Sample liquid concentration device, sample liquid analysis auxiliary device, method for manufacturing the same, and sample liquid concentration method

Abstract

To increase the efficiency of analysis that uses an enhanced electric field generated by a microstructure.SOLUTION: A certain embodiment of the present disclosure provides a plate-like sample liquid concentration device 10 that is used overlapping a microstructure substrate having microstructures arranged on its surface, and the microstructures each may generate an enhanced electric field to incident light. The sample liquid concentration device comprises a first surface and a second surface having a thickness together with the first surface, and a plurality of passage parts are formed which connect the first surface and the second surface to each other. First openings and second openings are formed in the first surface and the second surface, respectively, and the passage parts are defined by inside surfaces connecting the first openings and the second openings to each other. The arrangement of the first surface proximate to the surface of the microstructure substrate may locate the first openings in correspondence with the positions of the microstructures. The second openings are made to receive sample liquid containing an object to be detected.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a sample liquid concentrating device, a sample liquid analysis auxiliary device, a manufacturing method thereof, and a sample liquid concentrating method. More specifically, the present disclosure relates to a sample liquid concentrating device, a sample liquid analysis auxiliary device, a manufacturing method thereof, and a sample liquid concentrating method that improve the practicality of analysis using microstructures. [Background technology]

[0002] It is known that when light is irradiated onto tiny components ("microstructures") made of metals or other materials, a strong optical electric field can be generated due to the resonant interaction between the microstructure and the light waves. For example, when light of a specific wavelength is irradiated onto metal nanoparticles such as gold or silver, the free electrons within the nanoparticles can undergo collective oscillations, which are called localized surface plasmons. When localized surface plasmons are excited within the microstructure, an extremely strong electric field (called an enhanced electric field) is generated near the surface of the microstructure. In microstructures, strong enhanced electric fields can also be generated by the Mie resonance phenomenon that occurs in nanoparticles with high refractive indexes, such as silicon. These enhanced electric fields are generally generated in the vicinity of the microstructure or in a localized area of ​​the microstructure, and the location where the enhanced electric field is formed is sometimes called a hotspot.

[0003] The enhanced electric field generated at the hotspot can be considered a bright light source, and methods have been proposed to utilize the enhanced electric field to improve the sensitivity of various optical measurement methods. For example, when a material is irradiated with light, the scattered light generates a light component in which the molecular vibration frequency is added (or subtracted) from the original light frequency as a result of the interaction between the light and the molecules that make up the material. This is Raman scattered light, and precise measurement of the frequency of Raman scattered light can provide information about the composition of the material (Raman scattering spectroscopy). However, the intensity of this Raman scattered light is generally extremely low, and its scattering efficiency is about one millionth that of directly scattered light (Rayleigh scattering) without frequency change. This low intensity of Raman scattered light has limited the range of applications of Raman scattering spectroscopy. Therefore, a technology has been devised to overcome the low scattering efficiency of Raman scattered light by using the enhanced electric field described above and enhance the Raman scattered light itself. This technology is called surface-enhanced Raman scattering spectroscopy.

[0004] In addition to Raman scattering spectroscopy, many other methods have been proposed that utilize an enhanced electric field generated by illumination light using a microstructure, such as infrared spectroscopy and fluorescence observation.

[0005] Non-Patent Document 1 discloses a device with metal microstructures that respond differently to the chirality of circularly polarized light, which was previously developed by a group including the present inventor. Non-Patent Document 2 also relates to devices with microstructures, and discloses a device with metal microstructures patterned in the shapes of "L" and "I." [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Takumi Iida, Atsushi Ishikawa, Takuo Tanaka, Atsuya Muranaka, Masanobu Uchiyama, Yasuhiko Hayashi, and Kenji Tsuruta, "Super-chiral vibrational spectroscopy with metasurfaces for highly sensitive identification of alanine enantiomers," Applied Physics Letters 117, 101103 (DOI: 10.1063 / 5.0012331) (2020) [Non-patent document 2] Atsushi Ishikawa, Shuhei Hara, Takuo Tanaka, Yasuhiko Hayashi, and Kenji Tsuruta, "Cross-Polarized Surface-Enhanced Infrared Spectroscopy by Fano-Resonant Asymmetric Metamaterials," Scientific Reports 7, 3205 (DOI: 10.1038 / s41598-017-03545-8) (2017) Summary of the Invention [Problem to be solved by the invention]

[0007] To utilize an enhanced electric field, a substance to be measured, such as a sample molecule (referred to as a "detection target"), must be present within a hot spot near a microstructure. However, if the detection target is dispersed in a sample liquid (referred to as a "sample liquid" in this application) or if the concentration of the detection target is low, even if the sample liquid is brought into contact with the surface of a microstructure, the detection target in the liquid may not necessarily be appropriately positioned near the microstructure or within the hot spot. The present disclosure provides a novel method that can solve this problem, thereby contributing to significantly improving the practicality of analytical methods that utilize the enhanced electric field created by microstructures. [Means for solving the problem]

[0008] The inventor conceived the idea that if the concentration of the substance to be detected in the sample liquid could be locally increased in the hot spot area, the practicality of analytical methods that utilize microstructures could be improved, and completed the invention of the present disclosure.

[0009] That is, in one aspect of the present disclosure, there is provided a plate-shaped sample liquid concentrating device for use by being stacked on a microstructure substrate, in which a microstructure capable of generating an enhanced electric field in response to incident light is arranged on the surface of the microstructure substrate, the sample liquid concentrating device having a first surface and a second surface that forms a thickness together with the first surface, and a plurality of passage sections connecting the first surface and the second surface, the passage sections having first and second openings formed on the first and second surfaces, respectively, and defined by inner surfaces connecting the first openings and the second openings, the first surface being arranged close to the surface of the microstructure substrate, so that the first opening can be positioned corresponding to the position of the microstructure, and the second opening is adapted to receive a sample liquid containing a detection target.

[0010] In addition, in one aspect of the present disclosure, there is also provided a method for manufacturing a sample liquid concentration device, comprising the steps of: forming a passage portion in a plate-shaped member that connects a first surface and a second surface that form the thickness of the plate; wherein the passage portion has a first opening formed in the first surface and a second opening formed in the second surface, and is defined by an inner surface that connects the first surface and the second surface, and positioning the first opening to correspond to the position of a microstructure that can generate an enhanced electric field in response to incident light.

[0011] In addition, one aspect of the present disclosure also provides a sample liquid analysis auxiliary device that utilizes the above-described sample liquid concentrating device.

[0012] In addition, in one aspect of the present disclosure, there is also provided a method for concentrating a sample liquid, which includes the steps of: positioning a first opening formed on a first surface of a passage portion connecting a first surface and a second surface that form the thickness of a plate-like member, in correspondence with the position of a microstructure that can generate an enhanced electric field in response to incident light; receiving a sample liquid containing a substance to be detected into a second opening formed on the second surface of the passage portion; and volatilizing the solvent of the sample liquid.

[0013] In this application, the term "microstructure" generally refers to a nanostructure that utilizes a material that responds to incident electromagnetic waves. A sample liquid refers to a liquid or liquid-like substance that contains, in some form, the substance to be analyzed (referred to as the "detection target"). In this application, the term "electromagnetic wave" may include electromagnetic waves of any wavelength or frequency. In this application, terms for light, including visible light, may be used to describe interactions and phenomena with electromagnetic waves. [Effects of the Invention]

[0014] According to any aspect of the present disclosure, it is possible to improve the practicality of analytical techniques that utilize minute structures. [Brief explanation of the drawings]

[0015] [Figure 1A-E] 1A to 1E are explanatory diagrams illustrating examples of microstructures used in embodiments of the present disclosure, including a perspective view (FIG. 1A), scanning electron microscope images (FIGS. 1B and 1C), and calculated values ​​of optical chiral components (FIGS. 1D and 1E). [Figures 2A-E] 2A to 2E are explanatory diagrams illustrating another example of a microstructure used in an embodiment of the present disclosure, including a perspective view (FIG. 2A), a scanning electron microscope image (FIG. 2B), and calculated values ​​of light intensity distribution (FIGS. 2C to 2E). [Figure 3] FIG. 3 is a perspective view for explaining an outline of the inventor's idea in this embodiment. [Figure 4] FIG. 4 is a scanning micrograph image showing an example component that may be a candidate for a sample liquid concentrator in an embodiment of the present disclosure. [Figure 5A-C]5A to 5C are cross-sectional views illustrating steps in a method for concentrating a sample liquid in an embodiment of the present disclosure. [Figure 6] FIG. 6 is a flowchart of a concentration method according to an embodiment of the present disclosure. [Figure 7A-D] 7A to 7D are cross-sectional views showing modified examples of the sample liquid concentrating device and the method of using the same according to the embodiment of the present disclosure. [Figure 8] FIG. 8 is a flowchart showing an outline of a method for manufacturing a sample liquid analysis auxiliary device according to an embodiment of the present disclosure. [Figure 9] FIG. 9 is a flowchart showing another method for manufacturing the sample liquid analysis auxiliary device of this embodiment. [Figure 10A-C] 10A to 10C are cross-sectional views showing the configuration at each stage of the manufacturing process. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the diffuser according to the present disclosure will be described with reference to the drawings. In the description, common parts or elements are designated by common reference numerals unless otherwise specified. Furthermore, in the drawings, elements of each embodiment are not necessarily shown to scale.

[0017] 1. Overview 1-1. Relationship between enhanced electric field and detection target 1A-1E are explanatory diagrams illustrating an example of a microstructure used in this embodiment, including a perspective view (FIG. 1A), scanning electron microscope images (FIGS. 1B and 1C), and calculated values ​​of optical chiral components (FIGS. 1D and 1E). FIGS. 1B and 1C also show enlarged partial images. The microstructure 52A is formed on a substrate 50 by repeatedly arranging a pattern of a material, such as gold, that responds to incident electromagnetic waves. The material that responds to incident electromagnetic waves is typically a noble metal, but may also include inorganic materials such as Si, Ge, and Ga, or compounds such as TiN and HfN. FIG. 1A shows the scope of the unit cell of this repeated arrangement. The substrate is made of any material, such as silicon, that can form a fine pattern. Localized surface plasmons, for example, are induced in the layer of the microstructure 52A as electrons respond to the incident electromagnetic waves. These localized surface plasmons resonantly respond to the vibrations of the electromagnetic waves. If we define the substrate surface as the xy plane and the normal direction to it as the z-axis, as shown in the figure, then of the various polarizations of electromagnetic waves incident generally perpendicularly with their wave vectors pointing toward the -z axis, the electric field E and magnetic field H components that are oriented along the y-axis and z-axis, respectively, are involved in this resonance. The unit cell in Figure 1A is 2000 nm (2 μm) square, and the representative dimensions of each component are clearly shown in Figure 1A. In this example, a metal pattern, e.g., a gold thin film, is formed within the unit cell. Two rectangular patterns, each 300 nm wide in the x-axis and 800 nm long in the y-axis, are offset along the y-axis with a 300 nm gap between them. The two metal patterns are offset by 400 nm, and depending on the offset, two types of arrangements are possible, as shown in Figures 1B and 1C. These are called left-handed and right-handed, respectively. Figures 1D and 1E show the chiral component, or handedness, as a concentration plot of the electric field strength calculated using the FDTD method. Electromagnetic waves are classified in order of the amount of chiral component, from circularly polarized to elliptically polarized and linearly polarized. Dark areas indicate areas where chiral components close to circular polarization are dominant, while bright areas indicate areas where linear polarization is dominant. Locations where the chiral components, which indicate handedness (+ and -), are biased also have a strong electric field, forming an enhanced electric field. The enhanced electric field reaches its maximum in the area between adjacent patterns.

[0018] 2A to 2E are explanatory diagrams illustrating another example of a microstructure used in this embodiment, including a perspective view (FIG. 2A), a scanning electron microscope image (FIG. 2B), and calculated values ​​of light intensity distribution (FIGS. 2C to 2E). A partially enlarged image of FIG. 2B is also shown. The microstructure 52B is also formed by repeatedly arranging a metal pattern, such as gold, on the substrate 50. FIG. 2A shows the range of the unit cell of this repeated arrangement. The substrate is made of any material, such as silicon, that can support a flat, fine pattern. The size of each component indicated by the symbols in FIG. 2A is adjusted; typically, Px = Py = 1 μm, and h / S = 0.75. Enhanced electric fields in dipole and quadrupole modes are induced in the metal layer of the microstructure 52B. These are shown as intensities in FIGS. 2C and 2D. At the position, the electric field is strengthened by localized surface plasmons, resulting in the formation of an enhanced electric field. The enhanced electric field is primarily formed adjacent to the metal patterns and in the region between adjacent metal patterns. When molecules characteristic of the target substance, which have a chemical bond C=O (carbonyl group), are present near the gap, electrical vibrations are excited by Fano resonance. This is illustrated in Figure 2E. The enhanced electric field is primarily maximized in the region between adjacent metal patterns.

[0019] In this way, localized surface plasmons are induced in the microstructure, and an enhanced electric field is formed around it due to its action. The position affected by this enhanced electric field (hot spot) is strongly related to the position of the microstructure. In order to detect a target substance with high sensitivity using a microstructure, it is important that the target substance is present in the hot spot.

[0020] 1-2. Concept / Structure The inventors of the present disclosure have focused on the idea that if sample liquid is placed near microstructures or in hotspot areas and the solvent (e.g., water) can be evaporated from the sample liquid, the concentration of the target substance near the microstructures or in the hotspot areas can be increased, thereby improving the sensitivity of subsequent analysis. Specifically, they came up with the idea of ​​stacking a sample liquid concentrator 10 having a channel 20 on a microstructure substrate 50 on which microstructures 52 are formed. Figure 3 is a perspective view illustrating the outline of the inventors' idea in this embodiment. The microstructures 52 are arranged on the surface of the microstructure substrate 50. The microstructures 52 can generate an enhanced electric field in response to incident light (incident electromagnetic field). The arrangement of the channel 20 in the sample liquid concentrator 10 can be adapted to the arrangement of the microstructures 52. The channel 20 is formed on a concentrator substrate 16. The first surface 11 and the second surface 12, which form the thickness of the concentrator substrate 16, are connected by the channel 20. The passage portion 20 has a first opening 21 and a second opening 22 on the first surface 11 and the second surface 12, and is defined by an inner surface 23 that penetrates the concentrator substrate 16. The first surface 11 is disposed in close contact with or close to the surface of the microstructure substrate 50, i.e., in close proximity. In FIG. 3, for the sake of explanation, the sample liquid concentrator 10 is depicted separated from the microstructure substrate 50. This allows the first opening 11 to be positioned corresponding to each position on the microstructure 50. The second surface 12 is configured to receive a sample liquid containing a detection target substance.

[0021] 4 is a scanning microscope image showing an example of a component that can be a candidate for the sample liquid concentrating device 10. The silicon substrate 80 is <100> This is a substrate with a specific orientation. When a crystal such as silicon is chemically etched using an etching solution, the etching rate varies depending on the crystal orientation, so the etching occurs anisotropically, and a self-organizing uneven structure is formed on the surface of the material. This passage 90 is also formed by etching silicon with a potassium hydroxide solution using crystal anisotropic etching, and is etched into an inverted pyramid (quadratic pyramid) shape. For example, a concave structure in the shape of a quadrangular pyramid can be created in any location using microfabrication technology. Details will be described later.

[0022] 1-3. Concentration operation 5A-5C are cross-sectional views illustrating each step of a method for concentrating a sample liquid according to this embodiment. FIGS. 5A-5C show, in chronological order, each step of concentrating a sample liquid using a sample liquid concentrating device 10 having a structure similar to that of FIG. 3. FIG. 6 is a flowchart of the concentration method according to this embodiment. In the concentration operation, first, the sample liquid concentrating device 10 is positioned so that the first opening 21 of the passage 20 corresponds to the position of the hot spot of the microstructure (FIG. 6, S02). Next, the sample liquid 70 containing the target substance 72 is placed in the second opening 22 of the passage 20 (S04). This placement can be performed by any method, such as dropping the sample liquid or dipping the entire device including the sample liquid concentrating device 10 into a container containing the sample liquid 70. The sample liquid 70 is typically a solution of the target substance 72 in an appropriate solvent. As a result, as shown in FIG. 5A, the sample liquid 70 is placed in the passage 20 defined by the inner surface 23. The solvent in the sample liquid 70 is then evaporated (S06). This reduces the volume of the sample liquid 70, as shown in FIG. 5B, and increases the concentration of the target substance 72. As the evaporation proceeds, the concentration of the target substance 72 in the sample liquid 70 increases sufficiently, resulting in a high probability of the target substance 72 being located in a hot spot near the microstructure 52. Because the inner surface 23 of the passage 20 typically functions as a funnel, the concentrated sample liquid 70 collects near the microstructure 52. Whether to completely evaporate the solvent to dry the sample liquid 70 or to stop evaporation midway and concentrate the sample liquid 70 can be determined depending on the properties of the sample liquid 70 and the analytical conditions. Then, an analysis is performed that utilizes the interaction between the target substance 72 and the microstructure 52 (S08). A typical example of this analysis is spectroscopic analysis, including Raman spectroscopy, but the analytical technique is not particularly limited. If it is acceptable for the sample liquid concentrating device 10 to be present during the analysis stage, the analysis may be carried out as is, or if there is some reason, the sample liquid concentrating device 10 may be removed and the analysis may be carried out.

[0023] 1-4. Improvements suitable for concentration To achieve the concentration described above, various modifications may be made to the sample liquid concentrating device 10. This is because the surface properties of the passages fabricated using such techniques are important for concentrating the sample liquid 70. For example, if the concentrating device substrate 16 for the sample liquid concentrating device 10 is a single-crystal silicon substrate, after forming the passages 20 using crystal anisotropic etching, it is useful to modify the outermost surface of the single-crystal silicon substrate, including the inner surface 23, to a superhydrophobic state using reactive ion etching at the final stage of forming the inner surface 23. More specifically, the native oxide film that naturally forms on the surface of the single-crystal silicon substrate, including the inner surface 23, is removed, and the surface is then treated with C4F8 plasma. This process can modify the surface to a superhydrophobic state.

[0024] Among the surfaces of the concentrator substrate 16, the surfaces whose properties are preferably controlled are typically the second surface 12 and the inner surface 23, or either of these. The properties suitable for these surfaces may be hydrophobic treatment, including superhydrophobic treatment, or hydrophilic treatment (including superhydrophilic treatment). The properties suitable for this surface depend on the substance of the sample liquid 70 and the concentration process. The solvent in the sample liquid 70 is typically water, but can also be an organic solvent. The operation shown in Figures 5A-5C is a process in which the concentration of the target substance 72 in the sample liquid 70 increases as the solvent evaporates. In this process, surfaces that can appropriately concentrate the sample liquid 70 include not only superhydrophobic surfaces, but also hydrophobic and hydrophilic surfaces. To create a hydrophobic surface, for example, a silane coupling agent treatment using hexamethyldisilazane (HMDS) or the aforementioned fluorine plasma treatment can be used. To create a hydrophilic surface, for example, if the concentrator substrate 16 is a silicon substrate, the native oxide film can be removed or oxygen plasma treatment can be used. In reality, a native oxide film forms on the surface of a Si substrate, but since this film is not necessarily clean, simply removing it can make the substrate hydrophilic. Oxygen plasma treatment can also make the substrate hydrophilic by removing organic matter adhering to the surface. Note that when a Si substrate is treated with oxygen plasma, a new oxide film is formed, so the oxide film remains. Other hydrophobic and hydrophilic treatment methods can also be used. The water repellency, hydrophobicity, and hydrophilicity of a surface can be quantitatively evaluated by measuring the contact angle.

[0025] In this embodiment, the surface properties of the second surface 12 and the inner surface 23 can be correlated with each other or controlled independently, thereby enabling the concentrator substrate 16 to exhibit its functions. Typical combinations include four patterns: one in which both the second surface 12 and the inner surface 23 are hydrophobic or superhydrophobic; one in which the inner surface 23 is hydrophobic and the surface 12 is hydrophilic; one in which the inner surface 23 is hydrophilic and the surface 12 is hydrophobic; and one in which both the inner surface 23 and the surface 12 are hydrophilic.

[0026] 1-5. Variations 7A to 7D are cross-sectional views showing modified examples of the sample liquid concentrating device 10 and its method of use according to this embodiment. The sample liquid concentrating device 10 in FIG. 7A is similar to that shown in FIG. 4 and shows the sample liquid 70 in FIG. 5C at a concentrated stage. Unlike the previous explanations, the passages 20 in the sample liquid concentrating device 10 do not necessarily have to be arranged in one-to-one correspondence with the microstructures 52. For example, as shown in FIG. 7B, when the microstructures 52 are formed at a high density, this embodiment also includes a configuration in which the first openings 21 of the passages 20 are positioned to correspond to only some of the multiple microstructures 52. Although not shown, this embodiment also includes a configuration in which multiple microstructures 52 are positioned corresponding to the first openings 21 of the passages 20.

[0027] 7C, a sample liquid concentrating device 10A in which passages 20A are formed in a columnar shape rather than a conical shape can also be used to concentrate sample liquid 70. Pillar-shaped passages 20A can be arranged with increased surface density.

[0028] The sample liquid concentrating devices 10 and 10A described above operate in combination with a microstructure 52 formed on a microstructure substrate 50. This embodiment also includes an arrangement in which a support film 30 is formed on the first surface 11 of the concentrating device substrate 16, and the microstructure 52 is formed at a position through the thickness of the support film 30, as shown in FIG. 7D . If the support film 30 has appropriate dielectric properties and thickness, an enhanced electric field due to the microstructure 52 is also formed at a position through the thickness of the support film 30, allowing the concentrated sample liquid 70 to be placed within the range of the enhanced electric field. Even with this configuration, analytical sensitivity can be improved. Furthermore, this configuration has the advantage that the sample liquid 70 does not directly contact the microstructure 52 but is placed through the support film 30, thereby increasing the options for materials for the sample liquid 70 and the microstructure 52. Note that if the support film 30 is thin and mechanically weak, it is preferable to add a protective layer 32 as needed to easily maintain the shape of the sample liquid concentrating device 10 for analysis, for example.

[0029] Furthermore, this embodiment also includes a configuration in which, instead of the passage 20 connecting both sides of the sample liquid concentrating device 10, a structure (recessed structure) deeply carved from one side but not extending to the other side is used (not shown). Substrates such as silicon wafers can be used as substrates for forming the microstructure 52, as well as for forming the passage 20 or similar structures. Therefore, by forming a recessed structure corresponding to the passage 20 on one side of the substrate and placing the microstructure 52 on the other side, the concentrated sample liquid 70 can be placed within the range where the enhanced electric field is generated by the microstructure 52. To achieve this, the bottom of the recessed structure must be sufficiently thin, and both sides of the substrate must be processed in alignment. This configuration can also have the same advantages as the sample liquid concentrating device 10A. Furthermore, when using both sides of such a single substrate, it is advantageous to penetrate the bottom of the recessed structure to form the passage 20 and place the microstructure 52 so that it is partially floating above the first opening 21.

[0030] 1-6. Manufacturing of auxiliary equipment for sample liquid analysis Figure 8 is a flowchart showing an outline of a method for manufacturing the sample liquid analysis auxiliary device of this embodiment. Here, the sample liquid analysis auxiliary device is a device that simplifies the analysis of sample liquid by combining sample liquid concentrating device 10 having the configuration shown in Figure 4 with a microstructure substrate 50 on which microstructures 52 are formed. The process for manufacturing the sample liquid analysis auxiliary device generally includes a nanostructure array manufacturing process (S22 to S28) for forming microstructures 52 on microstructure substrate 50, a funnel array manufacturing process (S42 to S48) for forming passages 20 on the substrate, and an assembly process (S62 to S64) for combining these processes.

[0031] 1-6-1. Fabrication of nanostructure arrays The microstructure 52 is formed by forming a film of a material that responds to incident electromagnetic waves on one side of a silicon wafer (S22), and then performing resist patterning (S24) and etching (S26) using a technique such as photolithography. The resist is then removed (S28). Various specific microfabrication techniques can be used, and a technique can be selected appropriately based on the size and material of the microstructure 52.

[0032] 1-6-2. Manufacturing of funnel array The sample liquid concentrating device 10 includes: <100> A silicon wafer with a first surface is prepared as the concentrator substrate 16, and SiO2 or Si3N4 mask layers are formed on both surfaces of the wafer. A photoresist layer is then formed on the mask layer on the second surface 12, which is one of the surfaces, and the photoresist layer is exposed to light and dry-etched (S42), forming window-shaped openings in the mask layer (S44). The second surface 12 of the silicon substrate is then wet-etched through the window-shaped openings with an etching solution such as KOH (S46). If the wet-etching conditions are appropriately set, a quadrangular pyramidal recess is formed on the second surface 12 of the silicon substrate according to the crystal orientation, forming a passage 20 defined by the inner surface 23. The mask layer is then removed as necessary (S48). Note that the passage 20 connects both surfaces of the silicon substrate; however, recess structures in which the bottom of the recess structure is sufficiently thin but not interconnected can also be fabricated by setting the conditions appropriately.

[0033] 1-6-3. Assemble The concentrator substrate 16 on which the passage section 20 is formed and the microstructure substrate 50 on which the microstructure 52 is formed are aligned so that the microstructure 52 is positioned in the first opening 21 of the passage section 20 (S62). At this time, the first surface 11 of the concentrator substrate 16 faces the surface of the microstructure substrate 50 on which the microstructure 52 is formed. In this state, the concentrator substrate 16 and the microstructure substrate 50 are fixed to each other (S64). Thereafter, any necessary protective treatment (not shown) is carried out as appropriate. By assembling the concentrator substrate 16 and the microstructure substrate 50 in this manner, the sample liquid concentrating device 10 shown in FIG. 3 is fabricated.

[0034] 1-6-4. Modifications of the manufacturing of the sample liquid analysis auxiliary device The sample liquid analysis auxiliary device of this embodiment can be manufactured by any manufacturing method that can ultimately produce the configuration of sample liquid concentrating device 10 shown in Figures 7A to 7D. Figure 9 is a flowchart showing another manufacturing method of the sample liquid analysis auxiliary device of this embodiment, and Figures 10A to 10C are cross-sectional views showing the configuration at each stage of manufacturing.

[0035] The sample liquid concentrating device 10 can also be manufactured by using a different method for manufacturing the funnel array. First, as shown in FIG. 9, the nanostructure array manufacturing process (S22 to S28) is performed to form the microstructures 52 on the microstructure substrate 50. This is similar to the process described above. At this stage, the microstructures 52 are formed on the microstructure substrate 50 (FIG. 10A). Then, a funnel array layer 162 is formed on the surface of the microstructure substrate 50 on which the microstructures 52 are formed (S72, FIG. 10B). The material to be formed is a layer of polysilicon or the like, which will later form the passage 20. A suitable method is used for forming the layer depending on the material. Next, a mask layer (not shown) is formed on the surface of the funnel array layer 162 to coincide with the positions of the microstructures 52 (S74). Furthermore, the mask layer is etched (S76), and openings are formed in the mask layer (S78). Then, crystal anisotropic etching is performed on the funnel array layer 162 (S80). This forms the passages 20 in the funnel array layer 162. Thereafter, the mask layer is removed as needed (S82, FIG. 10C).

[0036] 1-6-5. Material variations The sample liquid concentrating device 10 (FIG. 3) of this embodiment also uses silicon to form the passage 20. <100> Materials that generate self-organized shapes using crystalline anisotropy, such as substrates with a specific orientation, can be used. Examples of such materials other than silicon include CaF2, which exhibits crystalline anisotropy during etching. CaF2 is also highly useful because it is transparent from the visible to infrared range. For example, the positions of the holes in the formed funnel can be aligned while being checked using an optical microscope. The sample liquid concentrating device 10 can be formed into any pattern using existing microfabrication techniques in other fields, such as MEMS (Micro Electro Mechanical Systems).

[0037] The embodiments of the present disclosure have been specifically described above. The above-mentioned embodiments and examples have been described to explain the invention, and the scope of the invention of this application should be determined based on the description of the claims. In addition, modifications within the scope of the present disclosure, including other combinations of the embodiments, are also included in the claims. [Explanation of symbols]

[0038] 10, 10A Sample liquid concentrator 11 Page 1 12 Side 2 16 Concentrator board 162 Funnel Array Layer 20, 20A passage section 21 First Opening 22 Second opening 23 Inner surface 30 Support membrane 32 Protective layer 50 Microstructure substrate 52, 52A, 52B Microstructure 70 sample liquid 72 Object to be detected 80 Silicon substrate 90 Passage section

Claims

1. A plate-shaped sample liquid concentrating device for use by being placed on a microstructure substrate, the microstructure being capable of generating an enhanced electric field in response to incident light and disposed on a surface of the microstructure substrate, the sample liquid concentrating device has a first surface and a second surface that forms a thickness together with the first surface, and a plurality of passages that connect the first surface and the second surface are formed; the passage portion is defined by an inner surface connecting the first opening and the second opening, the first opening and the second opening being formed in the first surface and the second surface, respectively; the first surface is disposed in proximity to the surface of the microstructure substrate, so that the first opening can be positioned corresponding to the position of the microstructure; The second opening is adapted to receive a sample liquid containing a substance to be detected. Sample liquid concentrator.

2. Either the second surface or the inner surface or both of the second surface and the inner surface are super water-repellent surfaces. The sample liquid concentrating device according to claim 1 .

3. Either the second surface or the inner surface or both are hydrophobic surfaces. The sample liquid concentrating device according to claim 1 .

4. Either the second surface or the inner surface or both are hydrophilic surfaces. The sample liquid concentrating device according to claim 1 .

5. Either the second surface or the inner surface is a hydrophilic surface, and the other is a hydrophobic surface. The sample liquid concentrating device according to claim 1 .

6. the passage is formed in a silicon crystal substrate; The second opening is larger than the first opening, and the passage is funnel-shaped. The sample liquid concentrating device according to claim 1 .

7. The inner surface is a polygonal pyramid shape. The sample liquid concentrating device according to claim 6.

8. The sample liquid concentrating device according to claim 1 ; a microstructure substrate on the surface of which a microstructure capable of generating an enhanced electric field in response to incident light is disposed; Equipped with The sample liquid concentrating device and the microstructure substrate are arranged such that the first surface is close to the surface of the microstructure substrate, thereby positioning the first opening in correspondence with the position of the microstructure. Auxiliary equipment for sample liquid analysis.

9. A plate-shaped sample liquid analysis auxiliary device, the sample liquid analysis auxiliary device has a first surface and a second surface that defines a thickness together with the first surface, and a plurality of passages are formed connecting the first surface and the second surface; the passage portion is defined by an inner surface connecting the first opening and the second opening, the first opening and the second opening being formed in the first surface and the second surface, respectively; a film that covers at least a part of the first opening is formed on the first surface, and a microstructure that can generate an enhanced electric field in response to incident light is disposed on a portion of any surface of the film that corresponds to the first opening; The second opening is adapted to receive a sample liquid containing a substance to be detected. Auxiliary equipment for sample liquid analysis.

10. a microstructure substrate having a surface on which a microstructure capable of generating an enhanced electric field in response to incident light is disposed; a funnel array layer disposed in contact with the surface of the microstructure substrate; Equipped with the funnel array layer has a first surface in contact with the surface of the microstructure substrate and a second surface forming a thickness together with the first surface, and a plurality of passages connecting the first surface and the second surface are formed; the passage portion is defined by an inner surface connecting the first opening and the second opening, the first opening and the second opening being formed in the first surface and the second surface, respectively; the first opening is positioned corresponding to the position of the minute structure, The second opening is adapted to receive a sample liquid containing a substance to be detected. Auxiliary equipment for sample liquid analysis.

11. forming a passage portion in a plate-like member, the passage portion connecting a first surface and a second surface that form the thickness of the plate; wherein the passage portion has a first opening formed in the first surface, a second opening formed in the second surface, and is defined by an inner surface that connects the first surface and the second surface; positioning the first opening in correspondence with the position of a microstructure capable of generating an enhanced electric field for incident light; A method for manufacturing a sample liquid concentrating device comprising:

12. disposing a microstructure capable of generating an enhanced electric field for incident light on a surface of a microstructure substrate; forming a funnel array layer in contact with the surface of the microstructure substrate, covering the microstructure, and having a thickness between a first surface and a second surface in contact with the surface; forming a passage portion in the funnel array layer connecting the first surface and the second surface, wherein the passage portion has a first opening formed in the first surface and a second opening formed in the second surface, the passage portion being defined by an inner surface connecting the first surface and the second surface, and the first opening being positioned corresponding to the position of the microstructure; A method for manufacturing a sample liquid concentrating device comprising:

13. the step of forming the passage portion is a step of forming the inner surface by crystal anisotropic etching on a silicon crystal substrate; A method for producing the sample liquid concentrating device according to claim 11 or 12.

14. a step of positioning a first opening formed in a first surface of a passage portion connecting a first surface and a second surface forming a thickness of a plate-like member, in correspondence with a position of a microstructure capable of generating an enhanced electric field in response to incident light; receiving a sample liquid containing a detection target substance into a second opening formed on a second surface of the passage portion; volatilizing the solvent of the sample liquid; A method for concentrating a sample liquid, comprising:

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