JP6544461B2 - Electrically conductive material for biosensors and biosensors - Google Patents

Description

  The present invention relates to a conductive material and a biosensor for a biosensor using metal nanowires.

Various methods have been developed as methods for quantifying or quantifying specific components in a sample using biorelevant substances.
For example, immunochromatography is a test method using an antigen-antibody reaction, and is capable of detecting a target substance by a simple procedure. Therefore, it is put to practical use in influenza virus test, pregnancy test, and the like. Immunochromatography has a great advantage in terms of excellent portability and being able to cope with various target substances, but has problems such as poor sensitivity. In addition, although the examination time is relatively short, detection in a shorter time may be required. Specifically, in immunochromatography, it can not be detected when the target substance is at a low concentration, and the screening test accuracy is low, and it takes about 5 to 30 minutes for the sample to move on the membrane, (Moving phase) is required, and high viscosity samples need to be diluted, which may complicate the operation, and there is still room for improvement in order to realize early detection and treatment of infectious diseases etc. .

  In order to solve the above problems, biosensors using electrochemical methods have been developed and much research has been conducted. For example, electrode materials and electrode structures have been studied, and recently, research on highly sensitive biosensors using nanomaterials such as carbon nanotubes has been advanced (see, for example, Patent Documents 1 and 2).

JP 2008-64724 A Unexamined-Japanese-Patent No. 2010-230379

  However, biosensors using carbon nanotubes have problems in that the manufacturing process is complicated and carbon nanotubes have difficulty in thinning and pattern formation. Another problem is that carbon nanotubes have lower conductivity than metals.

  The present invention has been made in view of the above problems, and it is a main object of the present invention to provide a conductive material for a biosensor capable of increasing the sensitivity of a biosensor and a biosensor using the same.

  The present invention has a substrate, and a conductive layer formed on the substrate and containing a resin and a metal nanowire to achieve the above object, and the conductive layer is at least a part of the metal nanowire. A conductive material for a biosensor, comprising: a metal nanowire exposed portion exposed on the surface of the conductive layer.

  In the present invention, the conductivity can be improved by containing the metal nanowires in the conductive layer, and therefore, the use of the conductive material for a biosensor of the present invention enables high-sensitivity and short-time inspection. It is also possible to detect trace components. Further, in the present invention, since the conductive layer contains metal nanowires and a resin, pattern formation and thinning can be facilitated.

  In the said invention, it is preferable that the said conductive layer is formed in pattern shape on the said base material. It is possible to obtain a biosensor conductive material according to various forms.

  In the present invention, a specific binding substance that specifically binds to the target substance or the target substance may be immobilized on the exposed portion of the metal nanowires. In this case, the specific binding substance is preferably an antibody or an aptamer. In the present invention, a specific reaction can be used to detect a target substance or a specific binding substance.

  In the present invention, the insulating layer may be formed in a pattern on the base on which the conductive layer is formed. It is possible to prevent the sample from coming into contact with an electrode, a wiring, or the like connected to the conductive layer.

  The present invention also provides a biosensor comprising a sensor unit having the above-described conductive material for a biosensor.

  In the present invention, by having the above-described conductive material for a biosensor, it is possible to perform inspection with high sensitivity and in a short time, and also to detect a trace component.

  The present invention has the effect of being able to provide a biosensor that can be tested with high sensitivity and in a short time, and that even trace components can be detected.

It is a schematic sectional drawing which shows an example of the electrically conductive material for biosensors of this invention. It is a schematic sectional drawing which shows an example of the conductive layer in the electroconductive material for biosensors of this invention. It is a schematic sectional drawing which shows the other example of the electrically conductive material for biosensors of this invention. It is a schematic diagram which shows an example of the usage method of the biosensor of this invention. It is a schematic sectional drawing which shows the other example of the electrically conductive material for biosensors of this invention. It is the schematic plan view and sectional drawing which show the other example of the electrically conductive material for biosensors of this invention. It is a schematic plan view which shows the other example of the electrically conductive material for biosensors of this invention. It is a schematic diagram which shows an example of the biosensor of this invention. It is a schematic diagram which shows the other example of the biosensor of this invention.

  Hereinafter, the conductive material for a biosensor and the biosensor of the present invention will be described in detail.

A. Electrically Conductive Material for Biosensor The electrically conductive material for biosensor of the present invention comprises a substrate, and a conductive layer formed on the substrate and containing a resin and a metal nanowire, wherein the conductive layer is the above-mentioned metal nanowire It is characterized by having a metal nanowire exposure part which at least one part exposed to the surface of the above-mentioned conductive layer.

The conductive material for a biosensor of the present invention will be described with reference to the drawings.
Fig.1 (a) is a schematic sectional drawing which shows an example of the electrically conductive material for biosensors of this invention, FIG.1 (b) is an enlarged view of the broken-line part of Fig.1 (a). As illustrated in FIG. 1A, the biosensor conductive material 1 is a substrate 2 on which a conductive layer 3 containing a resin and metal nanowires is formed. The conductive layer 3 has a metal nanowire exposed portion 5 in which a part of the metal nanowire 4 is exposed to the surface of the conductive layer 3 as illustrated in FIG. 1 (b).

  Here, "at least a part of the metal nanowires is exposed on the surface of the conductive layer" means that a state in which contact with the metal nanowires can be obtained on the surface of the conductive layer. For example, the case as shown in FIG. 2 (a) or FIG. 2 (b) is referred to. On the other hand, even if the metal nanowires 4 are present on the surface of the conductive layer 3 as shown in FIG. 2C, in the case where the metal nanowires 4 are covered with the resin contained in the conductive layer 3, the metal nanowires Does not apply to the state of being exposed on the surface of the conductive layer.

Fig.3 (a) is a schematic sectional drawing which shows the other example of the electrically conductive material for biosensors of this invention, FIG.3 (b) is an enlarged view of the broken-line part of Fig.3 (a). As illustrated in FIGS. 3 (a) and 3 (b), in the conductive material 1 for a biosensor, the metal nanowire exposed portion 5 in which a portion of the metal nanowire 4 is exposed on the surface of the conductive layer 3 is used as a target substance. The specific binding substance 7 that specifically binds is immobilized.
In the example shown in FIG. 3, the specific binding substance is immobilized on the metal nanowire exposed portion, however, it is not limited to this, and the target substance may be immobilized on the metal nanowire exposed portion.
In the present invention, when the conductive layer has the metal nanowire exposed portion, a specific binding substance or target substance can be immobilized on the metal nanowire.

FIG. 4 is a schematic view showing an example of a method for detecting a target substance using the conductive material for a biosensor of the present invention. The biosensor conductive material shown in FIG. 4 is the same as the biosensor conductive material shown in FIG. As shown in FIG. 4, when the sample containing the target substance 10 is brought into contact with the conductive layer 3 in the biosensor conductive material 1, the specific binding substance 7 immobilized on the metal nanowire exposed portion of the conductive layer 3 is the target substance It specifically binds to 10. Although not shown, an electrode is connected to the conductive layer 3, and the presence of the target substance 10 which specifically binds to the specific binding substance 7 can be measured as a change in current value.
In the example shown in FIG. 4, the target substance is detected using the conductive material for a biosensor of the present invention, but the present invention is not limited to this. When the target substance is immobilized on the metal nanowire exposed portion Can detect specific binding substances.

  In the present invention, since the conductive layer contains metal nanowires, the conductivity is very excellent. Therefore, by using the conductive material for a biosensor of the present invention, it is possible to detect a target substance or a specific binding substance with high sensitivity and in a short time. In addition, since the detection sensitivity is high, even a small amount of target substance or specific binding substance can be detected, and the screening test accuracy can be improved. Therefore, it is possible to realize, for example, early detection and treatment of infectious diseases and the like. Furthermore, in the present invention, since the sample does not need to move on the membrane as in immunochromatography, for example, there is no need to use a developing solution (mobile phase), and even if the sample has high viscosity, it is not necessary to dilute it. Since the sample can be supplied directly to the biosensor, the inspection can be performed with a simple operation.

FIG. 5 is a schematic cross-sectional view showing another example of the conductive material for a biosensor of the present invention. As illustrated in FIG. 5, in the biosensor conductive material 1, the conductive layer 3 is formed in a pattern on the base material 2.
In the present invention, since the conductive layer contains the metal nanowires and the resin, the conductive layer can be easily formed on the substrate, and the film can be easily thinned. In addition, it is possible to easily form a fine conductive layer pattern by a known method of photolithography. Therefore, application of the biosensor to various fields becomes possible by using the conductive material for biosensor of the present invention. In addition, miniaturization of the biosensor can be realized.

  Hereinafter, each structure in the electroconductive material for biosensors of this invention is demonstrated.

1. Conductive layer The conductive layer in the present invention is formed on a base material and contains a resin and a metal nanowire, and has a metal nanowire exposed portion in which at least a part of the metal nanowire is exposed on the surface of the conductive layer It is. Hereinafter, each structure in a conductive layer is demonstrated.

(1) Metal Nanowire The metal constituting the metal nanowire used in the present invention is not particularly limited as long as it can fix a specific binding substance or target substance, and, for example, silver, copper, gold, Platinum, palladium, rhodium, iridium, ruthenium, osmium, iron, cobalt, tin and the like can be mentioned. Among them, silver nanowires and copper nanowires are preferably used.

  The average diameter of the metal nanowires is not particularly limited as long as desired conductivity can be obtained, and can be, for example, in the range of 0.1 nm to 1000 nm. In addition, since transparency is not required for a conductive layer in this invention, the diameter of metal nanowire may be large.

The average length of the metal nanowires may be sufficiently larger than the average diameter of the metal nanowires, and is not particularly limited as long as desired conductivity can be obtained, and can be, for example, in the range of 50 nm to 2000 μm. Among them, since the distribution range of the length at the time of metal nanowire manufacture is wide, it is preferable to be in the range of 400 nm to 2000 μm. If the length of the metal nanowire is long, one metal nanowire can form a long conductive path.
Here, the diameter and length of the metal nanowires can be measured, for example, using a transmission electron microscope.

  It will not specifically limit, if it is a well-known method as a manufacturing method of metal nanowire.

  As content of the metal nanowire in a conductive layer, the conductive layer which has a metal nanowire exposure part can be obtained, and if desired conductivity is obtained, it will not be specifically limited, For example, 0.01 mass%-90 It can be in the range of% by mass, and it is preferably in the range of 1% by mass to 80% by mass, particularly preferably in the range of 5% by mass to 40% by mass. In addition, since transparency is not required for a conductive layer in this invention, content of metal nanowire may be large.

(2) Metal Nanowire Exposed Portion In the present invention, at least a portion of the metal nanowire is exposed on the surface of the conductive layer in the metal nanowire exposed portion.
Here, the fact that at least a part of the metal nanowires is exposed on the surface of the conductive layer is directly confirmed, for example, using a commercially available atomic force microscope (AFM) having a function capable of observing the conductivity of the layer surface. be able to. For example, using a NanoNavi probe station equipped with Nano Instruments Pico CURRENT / CITS mode manufactured by Seiko Instruments Inc. and an S-image high resolution small stage unit, a conductive cantilever (eg SI-DF3-R) and a conductive layer are used. The surface of the conductive layer is scanned while a bias voltage (for example, 3 V to 5 V) is applied therebetween, and the current flowing between the conductive cantilever and the conductive layer can be detected and the current distribution can be observed and confirmed.

  In the exposed portion of the metal nanowires, at least a part of the metal nanowires may be exposed to such an extent that the specific binding substance or the target substance can be immobilized, as the metal nanowire is exposed. For example, as shown in FIG. 2A, the metal nanowires 4 may be partially exposed to the diameter of the metal nanowires 4, but although not shown, all may be exposed to the diameter of the metal nanowires 4. Good. Specifically, the thickness of the portion where the metal nanowires protrude from the surface of the conductive layer is preferably 20 nm or less. Here, the thickness of the portion where the metal nanowires protrude from the surface of the conductive layer refers to the thickness d as shown in FIG. 2 (a).

  The number of exposed portions of the metal nanowires in the conductive layer is preferably 5 or more, and more preferably 20 or more, per conductive layer disposed in the reaction region to which the sample is supplied. For example, in FIG. 7, one conductive layer 3 is disposed in one reaction region 11, and the number of exposed metal nanowires in the conductive layer 3 in the reaction region 11 is preferably in the above range. Further, for example, in FIGS. 6 (a) and 6 (b), three conductive layers 3a, 3b and 3c are disposed in one reaction region 11, and in each of the conductive layers 3a, 3b and 3c in this reaction region 11, It is preferable that the number of metal nanowire exposed parts is in the above range. The details of FIGS. 6 and 7 will be described later.

  The conductive layer may have a metal nanowire exposed portion, and the ratio of the area occupied by the metal nanowire exposed portion on the surface of the conductive layer is not particularly limited, and may be appropriately adjusted according to the purpose.

(3) Resin As resin used for the conductive layer in this invention, it selects suitably according to the formation method of a conductive layer.
For example, when the conductive layer is formed by applying an ink containing a resin and a metal nanowire on a substrate, the resin is not particularly limited as long as it functions as a binder, and specifically, Examples thereof include curable resins such as thermosetting resins, ultraviolet curable resins, and electron beam curable resins, and thermoplastic resins. More specifically, polypropylene, polyethylene, polyethylene terephthalate, acrylic, polyester, polyurethane, polyvinyl chloride, acrylic urethane resin, polyester acrylate resin, epoxy acrylate resin, polyol acrylate resin and the like can be mentioned.
Moreover, the ink containing the solvent which swells a metal nanowire and a base material is apply | coated on a base material, a base material is made to swell, and when embedding a metal nanowire on the base material surface, it is a predetermined solvent as resin. Any resin may be used as long as it can swell. Examples thereof include thermosetting resins, ultraviolet curable resins, curable resins such as electron beam curable resins, and thermoplastic resins. Specifically, resins as described in U.S. Patent Application Publication No. 2011/0281070 and Japanese Patent Application Publication No. 2012-500856 can be used. More specifically, acrylonitrile butadiene styrene copolymer (ABS resin), polycarbonate, acrylic resin such as polyacrylate and polymethyl methacrylate (PMMA), polystyrene, polyvinyl chloride and the like can be mentioned.

(4) Conductive layer In the present invention, the conductive layer is preferably formed in a pattern on the base material.
For example, when the conductive layer is formed in a pattern on the base material and a plurality of conductive layers are provided, at least one of the plurality of conductive layers may be used for calibration or the number of samples may be increased. Alternatively, different specific binding substances or target substances can be immobilized on the exposed portions of the metal nanowires of each conductive layer. Also, it is possible to obtain a multi-faced conductive material for biosensors.
Specifically, as shown in FIGS. 6A to 6D, the conductive layers 3a, 3b, and 3c are formed in a pattern on the base material 2, and the plurality of conductive layers 3a, 3b, and 3c are formed. When provided, the specific binding substance 7 is fixed to the exposed portion 5 of the metal nanowires of the conductive layers 3a and 3b and used for inspection of the sample, and the exposed portion 5 of the metal nanowires of the other conductive layer 3c is unique It is possible to use it for calibration without fixing the target binding substance 7. The specific binding substances 7 fixed to the metal nanowire exposed portion 5 of the conductive layers 3a and 3b may be the same or different. In the case of the same case, the number of samples can be increased, and in the case of different cases, it becomes possible to simultaneously check a plurality of items in one test. 6 (b) is a cross-sectional view taken along the line A-A of FIG. 6 (a), FIG. 6 (c) is a cross-sectional view taken along the line B-B of FIG. 6 (a), and FIG. ) Is an enlarged view of the broken line portion of.
Moreover, as shown in FIG. 7, the conductive layer 3 can be formed in a pattern on the base material 2 to make a multi-sided conductive material for biosensor. In FIG. 7, a part of the insulating layer 6 described later is indicated by a broken line.

  When the conductive layer is formed in a pattern, one or more conductive layers may be disposed in the reaction region to which the sample is supplied. Among them, in view of the above, it is preferable that a plurality of conductive layers be disposed in the reaction region. For example, in FIGS. 6A and 6B, a plurality of conductive layers 3a, 3b and 3c are disposed in the reaction region 11, and in FIG. 7, one conductive layer 3 is disposed in the reaction region 11.

  When the conductive layer used for calibration is not formed, calibration data prepared in advance may be used.

  When the conductive layer is formed in a pattern, the width of the pattern of the conductive layer is not particularly limited as long as the desired conductivity can be obtained, and the width can be formed. It can be about μm to several hundred μm. In the present invention, since the conductive layer is not required to be transparent, the density of the metal nanowires in the conductive layer can be increased, so that the conductivity can be ensured even with a fine pattern.

  The pattern shape of the conductive layer is not particularly limited, and can be any shape.

The conductivity of the conductive layer is not particularly limited as long as it can be used as a biosensor, and, for example, the surface resistivity of the conductive layer can be 500 Ω / □ or less, and in particular, 100 Ω / □ or less, In particular, 50 Ω / □ or less is preferable. When the surface resistivity of the conductive layer is high, measurement can not be performed with a minute voltage, and when the voltage is high, water decomposition and corrosion reaction in the sample are promoted.
Here, the surface resistivity can be measured, for example, using a resistivity meter Loresta manufactured by Mitsubishi Chemical Corporation.

The thickness of the conductive layer is not particularly limited as long as desired conductivity can be obtained, and is appropriately selected according to the method of forming the conductive layer.
For example, when an ink containing a resin and metal nanowires is coated on a substrate to form a conductive layer, the thickness of the conductive layer can be, for example, in the range of 10 nm to 1 mm, and in particular 0.1 μm to 100 μm In particular, it is preferable to be in the range of 0.3 μm to 50 μm. If the conductive layer is thin, it is difficult to obtain conduction, and the manufacturing becomes difficult. On the other hand, when the conductive layer is thick, the manufacturing cost becomes high. In the present invention, since the conductive layer is not required to have transparency, the thickness of the conductive layer may be thick.
Also, when an ink containing metal nanowires and a solvent for swelling the substrate is applied onto the substrate, and the substrate is swollen to embed the metal nanowires on the substrate surface, the metal nanowires are embedded on the substrate surface. The thickness of the portion, that is, the thickness of the conductive layer is preferably equal to or greater than the diameter of the metal nanowires. Specifically, the thickness of the conductive layer can be in the range of 1 to 5 times the diameter of the metal nanowires. More specifically, the thickness of the conductive layer can be in the range of 0.1 nm to 5 μm. If the thickness of the portion in which the metal nanowires are embedded in the substrate surface is in the above range, a contact can be easily formed between the metal nanowires, and good conductivity can be obtained.

(5) Method of Forming Conductive Layer The method of forming the conductive layer is not particularly limited as long as it is a method capable of forming a conductive layer having a metal nanowire exposed portion, and, for example, a resin and metal nanowires on a substrate A method of forming an electroconductive layer by applying an ink containing an ink, applying an ink containing metal nanowires and a solvent for swelling the substrate on the substrate, swelling the substrate, and forming the metal nanowires on the substrate surface There is a method of embedding In the case of the former method, commercially available inks can be used as the ink containing the resin and the metal nanowires. Moreover, you may use the commercially available conductive film by which the conductive layer was laminated | stacked on the base material. On the other hand, in the case of the latter method, specifically, the methods described in U.S. Patent Application Publication No. 2011/0281070 and Japanese Patent Application Publication No. 2012-500856 can be applied.

  The method of forming the conductive layer in a pattern is not particularly limited. For example, a method of applying an ink containing a resin and metal nanowires in a pattern on a substrate, forming a resist pattern on the conductive layer And etching, a method of transferring the conductive layer onto the substrate, and a method of partially peeling off the conductive layer formed on the substrate.

  In addition, baking or pressurization may be performed to increase the conductivity of the conductive layer.

2. Substrate The substrate in the present invention supports the above-mentioned conductive layer.
The substrate is not particularly limited as long as it can form the conductive layer on the substrate. Also, the substrate may or may not have transparency. For example, a glass substrate, a resin substrate or the like can be used, and among them, a resin substrate is preferably used from the viewpoint of lightness and flexibility.
Examples of the resin substrate include polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene and modified polyester, polyolefins such as polystyrene and cyclic olefin resin, and vinyl resins such as polyvinyl chloride and polyvinylidene chloride And polyether ether ketone, polysulfone, polyether sulfone, polycarbonate, polyamide, polyimide, acrylic, triacetyl cellulose and the like.
Moreover, in order to ensure the wettability and adhesiveness of the ink, the resin base material can be subjected to surface treatment or provided with an easily adhesive layer. A general thing can be applied about a surface treatment and an easily bonding layer.
As a thickness of a substrate, if the above-mentioned conductive layer can be formed on a substrate, it should just be suitably chosen according to a use etc.

3. Specific Binding Substance and Target Substance In the present invention, a specific binding substance or target substance that specifically binds to the target substance may be immobilized on the metal nanowire exposed portion. In the biosensor using the conductive material for a biosensor of the present invention, a specific binding substance or target substance is immobilized on the metal nanowire exposed portion.

  The specific binding substance is not particularly limited as long as it specifically binds to the target substance, and examples include antibodies and aptamers.

  The target substance may include, for example, an antigen and a substance that specifically binds to an aptamer. Specifically, natural antigens such as viruses, bacteria, cells, proteins, peptides, saccharides, nucleic acids (DNA, RNA), lipids, coenzymes, complexes of these, derivatives of natural antigens, artificially synthesized Haptens, artificial antigens and the like.

  As a method of immobilizing a specific binding substance or target substance on the metal nanowire exposed portion, a general method can be used as a method of immobilizing an antibody, an aptamer, an antigen or the like on a metal surface. For example, a method of immobilizing a specific binding substance or a target substance on the surface of the metal nanowire exposed portion via a linker can be mentioned.

4. Insulating Layer In the present invention, as illustrated in FIGS. 6 (a) to (c) and FIG. 7, the insulating layer 6 is formed in a pattern on the base 2 on which the conductive layers 3a, 3b, 3c or 3 are formed. It may be formed. The insulating layer is provided to define a reaction area to which the sample is supplied, to hold the sample on the conductive layer, and to prevent the sample from contacting with the electrodes, wirings and the like.

  The insulating material used for the insulating layer is not particularly limited as long as it can form a patterned insulating layer on the substrate on which the conductive layer is formed, and either an organic material or an inorganic material can be used. Can also be used. As an organic material, photosensitive resin is mentioned, for example. Examples of the inorganic material include silicon oxide, silicon nitride, silicon oxynitride and the like.

  As the formation position of the insulating layer, as illustrated in FIGS. 6 (a) to (c) and FIG. 7, the conductive layer 3a, 3b, 3c or 3 is surrounded so as to surround the reaction region 11 to which the sample is supplied. The insulating layer 6 may be formed so as to expose the connection portions 12a and 12b connected to the electrodes, the wirings, and the like.

  The thickness of the insulating layer is not particularly limited as long as the sample does not overflow, and is appropriately adjusted.

  The method for forming the insulating layer is not particularly limited as long as it is a method capable of forming an insulating layer in a pattern on the base material on which the conductive layer is formed, and, for example, photolithography, printing, etc. It can be mentioned.

5. Electrically Conductive Material for Biosensor The form of the electrically conductive material for biosensor of the present invention is not particularly limited, and is appropriately selected according to the purpose of inspection, inspection object, inspection method, etc. For example, film, plate, rod Etc. can be mentioned.

B. Biosensor The biosensor of the present invention is characterized by including a sensor section having the above-described conductive material for a biosensor.

The biosensor of the present invention can perform inspection with high sensitivity and in a short time by having the above-described conductive material for a biosensor. In addition, detection of trace components is also possible, and the screening test accuracy can be improved.
Hereinafter, each structure in the biosensor of the present invention will be described.

1. Sensor part The sensor part in the present invention has the above-mentioned conductive material for biosensors.
In the biosensor of the present invention, the conductive material for a biosensor comprises a substrate and a conductive layer formed on the substrate and containing a resin and a metal nanowire, and the conductive layer is the metal nanowire. A specific binding substance that specifically binds to the target substance or the target substance is immobilized on the exposed portion of the metal nanowire, and at least a part of the metal nanowire has an exposed portion exposed on the surface of the conductive layer; It is
In addition, about the electroconductive material for biosensors, since it described in the item of said "A. electroconductive material for biosensors" in detail, description here is abbreviate | omitted.

2. Electrode and Wiring In the present invention, an electrode or a wiring is usually connected to the conductive layer of the biosensor conductive material.
As an electrode and wiring, it selects suitably according to the use, the structure, etc. of the biosensor of this invention. For example, as the electrode, a working electrode, a counter electrode, a reference electrode and the like can be mentioned. In a biosensor using a field effect transistor, a source electrode and a drain electrode are connected to the conductive layer. Specifically, in FIGS. 6A to 6C and 7, the source electrode is connected to one of the connection parts 12a of the connection parts 12a and 12b at both ends of the conductive layer 3a, 3b, 3c or 3, and the other is connected. The drain electrode is connected to the portion 12b.

3. Biosensor The form of the biosensor of the present invention is not particularly limited, and is appropriately selected according to the purpose of inspection, object of inspection, inspection method, etc., for example, film, plate, rod, cylinder, sphere, etc. Can be mentioned.

  Specifically, a flat biosensor as shown in FIGS. 6 (a) to 6 (c) and FIG. 7 can be mentioned.

A cotton swab-type biosensor 20 as shown in FIG. 8 can also be mentioned. The cotton swab-type biosensor 20 has a support 21, a sensor unit 15 disposed at the tip of the support 21, and a covering unit 22 disposed to cover the sensor unit 15.
For example, if you wipe the nasal cavity or oral cavity with a cotton swab-type biosensor 20 and attach nasal discharge, mucous membrane, saliva, etc. as a sample to the covering part 22, the sample passes through the covering part 22 and is introduced into the sensor part 15 for inspection. Be served. As described above, in the cotton swab-type biosensor, it is possible to simply and quickly collect a sample and to inspect a target substance contained in the sample.

In the swab type biosensor, as a support, materials used for conventional cotton swabs such as plastics and metal materials can be used. In the case of a metallic material, the support can function as an electrode. In this case, the support made of a metallic material may be coated on the surface with an insulating material. Although the shape of the support is not particularly limited, it is generally rod-like.
The covering portion is not particularly limited as long as the sample can pass therethrough, and it is preferable to have, for example, hydrophilicity or permeability to allow liquid to permeate. In addition, the material of the covering portion is preferably one that does not damage the skin and mucous membranes. Specifically, filter paper, resin-made membranes used for chromatography, resin-made meshes, etc. can be mentioned.
In the swab type biosensor, it is preferable that the sensor unit be replaceable. In this case, for example, the tip end provided with the sensor unit may be removable, and the cotton swab-type biosensor may be disposable.

Further, a toothbrush-type biosensor 30 as shown in FIG. 9 can be exemplified. The toothbrush-type biosensor 30 includes a support 31, a plurality of hair bundles 32 provided at the tip of the support 31, and a sample provided at the tip of the support 31 and disposed on the opposite side of the hair bundles 32. A sampling hole 33 and a sensor unit 15 connected to the sampling hole 33 are provided.
When teeth in the oral cavity are brushed with a toothbrush-type biosensor 30, saliva or plaque removed as a sample is injected into the sampling hole 33. Then, the sample is introduced into the sensor unit 15 connected to the sampling hole 33 and subjected to an inspection. As described above, in the toothbrush-type biosensor, it is possible to easily and quickly collect a sample and to inspect a target substance contained in the sample.
In this case, any specific antibody can be used as the specific binding substance in the sensor unit according to the purpose of examination. For example, a monoclonal antibody against Streptococcus (S. mutans, S. sobrinus, S. cricetus, S. rattus, etc.) which is the causative agent of dental caries can be used.

In a toothbrush-type biosensor, as a support, a material used for a conventional toothbrush such as resin can be used. The shape of the support may be the shape of a common toothbrush.
A plurality of hair bundles are arranged at the tip of the support. As the hair bundle, a material that is usually used as a hair bundle of a toothbrush can be used, such as an artificial material such as a resin or a natural material such as pig hair.
A sampling hole is provided in the vicinity of the hair bundle provided at the tip of the support. The position of the sampling hole is not particularly limited as long as it is the tip of the support, in the vicinity of the hair bundle, and can collect saliva or the like in the oral cavity when the toothbrush type biosensor is inserted into the oral cavity. It is not a thing.
In the toothbrush type biosensor, it is preferable that the sensor unit be replaceable. In this case, for example, the sensor unit may be detachable, the tip end provided with the sensor unit may be detachable, and the toothbrush-type biosensor may be disposable.

4. Inspection Method The biosensor of the present invention can be used in connection with a measuring device. A measuring device connects a biosensor and measures an electrical signal generated by the biosensor. As a measuring device, a general measuring device can be used. For example, the measurement apparatus includes a connection electrode for receiving an electrical signal generated by the biosensor, a calculation unit, a power supply, a display unit, and an operation unit. When the biosensor is mounted on the mounting portion of the measurement device, the end of the electrode or wiring of the biosensor is connected to the connection electrode of the measurement device. By this connection, the electrical signal generated by the biosensor is transmitted to the measuring device.
As an inspection method, for example, a measurer mounts a biosensor on a measurement apparatus, introduces a sample to the sensor unit of the biosensor, and operates the operation unit to start measurement. When the sample contains a target substance, the target substance and the specific binding substance of the sensor unit react, and an electrical signal is detected by the electrode of the biosensor and transmitted to the measurement device. The measuring device converts the electrical signal received from the biosensor into a measurement value in the operation unit. The obtained measured value is displayed on the display unit, and the measurer can visually recognize the measurement result.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has the substantially same constitution as the technical idea described in the claims of the present invention, and the same effects can be exhibited by any invention. It is included in the technical scope of

  Hereinafter, the present invention will be specifically described by way of examples.

Example 1
(Preparation of a biosensor)
First, the cover film of a transfer type thin film transparent conductive film (Transparent Conductive Transfer Film; TCTF) manufactured by Hitachi Chemical Co., Ltd. was peeled off to a PET substrate having a thickness of 200 μm, and thermally transferred at 115 ° C. Next, the TCTF support is exposed to a pattern formed of silver nanowires including an electrode pattern disposed in the reaction area, a wiring pattern drawn out from the electrode pattern, and a terminal connector pattern from above the TCTF support. Was peeled off to expose TCTF silver nanowires. Thereafter, it was washed with sodium carbonate to remove the unexposed part. Thus, a conductive film in which a conductive layer containing silver nanowires was formed in a pattern was obtained.

  Next, an insulating resist is coated on the conductive film to insulate the conductive pattern so that the pattern disposed in the reaction region and the pattern connected to the source electrode and the drain electrode in the fine pattern conductive layer are exposed. The layers were patterned and provided with an insulating and water resistant coating.

  Next, a solution prepared by adding 0.2% (W / W) dithiol to Roche Streptavidin 0.1% (W / W) Tris buffer pH 7.2 was prepared immediately before use. Under a microscope, this solution was dropped onto the conductive layer located in the reaction area, and naturally dried at room temperature to fix streptavidin by silver bond to silver nanowires. From this, a biosensor was produced.

(Evaluation)
The lead was fixed with silver paste in the pattern connected to the source electrode and the drain electrode of the conductive layer, and connected to the potentiostat. After that, control saline and Roche biotin 0.05% (W / W) saline were added to different reaction areas, and a cyclic voltammogram of 0.5 V to-0.2 V was applied. . Biotin was detected in the reaction area to which streptavidin was immobilized.

Example 2
(Preparation of a biosensor)
As described below, a biosensor was produced in the same manner as in Example 1 except that the aptamer was fixed to silver nanowires instead of streptavidin.
That was errands prepared Nippon Gene of Immuno-Aptamer ^TM, 0.2% Tris buffer Mouse IgG 0.05% (W / W ) and (W / W) solution was added dithiol immediately before. Under a microscope, this solution was dropped on the conductive layer located in the reaction area, and naturally dried at room temperature to fix the aptamer to the silver nanowire by the thiol bond.

(Evaluation)
The lead was fixed with silver paste in the pattern connected to the source electrode and the drain electrode of the conductive layer, and connected to the potentiostat. After that, control saline and Roche Mouse IgG 0.05% (W / W) saline are added to separate reaction areas, and a cyclic voltammogram of 0.5 V to-0.2 V is applied. did. Binding of IgG was detected in the reaction region where the aptamer was immobilized.

[Example 3]
(Preparation of a biosensor)
A biosensor was produced in the same manner as in Example 1 except that a conductive film was formed as described below.
That is, first, a coating material "CLEAR OHM" manufactured by Cambrios, Inc. was coated on a PET film to form a conductive layer. Next, a photoresist was coated on the conductive layer, and pattern exposure and cleaning were performed. Thereafter, full etching was performed using “silver nanowire etching solution Pure Etch GNW 300” manufactured by Hayashi Pure Chemical Industries, and the photoresist was peeled off to form a conductive film in which a conductive layer was formed in a pattern.

(Evaluation)
When evaluated in the same manner as in Example 1, similar results were obtained.

Example 4
(Preparation of a biosensor)
A biosensor was produced in the same manner as in Example 2 except that a conductive film was formed in the same manner as in Example 3.

(Evaluation)
When evaluated in the same manner as in Example 2, similar results were obtained.

DESCRIPTION OF SYMBOLS 1 ... Electrically conductive material for biosensors 2 ... Base material 3, 3a, 3b, 3c ... Conductive layer 4 ... Metal nanowire 5 ... Metal nanowire exposed portion 6 ... Insulating layer 7 ... Specific binding substance 10 ... Target substance 11 ... Reaction area 15 ... sensor unit 20, 30 ... biosensor

Claims (5)

A substrate,
And a conductive layer formed on the substrate and containing a resin and metal nanowires,
The conductive layer has a metal nanowire exposed portion in which the long axis of the metal nanowire extends along the in-plane direction of the conductive layer, and at least a portion of the metal nanowire is exposed on the surface of the conductive layer And
A conductive material for a biosensor, wherein a specific binding substance that specifically binds to a target substance or the target substance is immobilized on the exposed part of the metal nanowires.   The conductive material for a biosensor according to claim 1, wherein the conductive layer is formed in a pattern on the base material.   The conductive material for a biosensor according to claim 1 or 2, wherein the specific binding substance is an antibody or an aptamer.   The insulating material is formed in pattern shape on the said base material in which the said conductive layer was formed, The electrically conductive material for biosensors in any one of Claim 1- Claim 3 characterized by the above-mentioned.   A biosensor comprising a sensor unit having the biosensor conductive material according to any one of claims 1 to 4.