JP2008083041A - Detecting element, manufacturing method therefor, and detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detecting element capable of executing quick and highly sensitive measurement, and a simple manufacturing method therefor. <P>SOLUTION: This detecting element of the present invention is a detecting element contacting with gas or a liquid to detect a physical quantity or a chemical quantity. The detecting element has a base material having two main faces, and a detecting part formed on at least the one main face of the base material and constituted of a fiber. The fiber has preferably 1 nm-999 nm of diameter, and a substantially circular or elliptic cross section. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a detection element, a manufacturing method thereof, and a detection apparatus. More specifically, the present invention relates to a detection element that can be measured at high speed and high sensitivity, a simple manufacturing method thereof, and a detection apparatus using such a detection element.

  Detection devices that detect physical quantities or chemical quantities have been utilized as trace analysis techniques in the fields of chemistry and biotechnology. For example, it is possible to detect a change in weight with a sensitivity on the order of picograms by detecting a change in resonance frequency due to material adhesion to a cantilever having a cantilever structure by silicon (Si) microfabrication technology. Yes. More specifically, a cantilever coated with a specific adsorption film that specifically adsorbs a chemical substance to be measured is known (see Patent Document 1).

In recent years, problems such as environmental hormones and bioterrorism have been seriously discussed, and it is desired to develop a measurement analysis technique with higher accuracy and sensitivity and higher speed. However, the techniques as described above are insufficient to satisfy the demand for high sensitivity and high speed of the measurement analysis technique.
JP-T-2004-506872

  The present invention has been made to solve the above-described conventional problems. The object of the present invention is to provide a detection element that can be measured at high speed and high sensitivity, a simple manufacturing method thereof, and such a detection element. It is to provide a detection device used.

  The detection element of the present invention is a detection element that detects a physical quantity or a chemical quantity in contact with a gas or a liquid. This detection element has a base material having two main surfaces, and a detection part formed on at least one of the main surfaces of the base material and made of fibers.

  In a preferred embodiment, the fiber has a diameter of 1 nm to 999 nm. In a preferred embodiment, the fibers have a substantially circular or elliptical cross section.

  In a preferred embodiment, the detection unit includes a catalyst and / or an adsorbent supported on the fiber.

  In a preferred embodiment, the material forming the fiber specifically reacts with the substance to be detected and / or specifically adsorbs the substance to be detected. In a preferred embodiment, the material constituting the fiber is at least one selected from polyvinyl alcohol, a copolymer thereof, a high molecular polysaccharide and a derivative thereof. In another embodiment, the material constituting the fiber is at least one metal oxide selected from titanium oxide, zinc oxide, and tin oxide.

  In a preferred embodiment, the resonance frequency of the substrate is 10 kHz to 200 MHz. In a preferred embodiment, the substrate is silicon, quartz or ceramic.

  In another embodiment, the detected physical or chemical amount is a change in weight. In another embodiment, the detected physical or chemical quantity is an impedance change.

  According to another aspect of the present invention, a method for manufacturing a detection element is provided. In this manufacturing method, fibers are formed by injecting a solution containing a fiber-forming material under an electric field, and the fibers are transported to the substrate by the action of the electric field, and further attached to the substrate to form a detection unit. Forming.

  In a preferred embodiment, the solution further comprises a catalyst and / or adsorbent. In a preferred embodiment, the method includes selectively attaching the fibers to the substrate to form a patterned detector.

  According to another aspect of the present invention, a detection device is provided. This detection apparatus includes the detection element.

  According to the present invention, the specific surface area is remarkably increased by configuring the detection part of the detection element with a fiber (preferably a nanofiber non-woven fabric layer) as compared with a conventional detection part of a coating film. As a result, the contact area with the fluid (gas or liquid) containing the substance to be measured becomes very large, so the detection sensitivity and response speed are remarkably increased, and detection (measurement) is possible in a very short time. It becomes.

A. FIG. 1 is a schematic cross-sectional view of a detection element according to a preferred embodiment of the present invention. The detection element 10 includes a base material 11 and a detection unit 12. The base material 11 has two main surfaces (the front surface 14 and the back surface 15 in the illustrated example). The detection unit 12 is formed on at least one of the front surface 14 and the back surface 15 of the base material 11. Therefore, the detection part 12 may be formed in both the front surface 14 and the back surface 15, and may be formed only in any one. Moreover, the detection part 12 may be formed in the whole surface of the front surface 14 and / or the back surface 15, and may be formed in a part. In one embodiment, the detection unit 12 may be formed in a predetermined pattern.

  The detection part 12 is comprised with the fiber. FIGS. 2A and 2B are schematic diagrams illustrating the configuration of the detection unit 12. FIG. 2A is a schematic diagram of the detection unit viewed from the front, and FIG. 2B is a schematic diagram of a IIb-IIb cross section of the detection unit. As shown in FIGS. 2A and 2B, the detection unit is typically configured by entangled fibers. That is, the detection unit is substantially a non-woven fabric layer. By having such a configuration, the specific surface area is remarkably increased as compared with the coating film. As a result, the contact area with the fluid (gas or liquid) containing the substance to be measured becomes very large, so the detection sensitivity and response speed are remarkably increased, and detection (measurement) is possible in a very short time. It becomes.

  The diameter of the fiber is preferably 1 nm to 999 nm, more preferably 10 nm to 600 nm, and most preferably 50 nm to 400 nm. When the diameter of the fiber is in such a range, the contact area with the measurement sample is further increased, so that the detection sensitivity / response speed can be further increased and the detection time can be further shortened. For example, assuming that the surface area of a coating film having a thickness of 1 mm is 1, when a nonwoven fabric layer having a thickness of 1 mm is formed with fibers having a diameter of 100 nm, the surface area is about 20,000 times. Preferably, the fibers have a substantially circular or elliptical cross section. When a solution containing a fiber-forming material is injected under an electric field by a manufacturing method described later, a cross section close to a circle can be formed by the action of surface tension and / or by being stable in surface energy. In one embodiment, voids may be formed on the fiber surface, and the fiber may be porous. According to such a configuration, the contact area with the measurement sample is further increased.

  As the material for forming the fiber, any appropriate material can be adopted depending on the purpose, the substance to be detected, and the like as long as it has fiber forming ability. For example, the fiber forming material may be an organic material, an inorganic material, or an organic-inorganic hybrid material. Preferably, the material forming the fibers reacts specifically with the substance to be detected and / or specifically adsorbs the substance to be detected. By using such a material, a detection element having a very excellent detection sensitivity and response speed can be obtained in combination with the structure in which the above fibers are intertwined. For example, when the detection element of the present invention is used as an odor sensor, the substance or odor to be detected includes ammonia, methyl mercaptan, formaldehyde in life odor monitoring; carbon monoxide, hydrogen, in fire odor monitoring. Aldehyde, furan; trimethylamine for freshness monitoring; tumor odor and halitosis for initial diagnostic use; VOC and dioxin for detection of dangerous substances and environmental measurement use. A material that specifically reacts with and / or specifically adsorbs these substances can be suitably selected. Further, for example, when the detection element of the present invention is used as a humidity sensor, a material having an appropriate hygroscopic property and capable of appropriately changing the impedance of the element due to moisture absorption can be suitably selected. In addition, preferably, the material constituting the fiber has excellent adhesion to the substrate.

In one embodiment, an organic material is mentioned as a specific example of the above materials. Specific examples of the organic material include polymers and oligomers. Specific examples of the polymer include polyvinyl alcohol, high molecular polysaccharide, derivatives thereof, polylactic acid, polyacrylonitrile, polyethylene oxide, silk, nylon, polyethylene terephthalate, liquid crystal polymer (for example, aramid), and copolymers thereof. Derivatives. Polyvinyl alcohol, copolymers thereof, polymeric polysaccharides, and derivatives thereof are preferred. In another embodiment, specific examples of such materials include inorganic materials. Specific examples of inorganic materials include metal oxides. Specific examples of the metal oxide include titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), and silicon oxide (SiO ₂ ). Such an inorganic material may be fiberized together with an organic material. In yet another embodiment, specific examples of such materials include organic-inorganic hybrid materials. Specific examples of the organic-inorganic hybrid material include an inorganic particle-filled polymer (for example, polyvinyl alcohol filled with SiO ₂ particles) and an organic-inorganic hybrid polymer (for example, a copolymer of polysilane and acrylic). A fiber forming material may be used independently and may be used in combination of 2 or more type.

  In one embodiment, the detection unit 12 includes a catalyst and / or an adsorbent supported on the fiber. According to such an embodiment, even if the fiber itself does not have reactivity or adsorption ability with respect to the measurement substance, it reacts specifically with the substance to be detected or the substance to be detected is specifically detected. Can be adsorbed. Moreover, even if the catalyst or the adsorbent does not have fiber forming ability, a detection unit having excellent characteristics can be configured. Any appropriate substance can be adopted as the catalyst as long as it promotes the reaction with the substance to be detected. Accordingly, the term “catalyst” as used herein encompasses not only a catalyst in the usual sense, but also an enzyme. Specific examples of catalysts include palladium, platinum, alumina for hydrogen; gold for carbon monoxide; glucose oxidase for glucose or urea; AA. Oxygenase for amino acids. Any appropriate substance can be adopted as the adsorbent as long as it specifically adsorbs the substance to be detected. Adsorption may be physical, chemical, or biological. Therefore, the term “adsorbent” in the present specification includes not only a physical adsorbent such as a porous particle but also an antigen, an antibody, a molecularly imprinted particle, a specific adsorbed particle and the like. Specific examples of the adsorbent include catechins for formaldehyde; polystyrene (PS) for volatile organic compounds (VOC), polycaprolactone (PCL), cycloolefin polymer (for example, trade name ZEONEX); antibodies for various antigens (for example, IgG); microorganisms for assimilation sugars or biochemical oxygen demand (BOD); for various chemical substances, molecularly imprinted particles specific for the chemical substances. The shape of the adsorbent is not particularly limited.

  In one embodiment, the substrate 11 is comprised of any suitable material that can be used, for example, in a cantilever. The resonance frequency of the substrate is preferably 10 kHz to 200 MHz, more preferably 100 kHz to 100 MHz, and most preferably 1 MHz to 30 MHz. Since the substrate has such a very high resonance frequency, it is possible to detect adhesion of a very small amount of substance. By such a synergistic effect of the base material and the detection unit, a detection element having extremely excellent detection sensitivity and response speed can be obtained. More specifically, when the spring constant of the substrate is K and the effective mass is M, the resonance frequency is obtained by f = (1 / 2π) * √ (K / M). Furthermore, when the mass of the base material is m, the change in weight is obtained by Δf = −2 (m / f) * Δf. Therefore, if the resonance frequency of the substrate is within the above range, the adhesion of a substance in femtogram order can be detected.

  Specific examples of the base material having the above characteristics include semiconductors such as silicon, gallium arsenide, and silicon nitride; and quartz. Since such a material can be formed on a substrate by a semiconductor microfabrication process, it is excellent in manufacturing efficiency and shape controllability. Silicon is particularly preferable. This is because both acquisition and processing are easy, hysteresis due to excitation is small, and durability is excellent.

  As described above, the base material is typically formed by a semiconductor microfabrication process. For example, the base material is formed by etching away a part of a silicon wafer. This silicon wafer is typically (100) or (111) oriented. In one embodiment, (100) oriented silicon is wet etched using ethyl diamine pyrocatechol or KOH solution. (100) oriented silicon exhibits a very low etch rate at the (111) plane, resulting in a good etch stop along the (111) axis, resulting in (100) to 54.7 ° A clear etch plane is produced. In another embodiment, dry etching techniques such as reactive ion beam etching (RIE), chemically excited ion beam etching, microwave excited plasma etching, inductively coupled plasma etching are used. By adjusting the processing conditions, a deep anisotropic or isotropic structure can be obtained and excellent dimensional control can be achieved. In yet another embodiment, the substrate may be formed or reshaped using a focused ion beam milling technique. By using such a microfabrication technique, a very small base material (finally a detection element) can be produced. As a result, the resonance frequency can be made very large, so that the response speed and detection sensitivity can be made very large. For example, the resonance frequency of a 50 × 300 × 100 (μm) base material having a double-supported beam structure using silicon is 61 MHz.

  In another embodiment, the substrate 11 is made of ceramic. Specific examples of the ceramic include alumina and zirconia. Since ceramic is excellent in heat resistance, it is useful when used in a detection device that requires high-temperature measurement. Since ceramic has appropriate insulation, it is useful when detection is performed using a change in impedance.

  The shape of the substrate 11 is not particularly limited. In one embodiment for detecting a change in weight, the shape of the substrate viewed from the front 14 direction is a rectangle. With such a shape, it is easy to form an array in the detection apparatus. When the substrate has a cantilever structure, in one embodiment, the shape of the substrate viewed from the front direction has a shape in which a portion near the fixed end is thick and a portion near the free end is thin. The cross-sectional shape perpendicular to the longitudinal direction of the substrate is, for example, a rectangle, a circle, an ellipse, or a polygon. In another embodiment for detecting impedance changes, the substrate may be plate-shaped. In this case, an electrode patterned in a predetermined shape can be formed on the base material to form an electrode substrate.

B. Manufacturing method of detection element The manufacturing method of the detection element of the present invention forms a fiber by injecting a solution containing a fiber-forming material under an electric field, and transports the fiber to a substrate by the action of the electric field. Further, the detection unit is formed by being attached to the substrate. Hereinafter, a preferable example of the production method will be specifically described.

  FIG. 3 is a schematic diagram for explaining a preferred example of the production method of the present invention. First, a solution 31 containing a fiber forming material is prepared. The fiber forming material is as described in the above section A. An appropriate solvent can be used as the solvent depending on the type of the fiber-forming material. Therefore, the solvent may be an aqueous solvent or an organic solvent. The concentration of the solution can vary depending on the viscosity of the solution, the surface tension of the solution, the strength of the applied electric field E, the interelectrode distance D, the molecular weight of the fiber-forming material, and the like. In one embodiment, the solution concentration is preferably 0.3-15% by weight; the viscosity of the solution is preferably 10-400 cp. For example, when the fiber forming material is polyvinyl alcohol (PVA), the molecular weight (here, the degree of polymerization) is preferably 1000 to 3000. The solution concentration in this case is preferably 3 to 10% by weight. Alternatively, when the fiber forming material is a high molecular polysaccharide, the molecular weight is preferably 1.5 million to 2 million. The solution concentration in this case is preferably 0.3 to 2% by weight.

  Preferably, the solution further comprises a catalyst and / or an adsorbent. The catalyst and the adsorbent are as described in the above section A. The content of the catalyst and / or the adsorbent can vary depending on the purpose, catalytic ability, adsorption ability and the like. By including the catalyst and / or the adsorbent, a detection unit in which the catalyst and / or the adsorbent is supported on the fiber can be formed. The solution may further contain any appropriate additive as required. Specific examples of the additive include a surfactant and a conductivity imparting agent (for example, lithium chloride).

  Next, the solution 31 is put into an injection device (in the illustrated example, a syringe pump) 32 and injected. The injection speed (speed at which the pump is pressed) can vary depending on the viscosity of the solution, the surface tension of the solution, the nozzle diameter, the strength of the applied electric field, and the like. In one embodiment, the injection speed is preferably 5-40 μl / min and the nozzle diameter is preferably 0.5-1.5 mm. By adjusting the injection speed, the viscosity of the solution, the surface tension of the solution, the nozzle diameter, the strength of the applied electric field, the distance between the electrodes, the ambient temperature, etc., the fibers can be formed satisfactorily. If these condition settings are inappropriate, there are cases where particles are formed and fibers are not formed, or even if fibers are formed, they do not reach the substrate.

  The solution 31 is ejected in a state where an electric field E is applied. In one embodiment, the strength (applied voltage) of the electric field E is preferably 5 to 30 kV, and the interelectrode distance D is preferably 3 to 15 cm. When a positively charged solution is injected by adjusting the injection speed, solution viscosity, solution surface tension, nozzle diameter, applied electric field strength, interelectrode distance, ambient temperature, etc. The fiber 33 is formed by drawing by an electric field. By the stretching, fibers having a very small diameter (so-called nanofibers) can be formed. The fibers 33 thus formed are transported as they are to the substrate 11 by the action of the electric field, and adhere to the negatively charged substrate 11. By appropriately selecting the fiber forming material and the additive, the fiber can be attached to the substrate without performing a special bonding operation (for example, without using an adhesive). For example, when polyvinyl alcohol (degree of polymerization 1170) is used as the fiber forming material, the solvent is water, the solution concentration is 8% by weight, the nozzle diameter is 0.8 mm, the electric field strength (applied voltage) is 10 kV, and the distance between the electrodes. When the distance D is set to 9 cm and the ambient temperature is set to 24 ° C., the detection unit (nonwoven fabric layer) 12 can be satisfactorily formed on the substrate 11. In this case, the diameter of the fiber is 200 nm, and the thickness of the nonwoven fabric layer is 30 μm.

  In one embodiment, the fiber 33 may be selectively attached to the substrate 11 to form the patterned detection unit 12. Specifically, the fibers may be formed, transported, and attached in a state where a peelable mask having a predetermined pattern is attached to the substrate.

  The nozzle of the syringe pump 32 may have a single injection hole or may have a plurality of injection holes. In the case of having a single injection hole, the shape control of the fiber is easy, and in the case of having a plurality of injection holes, the productivity is excellent.

C. Detection Device FIG. 4A is a schematic perspective view of a detection device according to a preferred embodiment of the present invention. The detection device 100 includes a detection element 10. The detection element is as described in the above items A and B. The detection element may be a single element, or an array may be constituted by a plurality of detection elements as shown in the illustrated example. In the illustrated example, the case where the detection element has a cantilever structure is described. However, the detection element may have a double-sided beam structure. The detection apparatus 100 further includes an electrode for exciting the detection element 10 and a detector unit that detects a change in the resonance frequency of the detection element 10 (none is shown).

  When the detection element 10 comes into contact with a fluid (gas or liquid) containing a substance to be measured, the substance to be measured reacts with the detection unit 12 and / or adheres to the detection unit 12. As a result, the resonance frequency of the detection element changes, the frequency change is detected by a detector unit (not shown), and the presence of the substance to be measured is confirmed in the fluid (test sample). As described in the above section A, the specific surface area of the detection unit 12 of the detection element 10 is very large, so that the substance to be measured reacts with the detection unit 12 very well and / or in the detection unit 12. It adheres very well and specifically. Therefore, measurement / detection with very high accuracy and high sensitivity is possible.

  FIG. 4B is a schematic perspective view of a detection device according to another preferred embodiment of the present invention. In this detection device 200, a patterned electrode (comb-like electrode in the illustrated example) is formed on a plate-like base material 11 to form an electrode substrate. The electrodes are connected to a detector unit (not shown). The detection part 12 is formed on the said electrode, and the detection element is comprised. The detection part 12 is as having demonstrated by the said A term and B term. According to the detection device of this embodiment, when the detection element 10 comes into contact with a fluid containing a substance to be measured, the impedance of the detection element changes, and the change in impedance is detected by a detector unit (not shown). The presence of the substance to be measured is confirmed in (inspection sample). Also in the present embodiment, measurement and detection with very high accuracy and high sensitivity are possible, as in the above embodiment.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

  Using a commercially available polyvinyl alcohol (degree of polymerization 2000, manufactured by Nacalai Tesque, trade name polyvinyl alcohol 200), a 5% by weight PVA aqueous solution was prepared. The viscosity of this solution was 75 cp. This solution was placed in a syringe pump connected to the positive electrode of the power source. On the other hand, a silicon wafer connected to the negative electrode of the power source was arranged as a target. The distance between the syringe pump tip and the silicon wafer was set to 9 cm. With the voltage of 10 kV applied, the syringe pump was pushed to inject the solution. As a result, fibers were formed, and the fibers reached and adhered to the silicon wafer by an electric field to form a fiber layer (nonwoven fabric layer). The thickness of the fiber layer was 22 μm.

  Fibers were formed in the same manner as in Example 1 except that the concentration of the aqueous PVA solution was 8% by weight. The viscosity of this solution was 357 cp. The formed fiber reached and adhered to the silicon wafer by an electric field, and a fiber layer (nonwoven fabric layer) was formed. The thickness of the fiber layer was 30 μm. An electron micrograph of the fiber layer is shown in FIG.

10 parts of polyvinylpyrrolidone (PVP) (manufactured by ISP TECHNOLOGIES, INC., Trade name K-90, molecular weight 360,000) was dissolved in 80 parts of ethanol, and 31 parts of acetic acid was added thereto. To this solution, 15 parts of titanium isopropoxide was mixed and stirred for 30 minutes or more to prepare a PVP-TiO ₂ sol solution. This sol solution was placed in a syringe pump connected to the positive electrode of the power source. On the other hand, a silicon wafer connected to the negative electrode of the power source was arranged as a target. The distance between the syringe pump tip and the silicon wafer was set to 10 cm. With the voltage of 10 kV applied, the syringe pump was pushed to inject the solution. The injection rate was 8.3 μl / min. As a result, fibers were formed, and the fibers reached and adhered to the silicon wafer by an electric field to form a fiber layer (nonwoven fabric layer). The thickness of the fiber layer was 20 μm. The obtained fiber layer was baked in an air atmosphere at 500 ° C. for 3 hours to obtain a crystallized (anatase phase) TiO ₂ nanofiber nonwoven fabric layer. The electron micrographs of the fiber layer before and after crystallization are shown in FIG.

  2 parts of zinc acetate dihydrate was dissolved in 4 parts of distilled water and stirred for 1 hour. To this solution, 6 parts of a 20 wt% PVA aqueous solution was gradually added and stirred for 3 hours or more after the addition. Further, this solution was heated to 50 ° C. and stirred for 6 hours to prepare a PVA-ZnO precursor solution. This precursor solution was placed in a syringe pump connected to the positive electrode of the power source. On the other hand, a silicon wafer connected to the negative electrode of the power source was arranged as a target. The distance between the syringe pump tip and the silicon wafer was set to 5 cm. With the voltage of 18 kV applied, the syringe pump was pushed to inject the solution. As a result, fibers were formed, and the fibers reached and adhered to the silicon wafer by an electric field to form a fiber layer (nonwoven fabric layer). The obtained fiber layer was fired at 400 ° C. for 3 hours in an air atmosphere to obtain a PVA-ZnO nanofiber nonwoven fabric layer. An electron micrograph of the fiber layer after crystallization is shown in FIG.

  A solution was prepared by mixing 10 parts of an 8 wt% DMF solution of polyacrylonitrile (trade name, manufactured by Aldrich) and 8 parts of a 10 wt% DMF solution of cellulose diacetate (trade name, CAL20, manufactured by Daicel Chemical Industries). On the other hand, titanium was formed in a comb-like shape with a thickness of 30 nm on a 10 mm × 10 mm alumina ceramic substrate by sputtering, and platinum was formed thereon with a thickness of 50 nm to form a comb-like electrode. In this way, an electrode substrate for impedance measurement was produced. The solution was placed in a syringe pump connected to the positive electrode of the power source. On the other hand, an electrode substrate connected to the negative electrode of the power source was disposed as a target. The distance between the tip of the syringe pump and the electrode substrate was set to 7 cm. With the voltage of 17 kV applied, the syringe pump was pushed to inject the solution. As a result, fibers were formed, and the fibers reached and adhered to the electrode substrate by an electric field, and a fiber layer (nonwoven fabric layer) was formed on the comb-like electrode. The thickness of the fiber layer was 10 μm. In this way, a detection element (humidity sensor) was produced.

  Using the humidity sensor produced above, impedance change was measured when the humidity was changed from 85% to 20% at a frequency of 1 kHz, an applied voltage of 1 V, and a temperature of 25 ° C. The results are shown in FIG. 8 together with the results of Comparative Example 1 described later. The saturation time was obtained from the curve of the graph shown in FIG. 8, and this was used as the response speed. The response speed was 8 minutes.

(Comparative Example 1)
A detection element (humidity sensor) was produced in the same manner as in Example 5 except that a cast film (thickness: 10 μm) was formed on the comb-like electrode of the electrode substrate of Example 5 using the solution of Example 5. did. With respect to the obtained humidity sensor, the impedance change was measured in the same manner as in Example 5. The results are shown in FIG. The saturation time was obtained from the curve of the graph shown in FIG. 8, and this was used as the response speed. The response speed was 32 minutes.

  As is clear from the comparison between the results of Example 5 and Comparative Example 1, it can be seen that the detection element using the nonwoven fabric layer of the present invention has a response speed four times faster than the detection element using the conventional coating film. .

  The detection element of the present invention can be suitably used for various sensors. For example, life odor monitoring, fire odor monitoring, freshness monitoring, initial diagnosis, detection of dangerous substances, etc. and odor sensor for environmental measurement, hydrogen gas sensor, glucose enzyme sensor for blood glucose measurement, microbial sensor for BOD measurement, humidity It can be suitably used as a sensor.

It is a schematic sectional drawing of the detection element by preferable embodiment of this invention. (A) And (b) is a schematic diagram explaining the structure of the detection part in the detection element of this invention, respectively. It is a schematic diagram explaining a preferable example of the manufacturing method of the detection element of this invention. 1 is a schematic perspective view of a detection device according to a preferred embodiment of the present invention. FIG. 6 is a schematic perspective view of a detection device according to another preferred embodiment of the present invention. It is an electron micrograph of the fiber layer formed in the Example of this invention. It is an electron micrograph of the fiber layer formed in another Example of this invention. It is an electron micrograph of the fiber layer formed in another Example of this invention. It is a graph which compares and shows the impedance change of the detection element of the Example of this invention, and the detection element of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Detection element 11 Base material 12 Detection part 100 Detection apparatus 200 Detection apparatus

Claims (15)

A detection element that detects a physical quantity or a chemical quantity in contact with a gas or a liquid,
A detection element comprising: a base material having two main surfaces; and a detection portion formed on at least one of the main surfaces of the base material and made of fibers.   The detection element according to claim 1, wherein the fiber has a diameter of 1 nm to 999 nm.   The detection element according to claim 1, wherein the fibers have a substantially circular or elliptical cross section.   The detection element according to claim 1, wherein the detection unit includes a catalyst and / or an adsorbent supported on the fiber.   The detection element according to claim 1, wherein the material forming the fiber specifically reacts with the substance to be detected and / or specifically adsorbs the substance to be detected.   The detection element according to any one of claims 1 to 5, wherein the material constituting the fiber is at least one selected from polyvinyl alcohol, a copolymer thereof, a high molecular polysaccharide, and a derivative thereof.   The detection element according to claim 1, wherein the material constituting the fiber is at least one metal oxide selected from titanium oxide, zinc oxide, and tin oxide.   The detection element according to claim 1, wherein a resonance frequency of the base material is 10 kHz to 200 MHz.   The detection element according to claim 1, wherein the detected physical quantity or chemical quantity is a change in weight.   The detection element according to claim 1, wherein the detected physical quantity or chemical quantity is an impedance change.   The detection element according to claim 1, wherein the base material is silicon, crystal, or ceramic. Forming a fiber by injecting a solution containing a fiber-forming material under an electric field, and transporting the fiber to a substrate by the action of the electric field, and further attaching the fiber to the substrate to form a detection unit. A method for manufacturing a detection element.   The production method according to claim 12, wherein the solution further contains a catalyst and / or an adsorbent.   The manufacturing method of Claim 12 or 13 including making the said fiber selectively adhere to the said board | substrate, and forming the patterned detection part. A detection device comprising the detection element according to claim 1.