JP4591963B2 - Nanochannel for near-field optical sensor and manufacturing method thereof - Google Patents

Description

  In an optical sensor based on the detection principle of surface plasmon resonance and light absorption using evanescent waves as probe light, the amount of sample required for measurement is kept small, and from the nanoliter used for efficient capture of reactions in the sensing section The present invention relates to a nanochannel for a near-field optical sensor having a microliter scale volume and a manufacturing method thereof.

  A substance that generates a molecule-specific reaction on the surface of the sensing unit, such as an ionophore, antibody, enzyme, molecular imprint polymer, or mediator, is immobilized on a metal thin film, and is generated by molecular selective reaction with the measurement target. Sensors that measure changes in the rate or extinction coefficient are applied in the fields of medicine, environment, and food. This change in refractive index or extinction coefficient is obtained by applying measurement light so as to totally reflect the metal thin film on which the measurement object is fixed and measuring the surface plasmon or light absorption change of the totally reflected light. be able to. This is because an evanescent wave is generated when the measurement light is totally reflected, and this evanescent wave acts as probe light that interacts with molecules. As described above, in the sensor using the evanescent wave as the probe light, the measurable region is limited within the reach of the probe light. In addition, when an animal or a person is used as a sample, the burden on the sample increases, so it is desirable to keep the amount of sample necessary for measurement small. Therefore, a cell having an internal volume of the flow path of about 8 nL has been devised (see Non-Patent Document 1), and it is shown that the required sample amount can be kept small.

M. Furuki, J. Kameoka. H. G. Craighead, M. S. Isaacson, “Surface plasmon resonance sensors utilizing microfabricated channels”, Sensors and Actuators B, vol. 79, 2001, P.63-69.

  However, since there are still many areas that cannot be measured in the flow path, there is a problem that an extra sample is required to perform the measurement. When ultraviolet, visible, or near infrared light having a wavelength of 300 to 1000 nm is used as measurement light, the reachable distance of the evanescent wave depends on the incident angle and the refractive index of the material of the total reflection surface, but at least the measurement light It becomes shorter than the wavelength. Therefore, in the case of a channel having a distance (depth) of about 15 μm between the inner wall on which the conventional metal thin film is formed and the inner wall facing the inner wall, the measurement object (molecule) contained in the sample solution introduced into the channel. Most of them exist outside the sensing area and contribute little to sensing data.

  The object of the present invention is to reduce the amount of sample required for measurement to the nanoliter scale, and at the same time, to measure the target molecule in the near field so that the probe light can capture the target object contained in the sample with high probability. An object of the present invention is to provide a nanochannel for a near-field optical sensor that can be confined in a space having a submicrometer-scale depth, which is a probeable region, and a method for manufacturing the nanochannel.

In order to achieve such an object, the present invention is characterized in that the invention according to claim 1 is made of a glass material that is transparent to the wavelength of the measurement light in the nanochannel for the near-field optical sensor, and the measurement light. The near-field optical sensor nanochannel has a metal thin film formed on the inner wall on the side where the light is incident, and the distance from the inner wall on which the metal thin film is formed to the inner wall facing the inner wall is the distance between the inner wall and the metal thin film. measuring light at the interface Ri der substantially the same or less than evanescent waves and distance oozing from the metal thin film that occurs when totally reflected, the near-field nanochannels optical sensor, a first substrate made of a glass material, A measurement light incident side, and a second substrate made of a glass material,
A region serving as a flow path is formed on at least one surface of the first substrate and the second substrate, and the first substrate and the second substrate are bonded to each other through an adhesive layer made of a silicon nitride film. The flow path is formed by adhering with the above.
A second aspect of the present invention is the nanochannel for a near-field optical sensor according to the first aspect, wherein the glass material is BK7 which is a poron silicate glass.

A second aspect of the present invention is the nanochannel for a near-field optical sensor according to the first aspect, wherein the glass material is BK7 which is a poron silicate glass .

A third aspect of the present invention is the near-field optical sensor nanochannel according to the first or second aspect , wherein the region to be the flow path is a groove formed by etching.

A fourth aspect of the present invention is the nanochannel for a near-field optical sensor according to the first or second aspect , wherein the adhesive layer is formed to be separated from the first adhesive layer and the second adhesive layer. is, a region serving as a flow path, characterized in that the first adhesive layer is a region between the second adhesive layer.

Invention of Claim 5 is the nanochannel for near-field optical sensors in any one of Claim 1 thru | or 4 , Comprising: The depth of the nanochannel for near-field optical sensors is 200 nm or more and 1 micrometer or less It is characterized by being.

A sixth aspect of the present invention is the near-field optical sensor nanochannel according to any one of the first to fifth aspects , wherein the distance between the side walls of the near-field optical sensor nanochannel is 0.15 mm. It is characterized by being 5 mm or less.

It invention according to claim 7, a nano channel for near field optical sensor according to any of claims 1 to 6, the metal thin film is any one of gold, silver, and copper It is characterized by.

The invention according to claim 8 is the nanochannel for a near-field optical sensor according to any one of claims 1 to 7 , wherein the antibody, DNA, enzyme, ionophore, molecule on the surface of the metal thin film inside the channel One of the imprint polymer and the mediator is immobilized.

According to a ninth aspect of the present invention, in the method for producing a nanochannel for a near-field optical sensor, the first substrate made of a glass material transparent to the wavelength of the measurement light and the side on which the measurement light is incident. Te, comprising: providing a second substrate made of a glass material, the surface of the first base plate, thereby forming an adhesive layer made of a silicon nitride film, forming a region serving as a flow path, the flow A step of forming a metal thin film on the surface of the second substrate so as to be within a region to be a path, and bonding the first substrate and the second substrate by an anodic bonding method through an adhesive layer , The distance from the inner wall where the metal thin film is formed in the flow path to the inner wall facing the inner wall is determined by the evanescent wave generated when the measurement light is totally reflected at the interface between the inner wall and the metal thin film. About the same as the distance Characterized in that is less.
A tenth aspect of the invention is a method for producing a nanochannel for a near-field optical sensor according to the ninth aspect of the invention, wherein the glass material is BK7, which is a porous silicate glass.

  According to the present invention, since the metal thin film has a depth of nanometer scale and a capacity of nanoliter scale, the amount of sample necessary for measurement is suppressed to the nanoliter scale, and probe light is included in the sample. Therefore, it is possible to increase the sensitivity of surface plasmon resonance measurement and total reflection absorption measurement. It is also possible to measure the antigen-antibody reaction by immobilizing the antibody on the metal thin film of the nanochannel. In addition to the antibody, the metal selective substance is an ionophore, enzyme, molecular imprint polymer, and mediator. It is also possible to efficiently measure various types of objects from a very small amount of sample by immobilizing on a thin film.

  1A to 1D show a configuration of a nanochannel according to an embodiment of the present invention. The upper glass substrate 1 and the lower glass substrate 6 included in the nanochannel having a depth corresponding to the reach distance of the near-field probe light have transparency with respect to light in a wavelength band used for optical measurement. In addition, a glass material or a polymer material having a refractive index adjusted is used. The flow path portion 5 of the upper glass substrate 1 is formed by etching the substrate, depositing a material on the substrate, or molding a die from the substrate material, and is a surface of the lower glass substrate 6 on the upper glass substrate 1 side. Thus, the metal thin film 3 for generating or enhancing the near-field probe light including the surface plasmon is formed in at least a part of the flow path portion 5. Then, the upper glass substrate 1 and the lower glass substrate 6 are bonded by the adhesive layer 4. The metal thin film 3 can be a gold (Au), silver (Ag), or copper (Cu) metal thin film.

  In the present specification, the distance between the inner wall of the flow channel portion 5 on which the metal thin film 3 is formed and the inner wall facing the metal thin film 3 is set as the depth, and is orthogonal to the inner wall of the flow channel portion 5 on which the metal thin film 3 is formed. The inner wall is a side wall, and the interval between these side walls is the width.

  After forming the nanochannel, the surface of the metal thin film 3 is modified with an ionophore, an antibody, an enzyme, a molecular imprint polymer, or a mediator, which is a substance that generates a molecule-specific reaction, so that ions, antigens, Various nano-channels for biochemical sensing that measure substrates or organic substances are prepared.

  FIG. 2 shows a configuration of an optical system for performing measurement using a nanochannel according to an embodiment of the present invention. The nanochannel 8 is attached to the prism 9 of the optical measurement system, and the measurement channel emitted from the light source 7 is totally reflected at the interface between the lower glass substrate 6 and the metal thin film 3 through the prism 9. , A prism 9 and a light source 7 are arranged. Then, the measuring light totally reflected at the interface between the lower glass substrate 6 and the metal thin film 3 is detected by the detector 10 via the prism 9.

  Since the metal thin film 3 is formed at least on the surface of the lower glass substrate 6 in the flow path portion 5 through which the sample passes, the total reflection condition of incident light on the interface between the metal thin film 3 and the lower glass substrate 6 is satisfied. The evanescent wave enters the flow path portion 5 through the metal thin film 3. The incident angle or wavelength spectrum due to surface plasmon resonance, or the wavelength spectrum related to light absorption changes depending on how the object to be measured (molecules) contained in the sample of the evanescent wave that has oozed into the flow path section 5 is absorbed. In order to measure molecule-specific reactions such as antigen-antibody reaction, a molecule-selective substance is immobilized on the metal thin film 3 to generate surface plasmon resonance and light absorption resulting from interaction with the molecule to be measured. It is necessary to let The measurement sensitivity also improves when the probability of occurrence of surface plasmon resonance and light absorption increases.

  The intensity of the evanescent wave that is the probe light decreases exponentially with respect to the distance from the total reflection interface. Therefore, if the depth t of the flow path part 5 is equal to or less than the reach distance of the evanescent wave, all the molecules to be measured introduced into the flow path part 5 are present in the probeable region. Become. Further, in the case of the nanochannel 8 in which the molecule-selective substance is immobilized on the metal thin film 3, the measurement target (molecule) is introduced into the channel 5 and the measurement target is diffused to cause the molecule selectivity. It is necessary to wait until a chemical equilibrium between the substance and the measurement object is achieved. Imprinted in the reaction time to reach this chemical equilibrium state and in the antigen, complementary DNA, enzyme substrate, ion, and polymer, which are the measurement objects (molecules) in the sample introduced into the flow path section 5 There is a correlation between the average diffusion distance of molecules and molecules with similar structures. Since the depth t of the channel portion 5 of the nanochannel 8 according to the embodiment of the present invention is equal to or less than the reach distance of the evanescent wave and is smaller than the depth of the conventional channel, The average diffusion distance of the measurement object (molecule) in the sample to be introduced is short. As a result, the time to reach the chemical equilibrium state is shortened, the reaction time constant is increased, and the amount of reaction required for measurement occurs from a small amount of sample within a certain measurement time. The lower detection limit can be lowered.

  The depth t of the flow channel unit 5 is a submicrometer scale, but by increasing the width scale of the flow channel unit 5 from several hundred μm to several mm units, the sample solution can be easily flown by capillary action. 5 can flow into. Even if the sample solution that has flowed into the flow path portion 5 from one opening reaches the opening on the opposite side, the sample solution remains in the flow path portion 5 because the flow path portion 5 is narrow. In this way, the sample solution can be filled in the flow channel unit 5 without using an external pump, and the sample solution filled in the flow channel unit 5 remains in the flow channel unit 5, so that the measurement target The measurement which ensured the reaction time for interaction with a thing (molecule) and the immobilized molecular selective substance can be implemented.

  Furthermore, since the capacity | capacitance in the flow-path part 5 is 1 nL-1 microliter, a required sample amount can be restrained to a small quantity conventionally.

[Example of estimation of probeable area by optical model]
The model assumed in the present embodiment is a Kretschmann optical system that measures surface plasmon resonance. The material of the upper glass substrate 1 and the lower glass substrate 6 of the prism 9 and the nanochannel 8 is BK7 which is a polysilicate glass, the wavelength of the measurement light emitted from the light source 7 is 770 nm, and the incident angle of the measurement light to the prism 9 is 60 degrees. Therefore, a nano-channel of a four-layer model in which the first layer is BK7, the second layer is a gold thin film (thickness of 50 nm), the third layer is water, and the fourth layer is BK7 is constructed, and the incident angle in surface plasmon resonance The spectrum was simulated. FIG. 3 is a line graph showing the reflectance of light at the surface plasmon resonance angle obtained by simulation.

  The light reflectance at the minimum value in the surface plasmon resonance spectrum is higher as the depth of the flow path portion 5 is thinner, and reaches about 20% when the depth of the flow path portion 5 exceeds 800 nm. From around 800 nm, the change in light reflectance is negligible even when the thickness of the water layer is increased. This reflectance of light reflects the amount of water that interacts with the evanescent wave, that is, the thickness of the water layer that interacts with the evanescent wave. The fact that the reflectance of light does not change even when the thickness of the water layer is increased means that the thickness of the water layer that interacts with the evanescent wave does not change. Therefore, the upper limit of the thickness of the water layer interacting with the evanescent wave, that is, the thickness of the water layer on which the optical absorption measurement effectively functions by the evanescent wave can be estimated to be about 1 μm.

  FIG. 3 is a bar graph showing the refractive index sensitivity obtained by the simulation. The refractive index sensitivity expressed by the change in the surface plasmon resonance angle per unit relative refractive index (RIU) increases as the water layer thickness decreases, and decreases as the water layer thickness increases. However, when the thickness of the water layer reaches 800 and 900 nm, which is also near the limit of the evanescent wave reach, the refractive index sensitivity hardly changes. From this, it can be estimated that the probeable region of the water layer interacting with the evanescent wave is a distance from the metal thin film surface to about 1 μm.

[Production of nanochannels]
4A to 4F and FIG. 4B to FIG. 4E show an example of a nanoflow channel manufacturing flow according to an embodiment of the present invention. The upper glass substrate 1 and the lower glass substrate 6 are made of poron silicate glass (BK7) whose refractive index is adjusted.

  The production flow of the upper part is shown. An adhesive layer 4 made of a silicon nitride film is formed with a thickness of 200 nm on the surface of the upper glass substrate 1 (FIG. 4A). Next, a resist polymer 11 having a thickness of 20 μm is applied (FIG. 4B), and a pattern of grooves 2 is formed in the resist polymer 11 by photolithography (FIG. 4C). The interval between the side walls of the groove 2 can be arbitrarily determined within a range of 0.15 to 5 mm. Thereafter, in order to form a region to be a flow path in the upper glass substrate 1, the adhesive layer 4 and the upper glass substrate 1 are shaved by dry etching using a carbon hexafluoride gas, from the upper surface to the bottom surface of the adhesive layer 4. A groove 2 having a depth of 200 nm to 1 μm is formed (FIG. 4D). That is, the groove 2 is formed so that the distance from the upper surface of the adhesive layer 4 to the bottom surface of the groove 2 is equal to or less than the reach distance of the evanescent wave. Next, the resist polymer 11 is dissolved and removed by a piranha solution (FIG. 4E).

  The production flow of the lower part is shown. A resist polymer 11 is applied to the surface of the lower glass substrate 6 (FIG. 4 (b ′)), and the resist thin film 3 is designed to fit into the resist polymer 11 by photolithography inside the groove 2 of the upper glass substrate 1. A pattern is formed (FIG. 4 (c ′)). Next, a metal thin film 3 is formed on the lower glass substrate 6 and the resist polymer 11 by sputtering or vapor deposition (FIG. 4 (e ′)), and then the resist polymer 11 is peeled off with a piranha solution (FIG. 4 (e)). ).

  Then, the positions of the upper part and the lower part are adjusted so that the metal thin film 3 of the lower part enters the groove 2 of the upper part, and the solution sample passing through the flow path part 5 contacts the surface of the metal thin film 3. Then, the nanochannel can be produced by pasting together by an anodic bonding method (FIG. 4 (f)).

  In the present embodiment, since the adhesive layer 4 is used for bonding the upper glass substrate 1 and the lower glass substrate 6, the distance from the upper surface of the adhesive layer 4 to the bottom surface of the groove 2 is the arrival of the evanescent wave. It is equal to or less than the distance. However, what is important in the present invention is that the height t of the flow path is equal to or less than the reach distance of the evanescent wave. Therefore, for example, the upper glass substrate 1 is installed on the lower glass substrate 6, and the contact surface between the upper glass substrate 1 and the lower glass substrate 6 is adhered with an adhesive from the outside of the flow path, and the adhesive layer 4 is used. If not, the groove 2 may be formed so that the distance from the upper surface of the upper glass substrate 1 to the bottom surface of the groove 2 is equal to or less than the reach distance of the evanescent wave.

  Here, an example of another nano-channel manufacturing flow is shown. Patterning with the resist polymer 11 is performed on the surface of the upper glass substrate 1, and then the portion not covered with the resist polymer 11 is selectively etched to form the grooves 2. Next, the resist polymer 11 is dissolved and removed with a piranha solution. An upper part is produced by forming an adhesive layer 4 on the upper glass substrate 1 on the adhesive surface with the lower glass substrate 6 which is a lower part. Moreover, the lower part is produced by forming the metal thin film 3 in a pattern on the surface of the lower glass substrate 6. And a nanochannel can be produced by adjusting the position of these upper parts and lower parts and bonding them together by an anodic bonding method.

  Furthermore, another example of the production flow of the nanochannel is shown. After patterning with the resist polymer 11 on the surface of the upper glass substrate 1, an adhesive layer 4 having a thickness of 100 to 1000 nm is deposited, and the resist polymer 11 is peeled off to pattern the adhesive layer 4 to form a flow path. Create the area and make the upper part. The lower part is produced by forming the metal thin film 3 on the surface of the lower glass substrate 6 by patterning so as to be within the region to be the flow path of the upper part. And a nanochannel can be produced by adjusting the position of these upper parts and lower parts and bonding them together by an anodic bonding method.

  In any of the manufacturing methods, silicon and silicon nitride can be used for the adhesive layer 4. Moreover, as a substrate material, a polymer having transparency with respect to measurement light is used, a groove 2 is formed by molding, an upper part is produced, and an organic solvent is applied to an adhesive surface with a polymer to be a lower part. The flow path part 5 can be formed by pressing both parts together.

  FIG. 5 shows a pattern example of the nanochannel according to one embodiment of the present invention. The groove 2 formed in the upper glass substrate 1 includes a first width region near both openings, a second width region narrower than the first width near the middle point, and a second region to a second region. And a third region that gradually decreases in width. That is, the groove 2 is configured in the order of the first region, the third region, the second region, the third region, and the first region. In addition, a metal thin film 3 that fits inside the groove 2 and is similar to the groove 2 is formed on the lower glass substrate 6. The upper glass substrate 1 and the lower glass substrate are bonded to each other by adjusting the position so that the metal thin film 3 is accommodated in the groove 2. Thus, the nanochannel according to the present embodiment arbitrarily determines the interval between the sidewalls, which is the width of each region of the channel unit 5, within a range of 0.15 to 5 mm, and sets the volume in the channel unit 5. It can be 1 nL-1 microliter.

[Solution entering the nanochannel]
When a liquid is dropped into one opening of the manufactured nanochannel, the liquid penetrates into the channel 5 due to a capillary phenomenon. When air exists in the nanochannel, interference fringes generated by interference of light reflected by the upper glass substrate 1 and the lower glass substrate 6 disappear when the channel portion 5 is filled with liquid. It can be visually confirmed. The liquid once immersed in the flow path portion 5 can be driven out of the flow path portion 5 by heating or shaking it strongly.

[Surface plasmon resonance spectrum using nanochannel]
FIG. 6 shows a surface plasmon resonance spectrum of water when the nanochannel according to one embodiment of the present invention is used. This is a measurement result in a nanochannel where the depth of the channel portion 5 is 340 nm and silicon nitride is used as the adhesive layer 4. The height of the reverse peak is about 2000A. U. There is an inverse peak height similar to that obtained by the same surface plasmon resonance measurement system using an Au thin film formed on the surface of a flat glass substrate.

[Surface plasmon resonance measurement of antigen-antibody reaction using nanochannel]
After filling the flow path part 5 with the solution containing the antibody and allowing it to stand for several hours, the liquid in the flow path part 5 is extracted. Next, an aqueous solution of polyethylene glycol was added to the flow path part 5 and left still for several hours, and then the liquid in the flow path part 5 was extracted, and the antibody was immobilized on the metal thin film 3 in the flow path part 5.

  FIG. 7 shows a surface plasmon resonance spectrum when only the buffer solution is introduced into the channel portion 5 in which the antibody is immobilized in the nanochannel according to one embodiment of the present invention (a in FIG. 7), and a buffer containing the antigen. The surface plasmon resonance spectrum (b of FIG. 7) when a liquid is introduced is shown. As a result of the antigen-antibody reaction, the surface plasmon resonance angle when only the buffer solution is introduced is 69.14 degrees, whereas the surface plasmon resonance angle when the buffer solution containing the antigen is introduced is 69.18 degrees. It rose 0.04 degrees. Thus, in the nanochannel according to the present embodiment, it is possible to immobilize an antibody that is a molecule-specific substance while maintaining the specificity in the antigen-antibody reaction.

(A) is a top view of a nanochannel according to an embodiment of the present invention, (b) is a cross-sectional view taken along line aa ′ of (a), and (c) is (a). FIG. 4B is a cross-sectional view taken along the line bb ′, and FIG. 4D is a cross-sectional view taken along the line cc ′ of FIG. It is a figure which shows the structure of the optical system for performing the measurement using the nanochannel which concerns on one Embodiment of this invention. It is a figure which shows the reflectance of the light in the surface plasmon resonance angle obtained by simulation with a line graph, and shows a refractive index sensitivity with a bar graph. (A)-(f), (b ')-(e') is a figure which shows the preparation flow of the nanochannel based on one Embodiment of this invention. It is a figure which shows the nanochannel pattern example which concerns on one Embodiment of this invention. It is a figure which shows the surface plasmon resonance spectrum of water when the nanochannel which concerns on one Embodiment of this invention is used. It is a figure which shows the measured value of the surface plasmon resonance of an antigen-antibody reaction when the nanochannel (depth 340nm) which concerns on one Embodiment of this invention is used.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper glass substrate 2 Groove 3 Metal thin film 4 Adhesive layer 5 Channel part 6 Lower glass substrate 7 Light source 8 Nanochannel 9 Prism 10 Detector 11 Resist polymer

Claims (10)

A nano-channel for a near-field optical sensor, which is made of a glass material that is transparent to the wavelength of the measurement light and in which a metal thin film is formed on the inner wall on the side on which the measurement light is incident,
The distance from the inner wall where the metal thin film is formed to the inner wall facing the inner wall is the distance that the evanescent wave generated when the measurement light is totally reflected at the interface between the inner wall and the metal thin film oozes out from the metal thin film When Ri der substantially the same, or lower,
The near-field optical sensor nanochannel includes a first substrate made of the glass material, and a second substrate made of the glass material on the measurement light incident side.
A region serving as a flow path is formed on at least one surface of the first substrate and the second substrate, and the first substrate and the second substrate are connected to each other via an adhesive layer made of a silicon nitride film. A nano-channel for a near-field optical sensor, wherein the channel is formed by bonding with an anodic bonding method . A nanochannel for a near-field optical sensor according to claim 1,
The glass material is BK7 which is a poron silicate glass.
A nanochannel for a near-field optical sensor . A nanochannel for a near-field optical sensor according to claim 1 or 2 ,
The nanochannel for a near-field optical sensor, wherein the region to be the channel is a groove formed by etching. A nanochannel for a near-field optical sensor according to claim 1 or 2 ,
The adhesive layer is formed separately from the first adhesive layer and the second adhesive layer,
Area formed with the flow path, the nano channel near field optical sensor, which is a region between the first adhesive layer and the second adhesive layer. A nano channel for near field optical sensor according to any of claims 1 to 4,
The near-field optical sensor nanochannel has a depth of 200 nm or more and 1 μm or less. A nanochannel for a near-field optical sensor according to any one of claims 1 to 5 ,
The distance between the side walls of the near-field optical sensor nanochannel is 0.15 mm or more and 5 mm or less. A near-field optical sensor nanochannel according to any one of claims 1 to 6 ,
The metal thin film is any one of gold, silver, and copper. A nanochannel for a near-field optical sensor, wherein: A nanochannel for a near-field optical sensor according to any one of claims 1 to 7 ,
One of antibody, DNA, enzyme, ionophore, molecular imprint polymer, and mediator is immobilized on the surface of the metal thin film. Providing a first substrate made of a glass material transparent to the wavelength of the measurement light, and a second substrate made of the glass material on the side on which the measurement light is incident;
To the surface of the first base plate, thereby forming an adhesive layer made of a silicon nitride film, forming a region serving as a flow path,
Forming a metal thin film on the surface of the second substrate so as to be within the region to be the flow path;
Bonding the first substrate and the second substrate through the adhesive layer by an anodic bonding method to form the flow path,
The distance from the inner wall where the metal thin film is formed in the flow path to the inner wall facing the inner wall is such that an evanescent wave generated when the measurement light is totally reflected at the interface between the inner wall and the metal thin film A method for producing a nanochannel for a near-field optical sensor, characterized in that the distance is substantially the same as or less than a distance that oozes from the near-field optical sensor. A method for producing a nanochannel for a near-field optical sensor according to claim 9,
The glass material is BK7 which is a poron silicate glass.
A method for producing a nanochannel for a near-field optical sensor, comprising:

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