JP2006276029A - Proton acceptor type sensor, hydrogen gas sensor, and acid sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cheaper hydrogen gas sensor which has highest responsive selectivity with respect to proton and operates at room temperature. <P>SOLUTION: These hydrogen gas sensor and acid sensor allow protons to be in contact with an organic compound which can introduce pyridine ring such as a pyridine DPP, detecting variations in electrical resistivity, photoconductivity and photoabsorption band of the organic compound involved in protonation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a sensor having good sensitivity selectivity to protons (H ⁺ ), and more particularly to a hydrogen gas sensor and an acid sensor.

  In recent years, there are many cases where various gases are used in the manufacturing process of products, and in particular, semiconductor manufacturing factories employ a gas chemical reaction process on a single crystal silicon substrate, so there are volatile and toxic gases. Is often used. Hydrogen gas is used in large quantities as a carrier gas for this type of gas. However, hydrogen gas itself is a highly explosive gas, and it is necessary to quickly detect leakage of hydrogen gas.

Furthermore, there is concern about the depletion of fossil fuels such as oil, and various energy sources have been studied as alternative energy sources. Hydrogen can be easily obtained by electrolysis of water, and its combustion product is water, and it has the characteristics that it does not emit CO ₂ , NO _X , SO _X, etc. It can be said.

  As a method for converting hydrogen energy into electric power, a fuel cell using a chemical reaction between hydrogen and oxygen has received the most attention. In particular, fuel cell vehicles equipped with fuel cells are regarded as promising as “the favorite of environmentally-friendly vehicles”. However, since hydrogen is the lightest and smallest molecule, it has the characteristics of being easily leaked, and it can be said to be an extremely dangerous gas because it ignites easily and the combustion speed is high. Therefore, if hydrogen energy systems become popular in the future, the positioning of hydrogen gas sensors is expected to become increasingly important.

  At present, a semiconductor gas sensor using a metal oxide is representative as a hydrogen gas sensor. This has high sensitivity and high reliability, but the sensor element itself needs to be heated to a high temperature. For this reason, there is a limit to reducing the size and weight, reducing the power consumption, or reducing the cost of the sensor, and it is considered that it cannot be used for a wide variety of applications.

A specific example of the hydrogen gas sensor is disclosed in, for example, Japanese Patent Laid-Open No. 59-120945. This is composed of a pair of opposed electrodes formed on one surface of an insulating substrate, a gas sensitive film (SnO ₂ ) covering these electrodes, a heater provided on the opposite surface of the substrate, and a heater connected to the heater. A hydrogen gas sensor comprising a lead wire and a catalyst layer (such as Pt) formed on a gas sensitive film has been proposed. However, in this hydrogen gas sensor, since the catalyst layer is formed by screen printing, it is difficult to control the film thickness, resulting in large variations, and it is difficult to manage the characteristics of the sensor. Furthermore, this hydrogen gas sensor has a drawback that the operating temperature is as high as about 400 ° C.

Further, for example, in a semiconductor manufacturing factory, isopropyl alcohol is used as a cleaning agent, and is always volatilized in the air. Under such conditions, it is difficult to reliably detect the leakage of hydrogen gas. For this reason, as proposed in Japanese Patent Laid-Open No. 01-250851, a gas insensitive thin film layer (SiO _{2) is formed} on the gas sensitive film. However, it is difficult to produce a gas-insensitive thin film layer, the cost is unavoidable, and the management cost for managing the sensor characteristics also increases. .

  Furthermore, although there has been a report of a gas detection element using a phthalocyanine vapor-deposited film, it is intended to monitor the electrical conductivity associated with gas adsorption / desorption, and has no gas selectivity for electron donating or electron withdrawing gas. The operation was also extremely unstable.

  The present invention has been developed in view of the above-described conventional technology, and provides a proton-accepting gas sensor such as a hydrogen sensor or an acid sensor that has good sensitivity selectivity to protons and operates at room temperature at low cost. Is.

The present invention is characterized in that a proton is brought into contact with an organic compound into which a heterocyclic ring containing a nitrogen atom is introduced, and a change in electrical resistivity, photoconductivity, or optical absorption band of the organic compound due to proton addition is detected. The present invention relates to a proton-accepting gas sensor.
The present invention also relates to the above proton-accepting gas sensor, wherein the heterocyclic ring containing a nitrogen atom is a pyridine-based heterocyclic ring.
The present invention also relates to the above proton-accepting gas sensor, wherein the organic compound is an organic pigment into which a heterocyclic ring containing a nitrogen atom is introduced.
The present invention also relates to a hydrogen gas sensor obtained by bringing a proton into contact with an organic compound into which a pyridine ring is introduced and detecting a change in electrical resistivity, photoconductivity, or optical absorption band of the organic compound accompanying proton addition. .
The present invention also relates to the hydrogen gas sensor, wherein the organic compound is an organic pigment having a pyridine ring introduced.
In the present invention, the organic pigment may be pyrrolopyrrole, quinacridone, indigo, phthalocyanine, anthraquinone, indanthrone, anthanthrone, perylene, pyrazolone, perinone, isoindolinone, isoindoline, dioxazine, or a derivative thereof. It relates to a hydrogen gas sensor.
The present invention also relates to the hydrogen gas sensor in which the organic compound and a hydrogen gas protonation catalyst are brought into contact with each other.
The present invention also relates to the hydrogen gas sensor, wherein the protonation catalyst is Pt, Pd, Ni, or a binary or ternary alloy thereof.
The present invention also relates to the hydrogen gas sensor in which an organic pigment film is laminated as a sensitivity promoter on one or both surfaces of the organic compound film.
The present invention also relates to the hydrogen gas sensor, wherein at least one pair of electrodes is arranged in contact with the organic compound film to detect a change in electrical resistivity or photoconductivity.
The present invention also relates to the hydrogen gas sensor, wherein the organic compound film is a vacuum deposited film or a sputtered film.
In the present invention, at least one pair of electrodes are arranged opposite to each other on a substrate, and the organic compound film is provided on the electrode, and a protonation catalyst is in contact with one side or both sides of the organic compound film, or organic The present invention relates to the hydrogen gas sensor in an electric resistance mode in which a protonation catalyst is distributed in a compound film and detects a change in electric resistivity between electrodes.
The present invention also relates to the hydrogen gas sensor, wherein the protonation catalyst is provided in an island shape by vacuum deposition or sputtering on the substrate and the electrode, on the organic compound film, or in the organic compound film. .
The present invention also provides an electric field in which an n ⁺ -Si substrate is used as a gate, source and drain electrodes are formed on the substrate via a silicon oxide insulating film, and the organic compound film is formed on the silicon oxide and the electrode. The present invention relates to the hydrogen gas sensor having an effect transistor structure (FET).
The present invention also relates to the hydrogen gas sensor in a photoconductive mode that detects a change in photoelectric conductivity by combining an excitation light source.
The present invention also relates to the hydrogen gas sensor in an optical absorption band mode for detecting a change in an optical absorption band by combining a photodiode or an electron multiplier.
The present invention also provides an acid characterized in that a proton is brought into contact with an organic compound into which a pyridine ring is introduced, and a change in electrical resistivity, photoconductivity, or optical absorption band of the organic compound due to proton addition is detected. Regarding sensors.
The present invention also relates to the acid sensor, wherein the organic compound is an organic pigment having a pyridine ring introduced.
Further, in the present invention, the organic pigment is pyrrolopyrrole, quinacridone, indigo, phthalocyanine, anthraquinone, indanthrone, anthanthrone, perylene, pyrazolone, perinone, isoindolinone, isoindoline, dioxazine, or a derivative thereof. It relates to an acid sensor.
The disclosure of the present application relates to the subject matter described in Japanese Patent Application No. 2003-36212 filed on October 22, 2003 and Japanese Patent Application No. 2004-144138 filed on May 13, 2004. The disclosure is incorporated herein by reference.

  The proton-accepting gas sensor of the present invention brings a proton into contact with an organic compound into which a heterocyclic ring containing a nitrogen atom is introduced, and changes the electrical resistivity, photoconductivity, or optical absorption band of the organic compound accompanying proton addition. It is characterized by detecting.

  Hereinafter, the proton-accepting gas sensor of the present invention will be described focusing on a hydrogen gas sensor using a pyridined pyrrolopyrrole pigment.

  Now, the present inventors have clarified the electronic structure (particularly the color tone in the solid state) of pyrrolopyrrole (hereinafter referred to as DPP), which is known as an organic pigment, from the standpoint of molecular structure, crystal structure and intermolecular interaction. Various proposals have been made for its application. However, among DPPs, it was found that DPP having a pyridine ring (preferably a nitrogen atom at the para position) (hereinafter referred to as pyridine / DPP or DPPP) reacts very sensitively with protons. That is, pyridine.DPP having a pyridine ring in the DPP skeleton is extremely sensitive to protons, and a large change appears in the electrical resistivity, photoconductivity, optical absorption band, etc. at room temperature with proton addition. Based on this finding, the present invention has been completed, and it has been found that a highly reliable hydrogen gas sensor can be provided. Reference {J. Mizuguchi, H. Takahashi and H. Yamakami: Crystal structure of 3,6-bis (4'-pyridyl) -pyrrolo [3,4-c] pyrrole-1,4-dione, Z. Krist As shown in NCS 217, 519-520 (2002)}, there are two crystalline phases in pyridine DPP, but in the hydrogen gas sensor, crystalline phase I (the nitrogen atom of the pyridine ring is NH… N The crystalline phase in which no hydrogen bond is formed is preferred.

Pyridine / DPP is extremely stable against light and heat, but when protons (H ⁺ ) arrive, it reacts immediately even at room temperature, and the optical absorption band changes from 540 nm (red) to 580 nm (purple). Along with this, the electrical resistivity decreases by 3 to 5 orders of magnitude, and large photoconduction appears. Any of these phenomena can be used to provide a highly sensitive hydrogen gas sensor that operates at room temperature.

  The organic compound used in the present invention is preferably an organic pigment into which a heterocyclic ring containing a nitrogen atom is introduced. For example, the pyridine-DPP and its derivative (Chemical Formula 2), pyridined quinacridone and Derivatives (Chemical formula 3), Indigo and its derivatives (Chemical formula 4), Phthalocyanine and its derivatives (Chemical formula 5), Anthraquinone and its derivatives (Chemical formula 6), Indanthrone and its derivatives (Chemical formula 7), Anthanthrone and its derivatives (Chemical formula 6) 8), perylene and its derivatives (Chemical 9-1), (Chemical 9-2), pyrazolone and its derivatives (Chemical 10), perinone and its derivatives (Chemical 11-1), (Chemical 11-2), Similar compounds such as indolinone and derivatives thereof (Chemical Formula 12), isoindoline and derivatives thereof (Chemical Formula 13), dioxazine (Chemical Formula 14) and derivatives thereof are also possible.

  Furthermore, the organic compound selected in the present invention is not limited to the above. The organic compound selected in the present invention is an organic compound into which a heterocyclic ring containing a nitrogen atom, preferably a pyridine type heterocyclic ring is introduced. For example, an organic compound having the following six-membered ring containing a nitrogen atom (also referred to as a pyridine-based heterocycle in the present invention) (Chemical Formula 15), or cinnoline (Chemical Formula 16) or phthalazine (Chemical Formula 17). ), An organic compound having a condensed ring containing a nitrogen atom, such as phenazine (Chemical Formula 18).

  Specifically, in the compounds of (Chemical Formula 2) to (Chemical Formula 14) described above, compounds in which the pyridine ring is replaced by (Chemical Formula 15) to (Chemical Formula 18) can be mentioned.

  DPP having a pyridine ring can be synthesized from cyanopyridine and oxalic acid, for example, according to the method described in Japanese Patent Publication No. 4-25273. Further, other organic compounds having nitrogen atoms are described in, for example, W. Herbst and K. Hunger, Industrial Organic Pigments -Production, Properties, Applications-, VCH Weinheim, New York, Basel, Cambridge (1993). It can be synthesized according to the existing method.

In the following, the example of pyridine / DPP will be mainly described. The basic process of the present invention consists of the following two processes. The first process is a process of dissociation and protonation of hydrogen gas (hydrogen molecule) ( H ₂ → H + H → 2H ⁺ + 2e), the second process is a process of detecting a change in physical properties accompanying addition of protons to pyridine / DPP.

  In the first process, protonation of hydrogen gas becomes a problem, but it can be preferably solved by using a catalyst such as Pt, Pd, Ni, or a binary alloy or a ternary alloy thereof. That is, when coming into contact with these metals, hydrogen molecules become unstable and protonate via atomic hydrogen (H). Specifically, protonation of hydrogen gas is promoted by sputtering Pd and Pt.

  The element structure in the second process basically includes at least one pair of electrodes, and pyridine / DPP is arranged between the electrodes, and the above catalyst for protonating hydrogen gas is arranged in an island shape. It is. Here, the island shape is a state in which metal particles are scattered in an island shape to such an extent that electrical continuity does not appear in a film manufactured by a sputtering method.

  Therefore, in the hydrogen gas sensor of the present invention, the organic compound and the hydrogen gas protonation catalyst are preferably in contact with each other.

  The hydrogen gas sensor of the present invention is preferably a hydrogen gas sensor that detects a change in electrical resistivity or photoconductivity by disposing at least one pair of electrodes in contact with the organic compound film described above. In the hydrogen gas sensor of the present invention, it is particularly preferable that at least one pair of electrodes are arranged opposite to each other on a substrate, the organic compound film is provided on the electrode, and protons are formed on one or both sides of the organic compound film. This is an element in which a protonation catalyst is contacted or a protonation catalyst is distributed in an organic compound layer, and is an electric resistance mode hydrogen gas sensor that detects a change in electrical resistivity between electrodes. The film of the organic compound can be provided by a vacuum evaporation method or a sputtering method, and can be preferably provided by a vacuum evaporation method. In addition, the protonation catalyst can be provided in an island shape on the substrate and the electrode, on the organic compound film, or in the organic compound film by vacuum evaporation or sputtering, preferably sputtering.

One specific example is shown in FIG. 1, in which comb-shaped electrodes (2, 2 ₁ , 2 ₂ ) are alternately arranged on a substrate (1) such as glass, and Pd (3), for example, is used as a catalyst. Sputter deposition (about several Å) in an island shape (E-1030 ion sputtering, manufactured by Hitachi, Ltd.), and pyridine · DPP (4) is vacuum-deposited into a film shape (about several tens to several hundred Å) (EG240 This is an element structure (A) made by Tokyo Vacuum Co., Ltd.). Pyridine · DPP is X = Y in the compound 2, and X is a pyridine ring having a nitrogen atom at the para position. However, R ₁ = R ₂ = R ₃ = R ₄ = H. In this example, sufficient sensitivity was obtained at room temperature and 1% hydrogen gas atmosphere.

  In addition, the area (electrode part) of the element shown in FIG. 1 is 5 mm × 10 mm, and the electrode width and the electrode interval are 100 μm.

A second example is shown in FIG. 2, in which pyridine DPP (4) is deposited in a film shape on the electrodes (2, 2 ₁ , 2 ₂ ), and Pd (3) is formed in an island shape on the surface. It is the element structure (B) sputter | spattered to.

  Further, a third example is shown in FIG. 3, and is an element structure (C) in which protonation catalysts are distributed in a film of an organic compound. The electrode is not particularly limited, and for example, Al, ITO (Indium-Tin-Oxide: transparent electrode), Au, Ag, Pd, Pt, Pd—Pt alloy, or the like is used. By detecting the change in electrical resistivity between the electrodes, an electrical resistance mode hydrogen gas sensor is completed. As a matter of course, the hydrogen gas sensor having this structure can also detect the vapor-like proton gas found in the acid, and functions as an acid sensor with the same element structure.

  Of course, it is needless to say that a hydrogen gas sensor in a photoconductive mode in which an excitation light source is combined, or in an optical absorption band change mode in which a photodiode, a photomultiplier tube, or the like is combined can be provided. Needless to say, these elements also operate as acid sensors as before.

A fourth example is shown in FIG. The hydrogen gas sensor shown in FIG. 9 is a sensor having a so-called organic FET (field effect transistor) structure. A further improvement in sensitivity is recognized in a hydrogen gas sensor in which a protonation catalyst is sputtered on an element having an electrode structure of an FET structure and an organic compound layer is further formed thereon. The hydrogen gas sensor shown in FIG. 9 has an n ⁺ Si substrate (14) as a gate, and a source and drain electrode (12) formed thereon via a silicon oxide insulating film (13). The two-layer film (protonated catalyst layer and organic compound layer formed in an island shape) (11) is formed therebetween. Here, Vg, Id, and Vs-d are a gate voltage, a drain current, and a source / drain voltage, respectively. A sensor having such an FET structure can improve sensitivity several times more than the above-described sensor having only a comb-shaped electrode by controlling the gate voltage.

Now, the principle of the present invention will be further described with reference to the example of FIG. 1. Hydrogen gas is first adsorbed on the surface of pyridine · DPP (4) and then diffuses inside the pyridine · DPP (4). Then, the hydrogen gas encounters Pd (3) and dissociates there to become protons (H ₂ → H + H (dissociation) → 2H ⁺ + 2e (protonation)). This proton is protonated to the nitrogen atom of the pyridine ring of pyridine.DPP (4). Due to the electrons emitted at this time, the electrical resistivity of pyridine.DPP (4) decreases by 2 to 4 orders of magnitude at room temperature. This decrease in resistivity is electrically detected to provide a hydrogen gas sensor.

FIG. 4 shows the change in resistivity under the 100% H ₂ atmosphere in the example of the element shown in FIG. 1. The electrode was ITO, the thickness of pyridine / DPP was 500 mm, and Pd was used as the catalyst. FIG. 5 shows the result of using Pt as a catalyst in the same experiment. In the figure, a (black circle) indicates the result before proton addition, and b (white mark) indicates the result after proton addition.

  When the nitrogen atom of the pyridine ring of pyridine / DPP is protonated, not only the electric resistance value is reduced as described above, but also photoconductivity appears. The optical absorption band near 540 nm in the visible part of pyridine / DPP shifts to 580 nm, and the color tone changes from red to purple. Therefore, as a detection method as a hydrogen gas sensor, a change in electrical resistivity (electric resistance mode), the appearance of photoconductivity (photoconduction mode), or a longer wavelength of the optical absorption band (540 nm → 580 nm) (color change mode). Either one is used as a detection function.

FIG. 6 is an absorption spectrum before and after proton addition by HNO ₃ vapor of a pyridine / DPP vapor deposition film (thickness: 1200 mm), and FIG. 7 is a photoconduction spectrum.

FIG. 10 shows the change in electrical resistivity under 100% H ₂ concentration in another example of the device of FIG. 1, wherein the electrode is ITO, the thickness of pyridine · DPP is 500 mm, and Pd is used as the catalyst. Pyridine · DPP is X = Y in the compound 2 and X is a pyridine ring having a nitrogen atom at the para position. However, R ₁ = R ₂ = R ₃ = R ₄ = H. In this example, sublimation-purified pyridine / DPP is used.

FIG. 11 shows changes in electrical resistivity accompanying proton addition by HNO ₃ vapor in a pyridine / DPP vapor deposition film (thickness: 1200 mm).

  FIG. 12 shows the hydrogen gas concentration dependence of the change in electrical resistivity in another example of the element shown in FIG. 1. The electrode was ITO, the thickness of pyridine / DPP was 500 mm, and Pd was used as the catalyst.

  FIG. 13 shows the time response characteristics of another example of the element shown in FIG. 1. The electrode was ITO, the pyridine / DPP thickness was 500 mm, and the catalyst was Pd.

FIG. 14 is another example having the element structure of FIG. 1, and shows an example of a change in electrical resistivity of an element using pyridine / perylene instead of pyridine / DPP as an organic compound. Pyridine / perylene is X = Y in the compound 9-1, and X is a pyridine ring having a nitrogen atom at the para position. However, R ₁ = R ₂ = R ₃ = R ₄ = H. The electrode was ITO, the thickness of pyridine / perylene was 500 mm, and Pd was used as the catalyst. In the figure, a (black circle) indicates the result before proton addition, and b (white mark) indicates the result after proton addition. The electrical resistivity of pyridine / perylene varies by about 20,000 times or more depending on the presence or absence of hydrogen gas. An element using pyridine / perylene shows the same reaction even when Pt is used as a catalyst, like pyridine / DPP.

  In addition, when the above-mentioned various organic compounds are used, as in the case of pyridine / DPP and pyridine / perylene, a significant change in electrical resistivity can be confirmed depending on the presence or absence of hydrogen gas.

  For the purpose of increasing the sensitivity of the sensor, an organic pigment thin film such as phthalocyanines can be provided as a sensitivity promoter on the upper or lower surface of pyridine / DPP or on the upper and lower surfaces of pyridine / DPP. It is also possible to co-evaporate pyringin / DPP and phthalocyanines. The ratio of pyridine DPP and phthalocyanines is about 10: 1 in terms of film thickness, and the weight ratio in the case of co-deposition is about 10: 1.

  As described above, the present invention has been described mainly with respect to a sensor that detects hydrogen gas using pyridine / DPP as an organic compound into which a heterocyclic ring containing a nitrogen atom is introduced. However, as described above, a heterocyclic ring containing a nitrogen atom is limited to pyridine. The above-mentioned triazine, pyrazine, pyrimidine, pyridazine and the like can be used. Further, the gas to be detected is not limited to hydrogen gas, and any sensor can be used as long as it generates protons by dissociation such as nitric acid gas, hydrogen chloride gas, hydrogen fluoride gas, etc. Can be detected.

  INDUSTRIAL APPLICABILITY The present invention can provide a hydrogen sensor with good sensitivity sensitivity to protons at a low cost, and in recent years, a manufacturing plant that uses hydrogen gas as a carrier, a hydrogen gas storage facility, and hydrogen gas as energy. In a so-called fuel cell used as a power source, a sensor that greatly plays a role in hydrogen gas detection and leakage accident prevention measures could be provided. The present invention is not limited to a hydrogen sensor, and can provide a wide range of highly sensitive proton-accepting gas sensors including an acid sensor at low cost. Nitric acid gas, hydrogen fluoride gas, hydrogen chloride gas Even in manufacturing plants where there is a possibility of generation of toxic gases such as the above, it has been possible to provide a sensor that plays a major role in detecting various proton donating gases and preventing leakage accidents.

Example 1
1. Electrical resistance mode When an element having the structure shown in FIG. 1 is placed in an atmosphere of hydrogen gas, nitric acid gas, hydrogen chloride gas, hydrogen fluoride gas, ammonia gas or the like, the electrical resistance rapidly decreases. Normally, since the electrical resistivity of pyridine / DPP is very high and close to an insulator, a voltage is applied between the electrodes to detect a flowing small current. That is, it is used as a sensor by detecting and amplifying the change of this minute current. The element according to the present invention is very easy to detect because the change in electrical resistivity is 1 to 4 digits or more. However, since the detection system, that is, the input system has a high impedance, it is desirable to cope with the circuit design. For example, it is effective to perform impedance conversion by inserting a buffer using a high input impedance OP amplifier in the previous stage of the detection signal amplifier circuit.

As a specific circuit, the circuit shown in FIG. 8 is formed by using the element shown in FIG. 1, and every other opposing electrode (2 ₁ , 2 ₂ ) is connected, and one of them is connected to a power source (5 ) To the cathode and the other to the anode. A circuit (6) for detecting a current is inserted in the closed circuit of the electrode and the power source, and a change in current due to a change in electrical resistivity of pyridine · DPP / Pd is detected.

(Example 2)
2. Photoconductive mode The electrical resistance mode and the structure of the element are the same except that a glass plate is used as the substrate and ITO is used as the electrode. When this element is irradiated with visible light, the electrical resistance is greatly reduced (photoconductive phenomenon), and hydrogen gas can be detected.

(Example 3)
3. Absorption band mode In this optical absorption band mode, no electrode is required, and other structures are the same as those in the electric resistance mode and the photoconductive mode. When proton addition occurs in the pyridine / DPP film, the absorption band of 540 nm shifts to 580 nm. This is a mode in which a change in the optical absorption band is detected by a semiconductor detector or a photomultiplier tube and used for a hydrogen gas sensor.

  In either case, the electrical resistance and the photoconductive mode basically use a change in electrical resistance for the sensor. As the operation mode, a detection method using either direct current or alternating current can be used.

  The present invention provides a proton-accepting gas sensor with good sensitivity selectivity to protons, particularly a hydrogen gas sensor at a low cost, and has various detection means, such as an electric resistance mode, a photoconductive mode, and an optical absorption band mode. This is a device that detects changes in gas and makes a great contribution to hydrogen gas detection and leakage accident prevention measures, and its range of use is extremely wide. It is also effective as an acid sensor for hydrogen fluoride gas and the like.

FIG. 1 is a conceptual diagram showing a first element structure of the present invention. FIG. 2 is a conceptual diagram showing a second element structure of the present invention. FIG. 3 is a conceptual diagram showing a third element structure of the present invention. FIG. 4 is a diagram showing a change in electrical resistivity in the pyridine / DPP element (catalyst Pd) of FIG. FIG. 5 is a diagram showing a change in electrical resistivity in the pyridine / DPP element (catalyst Pt) of FIG. FIG. 6 shows absorption spectra before and after proton addition to pyridine / DPP. FIG. 7 is a photoconductivity spectrum before and after proton addition to pyridine DPP. FIG. 8 is a conceptual diagram of a circuit for detecting a change in electrical resistance. FIG. 9 is a conceptual diagram showing a fourth element structure of the present invention. FIG. 10 is a diagram showing a change in electrical resistivity in the pyridine / DPP element (catalyst Pd) of FIG. FIG. 11 shows electrical resistivity before and after proton addition to pyridine / DPP. FIG. 12 is a graph showing the dependence of the change in electrical resistivity on the hydrogen gas concentration in the pyridine / DPP element (catalyst Pd) of FIG. FIG. 13 is a diagram showing time response characteristics of electrical resistivity in the pyridine / DPP element (catalyst Pd) of FIG. FIG. 14 is a graph showing changes in electrical resistivity in the pyridine / perylene element (catalyst Pd) of FIG.

Claims (2)

  A proton-accepting gas sensor comprising an organic compound into which a heterocyclic ring containing a nitrogen atom is introduced, wherein the electrical resistivity, photoconductivity, or optical absorption band of the organic compound can be changed with the addition of a proton to the organic compound. The organic compound is an organic pigment introduced with a heterocyclic ring containing a nitrogen atom, and the organic pigment is quinacridone, indigo, phthalocyanine, anthraquinone, indanthrone, anthanthrone, perylene, pyrazolone, perinone, isoindolinone, A proton-accepting gas sensor, which is isoindoline, dioxazine, or a derivative thereof.   The proton-accepting gas sensor according to claim 1, wherein the heterocycle containing a nitrogen atom is a pyridine-based heterocycle.

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