattered by the amount of vibration energy of the target substance. Such scattering is surface enhanced Raman scattering (SERS), and Raman scattered light is enhanced by 10 ² to 10 ¹⁴ times. By spectrally processing this SERS light, a spectrum (fingerprint spectrum) unique to the type (molecular species) of the target substance can be obtained with high sensitivity.

  Hereinafter, as an embodiment of the electric field enhancement element, an electric field enhancement element 50 including metal particles 54 and a metal layer 52 as an example of the metal microstructure layer 20 on the surface will be described. Note that the metal layer 52 is an effective configuration when using propagation type surface plasmons in order to obtain an enhanced electric field, and is not an essential configuration. Further, when the substrate 10 is transparent and the metal layer 52 is not present, the metal microstructure layer 20 can be observed from the substrate 10 side, and quality check and the like can be facilitated.

  FIG. 4 is a schematic diagram of a cross section of the electric field enhancing element 50. FIG. 5 is a plan view of two modes of the electric field enhancing element 50 (viewed from the thickness direction of the metal layer 52) and a cross-sectional view thereof. 5A-1 corresponds to FIG. 5A-2, and the section taken along line II-II in FIG. 5B-1 corresponds to FIG. 5B-2. . The electric field enhancing element 50 of this embodiment includes a metal layer 52, a dielectric layer 53, and a metal microstructure layer 20.

1.4.1. Metal Layer The electric field enhancing element 50 of this embodiment has a metal layer 52. The metal layer 52 is not particularly limited as long as it provides a metal surface that does not transmit light, and may be, for example, a film, a plate, a layer, or a film. The metal layer 52 may be provided on the element substrate 51. The element substrate 51 in this case is not particularly limited, but a substrate that does not easily affect the propagation type surface plasmon excited by the metal layer 52 is preferable. Examples of the element substrate 51 include a glass substrate, a silicon substrate, and a resin substrate. The shape of the surface on which the metal layer 52 of the element substrate 51 is provided is not particularly limited. When a predetermined structure is formed on the surface of the metal layer 52, it may have a surface corresponding to the structure. When the surface of the metal layer 52 is a plane, the surface of the corresponding portion is a plane. Also good. In the example of FIG. 4, a layered metal layer 52 is provided on the surface (plane) of the element substrate 51.

  In the present specification, in the electric field enhancing element 50, the thickness direction of the metal layer 52 may be referred to as a thickness direction, a height direction, or the like. In the present embodiment, the thickness direction of the metal layer 52 coincides with the thickness direction of a dielectric layer 53 and a metal microstructure layer 20 described later. When the metal layer 52 is provided on the surface of the element substrate 51, the normal direction of the surface of the element substrate 51 may be referred to as a thickness direction, a thickness direction, or a height direction. Furthermore, when viewed from the element substrate 51, the direction on the metal layer 52 side may be expressed as “up” or “up”, and the opposite direction may be expressed as “down” or “down”.

  In addition, in this specification, for example, the expression “the member B is provided on the member A” includes the case where the member B is provided on the member A and another member or the member A on the member A. And the case where the member B is disposed through the space.

Furthermore, the words “upper”, “lower”, etc. are not intended to be in a vertical relationship depending on the installation state of the electric field enhancement element, but are in a state where the element substrate exists below regardless of the installation state of the electric field enhancement element. This is a word intended for the vertical relationship when viewed in (when the field of view is taken so that the substrate comes down). Therefore, for example, if it is seen that the direction in which gravity acts is downward, even if the electric field enhancing element is installed so that the element substrate is above and the metal layer is below, The meaning of having a metal layer is that the field of view is selected so that the element substrate is positioned below (that is, in this case, the direction in which gravity acts is upward), and literally above the element substrate. It will be understood that the metal layer is located.

  The metal layer 52 can be formed, for example, by a technique such as vapor deposition, sputtering, casting, or machining. When the metal layer 52 is provided on the element substrate 51 in a thin film shape, it may be provided on the entire upper surface of the element substrate 51 or may be provided on a part of the element substrate 51. The thickness of the metal layer 52 is not particularly limited, and can be, for example, 10 nm to 1 mm, preferably 20 nm to 100 μm, more preferably 30 nm to 1 μm.

  The metal layer 52 is a metal in which an electric field applied by incident light (excitation light) and an electric field in which the polarization induced by the electric field oscillates in an opposite phase exists, that is, when a specific electric field is applied. In addition, the real part of the dielectric function has a negative value (has a negative dielectric constant) and the dielectric constant of the imaginary part can have a dielectric constant smaller than the absolute value of the dielectric constant of the real part. Preferably, it is configured. Examples of metals that can have such a dielectric constant in the visible light region include silver, gold, aluminum, copper, platinum, and alloys thereof. Further, the surface (end surface in the thickness direction) of the metal layer 52 may or may not be a specific crystal plane. Further, the metal layer 52 may be formed to the outside of the dielectric layer 53 in a plan view.

  The metal layer 52 may have a function of generating a propagation surface plasmon (PSP) in the electric field enhancing element 50. Under certain conditions, when light enters the metal layer 52, propagation-type surface plasmons are generated near the surface of the metal layer 52 (end surface in the thickness direction). In this specification, the quantum of vibration in which the vibration of electric charges near the surface of the metal layer 52 and the electromagnetic wave are combined may be referred to as surface plasmon polariton (SPP). When propagating surface plasmons are generated in such a metal layer 52, they may interact with localized surface plasmons (LSP) generated in the metal microstructure layer 20 described later.

1.4.2. Dielectric Layer The electric field enhancing element 50 of the present embodiment includes a dielectric layer 53 that electrically separates the metal layer 52 and the metal microstructure layer 20 (metal particles 54). The dielectric layer 53 is provided on the metal layer 52 as shown in FIG. Thereby, the metal layer 52 and the metal particle 54 contained in the metal microstructure layer 20 can be separated. The dielectric layer 53 can have the shape of a film, layer or film.

The dielectric layer 53 only needs to have a positive dielectric constant, and can be formed of, for example, SiO ₂ , Al ₂ O ₃ , TiO ₂ , polymer, ITO (Indium Tin Oxide), or the like. The dielectric layer 53 may be composed of a plurality of layers made of different materials. Among these, the material of the dielectric layer 53 is more preferably SiO ₂ . If it does in this way, when measuring a sample using incident light (excitation light) with a wavelength of 400 nm or more, it can make it easy to strengthen both incident light (excitation light) and Raman scattering light.

  The thickness of the dielectric layer 53 is designed in consideration of the wavelength of Raman scattered light when incident light (excitation light) having a specific wavelength irradiated on the electric field enhancing element 50 is incident. The dielectric layer 53 can be formed by, for example, techniques such as vapor deposition, sputtering, CVD, and various coatings. The dielectric layer 53 may be provided on the entire surface of the metal layer 52 or may be provided on a part of the surface of the metal layer 52. The dielectric layer 53 is provided at least under the metal microstructure layer 20 and may also be provided at a position where the metal microstructure layer 20 does not exist.

The thickness of the dielectric layer 53 is not particularly limited, and can be, for example, 10 nm to 2000 nm, preferably 20 nm to 500 nm, more preferably 20 nm to 300 nm. Light can be propagated in the dielectric layer 53 (plane direction: a direction parallel to the dielectric layer 53). Further, the dielectric layer 53 can propagate the propagation type surface plasmon (PSP) generated in the vicinity of the interface between the dielectric layer 53 and the metal layer 52 in the dielectric layer 53 (plane direction). Further, when the metal microstructure layer 20 is regarded as one layer, the metal layer 52 and the metal microstructure layer 20 can be regarded as a resonator having a structure in which light is reflected at both ends. , Can function as an optical path of the resonator. In such a resonator, superposition of incident light (excitation light) and reflected light can be caused. The thickness of the dielectric layer 53 is set so that the antinodes of the standing wave generated by superimposing the incident light (excitation light) and the reflected light are near the center of the metal microstructure layer 20 in the thickness direction. As a result, the strength of the LSP generated in the metal microstructure layer 20 can be further increased. In consideration of such points, the thickness of the dielectric layer 53 can also be set. In this case, for example, the thickness of the dielectric layer 53 is set when the wavelength of incident light (excitation light) is 633 nm. Although the thickness may be 230 nm, the thickness of the dielectric layer 53 is not limited to this.

1.4.3. Metal Microstructure Layer The metal microstructure layer 20 is provided on the dielectric layer 53. In plan view, the metal microstructure layer 20 is formed on a part or all of the region in which the dielectric layer 53 is formed. The metal microstructure layer 20 includes metal particles 54. In the illustrated example, the metal particles 54 have a particulate structure, but the metal particles 54 are not limited to such an embodiment. The number, size (dimension), shape, arrangement, and the like of the metal particles 54 included in the metal microstructure layer 20 are not particularly limited. The metal microstructure layer 20 may include a gas (space), a dielectric, and the like in addition to the metal particles 54.

  The metal microstructure layer 20 is defined as a portion between the upper surface of the dielectric layer 53 and the surface in contact with the upper end of the metal particle 54 on the side away from the dielectric layer 53. For example, the upper and lower surfaces of the metal microstructure layer 20 are virtual surfaces when the metal microstructure layer 20 includes metal particles 54 and gas (space). The gas (space) arrange | positioned at the side of the metal particle 54 shall also be included.

  The planar shape of the metal microstructure layer 20 is not particularly limited, and may be an arbitrary shape such as a rectangle, a polygon, a circle, an ellipse, or the like. Further, when the planar shape of the metal microstructure layer 20 is similar to the shape of the irradiation region of the incident light (excitation light), the energy of the incident light (excitation light) is more efficiently used for electric field enhancement. There are cases where it is possible.

  If the metal particles 54 included in the metal microstructure layer 20 can generate localized surface plasmons by irradiation with incident light (excitation light), the number, size (dimension), shape, arrangement, etc. There is no particular limitation. FIG. 4 shows an example of the metal particles 54 included in the metal microstructure layer 20 as a particulate microstructure (metal particles). 5A-1 and 5A-2, the metal microstructure layer 20 has a stripe shape in which a plurality of metal particles 54 are arranged at a predetermined pitch in a predetermined direction in a plan view. It has become. That is, in this example, in the metal microstructure layer 20, the metal particles 54 are arranged in a grating shape (stripe shape) in plan view. Further, in the example shown in FIGS. 5B-1 and 5B-2, the metal fine structure layer 20 includes a metal fine structure row in which a plurality of metal particles 54 are arranged at a predetermined pitch in a predetermined direction in a plan view. And a plurality of metal microstructure rows are arranged at a predetermined pitch in a direction intersecting the predetermined direction (orthogonal direction in the figure). That is, in this example, the metal microstructure layer 20 has the metal particles 54 arranged in a lattice shape in a plan view.

  When the metal microstructure layer 20 is composed of particles or stripe-shaped metal particles 54, the number of the metal particles 54 may be plural, preferably 10 or more, more preferably 100 or more. In the example of FIG. 4, a plurality of metal particles 54 having the same shape are provided, but metal particles 54 having different shapes may be provided. For example, stripe-shaped metal particles 54 and particle-shaped metal particles may be provided. The particles 54 may be mixed.

  The metal particles 54 are provided away from the metal layer 52 in the thickness direction due to the presence of the dielectric layer 53. The metal particles 54 are disposed on the metal layer 52 via the dielectric layer 53. In the example of FIG. 3, the dielectric layer 53 is provided on the metal layer 52 and the metal particles 54 are formed thereon. However, even if the dielectric layer 53 is not layered, the metal layer 52 and the metal particles 54 may be spaced apart from each other in the thickness direction. Furthermore, although not shown, when the metal particles 54 are disposed on the dielectric layer 53, an adhesion layer may be interposed. Examples of the material for the adhesion layer include gold, copper, aluminum, palladium, nickel, platinum, molybdenum, chromium, titanium, or alloys or composites thereof, titanium oxide, and tungsten oxide.

  The shape of the metal particles 54 is not particularly limited. For example, in the case of a particle-like structure, when projected in the thickness direction of the metal layer 52 or the dielectric layer 53 (in plan view from the thickness direction) ) It can be circular, elliptical, polygonal, indeterminate, or a combination thereof, and even when projected in a direction perpendicular to the thickness direction, it can be circular, elliptical, polygonal, indefinite or It can be a combined shape. In the example of FIG. 3, the metal particles 54 are drawn in a cylindrical shape having a central axis in the thickness direction of the dielectric layer 53, but the shape of the metal particles 54 is not limited to this, for example, a prismatic shape , Elliptical columnar shape, hemispherical shape, spherical shape, cone shape, frustum shape and the like.

  The size T in the height direction of the metal particles 54 (thickness direction of the dielectric layer 53) refers to the length of a section in which the metal particles 54 can be cut by a plane perpendicular to the height direction. It can be. The size in the first direction orthogonal to the height direction of the metal particles 54 refers to the length of a section in which the metal particles 54 can be cut by a plane perpendicular to the first direction, and is 5 nm or more and 300 nm or less. Can do. For example, when the shape of the metal particle 54 is a cylinder having the height direction as the central axis, the size of the metal particle 54 in the height direction (the height of the cylinder) is 1 nm or more and 300 nm or less, preferably 2 nm or more. The thickness can be 100 nm or less, more preferably 3 nm to 50 nm, and still more preferably 4 nm to 40 nm. Further, when the shape of the metal particles 54 is a cylinder having the height direction as the central axis, the size of the metal particles 54 (diameter of the bottom surface of the cylinder) is 10 nm to 300 nm, preferably 20 nm to 200 nm, more preferably. May be 25 nm or more and 180 nm or less.

  The shape and material of the metal particles 54 are arbitrary as long as localized surface plasmon (LSP) can be generated by irradiation with incident light (excitation light). Examples of materials that can generate localized surface plasmons by light in the vicinity of visible light include gold, silver, aluminum, copper, platinum, palladium, nickel, and alloys thereof. Among these, the material of the metal particles 54 is more preferably Au or Ag. By selecting such a material, a stronger LSP can be obtained and the electric field enhancement of the entire device can be increased.

  The metal particles 54 can be formed by, for example, a patterning method after forming a thin film by sputtering, vapor deposition, or the like, a microcontact printing method, a nanoimprinting method, or the like. The metal particles 54 may be formed by a lithography method or the like in which a resist coated on a substrate is exposed by electron beam drawing or the like, a metal thin film is formed by sputtering, vapor deposition, or the like, and then the resist is removed and patterned. it can.

  Furthermore, the metal particles 54 can also be formed by an interference exposure method. That is, exposure for pattern formation can be performed by using interference fringes of laser light. Further, according to this method, multiple exposure and multi-beam exposure are possible, and the metal particles 54 having a periodic pattern can be formed very easily. For example, when a striped pattern is formed, it can be formed by exposing a laser beam interference fringe to a resist or the like. In the case of forming a two-dimensional lattice pattern, it can be formed by exposing the resist or the like simultaneously or batchwise so that the interference fringes of the laser beam intersect. According to this method, the apparatus configuration can be reduced in scale as compared with electron beam drawing, and a large number of electric field enhancing elements 50 can be more efficiently manufactured as necessary.

  The metal particles 54 have a function of generating localized surface plasmons (LSP) in the electric field enhancing element 50 of the present embodiment. By irradiating the metal particles 54 with incident light (excitation light) under specific conditions, localized surface plasmons can be generated around the metal particles 54. The wavelength of the incident light (excitation light), the dielectric layer so that the localized surface plasmon generated in the metal particle 54 can interact with the propagating surface plasmon generated in the vicinity of the interface between the metal layer 52 and the dielectric layer 53. The thickness of 53, the arrangement of the metal particles 54, and the like may be set.

  Since the electric field enhancing element 50 illustrated here has the metal layer 52, incident light (excitation light) is irradiated from the metal microstructure layer 20 side. Incident light (excitation light) is irradiated with incident light (excitation light) through various interactions such as diffraction, refraction, and reflection with the metal microstructure layer 20, the dielectric layer 53, and the metal layer 52. Plasmon resonance is generated in and near the region, and a high electric field enhancement effect can be shown. In the case where the metal layer 52 is not provided, excitation light can be irradiated from the element substrate 51 side.

  In the electric field enhancing element 50 exemplified above, a very large enhanced electric field is formed in the vicinity of the metal particles 54 of the metal microstructure layer 20 by irradiation of incident light (excitation light). Therefore, by irradiating incident light (excitation light) with the target substance adsorbed (attached, contacted) to the metal particles 54 of the metal microstructure layer 20 of the electric field enhancing element 50, incident light (excitation light) and Both Raman scattered light by the target substance can be greatly amplified. Note that the periodic structure of the metal fine structure layer 20 may or may not be recognized visually by a visually repetitive period when observed under a microscope or the like.

1.5. Changes in the metal microstructure layer A typical model for estimating the lifetime of the metal microstructure layer 20 is the Reich-Hakim Model. Such a model is represented by the following formula (1).

t _s = A · exp {−B (T _s + RH)} (1)
Here t _s is the life of the metal fine structure layer 20, T _s is the temperature of the environment, RH is the environmental humidity, A and B are constants determined experimentally. According to this equation, it is understood that it is possible to extend the life of the metal fine structure layer 20 by lowering the T _s or RH. FIG. 6 shows the lifetime of the metal microstructure layer 20 when the temperature and humidity obtained by original research are changed (in the case of a detection apparatus using surface-enhanced Raman spectroscopy). It can be seen that the lifetime of the metal microstructure layer 20 is extended as the temperature and humidity are lowered. For this reason, for example, it will be understood that the lifetime of the metal microstructure layer 20 can be extended as the humidity of the gas contacting the metal microstructure layer 20 is lower and / or the temperature at which the gas is installed is lower. For example, at room temperature of 20 ° C. and humidity of 60%, the lifetime of the metal microstructure layer 20 can be read as 3.2 days from FIG. 6, but at a temperature of 20 ° C. and humidity of 20%, the metal microstructure layer 20 The lifetime can be read as 7.0 days.

  FIG. 7 shows a part of the metal microstructure layer 20 stored in an environment (a) at a temperature of 23 ° C. and a humidity of 54% (a) and an environment (b) of a temperature of 23 ° C. and a humidity of 20% (SEM). It is the result observed in. In the metal microstructure layer 20 of FIG. 7, silver (Ag) particles (metal particles) are regularly arranged on a silicon oxide film. 7 (a) and 7 (b) have the same structure immediately after fabrication, but the structure (a) stored at a humidity of 54% changes its shape over time while it is stored at a humidity of 20%. It can be seen that the structure (b) maintains the structure immediately after the production even 14 days after the production. Thus, it can be seen that reducing the humidity around the metal microstructure layer 20 has the effect of extending the life. Therefore, when manufacturing the sensor element 100 of this embodiment, if the humidity of the gas inside the cavity 30 is about 20%, it can be seen that a life of 14 days or longer can be expected.

  On the other hand, when the volume and temperature do not change, the amount of water vapor contained in the gas is the gas equation of state (P · V = n · R · T (P: pressure, V: volume, n: amount of gaseous substance, T: temperature, R: gas constant)), it is understood that it is proportional to the pressure. Therefore, in the sensor element 100 of the present embodiment, when the cover 40 is brought into close contact with the substrate 10, the pressure in the cavity 30 is reduced by reducing the pressure from the state in which a gas having a humidity of 60% exists in the cavity 30 at normal temperature and normal pressure. When lowering the pressure, the humidity in the cavity 30 can be reduced to 20% by reducing the pressure to about 1/3 (about 33.8 kPa). After that, by returning the pressure outside the cavity 30 to normal pressure, the cover 40 is brought into close contact with the substrate 10 to form the cavity 30 sealed with a gas having a humidity of 20%. Therefore, the sensor element 100 of this embodiment when the cavity 30 is formed in this way can be expected to have a life of 14 days or longer.

1.6. Operational Effect In the sensor element 100 of the present embodiment, when the metal microstructure layer 20 is accommodated in the cavity 30 and the cavity 30 is sealed, the metal microstructure layer 20 is not exposed to the atmosphere outside the cavity 30. Changes in the structure of the metal microstructure layer 20 during storage are suppressed. Further, by reducing the pressure outside the cavity 30, the cover 40 can be easily removed, and can be easily used in a state as close as possible to the designed structure. Furthermore, the sensor element 100 of the present embodiment can reduce the pressure outside the cavity 30 to be equal to or lower than the pressure inside the cavity 30 in a state where the sensor element 100 is installed in such a manner that the cover 40 falls due to the action of gravity. In this case, since the cover 40 can be dropped from the substrate 10 and separated, it can be used for measurement very easily.

2. Analysis Device The analysis device 200 of the present embodiment is, for example, a Raman spectroscopic device, and hereinafter, the analysis device 200 will be described as a Raman spectroscopic device. FIG. 8 is a schematic diagram showing a schematic configuration of the analyzer 200. As shown in FIG. 8, the analysis device 200 includes the above-described sensor element 100, a measurement cell 210 that houses the sensor element 100, a decompression unit 220 that decompresses the measurement cell 210, and excitation light on the metal microstructure layer 20. And a light detector 240 that detects light emitted from the metal microstructure layer 20. Since the sensor element 100 is the same as described above, detailed description thereof is omitted.

2.1. Measurement Cell The measurement cell 210 forms a space in which the sensor element 100 can be accommodated. The measurement cell 210 includes a valve 211 and a valve 212 through which a sample containing a target substance can be introduced and circulated. In addition, the measurement cell 210 can seal the internal space by closing the valve 211 and the valve 212. In addition, the measurement cell 210 can discharge the gas in the internal space by the decompression means 220.

  The measurement cell 210 can supply the sample to the sensor element 100, and can distribute the sample so that the target substance contacts the metal microstructure layer 20. The mode in which the sample is circulated is arbitrary. For example, the sample circulates in the measurement cell 210 in a state where two vent holes are provided in the measurement cell 210 (in the illustrated example, the valves 211 and 212 are opened). Thus, the sample can be circulated by press-fitting or sucking the sample.

In addition, the measurement cell 210 is configured to be able to irradiate the metal microstructure layer 20 with excitation light from the light source 230, and is configured to be able to detect the light emitted from the metal microstructure layer 20 by the photodetector 240. Is done. The configuration is not particularly limited. For example, the light source 230 and the photodetector 240 are arranged in the measurement cell 210, the measurement cell 210 is formed of a transparent material such as glass, or an appropriate transparent material. A configured window or the like may be provided so that excitation light irradiation and light detection can be performed from outside the measurement cell 210.

2.2. Decompression Unit The decompression unit 220 can exhaust the gas in the measurement cell 210. In the illustrated example, the decompression means 220 is connected to a three-way valve 221, the valve 211 is closed, the valve 212 is opened, and the measurement cell 210 and the decompression means 220 are opened by the three-way valve 221. By driving the decompression means 220, the gas in the measurement cell 210 can be exhausted and the pressure in the measurement cell 210 can be reduced. The decompression means 220 can be constituted by various vacuum pumps, for example.

  The decompression means 220 can decompress the inside of the measurement cell 210 so that the pressure outside the cavity 30 of the sensor element 100 can be equal to or lower than the pressure inside the cavity 30 of the sensor element 100. Thereby, the pressure condition for separating the cover 40 from the substrate 10 can be achieved. The illustrated example schematically shows a state in which the cover 40 of the sensor element 100 is arranged so as to drop due to the action of gravity, and the cover 40 falls by driving the decompression means 220.

  The decompression means 220 has a function of cleaning the measurement cell 210 in addition to the function of realizing the conditions for separating the cover 40. Furthermore, the decompression means 220 may have a function of sucking the sample when the sample is circulated in the measurement cell 210.

  The cleaning in the measurement cell 210 means, for example, that after the first sample is measured and before the second sample is introduced, the measurement cell 210 is depressurized to reduce the first sample adsorbed on the measurement cell 210. It is to remove the components. If the components of the first sample remain in the measurement cell 210, there is a possibility that noise will occur during measurement of the second sample. Therefore, by depressurizing the measurement cell 210 by the decompression means 220, the noise substance can be desorbed and removed by shifting the adsorption equilibrium of the noise substance to the desorption side.

  Further, after the measurement of the first sample, the sensor element 100 is replaced, and the cover 40 is introduced into the measurement cell 210 in a state where the cover 40 is adsorbed to the substrate 10. The decompression means 220 can perform both the cleaning of the measurement cell 210 and the separation of the cover 40 in the same process. In this case, it is more preferable that the cover 40 is separated after the cleaning is sufficiently performed. For example, the cover 40 is separated after the pressure in the measurement cell 210 is lowered to a predetermined pressure for cleaning. By setting the pressure inside the cavity 30, the metal microstructure layer 20 can be exchanged efficiently without breaking the hermeticity of the measurement cell 210.

2.3. Light source The light source 230 irradiates the metal microstructure layer 20 with light (for example, laser light having a wavelength of 633 nm, excitation light i). As the light source 230, for example, a semiconductor laser or a gas laser can be used. The light emitted from the light source 230 is appropriately condensed by a lens or the like, and then enters the metal microstructure layer 20 through a half mirror and a lens as necessary. The arrangement and configuration of the light source 230 are not particularly limited.

2.4. Photodetector When the metal microstructure layer 20 is irradiated with light from the light source 230, SERS light is emitted from the metal microstructure layer 20. The emitted light is appropriately configured to reach the photodetector 240 via a lens, a half mirror, or the like. That is, the photodetector 240 detects light emitted from the metal microstructure layer 20. Since the SERS light includes Rayleigh scattered light having the same wavelength as the incident wavelength from the light source 230, the photodetector 240 may be appropriately provided with a filter to remove the Rayleigh scattered light. The light from which the Rayleigh scattered light is removed is received as a Raman scattered light by a light receiving element via a spectroscope provided in the photodetector 240. For example, a photodiode is used as the light receiving element.

  The spectroscope of the photodetector 240 is formed of, for example, an etalon using Fabry-Perot resonance, and the pass wavelength band can be made variable. The light receiving element of the photodetector 240 obtains a Raman spectrum peculiar to the target substance. For example, the signal intensity of the target substance can be detected by collating the obtained Raman spectrum with previously stored data. .

  Such an analyzer 200 includes the sensor element 100 in which the metal microstructure layer 20 is accommodated in the cavity 30 and the metal microstructure layer 20 is not exposed to the atmosphere outside the cavity 30, and the cover 40 of the sensor element 100 is attached to the sensor element 100. It can be easily removed during use. This makes it possible to measure the target substance with high sensitivity.

2.4. In the example shown in FIG. 8, the substrate 10 of the sensor element 100 is transparent and the light source 230 and the photodetector 240 face the metal microstructure layer 20 from the substrate side of the sensor element 100 with the cover 40 separated. It was an aspect. However, for example, when an opaque member exists between the substrate 10 of the sensor element 100 and the metal microstructure layer 20, the light source 230 and the photodetector 240 are disposed on the metal microstructure layer 20 side. Become. When the opaque cover 40 falls and separates vertically below the substrate 10 as in the example shown in FIG. 8, the optical axis from the light source 230 to the metal microstructure layer 20 and the photodetector 240 is secured. Can be difficult. Therefore, for example, the sensor element 100 (the substrate 10) may be inclined with respect to the direction in which the gravity acts, and the cover 40 may be installed in a posture in which the cover 40 can drop due to the gravity. In this way, even if the cover 40 falls due to the action of gravity, the optical axis from the light source 230 to the metal microstructure layer 20 and the photodetector 240 can be secured.

  In the example of the above embodiment, one sensor element 100 is arranged in the measurement cell 210. However, a plurality of sensor elements 100 may be arranged in the measurement cell 210. 9 to 11 are diagrams schematically illustrating one aspect of the element holder 250 installed in the measurement cell 210. FIG. FIG. 10 schematically shows a cross section taken along line III-III in FIG.

  The element holder 250 shown in FIGS. 9 and 10 has a disk shape, is circular in plan view, and has a rotation axis R at the center of the circle. Then, four sensor elements 100 can be arranged in a circle around the rotation axis R. In this example, four sensor elements 100 are arranged, but the number of sensor elements 100 arranged is arbitrary.

  Further, as shown in FIGS. 9 and 10, the element holder 250 holds the sensor element 100 by providing a counterbore 251. The counterbore 251 holds the substrate 10 of the sensor element 100 so that the cover 40 can fall in the direction in which gravity acts. By doing in this way, when separating the cover 40 of the sensor element 100, it can be easily dropped. In this example, the sensor element 100 is held in the element holder 250 by the counterbore 251, but the mechanism for holding the sensor element 100 in the element holder 250 is not particularly limited.

Furthermore, as shown in FIG. 9, the element holder 250 can rotate around the rotation axis R. In order to rotate the element holder 250 around the rotation axis R, for example, a mechanical mechanism that can be operated from a motor or the outside may be provided. Thereby, the position where the sensor element 100 exists can be changed around the rotation axis R. Accordingly, the plurality of sensor elements 100 can be moved to positions where the light source 230 and the light detector 240 can face without changing the positions where the light source 230 and the light detector 240 are installed, and each sensor element can be moved. A measurement at 100 can be performed.

  Further, in the case where the sensor element 100 cannot irradiate the metal microstructure layer 20 with light from the substrate 10 side, for example, a position where the cover 40 is removed from the sensor element 100 (first arrangement p1) and a position used for measurement (second position) The arrangement p2) can be set. That is, the element holder 250 arranges the sensor element 100 in the first arrangement p1 for separating the cover 40 from the sensor element 100, and the first irradiation of the excitation light from the light source 230 to the metal microstructure layer 20 of the sensor element 100. It can be said that it is a switching mechanism that switches between two arrangements p2. In this way, in the second arrangement p2 where the removed cover 40 does not exist, the measurement can be performed more easily by setting the optical axis from the light source 230 to the metal microstructure layer 20 and the photodetector 240. Can do.

  The element holder 250 can be taken in and out of the measurement cell 210, and a plurality of sensor elements 100 can be exchanged at a time. For example, after all the sensor elements 100 placed on the element holder 250 are used for measurement, the measurement cell 210 is opened, the element holder 250 is taken out, and the cover 40 is replaced with the used sensor element 100. A new sensor element 100 in a state of being adsorbed on the substrate 10 can be placed on the element holder 250 and introduced into the measurement cell 210.

  It is more preferable that the plurality of new sensor elements 100 placed on the element holder 250 have different pressures in the cavity 30 from each other. In this way, according to the pressure when the measurement cell 210 is depressurized, the covers 40 of the sensor elements 100 can be dropped one by one in the measurement cell 210 in descending order of the pressure in the cavity 30. . Thereby, the sensor elements 100 can be subjected to measurement one by one, and deterioration of the metal microstructure layer 20 of the sensor element 100 before measurement can be suppressed to prepare for the next measurement.

  The pressures in the cavities 30 of the plurality of sensor elements 100 introduced into the measurement cell 210 preferably have a difference of 5 Pa or more. If it does in this way, the cover 40 of the several sensor element 100 can be dropped more reliably sequentially.

  As an example, when the measurement cell 210 is a cube having a side of 20 cm and the exhausting speed of the decompression means 220 (vacuum pump) is 6 liters per minute, it takes about 30 kPa from atmospheric pressure to 30 kPa. It can be estimated that it takes 96 seconds. Similarly, it can be estimated that it takes about 15 seconds from 30 kPa to 25 kPa, about 18 seconds from 25 kPa to 20 kPa, about 23 seconds from 20 kPa to 15 kPa, and about 32 seconds from 15 kPa to 10 kPa. . This trial calculation considers that the exhaust speed becomes slower as the degree of vacuum becomes higher (pressure becomes lower). Further, in this trial calculation, a diaphragm type dry vacuum pump (for example, model DAP-6D manufactured by ULVAC, Inc.) was assumed as the decompression means 220 (vacuum pump). The diaphragm-type dry vacuum pump is preferable as the exhaust unit 220 of the present embodiment because the exhaust rate is low but the exhaust rate change due to pressure is small.

  In this way, by adjusting the pressure of the measurement cell 210, the metal microstructure layer 20 close to a plurality of designed structures can be easily used for sequential measurement without opening the measurement cell 210. .

Furthermore, as a switching mechanism for switching the arrangement of the sensor element 100 between a first arrangement p1 for separating the cover 40 from the sensor element 100 and a second arrangement p2 for irradiating the metal fine structure layer 20 of the sensor element 100 with excitation light. In addition to the element holder 250, a mechanism for mechanically moving the sensor element 100 (for example, parallel movement) may be provided. FIG. 11 is a schematic diagram of a main part of an analyzer 201 according to a modification. As shown in FIG. 11, the analysis apparatus 201 includes a first arrangement p1 for separating the cover 40 from the sensor element 100 by translating the sensor element 100 in the measurement cell 210, and a metal microstructure layer of the sensor element 100. 20 can be switched to the second arrangement p2 in which excitation light is irradiated. The mechanism for the parallel movement is not particularly limited, and can be constituted by a guide rail, a manipulator, or the like. In the example of FIG. 11, it is constituted by a guide rail 254 and a linear motor (not shown).

  Further, the analyzer 201 is provided with a tray 252 for receiving the removed cover 40 in the measurement cell 210. The tray 252 can accommodate one or a plurality of covers 40 and can be taken in and out of the measurement cell 210 at an appropriate timing for replacing the sensor element 100. The receiving tray 252 can prevent the cover 40 from falling to a position different from the predetermined position in the measurement cell 210. In addition, the plurality of covers 40 can be efficiently recovered. For example, when the cover 40 is recycled, it can be efficiently recovered. Other configurations of the analysis apparatus 201 illustrated in FIG. 11 are denoted by the same reference numerals as those in the above-described embodiment, and description thereof is omitted.

3. Next, an electronic device 300 according to the present embodiment will be described with reference to the drawings. FIG. 12 is a diagram schematically showing the electronic apparatus 300 according to the present embodiment. The electronic device 300 can include a Raman spectroscopic device according to the present invention. Hereinafter, an example including the analysis apparatus 200 as a Raman spectroscopic apparatus according to the present invention will be described.

  As shown in FIG. 12, the electronic device 300 includes an analyzer 200, a calculation unit 310 that calculates health and medical information based on detection information from the photodetector 240, a storage unit 320 that stores health and medical information, And a display unit 330 that displays health care information.

  The calculation unit 310 is, for example, a personal computer or a personal digital assistant (PDA), and receives detection information (signal or the like) sent from the photodetector 240. The calculation unit 310 calculates health and medical information based on detection information from the photodetector 240. The calculated health and medical information is stored in the storage unit 320.

  The storage unit 320 is, for example, a semiconductor memory, a hard disk drive, or the like, and may be configured integrally with the calculation unit 310. The health care information stored in the storage unit 320 is sent to the display unit 330.

  The display unit 330 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 330 displays or issues information based on the health and medical information calculated by the calculation unit 310 so that the user can recognize the contents.

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

  The electronic device 300 can easily detect a target substance with high sensitivity, and can provide highly accurate health care information.

  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. For example, the sensor element according to the present invention can be used as an affinity sensor for detecting the presence or absence of substance adsorption, such as the presence or absence of antigen adsorption in an antigen-antibody reaction. The affinity sensor makes white light incident on the sensor, measures the wavelength spectrum with a spectroscope, and detects the shift amount of the surface plasmon resonance wavelength due to adsorption, thereby increasing the absorption of the detection substance into the metal microstructure layer. Sensitivity can be detected.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. 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. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 20 ... Metal microstructure layer, 30 ... Cavity, 40 ... Cover, 42 ... Joining member, 50 ... Electric field enhancement element, 51 ... Element board | substrate, 52 ... Metal layer, 53 ... Dielectric layer, 54 ... Metal particle DESCRIPTION OF SYMBOLS 100 ... Sensor element 200, 201 ... Analytical device 210 ... Measurement cell 211, 212 ... Valve, 220 ... Pressure reducing means, 221 ... Three-way valve, 230 ... Light source, 240 ... Photo detector, 250 ... Element holder 251 ... Counterbore, 252 ... Receptacle, 254 ... Guide rail, R ... Rotating shaft, 300 ... Electronic equipment, 310 ... Calculation part, 320 ... Storage part, 330 ... Display part

Claims (7)

A substrate provided with a metal microstructure layer on one main surface;
A cover provided on the one main surface of the substrate and forming a cavity for accommodating the metal microstructure layer;
Including
When the pressure inside the cavity is less than the pressure outside the cavity, the cover adsorbs to the substrate;
A sensor element in which the substrate and the cover are separated when the pressure in the cavity is equal to or higher than the pressure outside the cavity. In claim 1,
A sensor element that separates the substrate and the cover when the pressure outside the cavity drops below the pressure inside the cavity. In claim 1 or claim 2,
When the sensor element is installed in such an arrangement that the cover is dropped by the action of gravity, and the pressure outside the cavity drops below the pressure in the cavity, the cover falls from the substrate. Sensor element to separate. A sensor element according to any one of claims 1 to 3,
A measurement cell containing the sensor element;
Decompression means for decompressing the inside of the measurement cell;
A light source for irradiating the metal microstructure layer with excitation light;
A photodetector for detecting light emitted from the metal microstructure layer;
Including
An analysis apparatus in which the sensor element is installed in the measurement cell, and the cover falls from the substrate and separates when the pressure in the measurement cell is reduced by the pressure reduction means. In claim 4,
A plurality of the sensor elements are accommodated in the measurement cell,
The analyzer in which the pressures of the cavities of the plurality of sensor elements are different from each other. In claim 4 or claim 5,
A switching mechanism that switches the arrangement of the sensor element between a first arrangement for separating the cover from the sensor element and a second arrangement for irradiating the metal microstructure layer of the sensor element with the excitation light. apparatus.   7. The analyzer according to claim 6, a calculation unit that calculates health and medical information based on detection information from the photodetector, a storage unit that stores the health and medical information, and a display that displays the health and medical information And an electronic device.