JP2013047661A - Detection plate, detection apparatus and detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection plate which contributes, when arranged in a detection apparatus for detecting an oil content and a surface active agent, to a compact, inexpensive and portable configuration of the detection apparatus, and is capable of quickly detecting the oil content and the surface active agent in water at high sensitivity, and to provide a detection apparatus including the detection plate, and a detection method using the detection apparatus.SOLUTION: In a detection plate, a detection electric field formation layer forming an electric field for detecting at least either one of an oil content and a surface active agent as a specimen, and a capture layer for capturing the specimen from water including the specimen are arranged in this order. On the capture layer, a capturing recess for capturing the specimen is formed on a face brought into contact with water; water repelling treatment is applied to the face brought into contact with water; and when water is dropped to the face forming the capturing recess under the atmospheric pressure, water does not infiltrate into and fill the capturing recess.

Description

  The present invention uses a detection plate capable of detecting an oil component and a surfactant contained in water as a specimen by using an optical waveguide mode and surface plasmon resonance, a detection device having the detection plate, and the detection device. It relates to a detection method.

Recently, from the viewpoint of environmental pollution and securing drinking water, mixing of oil into water has become a problem. The oil content not only harms the health of people but also causes clogging of the filtration filter at the water purification plant, so detection thereof is one of the important management items that require rapidity.
Currently, the normal hexane extraction method is often used to detect oil contamination in water, but this method requires time and effort to extract oil from water and is inferior in speed. There is a problem. There is also a high-precision measurement technique using gas chromatography. In this case, although high detection sensitivity is obtained, the apparatus is expensive and large-sized, so the apparatus cannot be carried, and therefore the subject (contaminated water) ) Must be collected on site and transported to the installation site of these devices. An oil film detector or the like is also commercially available as a device for detecting oil contamination, but the oil film detector cannot be detected unless the oil film is severely contaminated with an oil film on the water surface. In addition, like oil, mixing of a surfactant into water is an important management item that requires quick detection.

  A sensor using surface plasmon resonance (SPR) is known as a sensor that is small enough to be carried and capable of measuring oil contained in a liquid (see, for example, Non-Patent Documents 1 to 7). ). Sensors using this surface plasmon resonance are generally called SPR sensors and are sold by companies such as NTT Advanced Technology Co., Ltd. and OptQuest Inc.

  FIG. 1 shows a configuration example of the most popular SPR sensor 200 called a Kretschmann arrangement. In this SPR sensor 200, a metal thin film layer 202 is formed by vapor deposition of a metal such as gold or silver on a transparent substrate 201, and an optical prism 203 is formed on the surface of the transparent substrate 201 opposite to the surface on which the metal thin film layer 202 is formed. The laser light emitted from the light source 204 is polarized into p-polarized light by the polarizing plate 205 and irradiated onto the transparent substrate 201 through the optical prism 203. Incident light 210A is incident under conditions of total reflection. Surface plasmon resonance appears at a certain incident angle by the evanescent wave that oozes out to the metal surface side of the incident light 210A. The incident angle θ is appropriately changed by driving the optical system. When surface plasmon resonance occurs, the evanescent wave is absorbed by the surface plasmon, so that the intensity of the reflected light is remarkably reduced near this incident angle. The condition for surface plasmon resonance to appear varies depending on the dielectric constant in the vicinity of the surface of the metal thin film layer 202. Therefore, the dielectric constant changes when the sample to be detected binds or adsorbs on the surface of the metal thin film layer 202. When this occurs, a change occurs in the reflection characteristics of the incident light 210A. Therefore, the sample to be detected can be detected by monitoring the intensity change of the reflected light 210 </ b> B reflected from the metal thin film layer 202 with the photodetector 206.

  In addition, a wavelength-resolved measurement method has been reported as a system in which an optical system is simplified and a miniaturization is realized in an SPR sensor (for example, see Non-Patent Documents 6 and 7). FIG. 2 shows an outline of the SPR sensor 300 of the optical system according to the report of Non-Patent Document 6. Incident light 310A is guided from the light source 301 to the front of the optical prism 303 via the optical fiber 302A, converted into parallel light by the collimator lens 304, converted to p-polarized light by the polarizing plate 305, and then incident on the optical prism 303. The The incident light 310A is applied to the metal thin film layer 307 on the transparent substrate 306 arranged in close contact with the optical prism 303, and is reflected through the condenser lens 308 as reflected light 310B reflected from the metal thin film layer 307. The light is guided to the photodetector 309 through the fiber 302B. Here, the photodetector 309 includes a spectroscope 309A, and observes the reflection spectrum of the reflected light 310B. Similar to the SPR sensor 200 described above, the SPR sensor 300 can detect a change in dielectric constant when a change in dielectric constant occurs near the surface of the metal thin film layer 307, and can detect a change in dielectric constant. Unlike 200, the optical system is driven to resolve the wavelength of the reflected light 310B for measurement without changing the incident angle of the incident light 310A to the metal thin film layer, that is, to measure the spectrum. This has the advantage that the device can be miniaturized.

  As a sensor having a structure very similar to that of an SPR sensor and detecting a substance adsorption or a change in dielectric constant on the detection surface of the sensor, there is an optical waveguide mode sensor (Non-patent Documents 1, 2, 8 to 19, and Patent References 1 to 6). It is known that this optical waveguide mode sensor can use an optical system equivalent to all optical systems that can be used in the SPR sensor.

  FIG. 3 shows an optical waveguide mode sensor 400 using an arrangement similar to the Kretschmann arrangement. The optical waveguide mode sensor 400 includes a transparent substrate 401a, a thin film layer 401b composed of a metal layer or a semiconductor layer coated thereon, and an optical waveguide layer 401c formed on the thin film layer 401b. 401 is used. The optical prism 402 is brought into close contact with the surface of the detection plate 401 opposite to the surface on which the optical waveguide layer 401c is formed via refractive index adjusting oil. Light emitted from the light source 403 and polarized by the polarizing plate 404 is irradiated to the detection plate 401 through the optical prism 402. The incident light 410A is incident on the detection plate 401 under conditions that cause total reflection. When the incident light 410A is coupled with an optical waveguide mode (also called a leakage mode or leaky mode) propagating in the optical waveguide at a certain incident angle θ, the optical waveguide mode is excited, and light is reflected near the incident angle. The light intensity changes greatly. Such an optical waveguide mode excitation condition changes depending on the dielectric constant in the vicinity of the surface of the optical waveguide layer 401c. Therefore, if adsorption, approach, separation, or alteration of a substance occurs on the surface of the optical waveguide layer 401c, the reflected light 410B Changes appear in intensity. By observing this change with the photodetector 405, it is possible to detect phenomena such as adsorption, approach, separation, and alteration of substances on the surface of the optical waveguide layer 401c.

FIG. 4 shows an outline when the optical system of the SPR sensor 300 shown in FIG. 2 is applied to an optical waveguide mode sensor. The light irradiation means shown in FIG. 4 includes a light source 501, an optical fiber 502 A, a collimator lens 503, and a polarizing plate 504. Light from the light source 501 enters the optical fiber 502A and is guided to a position where it easily enters the optical prism 505. The collimating lens 503 disposed at the tip of the optical fiber 502A sets the outgoing light from the optical fiber 502A to be parallel light. The emitted light is polarized to a desired polarization state by the polarizing plate 504 and then enters the optical prism 505. The light incident on the optical prism 505 is reflected by the detection plate 506, is emitted from the optical prism 505 as reflected light, is condensed by the condenser lens 507, and is taken into the optical fiber 502B. The detector 509 can observe the reflection intensity or the reflection spectrum. The detection plate 506 includes a thin film layer 506b composed of a metal layer or a semiconductor layer and an optical waveguide layer 506c arranged in this order on a transparent substrate 506a. The optical waveguide layer 506c of the detection plate 506 is provided. The optical prism 505 is disposed in optical close contact with the surface opposite to the surface on which is disposed. When the optical waveguide mode sensor 500 having such a structure observes the characteristics after the incident light is reflected by the detection plate 506, for example, the reflected light spectrum, the light in the specific wavelength band of the incident light is reflected on the detection plate 506. A condition occurs in which the conditions for exciting the optical waveguide mode that locally propagates in and near the optical waveguide layer 506c formed on the surface are satisfied, and the reflection intensity changes significantly in this wavelength band. Since the optical waveguide mode excitation condition changes depending on the dielectric constant in the vicinity of the surface of the optical waveguide layer 506c of the detection plate 506, the reflection spectrum changes when the dielectric constant in the vicinity of the surface of the optical waveguide layer 506c changes. Accordingly, by observing a change in the reflection spectrum or a change in the reflected light intensity in a specific wavelength band, the cause of the change in the dielectric constant in the vicinity of the surface of the optical waveguide layer 506c, for example, adsorption, approach, separation, Alteration can be detected by a photodetector 509.
In addition, it has been reported so far that in the optical waveguide mode sensor, when nanopores are formed in the optical waveguide layer and the surface area of the detection surface is increased, the detection sensitivity is dramatically improved. (For example, see Patent Documents 4 and 5 and Non-Patent Documents 10 to 13)

  Patent Document 7 discloses a sensor for detecting oil content by covering the surface of a metal thin film layer of an SPR sensor with a lipophilic film and capturing oil contained in water on the surface of a detection plate. However, in this case, the difference in permittivity between water and oil is small, and there is a problem that high detection sensitivity cannot be obtained even if the oil is caught on the surface of the detection plate.

Japanese Patent No. 4581135 Japanese Patent No. 4,595,072 JP 2007-271596 A JP 2008-46093 A JP 2009-85714 A International Publication No. 2010/87088 JP 10-38797 A (Patent No. 3447478)

W. Knoll, MRS Bulletin 16, pp. 29-39 (1991) W. Knoll, Annu. Rev. Phys. Chem. 49, pp. 569-638 (1998) H. Kano and S.K. Kawata, Appl. Opt. 33, pp. 5166-5170 (1994) C. Nylander, B.M. Liedberg, and T.M. Lind, Sensor. Actuat. 3, pp. 79-88 (1982/83) K. Kambhampati, T .; A. M.M. Jakob, J .; W. Robertson, M.C. Cai, J .; E. Pemberton, and W.C. Knoll, Langmuir 17, pp. 1169-1175 (2001) O. R. Bolduc, L.M. S. Live, and J.M. F. Masson, Talenta 77, pp. 1680-1687 (2009) I. Stammler, A.M. Brecht, and G.G. Gauglitz, Sensor. Actuat. B54, pp98-105 (1999) M.M. Osterfeld, H .; Franke, and C.I. Feger, Appl. Phys. Lett. 62, pp. 2310-2312 (1993) E. F. Aust and W. Knoll, J.M. Appl. Phys. 73, p. 2705 (1993) M.M. Fujimaki, C.I. Rockstuhl, X.M. Wang, K .; Awazu, J. et al. Tominaga, T .; Ikeda, Y .; Ohki, and T.K. Komatsubara, Microelectronic Engineering 84, pp. 1685-1689 (2007) K. Awazu, C.I. Rockstuhl, M.M. Fujimaki, N .; Fukuda, J. et al. Tominaga, T .; Komatsusubara, T .; Ikeda, and Y.M. Ohki, Optics Express 15, pp. 2592-2597 (2007) K. H. A. Lau, L .; S. Tan, K .; Tamada, M .; S. Sander, and W.M. Knoll, J.M. Phys. Chem. B108, pp. 10812 (2004) M.M. Fujimaki, C.I. Rockstuhl, X.M. Wang, K .; Awazu, J. et al. Tominaga, Y. et al. Koganezawa, Y .; Ohki, and T.K. Komatsusubara, Optics Express 16, pp. 6408-6416 (2008) M.M. Fujimaki, C.I. Rockstuhl, X.M. Wang, K .; Awazu, J. et al. Tominaga, N .; Fukuda, Y .; Koganezawa, and Y.K. Ohki, Nanotechnology 19, pp. 095503-1-095503-7 (2008) M.M. Fujimaki, C.I. Rockstuhl, X.M. Wang, K .; Awazu, J. et al. Tominaga, T .; Ikeda, Y .; Koganezawa, and Y.K. Ohki, J .; Microscopy 229, pp. 320-326 (2008) M.M. Fujimaki, K .; Nomura, K .; Sato, T .; Kato, S .; C. B. Gopinath, X .; Wang, K .; Awazu, andY. Ohki, Optics Express 18, pp. 15732-15740 (2010) R. P. Podgorsek, H .; Franke, J .; Woods, and S.W. Morrill, Sensor. Actuat. B51 pp. 146-151 (1998) J. et al. J. et al. Saarinen, S .; M.M. Weiss, P.M. M.M. Fauchet, and J.M. E. Shipe, Opt. Express 13, pp. 3754-3764 (2005) G. Long, A .; Najmaie, J .; E. Shipe, and S.M. M.M. Weiss, Biosens. Bioelectron. 23, pp. 1572-1576 (2008)

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, according to the present invention, when arranged in a detection device for oil and surfactant, the detection device can be configured to be small, inexpensive and portable, and can detect oil and surfactant in water quickly and with high sensitivity. It is an object of the present invention to provide a detection plate having a detection plate, a detection device having the detection plate, and a method for detecting oil and surfactant using the detection device.

Means for solving the problems are as follows. That is,
<1> A detection electric field forming layer that forms an electric field for detecting at least one of oil and surfactant as a specimen, and a capturing layer that captures the specimen from water containing the specimen are arranged in this order, The trapping layer has a trapping recess for trapping the specimen on the surface in contact with the water, and a water-repellent treatment is applied to the surface in contact with the water, so that the trapping is performed under atmospheric pressure. A detection plate, wherein the water in the water does not enter the entire inside of the catching recess when the water is dropped on the surface on which the recess is formed.
<2> The detection plate according to <1>, wherein the capture recess is a hole formed in the capture layer.
<3> The detection plate according to <1>, wherein the capturing concave portion is formed by arranging a plurality of pillars on the surface of the detection plate on a side in contact with water containing the specimen so that the interval is a concave portion.
<4> The detection plate according to <3>, wherein the longest diameter of the pillar is shorter than the length of the wavelength of light used.
<5> The detection plate according to <1>, wherein the capturing recess is formed as surface roughness.
<6> The detection plate according to any one of <1> to <5>, wherein an opening diameter of the capturing recess is shorter than a wavelength of light to be used.
<7> The detection plate according to any one of <1> to <6>, wherein the depth of the recess for capturing is 5 nm or more and 5 μm or less.
<8> The detection plate according to <1>, wherein the capture concave portion is formed by arranging a plurality of beads on a surface of the detection plate on a side in contact with water containing the specimen so that the interval is a concave portion.
<9> From <1> to <1> above, the surface treatment using a silane coupling agent having a lipophilic group or the surface treatment using a fluorine coating agent is carried out as a water repellent treatment. The detection plate according to any one of 8>.
<10> The detection plate according to any one of <1> to <9>, wherein the detection electric field forming layer is formed by arranging a surface plasmon excitation layer that expresses surface plasmon resonance.
<11> The detection plate according to <10>, wherein the material for forming the surface plasmon excitation layer includes at least one of gold, silver, copper, platinum, and aluminum.
<12> The detection electric field forming layer is formed by arranging an optical waveguide layer formed of a transparent material and a thin film layer formed of a metal material or a semiconductor material in this order from the side where the capturing layer is disposed. The detection plate according to any one of <1> to <9>.
<13> The detection plate according to <12>, wherein the trapping layer is formed in a form that also serves as part or all of the optical waveguide layer.
<14> The detection plate according to any one of <1> to <13>, an optical element disposed on a surface of the detection plate on which the detection electric field forming layer is disposed, and the optical element A light irradiating means for irradiating the detection plate with light; and a light detecting means for detecting reflected light reflected from the detection plate, and changes depending on the presence or absence of the specimen in the capturing recess of the detection plate. A detection apparatus that detects the specimen from a change in characteristics of the reflected light.
<15> A detection method for detecting the presence of a sample contained in water by using the detection device according to <14>, wherein water that does not contain the sample is formed on the surface of the detection plate on which the capture layer is formed. A first light irradiation step of irradiating the detection plate with light from the light irradiation means via an optical element, and reflected light reflected from the detection plate based on the first light irradiation step. A first light detection step for detecting, and a capture step for capturing the sample in the capture recess of the capture layer by administering water containing the sample to the surface of the detection plate on which the capture layer is formed. And after the capturing step, a second light irradiation step of irradiating the detection plate with light, and a second light detection for detecting reflected light reflected from the detection plate based on the second light irradiation step. And detecting the first light detection step and the second light detection step. And detecting the specimen from a change in characteristics of each reflected light.

  According to the present invention, the above-mentioned problems in the prior art can be solved, and when arranged in a detection device for oil and surfactant, the detection device is configured to be small, inexpensive and portable, It is possible to provide a detection plate that can detect oil and surfactant quickly and with high sensitivity, a detection device having the detection plate, and a method for detecting oil and surfactant using the detection device.

It is explanatory drawing which shows an example of the optical arrangement | positioning of the SPR sensor using the surface plasmon resonance which concerns on a prior art. It is explanatory drawing which shows the other example of optical arrangement | positioning of the SPR sensor using the surface plasmon resonance which concerns on a prior art. It is explanatory drawing which shows an example of optical arrangement | positioning of the optical waveguide mode sensor which concerns on a prior art. It is explanatory drawing which shows the other example of optical arrangement | positioning of the optical waveguide mode sensor which concerns on a prior art. It is sectional drawing which shows an example of the detection board distribute | arranged to the detection apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the other example of the detection board distribute | arranged to the detection apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the other example of the detection board distribute | arranged to the detection apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the other example of the detection board distribute | arranged to the detection apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the other example of the detection board distribute | arranged to the detection apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the other example of the detection board distribute | arranged to the detection apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the optical arrangement | positioning of the detection apparatus which concerns on the Example of this invention. 2 is an electron micrograph of a capturing layer in which a capturing recess is formed in Example 1. FIG. 2 is a photograph when water droplets are dropped on the surface of a capturing layer in Example 1. FIG. It is the reflection spectrum before and behind the water-repellent process observed using the detection apparatus which concerns on Example 1. FIG. It is the reflection spectrum before and behind the dripping of the water containing the oil observed using the detection apparatus which concerns on Example 1. FIG. It is the reflection spectrum before and behind the water repellent process observed using the detection apparatus which concerns on Example 2. FIG. It is the reflection spectrum before and behind the dripping of the water containing the oil observed using the detection apparatus which concerns on Example 2. FIG. It is an electron micrograph of the capture layer in which the recess for capture in Example 3 was formed. It is the reflection spectrum before and behind the water repellent process observed using the detection apparatus which concerns on Example 3. FIG. It is the reflection spectrum before and after dripping of the water containing the oil observed using the detection apparatus which concerns on Example 3. FIG. It is the reflection spectrum before and after dripping of the water containing the oil observed using the detection apparatus which concerns on Example 4. FIG. It is the reflection spectrum before and behind the dripping of the water containing the oil observed using the detection apparatus which concerns on the comparative example 1. FIG. 6 is a photograph when water droplets are dropped on the detection surface in Comparative Example 1. It is the reflection spectrum before and behind the water repellent process observed using the detection apparatus which concerns on the comparative example 2. FIG. 6 is a photograph when water droplets are dropped on the detection surface in Comparative Example 2. FIG. It is the reflection spectrum before and behind the dripping of the water containing the oil observed using the detection apparatus which concerns on the comparative example 2. FIG. It is the reflection spectrum before and behind dripping of the water containing the surfactant observed using the detection apparatus which concerns on Example 5. FIG.

(Detection device and detection plate)
The detection apparatus of the present invention includes the detection plate of the present invention, an optical element, a light irradiation unit, and a light detection unit, and includes other members as necessary.

<Detection plate>
The detection plate includes a detection electric field forming layer and a capture layer in this order, and includes other layers as necessary. The detection plate uses oil and a surfactant as specimens.

-Detection electric field forming layer-
The detection electric field forming layer is a layer that forms an electric field (detection electric field) used for detecting the analyte localized near the capture layer. The detection electric field here refers to an electric field localized on the surface generated by excitation of surface plasmon resonance, or propagation that penetrates the surface of the optical waveguide when light propagates in the optical waveguide. It refers to the electric field caused by light. These electric fields are sensitive to changes in the dielectric constant in the electric field. For example, when a substance enters the electric field and the dielectric constant changes, the resonance condition of the surface plasmon resonance changes, or the optical A change occurs in the mode of light propagating in the waveguide. Therefore, the intrusion of the substance can be detected by observing these changes.
The detection electric field forming layer is not particularly limited and may be appropriately selected according to the purpose. The detection electric field forming layer is a surface plasmon excitation layer used for an SPR sensor using a known surface plasmon resonance, and light propagating in an optical waveguide. Examples thereof include an optical waveguide layer used in an optical waveguide mode sensor using a mode. For example, the metal thin film layer in the SPR sensor (see FIGS. 1 and 2) related to the Kretschmann arrangement and the wavelength resolution measurement, and the thin film layer and the optical waveguide layer in the optical waveguide mode sensor (see FIGS. 3 and 4) The layer comprised by these is mentioned.

Here, the forming material of the detection electric field forming layer (surface plasmon excitation layer) used in the SPR sensor is not particularly limited and can be appropriately selected according to the purpose. Although the metal material which has a dielectric constant is mentioned, The metal material containing at least any one of gold, silver, platinum, and aluminum is preferable.
When the metal layer formed of the metal material receives light at a certain incident angle through the prism, the evanescent wave that oozes to the surface side satisfies the excitation condition of the surface plasmon, and the surface plasmon is formed on the surface of the metal layer. Resonance is developed.
The optimum thickness of the metal layer is determined by the metal material and the wavelength of incident light. It is known that this value can be calculated from calculation using the Fresnel equation. Generally, when surface plasmon is excited from the near ultraviolet region to the near infrared region, the thickness of the metal layer is several nm to several tens of nm.

In addition, as a material used as a thin film layer and an optical waveguide layer as a detection electric field forming layer used in the optical waveguide mode sensor, for example, a metal or a semiconductor material can be cited as the thin film layer, and a dielectric can be used as the optical waveguide layer. Examples include transparent materials such as body materials.
The metal material for forming the thin film layer is not particularly limited, and for example, is generally available and includes a stable metal and its alloy, but at least one of gold, silver, copper, platinum and aluminum. It is preferable to contain.
There is no restriction | limiting in particular as a semiconductor material which forms the said thin film layer, For example, semiconductor materials, such as silicon and germanium, or a known compound semiconductor material are mentioned, However, Since silicon is cheap and easy to process, it is preferable.
The thickness of the thin film layer is the same as that of the metal layer of the surface plasmon excitation layer, and the optimum value is determined by the material of the thin film layer and the wavelength of incident light, and this value is calculated using the Fresnel equation. It is known that calculation is possible from calculation. Generally, when using light in a wavelength band from the near ultraviolet region to the near infrared region, the thickness of the thin film layer is several nm to several hundred nm.
The material for forming the optical waveguide layer is not particularly limited as long as it is a transparent material having high light transmittance. For example, a resin material such as silicon oxide, silicon nitride, and acrylic resin, a metal oxide such as titanium oxide, and aluminum nitride Examples of the metal nitride include silicon oxide, but silicon oxide is preferable because it is easy to manufacture and has high chemical stability. In this case, if the thin film layer is formed of silicon, it can be easily formed by oxidizing the surface side of the silicon layer.

  In addition to this, there are a detection electric field forming layer as an optical waveguide structure, and as a layer structure capable of forming a detection electric field that can be used for detection of the specimen, a flat optical waveguide, a slab optical waveguide, a silicon nanowire An optical waveguide structure using a ring, a ring resonator type optical waveguide structure, a Mach-Zehnder type optical waveguide structure, and the like.

-Trapping layer-
The capture layer has a function of capturing the sample from the water containing the sample, and a capture recess is formed on a surface in contact with the water containing the sample, and the capture layer captures the capture target. Water repellent treatment is performed on the surface on which the concave portions for forming are formed.
The core of the present invention is that when the water is dropped on the surface of the trapping layer where the trapping recess is formed under atmospheric pressure, the water in the water does not enter the entire trapping recess. And
That is, when the water is dripped onto the trapping layer under atmospheric pressure, which is a general use environment of the detection device of the present invention, the water in the water is repelled by the water repellent treatment, and the trapping is performed. The water in the water does not enter the recess, or even if it enters, the water in the water does not enter the entire recess for capturing, while the specimen in the water is subjected to the water repellent treatment. In order to adjust to the surface of the layer, it penetrates into the capturing recess.
In the capture recess, there is a space that is not filled with water before the specimen enters, that is, a space having a dielectric constant close to 1. Since the specimen enters the space, a large change in the dielectric constant occurs in the capturing recess, and as a result, the presence of the specimen can be detected with high sensitivity.
In the detection apparatus, since the sample is captured by the capture layer and the presence of the sample is detected, the surface on the detection plate where the capture layer is formed is referred to as a detection surface.

The state where the space into which the water does not enter exists in the capturing recess can be confirmed by the following measuring method.
That is, when the detection plate according to the present invention is manufactured, the detection surface before the water repellent treatment (in the case after the water repellent treatment, returns to the state before the water repellent treatment) is under atmospheric pressure. 2 in a state where an appropriate amount of pure water is dropped (about 1 μL to 100 mL) and a state where an appropriate amount of pure water is dropped on the detection surface after the water repellent treatment at atmospheric pressure as before the water repellent treatment. Observe optical signals in two states. From the observation result, the value of the dielectric constant on the detection surface obtained from the respective signals before and after the water repellent treatment is calculated. If there is a space without the water in the catching recess, the resulting dielectric constant will be low. Therefore, it can be confirmed from the difference in dielectric constant whether there is a space in which the water does not enter in the capturing recess.

There is no restriction | limiting in particular as a formation material of the said acquisition layer, According to the objective, it can select suitably, For example, a glass material, a resin material, a semiconductor material, a metal material etc. are mentioned.
The glass material is selected from the viewpoint of high chemical resistance and stability. Among them, silica glass having very high chemical stability and physical stability is preferable.
Further, the resin material is selected from the viewpoint of easy formation of the capturing recess.
The trapping layer can be given a function as the optical waveguide layer in the detection electric field forming layer by selecting a material. In this case, the trapping layer is an optical waveguide that excites the optical waveguide mode. It can be formed in a form that also serves as part or all of the layer.

  There is no restriction | limiting in particular as said recessed part for acquisition, According to the objective, it can select suitably, When forming a hole, it forms a hole of cross-sectional shapes, such as a perfect circle, an ellipse, and a polygon, and is recessed It can be. In addition, a plurality of pillars (columnar structures) may be formed on the surface of the detection plate on the side where the oil and the water containing the surfactant are in contact with each other so that the interval is a recess. Further, surface roughness such as randomly formed scratches, surface irregularities, and groove structures may be used as the capturing recesses.

The method for forming the capturing recess is not particularly limited and can be appropriately selected depending on the purpose. For example, a chemical etching method using a solution for dissolving the capturing layer or a dry etching method such as reactive ion etching, Examples include physical processing methods such as polishing.
In the case of forming a hole as the capturing recess, the most common forming method is to apply a resist on the surface of the capturing layer forming material, form a dot pattern on the resist by lithography, and then perform the chemical etching method. Or the method of forming a hole with the said dry etching method is mentioned.
When the capturing layer itself is formed of a resist material, the capturing recesses are obtained when the dot pattern is lithographically developed and the resist material is developed.
In the case of forming the hole as described above, the diameter of the hole does not have to be uniform in the depth direction, and the diameter may increase or decrease as the depth increases. However, when the hole diameter is uniformly formed in the depth direction, the holes can be formed most densely, and as a result, the total amount of the internal volume of the holes, that is, the amount capable of capturing the specimen can be increased. Is preferably a uniform hole in the depth direction.

In general, the formation of holes using the lithography is suitable for forming a regular pattern, but when used as the capturing recess, the arrangement of the holes is not particularly limited and is regular. May not be regular.
A method for forming the randomly arranged holes is not particularly limited, but a combination of a method of ion implantation into the material of the trapping layer and a method of chemical etching after ion implantation is very effective.
When ions are accelerated with high energy and injected into silicon oxide, titanium oxide, polymer compounds, organic thin films, glass materials, transparent conductor materials, etc., the portion where the ions have passed can be chemically selectively etched. . For example, after accelerating and injecting the ions into the silicon oxide or titanium oxide on the order of MeV and then etching with a solution or vapor of hydrofluoric acid or borohydrofluoric acid, the portion irradiated with the ions becomes The trapping recess having a very fine diameter can be formed by etching more efficiently than the portion not irradiated with the ions.

  In the case where a pillar is formed as the capturing recess, a technique combining lithography and etching can be applied as in the formation of the hole. When scratches, surface irregularities, groove structures, etc. are used as the capture recesses, they can still be formed by a combination of lithography and etching. However, when forming random irregularities, simply look at the capture layer. It can be easily formed by polishing using a fine polishing agent or using a technique of depositing a substance in an island shape.

In addition, as a method of forming the capturing recess, a method of forming a plurality of beads on the surface of the detection plate on the side in contact with the water containing the specimen so as to form a recess is provided.
For example, when beads such as silica beads and polystyrene beads are coated on the surface of the detection plate on the side in contact with water containing the specimen, the beads can be arranged densely, and the gap between the beads and the beads. Thus, the capturing layer having the capturing recesses can be formed.

When a hole is formed as the capturing recess, the opening diameter is not particularly limited as long as the effect of the present invention is not impaired, and can be appropriately selected according to the purpose, but the opening diameter becomes too large. Since the incident light may be scattered for detection of the specimen, the wavelength is preferably equal to or less than the wavelength of light used for the detection. In addition, if the opening diameter is large, even if a water repellent treatment is performed, there is a risk that it will not be possible to prevent water from entering the entire catching recess. Therefore, the opening diameter needs to be small enough to prevent water from penetrating into the entire catching recess by water repellent treatment. If the opening diameter becomes too small, the specimen does not enter the capture recess, and is preferably 10 nm or more.
In addition, the said opening diameter shows the diameter of the position which becomes the longest in the opening plane.

The depth of the hole may be such a depth that when the water is dropped onto the detection surface, a space not filled with the water can be secured in the hole.
The depth of the hole that satisfies this condition depends on the degree of water repellency on the water-repellent detection surface and the opening diameter of the hole, but if it is deep within the range allowed by the thickness of the trapping layer, It is preferable that the depth is deeper, preferably deeper than 5 nm, and more preferably 20 nm or more.

When the pillar is formed as the catching recess, the longest diameter is not particularly limited as long as the effect of the present invention is not impaired, and can be appropriately selected according to the purpose, but the longest diameter is too large. In addition, since there is a possibility that incident light may be scattered for detection of the specimen, the wavelength is preferably equal to or less than the wavelength of light used for the detection. Moreover, since the intensity | strength of a pillar will become remarkably low when the said longest diameter becomes small too much, it is preferable that it is 10 nm or more. In addition, the said longest diameter shows the diameter of the position where the pillar becomes the thickest.
Further, in this case, since the gap between the adjacent pillars becomes the capturing recess, the widest portion between the adjacent pillars corresponds to the opening diameter. Therefore, as in the formation of the holes, the opening diameter is preferably 10 nm or more, and is preferably less than the wavelength used. The opening diameter needs to be small enough to prevent the water from entering the entire inside of the catching recess by water repellent treatment.

The height of the pillar may be a height that can secure a space that is not filled with the water in the catching recess when the water is dropped onto the detection surface.
The height of the pillar that satisfies this condition depends on the degree of water repellency on the water-repellent detection surface and the diameter and arrangement interval of the pillars, but within the range allowed by the thickness of the capturing layer, The higher it is, the better, preferably higher than 5 nm, more preferably 20 nm or more.

  When the surface roughness is formed as the capturing recess, the size of the structure constituting the surface roughness is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. If the structure becomes too large, the incident light may be scattered for detection of the specimen. In this case, the widest portion of the capturing recess formed by surface roughness corresponds to the opening diameter. Therefore, also in this case, the opening diameter is preferably 10 nm or more, and is preferably less than the wavelength used. The opening diameter needs to be small enough to prevent water from penetrating into the entire catching recess by water repellent treatment.

As the depth of the surface roughness, that is, the depth of the concave portion formed by the structure constituting the surface roughness, when the water is dropped on the detection surface, a space that is not filled with the water can be secured in the hole. Such depth is sufficient.
The depth of the surface roughness that satisfies this condition depends on the degree of water repellency on the water-repellent detection surface and the width of the recess, but if it is deep within the range allowed by the thickness of the capture layer, It is preferable that the depth is deeper, preferably deeper than 5 nm, and more preferably 20 nm or more.

The thickness of the capture layer is not particularly limited as long as the effect of the present invention is not impaired, and can be appropriately selected according to the purpose. However, if the thickness is too thin, the amount of the sample that can be captured decreases, and the detection When the water is dripped onto the surface, the space that is not filled with the water formed in the catching concave portion is reduced, so that it is preferably thicker than 5 nm.
Further, in both the surface plasmon resonance and the optical waveguide mode, since a detection electric field is formed only up to about 500 nm from the surface of the detection electric field forming layer, an improvement in sensitivity can be expected even if the trapping layer is further thickened. For this reason, the thickness of the trapping layer is sufficient to be 500 nm or less. However, when the optical waveguide mode is used and the trapping layer is formed so as to be part or all of the optical waveguide layer, the trapping layer itself functions as the optical waveguide layer. There is no limit on the upper limit of. However, even in this case, if the acquisition layer is too thick, it is not preferable in terms of manufacturing cost. Therefore, the thickness of the acquisition layer is preferably 5 μm or less.

The method for performing the water repellency treatment is not particularly limited and may be appropriately selected depending on the purpose, and includes known water repellency treatment, lipophilic treatment, and water repellency treatment, but from the viewpoint of excellent stability, A method in which a compound having lipophilicity is surface-modified on the detection surface is preferred.
The surface modification method is not particularly limited and can be appropriately selected according to the type and purpose of the lipophilic group. From the viewpoint of easy introduction, a silane coupling agent having a lipophilic group is used. And a surface treatment method using a water-repellent fluorine coating agent is preferable.

-Other layers-
There is no restriction | limiting in particular as long as the said other layer does not impair the effect of this invention, According to the objective, it can select suitably, A transparent substrate, an adhesive layer, etc. are mentioned.

The transparent substrate is disposed on a surface of the detection electric field forming layer opposite to a surface on which the capturing layer is disposed. This transparent substrate is used to form the detection electric field forming layer and the trapping layer thereon.
The surface of the transparent substrate opposite to the surface on which these layers are formed is in close contact with the optical element with matching oil or the like.
However, whether or not to arrange the transparent substrate can be appropriately selected according to the purpose. For example, when an optical prism is used as the optical element, the role of the transparent substrate can be given to the optical prism. it can.
The material for forming the transparent substrate is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include glass materials such as silica glass (including thermally oxidized silicon), plastic materials, ceramic materials, and insulators. Examples thereof include a transparent dielectric material and a transparent conductor material such as ITO.

The adhesive layer is disposed between the metal thin film layer and the transparent substrate in the detection electric field forming layer, or between the metal thin film layer and the optical prism when the transparent substrate is not used. That is, since the metal thin film layer may have low adhesion to the transparent substrate made of a glass material or the optical prism, the adhesive layer is used to improve the adhesion to the glass material. it can.
Examples of the material for forming the adhesive layer include Cr.

A specific configuration example of the detection plate will be described with reference to the drawings.
FIG. 5 shows an embodiment of the detection plate when the surface plasmon resonance is used, that is, the detection plate used for the SPR sensor.
In this case, as shown in FIG. 5, the detection plate 10 has a metal thin film layer 12 (detection electric field forming layer 17) and a capture layer 13 arranged in this order on a transparent substrate 11. A plurality of catching recesses 14 are formed, and the surface (detection surface) is subjected to water repellent treatment.

FIG. 6 shows an embodiment of the detection plate used in the optical waveguide mode, that is, the detection plate used in the optical waveguide mode sensor.
In this case, as shown in FIG. 6, in the detection plate 20, a thin film layer 22 formed of a metal or a semiconductor material, an optical waveguide layer 25, and a capturing layer 23 are arranged in this order on a transparent substrate 21. Thus, the trapping layer 23 is formed with a plurality of trapping recesses 24 and subjected to water repellent treatment on the surface (detection surface). In this example, the thin film layer 22 and the optical waveguide layer 25 constitute a detection electric field forming layer 27.

The catching recess may be formed in the optical waveguide layer itself, and the surface thereof may be subjected to water repellent treatment, and this may be used as the catching layer. At this time, the capturing concave portion may penetrate the optical waveguide layer, or may be formed only on the surface side without penetrating the optical waveguide layer. Thus, it is preferable that the trapping layer is integrated with the optical waveguide layer in the optical waveguide mode detection plate because the manufacturing process becomes simpler than separately forming the trapping layer. One embodiment of the trapping layer in this case is shown in FIG.
That is, as shown in FIG. 7A, the detection plate 30 has a thin film layer 32 formed of a metal or a semiconductor material on a transparent substrate 31, and a trapping layer 33 that also functions as the optical waveguide layer. Arranged in this order, the trapping layer 33 is formed with a plurality of trapping recesses 34 penetrating the trapping layer 33, and the surface (detection surface) is subjected to water repellent treatment. The In this example, the detection electric field forming layer 37 is constituted by the thin film layer 32 and the capturing layer 33 that also functions as the optical waveguide layer.

FIG. 7B shows an embodiment of the detection plate formed in the detection plate 30 shown in FIG. 7A in a state where the capture recess 34 does not penetrate the capture layer 33.
That is, as shown in FIG. 7B, the detection plate 40 includes a thin film layer 42 formed of a metal or a semiconductor material on a transparent substrate 41, and a trapping layer 43 that also functions as the optical waveguide layer. Arranged in this order, the trapping layer 43 is formed with a plurality of trapping recesses 44 that do not penetrate the trapping layer 43, and the surface (detection surface) is subjected to water repellent treatment. The In this example, the detection electric field forming layer 47 is configured by the thin film layer 42 and the capturing layer 43 that also functions as the optical waveguide layer.

In addition, in the detection plate 30 shown in FIG. 7A, the concavity 34 has a conical shape in which the capture recess 34 does not penetrate the capture layer 33, and the shape of the hole gradually becomes narrower in the depth direction of the hole. One embodiment is shown in FIG.
That is, as shown in FIG. 7C, the detection plate 50 includes a thin film layer 52 formed of a metal or a semiconductor material on a transparent substrate 51, and a trapping layer 53 that also functions as the optical waveguide layer. Arranged in this order, the trapping layer 53 is formed with a plurality of trapping recesses 54 each having a conical shape that does not penetrate the trapping layer 53 and gradually narrows in the depth direction of the hole. At the same time, the surface (detection surface) is subjected to water repellent treatment. In this example, the detection electric field forming layer 57 is configured by the thin film layer 52 and the capturing layer 53 that also functions as the optical waveguide layer.

<Optical element>
The optical element is disposed on a surface of the detection plate on the side where the detection electric field forming layer is disposed.
The optical element has a function of guiding light emitted from the light irradiation means to the detection plate and guiding reflected light to the light detection means.

The optical element is not particularly limited as long as it has the above function, and can be appropriately selected depending on the purpose. Examples thereof include the optical prism, diffraction grating, and cylindrical lens.
There is no restriction | limiting in particular as a shape of the said optical prism, According to the objective, it can select suitably, For example, a triangular prism, a trapezoid prism, a semi-cylindrical prism, and a hemispherical prism are mentioned.
The material for forming the optical prism is not particularly limited as long as it is a material having high light transmittance, and can be appropriately selected according to the purpose. However, it is possible to suppress reflection and refraction of light at the interface with the detection plate. Therefore, when the detection plate includes the transparent substrate, a material having the same refractive index as that of the material constituting the transparent substrate or a material having an equivalent refractive index is preferable. For example, a glass material such as silica glass is preferable.

A method for arranging the optical element on the detection plate is not particularly limited and may be appropriately selected depending on the purpose. However, a refractive index adjusting oil or a refractive index is provided between the detection plate and the optical element. A method of filling with a regulating polymer sheet and arranging them so as to be optically continuous is preferable.
Further, the detection plate and the optical prism may be integrally formed from the viewpoint of more easily obtaining optical continuity.
In this case, it can be formed by polishing the transparent substrate of the detection plate into a prism shape.

  An example in which the detection plate and the optical prism are integrally formed is shown in FIG. In the detection plate 60 according to this example, a silicon layer is arranged as the thin film layer 62 in the detection plate for the optical waveguide mode sensor on an optical prism 66 formed by processing a silica glass substrate into an optical prism shape. On top of that, a trapping layer 63 that also functions as the optical waveguide layer is disposed. In this figure, the trapping layer 63 is formed with a plurality of trapping recesses 64 each having a conical shape that penetrates the trapping layer 63 but gradually decreases in the depth direction of the hole. Although an example in which the surface (detection surface) is subjected to a water repellent treatment is shown, the shape of the capturing concave portion 64 can be appropriately selected. In this example, the detection electric field forming layer 67 is constituted by the thin film layer 62 and the capturing layer 63 that also functions as the optical waveguide layer.

  A silica glass substrate is selected as the transparent substrate of the detection plate using the optical waveguide mode, a silicon layer is selected as the thin film layer, a silicon oxide layer is selected as the optical waveguide layer, and the optical element is the optical element. When the detection device is configured such that a prism is selected and the wavelength-resolved reflected light spectrum can be observed, the optical prism includes an incident surface on which light emitted from the light irradiation unit is incident, and the detection plate It is preferable that the angle formed by the contact surface to be in close contact with the surface is 43 ° or less at most. With such an angle, the specimen can be detected with high sensitivity. However, when the angle α of the prism is smaller than 30 °, the incident light does not satisfy the total reflection condition on the surface of the detection plate, that is, the incident angle of light on the detection surface of the detection plate is smaller than the critical angle. It may become.

<Light irradiation means>
The light irradiation means irradiates the detection plate with light through the optical element.

  The configuration of the light irradiation means is not particularly limited as long as it can irradiate the detection plate with light through the optical element, and can be appropriately selected according to the purpose. For example, laser, white lamp, LED A collimator that collimates the light emitted from the light source, a polarizing plate that polarizes the collimated light, an optical fiber that guides the light emitted from the light source to the collimator, and condenses the light from the light source. Thus, it can be configured by appropriately selecting from known optical members such as a condensing lens to be incident on the optical prism.

<Light detection means>
The light detection means detects reflected light reflected from the detection plate.

The configuration of the light detection means is not particularly limited and can be appropriately selected according to the purpose. A photodetector such as a CCD, a photodiode, or a photomultiplier tube that detects the reflected light, and the reflected light An optical fiber that leads to the photodetector and a condensing lens that collects the reflected light and guides it to the photodetector can be appropriately selected from known optical members.
When the wavelength-resolved measurement method is used, a spectroscope and a photodetector are provided as the light detection means, thereby measuring the spectrum of reflected light or measuring the intensity of reflected light in a specific wavelength region. .

  The optical arrangement of the detection device is not particularly limited and may be appropriately selected according to the purpose. For example, the SPR sensor (see FIGS. 1 and 2) related to the Kretschmann arrangement and the wavelength-resolved measurement, In addition, each optical system of the optical waveguide mode sensor (see FIGS. 3 and 4) can be configured. From the viewpoint of realizing a small and highly sensitive detection device, the optical waveguide using the optical waveguide mode is used. It is preferable that the optical system of the mode sensor is used. The detection apparatus configured as described above can detect the specimen from a change in the characteristic of the reflected light that changes depending on the presence or absence of the specimen in the capturing recess of the detection plate.

<Other members>
The other members are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. For example, water (subject) containing the sample on the detection surface of the detection plate is used. Examples include a guidance section for guidance.
The configuration of the guide section is not particularly limited as long as the specimen can be guided to the capture layer. For example, the inlet for injecting the specimen and the injected specimen on the surface of the capture layer. And a guide path that guides upward.

  Examples of the oil component include mineral oil and vegetable oil. Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Surfactant etc. are mentioned. The detection device can use water that is suspected of being mixed with at least one of these oils and surfactants, for example, drinking water, industrial water, river water, lake water, seawater, dam reservoir water, It can be widely used for water quality surveys such as rainwater and wastewater from factories.

(Detection method)
The detection method of the present invention is a method of detecting the presence of the specimen contained in the water using the detection device of the present invention, wherein the first light irradiation step, the first light detection step, and the capture It has a process, a 2nd light irradiation process, and a 2nd light detection process, and has another process as needed.

<First light irradiation step>
The first light irradiation step is a step of irradiating the detection plate with light from the light irradiation means via the optical element. This step is performed in a state in which water that does not include the sample serving as a reference is administered to the detection surface of the detection plate.
There is no restriction | limiting in particular as the light irradiation method in the said 1st light irradiation process, According to the objective, it can select suitably, For example, using the said light irradiation means demonstrated with the said detection apparatus of this invention Can do.
The detection plate is not particularly limited as long as it has the capture layer, and can be appropriately selected according to the purpose. For example, the detection plate of the present invention can be used.

<First light detection step>
The first light detection step is a step of detecting reflected light reflected from the detection plate based on the first light irradiation step.
The light detection method in the first light detection step is not particularly limited and may be appropriately selected depending on the purpose. For example, the light detection method described in the light detection device of the present invention is used. be able to.

<Capture process>
The capturing step is a step of administering water suspected of mixing the sample to the detection surface of the detection plate and capturing the sample contained in the water in the capturing recess of the capturing layer. This step may be performed after waiting for several seconds to several tens of minutes after adding the water in order to capture a sufficient amount of the specimen for detection.

<Second light irradiation step>
The second light irradiation step is a step of irradiating the detection plate with light after the capturing step.
As the light irradiation method in the second light irradiation step, the same method as the light irradiation method in the first light irradiation step can be used.

<Second light detection step>
The second light detection step detects reflected light reflected from the detection plate based on the second light irradiation step.
As the light detection method in the second light detection step, the same method as the light detection method in the first detection step can be used.

  The detection device used in the detection method is not particularly limited and can be appropriately selected according to the purpose. For example, the SPR sensor (see FIGS. 1 and 2) related to the Kretschmann arrangement and the wavelength-resolved measurement. ), And a detection device composed of each optical system of the optical waveguide mode sensor (see FIGS. 3 and 4), but from the viewpoint of using a small and highly sensitive detection device, An optical system of the optical waveguide mode sensor using the optical waveguide mode is preferable.

The detection method having such a process can detect the specimen based on a change in characteristics of each reflected light detected in the first light detection step and the second light detection step. The
The first light irradiation step and the first light detection step are performed at least before the capturing step, and the second light irradiation step and the second light detection step are performed after the capturing step. Although it is necessary to carry out, it is not necessary to intermittently perform the light irradiation and the light detection performed in these steps. In actual detection, the first light irradiation step and the first light irradiation are not necessary. The light irradiation and the light detection in the light detection step, the second light irradiation step, and the second light detection step may be continuously performed. That is, the light irradiation and the light detection can be performed constantly for a certain time, and the capturing step may be performed within the certain time.

Example 1
With the configuration shown in FIG. 9, the detection apparatus 100 in Example 1 was manufactured.
In this detection apparatus 100, the light irradiated from the tungsten halogen lamp light 101 is introduced in the order of the collimator lens 103 and the polarizing plate 104 through the optical fiber 102 </ b> A, converted into s-polarized parallel light, and then the optical prism 105. It was comprised so that it might irradiate. A detection plate 106 is optically adhered to the optical prism 105 through matching oil.

  In addition, the detection apparatus 100 reflects the light applied to the detection plate 106 via the light incident surface a of the optical prism 105 on the surface of the detection plate 106 and emits the light from the light emission surface b of the optical prism 105. The light was guided to the spectroscope 108 through the condensing lens 107 and the optical fiber 102B, and the spectrum was observed by the photodetector 109 (CCD array). In this embodiment, a trapezoidal prism having two base angles α of 38 ° is used as the optical prism 105.

In the detection plate 106, a thin film layer 106b made of a single crystal Si layer having a thickness of 220 nm is formed on a transparent substrate (made of silica glass) 106a having a thickness of 1.2 mm, and a thermally oxidized silicon layer having a thickness of 440 nm is formed thereon. And a plurality of recesses for capturing were formed on the surface of the thermally oxidized silicon layer by a method combining ion implantation and etching.
Specifically, in the ion implantation process, 1 × 10 ¹⁰ gold ions per 1 cm ² were irradiated perpendicularly from the upper surface of the thermally oxidized silicon layer at 137 MeV. Thereafter, this was immersed in an HF solution diluted to 5% for 2 minutes and chemically etched to selectively remove the ion irradiation portion, form the capturing recess, and produce the detection plate 106.

  After the formation of the capture recess, water repellent treatment was performed on the surface on which the capture recess was formed using dimethyldichlorosilane, which is a silane coupling agent having a lipophilic group, to form a capture layer 106c. The capturing layer 106c is formed integrally with the optical waveguide layer, and also functions as an optical waveguide layer.

An electron micrograph of the surface of the trapping layer 106c is shown in FIG. In FIG. 10, it is possible to confirm a large number of fine holes constituting the capturing recess. The diameter of the capture recess was about 70 nm. Although the depth of the hole could not be observed, according to past literature (reference document 1 below), the hole is considered to be conical.
FIG. 11 is a photograph when water droplets are dropped on the surface of the trapping layer 106c. It can be confirmed that water droplets are close to a sphere due to the water repellent effect. Further, the contact angle at this time was 115.8 °.
Reference 1: K. Awazu, S .; ishii, K .; Shima, S .; Rooda, J .; L. Brebner, Phys. Rev. B 62, pp. 3689 (2000)

FIG. 12 shows a state where the surface of the detection plate 106 before water repellent treatment is in the air state (A), a state where 150 μL of pure water is dropped on the detection surface of the detection plate 106 before water repellent treatment under atmospheric pressure (B), Further, detection is performed in a state where the surface of the detection plate 106 after water repellent treatment is in the air state (C), and in a state where 150 μL of pure water is dropped on the detection surface of the detection plate 106 after water repellent treatment under atmospheric pressure (D). The result of having observed the reflection spectrum with the apparatus 100 is shown.
Comparing the spectra of (A) and (C), when the chip surface is air before and after the water repellent treatment, there is no significant difference in the reflection spectrum. Although the spectrum of (C) is slightly shifted to the longer wavelength side, a water repellent layer is formed on the surface of the detection plate 106 by the water repellent treatment. As a result, the dielectric constant increases on the surface of the detection plate 106. It depends.
On the other hand, when the spectra in (B) and (D) are compared, it is observed that the observed dip position is shifted to the short wavelength side due to the water repellent treatment. This is because the water repellent treatment makes it difficult for water to enter the trapping recesses, creating a space that is not filled with water in the trapping recesses, and as a result, the average dielectric constant on the surface of the detection plate 106 is lowered.
Due to the spectrum change seen in (B) and (D), that is, the short wavelength shift of the dip position seen when the water-repellent effect is applied to the detection surface, a space not filled with water is formed in the catching recess. Can be confirmed.

  Canola oil (manufactured by Showa Sangyo Co., Ltd.) was used as the oil to be detected. The concentration of the oil in the aqueous solution to be tested was set to 2 mg / L, which is lower than the reference value (30 mg / L of animal and vegetable oil) in the water pollution prevention method wastewater. Further, at this time, 2.5 ppm of a surfactant (manufactured by Tokyo Chemical Industry Co., Ltd., Tween 20) was mixed so that the oil was dissolved in the water as the specimen.

FIG. 13 shows a reflection spectrum measured by the detection device 100 according to Example 1 after dropping water not containing oil and a reflection spectrum after 10 minutes have passed after dropping water containing oil.
As can be seen from the figure, the dip position shifts to the longer wavelength side as time passes after the water containing the oil is dropped. This shift is caused by the fact that the oil is gradually trapped in the trapping layer 106c, and as a result, the dielectric constant in the trapping layer increases.
Thus, it turns out that the density | concentration below the reference | standard defined by the water pollution prevention method can be detected within 10 minutes with the detection apparatus 100 which concerns on Example 1. FIG.

(Example 2)
In the detection apparatus according to the first embodiment, except that a trapezoidal prism having two base angles α of 38 ° is replaced with a trapezoidal prism having two base angles α of 32 °. A detection apparatus according to Example 2 was fabricated in the same configuration as Example 1.

FIG. 14 shows a state (B) in which 150 μL of pure water is dropped at atmospheric pressure on the detection surface of the detection plate before water repellent treatment with respect to the detection apparatus according to Example 2, and the detection plate after water repellent treatment The result of having observed the reflection spectrum of reflected light in the state (D) which dripped 150 microliters of pure water on the detection surface of this under atmospheric pressure is shown.
As shown in the figure, as in Example 1, when comparing the spectra in (B) and (D), it was observed that the observed dip position was shifted to the short wavelength side by the water repellent treatment, It can be confirmed that a space not filled with water is formed in the catching recess.

Using the detection apparatus according to Example 2, measured by the same method as in Example 1, measured after 5 minutes and 10 minutes after dropping the reflection spectrum after dropping water not containing oil, and water containing oil. The obtained reflection spectrum is shown in FIG.
As can be seen from the figure, after dripping water containing oil, the dip position shifts to the long wavelength side as time passes, and it is possible to detect a concentration below the standard defined by the Water Pollution Control Law in a few minutes. It turns out that it is possible. Further, the shift amount obtained at this time was larger than that measured using the detection apparatus according to Example 1. That is, it can be seen that higher sensitivity can be obtained by reducing the low angle of the prism.

(Example 3)
In the detection apparatus according to Example 1, a detection apparatus according to Example 3 was produced in the same manner as in Example 1 except that the method for forming the capturing recess was changed to the following method.
That is, in this example, after irradiating 1 × 10 ¹⁰ gold ions per cm ² vertically by 137 MeV vertically from the upper surface of the trapping layer in the ion implantation process, the detection plate is applied to the vapor of HF solution diluted to 20%. By performing chemical etching by exposure for 30 minutes, the ion-irradiated part was selectively removed, and a recess for capturing was formed. During the etching, the detection plate was held near the HF solution surface so as not to be immersed in the HF solution. Etching was performed with the temperature of the HF solution being 19 ° C. and the temperature of the detection plate being 30 ° C.

FIG. 16 shows an electron micrograph of the surface of the trapping layer 106c in which the trapping recesses are formed by the above method.
The opening diameter of the formed catching recess was about 15 nm. Although the depth of the hole could not be observed, according to the past literature (Non-Patent Document 10), unlike the case of Example 1, the hole is formed straight and deep, penetrates the optical waveguide layer, and is not etched by HF. It is considered that the film stops on the surface of the thin film layer made of the single crystal Si layer.

FIG. 17 shows a state (B) in which 150 μL of pure water is dropped under atmospheric pressure on the detection surface of the detection plate before water repellent treatment, and the detection plate after water repellent treatment with respect to the detection apparatus according to Example 3. The result of having observed the reflection spectrum of reflected light in the state (D) which dripped 150 microliters of pure water on the detection surface of this under atmospheric pressure is shown.
As shown in the figure, when the spectra in (B) and (D) were compared as in Example 1, it was observed that the observed dip position was shifted to the short wavelength side due to the water repellent treatment, and captured. It can be confirmed that a space not filled with water is formed in the concave portion for use.

Using the detection apparatus according to Example 3, the reflection spectrum measured by the same method as in Example 1 after dropping water not containing oil and the reflection spectrum measured after 10 minutes after dropping water containing oil were measured. Is shown in FIG.
As can be seen from the figure, after dripping water containing oil, the dip position shifts to the long wavelength side as time passes, and it is possible to detect a concentration below the standard defined by the Water Pollution Control Law in a few minutes. It turns out that it is possible.

Example 4
In the detection apparatus according to Example 1, a detection apparatus according to Example 4 was manufactured in the same manner as in Example 1 except that the water repellent treatment method was changed to the following method.
That is, after the formation of the catching recess by HF etching, rinsing and drying are performed, and water repellent treatment is performed on the surface on which the catching recess is formed using Dodecyltrichlorosilane, which is a silane coupling agent having a lipophilic group. It was.

Using the detection apparatus according to Example 4, measured by the same method as in Example 1, the reflection spectrum after dropping water not containing oil, and the reflection spectrum measured after 10 minutes after dropping water containing oil Is shown in FIG.
As can be seen from the figure, the dip position shifts to the longer wavelength side as time passes after the water containing the oil is dropped, and it is possible to detect the concentration below the standard defined by the Water Pollution Control Law in a few minutes. It turns out that it is. Further, the shift amount obtained at this time was larger than that measured using the detection apparatus according to Example 1. It can be seen that the water repellent treatment method can change the degree of water repellency and increase the sensitivity.

(Comparative Example 1)
In the detection apparatus according to Example 1, a detection apparatus according to Comparative Example 1 was produced in the same manner as in Example 1 except that a detection plate not subjected to water repellent treatment was provided. In Comparative Example 1, since no water repellent treatment is performed, there is no data relating to the difference in spectrum before and after the water repellent treatment.

Using the detection apparatus according to Comparative Example 1, measured by the same method as in Example 1, the reflection spectrum after dropping water not containing oil and the reflection spectrum measured after 10 minutes after dropping water containing oil Is shown in FIG.
As can be seen from the figure, the dip position hardly changes and it can be seen that the detection is not possible. From this, it can be seen that water repellent treatment is important for high sensitivity. FIG. 21 is a photograph when water droplets are dropped on the surface of the detection plate used in Comparative Example 1. It can be confirmed that there is almost no water repellent effect. The contact angle at this time was 52.3 °.

(Comparative Example 2)
In the detection apparatus according to Example 1, a detection apparatus according to Comparative Example 2 was produced in the same manner as in Example 1 except that a detection plate that did not form a capture recess was provided.

FIG. 22 shows a state (B) in which 150 μL of pure water is dropped on the detection surface of the detection plate before water repellent treatment under atmospheric pressure with respect to the detection apparatus according to Comparative Example 2, and the detection plate after water repellent treatment The result of having observed the reflection spectrum of reflected light in the state (D) which dripped 150 microliters of pure water on the detection surface of this under atmospheric pressure is shown.
As can be seen from the figure, unlike the cases of FIGS. 12, 14, and 17, there is no difference in the reflection spectrum before and after the water repellent treatment. FIG. 23 is a photograph when water droplets are dropped on the surface of the detection plate used in Comparative Example 2. It can be confirmed that water droplets are close to a sphere due to the water repellent effect. Further, the contact angle at this time was 101.7 °.

Using the detection apparatus according to Comparative Example 2, the reflection spectrum measured by the same method as in Example 1 after dropping water not containing oil and the reflection spectrum measured after 10 minutes after dropping water containing oil were measured. Is shown in FIG.
As can be seen from the figure, the dip position hardly changes and it can be seen that the detection is not possible. From this, it can be seen that the formation of the catching recess is important for high sensitivity.

(Example 5)
In the detection apparatus according to Example 1, a detection apparatus according to Example 5 was manufactured in the same manner as in Example 1 except that the method for forming the recess for capturing was changed to the following method.
That is, in this example, 1 × 10 ¹⁰ silver ions accelerated at 60 MeV perpendicularly from the upper surface of the trapping layer in the ion implantation process were irradiated per cm ^2, and then the detection plate was placed in an HF solution diluted to 5% for 2 minutes. Immersion and chemical etching were used to selectively remove the ion-irradiated portion and form the capturing recess.

In Example 5, a surfactant (manufactured by Tokyo Chemical Industry Co., Ltd., Tween 20) was used as a specimen. The concentration of Tween 20 in the aqueous solution was 1 ppm.
Using the detection apparatus according to Example 5, measurement was performed in the same manner as in Example 1, and the reflection spectrum after dropping the specimen-free water and the measurement after 10 minutes after dropping the water containing the specimen were measured. The reflection spectrum is shown in FIG.
As can be seen from the figure, the dip position shifts to the longer wavelength side as time passes after the water containing the specimen is dropped, and the surfactant can be detected in a few minutes.

10, 20, 30, 40, 50, 60, 106 Detection plate 11, 21, 31, 41, 51, 106a, 201, 306, 401a, 506a Transparent substrate 12, 202, 307 Metal thin film layer 13, 23, 33, 43, 53, 63, 106c Capture layer 14, 24, 34, 44, 54, 64 Capture recess 17, 27, 37, 47, 57, 67 Detection electric field forming layer 22, 32, 42, 52, 62, 106b, 401b, 506b Thin film layer 25, 401c, 506c Optical waveguide layer 66, 105, 203, 303, 402, 505 Optical prism 100 Detector 101 Tungsten halogen lamp light 102A, 102B, 302A, 302B, 502A, 502B Optical fiber 103, 304 , 503 Collimating lens 104, 205, 305, 404, 504 Optical plate 107, 308, 507 Condensing lens 108, 309A, 508 Spectroscope 200, 300 SPR sensor 204, 301, 403, 501 Light source 109, 206, 309, 405, 509 Photodetector 210A, 310A, 410A Incident light 210B, 310B, 410B Reflected light 400, 500 Optical waveguide mode sensor 401, 506 Detection plate a Light incident surface b Light exit surface α angle θ incident angle

Claims (15)

A detection electric field forming layer for forming an electric field for detecting at least one of oil and surfactant as a specimen;
A capture layer that captures the specimen from water containing the specimen is arranged in this order,
The capture layer is formed with a capture recess for capturing the specimen on the surface in contact with the water, and is subjected to water repellency treatment on the surface in contact with the water,
A detection plate according to claim 1, wherein when the water is dropped on the surface on which the catching recess is formed under atmospheric pressure, the water in the water does not enter the entire catching recess.   The detection plate according to claim 1, wherein the capture recess is a hole formed in the capture layer.   2. The detection plate according to claim 1, wherein the capture recess is formed by arranging a plurality of pillars on the surface of the detection plate on the side in contact with the water containing the specimen so that the interval is a recess.   The detection plate according to claim 3, wherein the longest diameter of the pillar is shorter than the wavelength of light used.   The detection plate according to claim 1, wherein the capturing recess is formed as surface roughness.   The detection plate according to any one of claims 1 to 5, wherein an opening diameter of the capturing recess is shorter than a wavelength of light to be used.   The detection plate according to any one of claims 1 to 6, wherein the depth of the capture recess is 5 nm or more and 5 µm or less.   2. The detection plate according to claim 1, wherein the capture concave portion is formed by arranging a plurality of beads on the surface of the detection plate on a side in contact with water containing the specimen so that the interval is a concave portion.   9. The water repellent treatment according to claim 1, wherein a surface treatment using a silane coupling agent having an oleophilic group or a surface treatment using a fluorine coating agent is performed on the surface on which the catching concave portion is formed. Description detection plate.   10. The detection plate according to claim 1, wherein the detection electric field forming layer is formed by arranging a surface plasmon excitation layer that expresses surface plasmon resonance.   The detection plate according to claim 10, wherein the material for forming the surface plasmon excitation layer includes at least one of gold, silver, copper, platinum, and aluminum.   The detection electric field forming layer is formed by arranging an optical waveguide layer formed of a transparent material and a thin film layer formed of a metal material or a semiconductor material in this order from the side on which the capturing layer is disposed. The detection plate according to any one of 9 to 9.   The detection plate according to claim 12, wherein the trapping layer is formed so as to serve as part or all of the optical waveguide layer. The detection plate according to any one of claims 1 to 13,
An optical element disposed on the surface on which the detection electric field forming layer of the detection plate is disposed;
A light irradiation means for irradiating the detection plate with light through the optical element;
Light detection means for detecting reflected light reflected from the detection plate,
A detection apparatus that detects the specimen from a change in characteristics of the reflected light that changes in accordance with the presence or absence of the specimen in the capture recess of the detection plate. A detection method for detecting the presence of a sample contained in water using the detection device according to claim 14,
A first light irradiation step of administering water not containing the specimen to the surface of the detection plate on which the capture layer is formed, and irradiating the detection plate with light from the light irradiation means via an optical element;
A first light detection step of detecting reflected light reflected from the detection plate based on the first light irradiation step;
A capturing step of administering water containing the sample to the surface of the detection plate on which the capturing layer is formed and capturing the sample in a capturing recess of the capturing layer;
A second light irradiation step of irradiating the detection plate with light after the capturing step;
A second light detection step for detecting reflected light reflected from the detection plate based on the second light irradiation step;
A detection method, comprising: detecting the specimen from a change in characteristics of each reflected light detected in the first light detection step and the second light detection step.