Method and use of amino-functionalized metal organic framework material for preparing chemical resistance sensor

Abstract

The present invention discloses a method for preparing a chemical resistance type sensor using an amino functionalized metal organic framework material, which comprises the following specific steps: S1: preparing or preparing an amino functionalized metal organic framework (NH 2 ‑MOFs) nanosheet powder; S2: NH 2 ‑MOFs nanosheet powder is dissolved in an organic solvent to prepare a paste, and then the paste is evenly coated on a non-conductive substrate, and the two ends of the non-conductive substrate are fixedly connected with wires, and heated to prepare a chemical resistance sensor. 2 ‑MOFs gas-sensitive materials have an ultra-high specific surface area, which greatly improves the material's adsorption of gas, while the amino functional groups can selectively adsorb gas, thereby improving the gas-sensing performance and selectivity of the gas, enabling it to detect nitro explosives and nitro-containing explosive raw materials in real time with high sensitivity and selectivity.

Description

Technical Field

[0001] The present invention relates to the fields of functional material science and chemical resistance type sensing, and in particular to a method and application of using an amino-functionalized metal organic framework material for thin film electrical devices such as gas sensors, lithium sulfur batteries, fuel cells, etc. to prepare chemical resistance type sensors. Background Art

[0002] The environmental pollution caused by nitro explosives has always been the focus of social attention. Nitro explosives such as trinitrotoluene (TNT), dinitrotoluene (DNT), picric acid (PA), and RDX are an important type of standard explosives. The saturated vapor pressure at room temperature is very low. For example, the saturated vapor pressures of TNT, DNT, PA, and RDX at room temperature are 9ppb, 180ppb, 0.97ppb, and 4.9PPT, respectively, making it difficult for many sensors to detect their atmosphere in real time online and quickly, and they have low sensitivity and poor selectivity. Ammonium nitrate explosives are made by mixing oxidants, combustibles, and sensitizers. Ammonium nitrate is the main oxidant of ammonium nitrate explosives. Urea nitrate is an explosive product, and it is also a raw material and intermediate for preparing explosives. It is easy to mix with organic matter, reducing agents, etc. to make explosives. Therefore, the detection of ammonium nitrate and urea nitrate can realize the detection of the raw materials of some nitro explosives.

[0003] In the prior art, metal oxide (MOX) or other polymers are often used as chemical resistance sensors to detect room temperature nitro explosive atmospheres. However, the sensors have low sensitivity and selectivity, which reduces the accuracy of nitro explosive atmosphere detection.

[0004] Metal-organic frameworks (MOFs) are a type of crystalline porous materials with a regular network structure that is self-assembled by inorganic nodes (metal ions or metal clusters) and organic ligands through coordination. As a new type of functional material, MOFs have the advantages of structural order and diversity, high tailorability and ultra-high specific surface area. They show good application prospects in the fields of drug carriers, gas separation, gas adsorption storage and removal, catalysis, magnetism, sensors, optics, etc. The introduction of different functional groups can give the material different properties. Amino groups are nucleophilic groups that can regulate the band gap of the material and make it absorb visible light. At the same time, as a Lewis base, they can selectively adsorb CO2, NO2, nitro compounds, etc. The application of amino-functionalized metal organic frameworks (NH2-MOFs) in gas detection is becoming more and more extensive.

[0005] There are many studies on the fluorescence detection of nitro explosives using NH2-MOFs, but there is no report on the detection of nitro explosive atmosphere at room temperature using chemiresistor-type sensors. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for preparing a chemical resistance sensor using an amino-functionalized metal organic framework material, the specific steps of which are:

[0007] S1: preparing or preparing amino-functionalized metal organic framework (NH2-MOFs) nanosheet powder;

[0008] S2: dissolving NH2-MOFs nanosheet powder in an organic solvent to prepare a paste, and then evenly coating the paste on a non-conductive substrate with wires fixedly connected at both ends of the non-conductive substrate, heating, and preparing a chemical resistance sensor.

[0009] According to the technical solution of the present invention, in step S2, evaporation or direct coating is adopted; specifically, one or more of spin coating, pulling, dipping, dripping, in-situ growth, and layer-by-layer self-assembly methods can be adopted to prepare NH2-MOFs into a film.

[0010] According to the technical solution of the present invention, the non-conductive substrate is one of an AL2O3 substrate, a sapphire substrate, a fragment carrier substrate, a polytetrafluoroethylene substrate, a quartz substrate, and a PDMS substrate.

[0011] According to the technical solution of the present invention, the specific preparation steps of the amino-functionalized metal organic framework (NH2-MOFs) powder in step S1 are: dissolving the amino-containing organic ligand and the metal salt in a mixed solvent of anhydrous methanol and DMF, mixing evenly, heating to react, and drying to prepare NH2-MOFs powder.

[0012] According to the technical solution of the present invention, the volume ratio of anhydrous methanol to DMF is (1-9):(9-1), preferably 1:9.

[0013] According to the technical solution of the present invention, the molar ratio of the amino-containing organic ligand to the metal salt is (20-1):1, preferably 1:1.

[0014] According to the technical solution of the present invention, the specific surface area of ​​the NH2-MOFs material is 1000-3000m 2 g -1 , the pore size is 0.2-2nm.

[0015] According to the technical solution of the present invention, the heating temperature is 100-220°C; the heating time is 15-96h; the drying temperature is 80-150°C, and the drying time is 12-48h; preferably, drying at 80°C for 12h.

[0016] According to the technical solution of the present invention, the organic ligand that functionalizes the amino group is at least one of diaminoterephthalic acid (NH2-BDC), 2.5-diaminoterephthalic acid ((NH2)2-BDC), and 2-amino-1.4-benzenedicarboxylic acid (ABDC), preferably NH2-BDC.

[0017] According to the technical solution of the present invention, the metal in the metal salt is one or more of titanium (Ti), zirconium (Zr), iron (Fe), chromium (Cr), aluminum (Al), copper (Cu) or indium (In); preferably titanium (Ti) and zirconium (Zr); preferably, when the metal salt is a titanium (Ti) salt, it can be tetra-n-butyl titanate, titanium tetrachloride or titanium trichloride, preferably, tetra-n-butyl titanate; when the metal salt is a zirconium salt, it can be zirconium tetrachloride.

[0018] According to the technical solution of the present application, step S2 also includes: dissolving NH2-MOFs nanosheet powder in an organic solvent to prepare a paste, and then uniformly coating the paste on a non-conductive substrate, wherein both ends of the non-conductive substrate are fixedly connected with wires to prepare an NH2-MOFs nanosheet thin film seed layer; dissolving an amino-containing organic ligand and a metal salt in a mixed solvent of anhydrous methanol and DMF to prepare a mixed solution, immersing the NH2-MOFs nanosheet thin film seed layer in the mixed solution, heating, and preparing a chemical resistance sensor.

[0019] The invention also provides a chemical resistance sensor prepared by the method.

[0020] The present invention also provides an application of the above chemical resistance type sensor, which is applied to the detection of nitro explosive atmosphere. The specific detection method is as follows:

[0021] The chemical resistance sensor is connected to a power source and energized to apply voltage to detect nitro explosive vapor.

[0022] According to the technical solution of the present invention, the nitro explosive is TNT, DNT, PA, RDX or its derivatives.

[0023] According to the technical solution of the present invention, a solvothermal method is used to obtain NH2-MOFs, including one or more of NH2-MIL-125(Ti), NH2-UIO-66(Zr), NH2-MIL-101(Fe), NH2-MIL-101(Cr), NH2-MIL-101(Al), NH2-MIL-53(Al), Fe-MIL-88B-NH2, MOF-5-NH2, NH2-MIL-68(In), and NH2-CU3(BTC)2.

[0024] Beneficial effects of the present invention

[0025] (1) The NH2-MOFs gas-sensitive material prepared in the present application has an ultra-high specific surface area, which greatly improves the material's adsorption of gas, and the amino functional group can selectively adsorb gas, thereby improving the gas-sensing performance and selectivity of the gas, enabling it to detect nitro explosives and nitro-containing explosive raw materials in real time with high sensitivity and selectivity.

[0026] (2) The NH2-MOFs film of the present application has enhanced adsorption of nitro explosives as the number of ligand amino groups increases due to acid-base interaction. Combined with its high specific surface area, it can pre-enrich and concentrate extremely low concentration nitro explosive atmospheres, thereby improving its sensitivity and selectivity in detecting nitro explosives. The response value to 0.97 ppb trinitrophenol (PA) at room temperature is 230%.

[0027] (3) The present application adopts a seed crystal assisted solvothermal method, which is used for secondary growth of oriented continuous MOF films to prepare NH2-MOF preferentially oriented thin films with controllable thickness. MOF nanoparticles prepared by direct solvothermal method without using seed crystal assisted solvothermal method produce disordered thick films, not continuous preferentially oriented films. Devices usually prepared from such thick films with disordered particles, when used in chemical resistance sensors to detect gases, have poor mass transfer and conduction, low sensitivity, slow response speed, and are difficult to recover. When the preferentially oriented continuous film is used in chemical resistance sensors to detect gases, the sensitivity and response speed can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a scanning electron microscope image of the octahedral NH2-MIL-125(Ti) in Example 1;

[0029] Figure 2 is a scanning electron microscope image of the NH2-MIL-125(Ti) nanosheet in Example 2;

[0030] Figure 3 is a scanning electron microscope image of the NH2-MIL-125(Ti) nanosheet in Example 3;

[0031] Figure 4 is a scanning electron microscope image of the NH2-MIL-125(Ti) nanosheet in Example 4;

[0032] Figure 5 is a scanning electron microscope image of the NH2-MIL-125(Ti) film in Example 5;

[0033] Figure 6 is the PXRD pattern of the NH2-MIL-125(Ti) film in Example 5;

[0034] Figure 7is the PXRD pattern of NH2-UiO-66(Zr) in Comparative Example 1;

[0035] Figure 8 This is a schematic diagram of the NH2-MOFs film performance test in Example 6;

[0036] Fig. 9 is a test diagram of the response of the chemical resistance sensor to the PA atmosphere in Example 6;

[0037] Fig.10 is a test diagram of the response of the chemical resistance sensor to the PA atmosphere in Example 7;

[0038] Fig.11 This is a test diagram of the response of the chemical resistance sensor in Example 8 to the PA atmosphere. DETAILED DESCRIPTION

[0039] The preparation method and application of the present invention will be further described in detail below in conjunction with specific examples. It should be understood that the following examples are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0040] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0041] Example 1

[0042] A synthesis of NH2-MOF material for chemical resistance type sensor to detect nitro explosive atmosphere, comprising the following steps:

[0043] a. Mix 18 ml of anhydrous DMF and 2 ml of anhydrous methanol, then dissolve 1.086 g of NH2-BDC in the mixed solvent and completely dissolve it by ultrasonication for 5 min;

[0044] b. Quickly add 0.52 ml of tetrabutyl titanate to the solution in step a and stir evenly;

[0045] c. Transfer the solution in step b to a polytetrafluoroethylene liner, then place it in a stainless steel autoclave, place it in an oven at 150°C for 72 hours, and then take it out; prepare a mixed solution.

[0046] d. The mixed solution in step c was washed by centrifugation with methanol and dried at 80 ° C for 12 h to obtain octahedral NH2-MIL-125 (Ti), the scanning electron microscope image of which is as follows Figure 1 shown.

[0047] Example 2

[0048] The synthesis of NH2-MOF material for chemical resistance type sensor to detect nitro explosive atmosphere includes the following steps:

[0049] a. Mix 18 ml of anhydrous DMF and 2 ml of anhydrous methanol, then dissolve 0.4344 g of NH2-BDC in the mixed solvent and sonicate for 5 min to completely dissolve it.

[0050] b. Quickly add 0.208 ml of tetra-n-butyl titanate to the solution in step a and stir evenly.

[0051] c. Pour the solution in step b into the polytetrafluoroethylene liner, flatten it, and then put it into a stainless steel autoclave. Put it into an oven at 150°C for 72 hours to prepare a mixed solution.

[0052] d. The mixed solution in step c was washed by centrifugation with methanol and dried at 80 ° C for 12 h. NH2-MIL-125 (Ti) nanosheets were obtained by scanning electron microscopy. Figure 2 As shown, the thickness of the nanosheets is in the range of 100-150 nm.

[0053] Example 3

[0054] The synthesis of NH2-MOF material for chemical resistance type sensor to detect nitro explosive atmosphere includes the following steps:

[0055] a. Take 18 ml of dry DMF and 2 ml of dry methanol and mix them evenly, then dissolve 0.2172 g of NH2-BDC in the mixed solvent and sonicate for 5 min to completely dissolve it.

[0056] b. Quickly add 0.104 ml of tetrabutyl titanate to the solution in step a and stir evenly.

[0057] c. The solution in step b was transferred into a polytetrafluoroethylene liner, and then placed in a stainless steel autoclave, which was placed in an oven at 150°C for 72 hours and then taken out to prepare a mixed solution.

[0058] d. The mixed solution in step c was washed by centrifugation with methanol and dried at 80 ° C for 12 h to obtain NH2-MIL-125 (Ti) nanosheets, the scanning electron microscopy image of which is as follows Figure 3 As shown, the thickness of the nanosheets is in the range of 50-100 nm.

[0059] Example 4

[0060] The synthesis of NH2-MOF material for chemical resistance type sensor to detect nitro explosive atmosphere includes the following steps:

[0061] a. Mix 18 ml of anhydrous DMF and 2 ml of anhydrous methanol, then dissolve 2.715 g of NH2-BDC in the mixed solvent and sonicate for 5 min to completely dissolve it.

[0062] b. Quickly add 0.21 ml of tetra-n-butyl titanate to the solution in step a and stir evenly.

[0063] c. Transfer the solution in step b to a polytetrafluoroethylene liner, then place it in a stainless steel autoclave, place it in an oven at 150°C for 72 hours, then take it out to prepare a mixed solution.

[0064] d. The mixed solution in step c was washed by centrifugation with methanol and dried at 80 ° C for 12 h to obtain NH2-MIL-125 (Ti) nanosheets, the scanning electron microscopy image of which is as follows Figure 4 As shown, the thickness is in the range of 5-50 nm.

[0065] Example 5

[0066] A method for preparing an amino-functionalized metal organic framework material comprises the following steps:

[0067] a. Mix 18 ml of anhydrous DMF and 2 ml of anhydrous methanol, then dissolve 2.715 g of NH2-BDC in the mixed solvent and completely dissolve it by ultrasonication for 5 min;

[0068] b. Quickly add 0.21 ml of tetrabutyl titanate to the solution in step a and stir evenly;

[0069] c. The solution in step b was transferred to a polytetrafluoroethylene liner and then placed in a stainless steel autoclave, which was placed in an oven at 150°C for 72 hours and then taken out to prepare a mixed solution;

[0070] d. The mixed solution in step c was washed by centrifugation with methanol and dried at 80 ° C for 12 h to obtain 5-50 nm NH2-MIL-125 (Ti) nanosheets;

[0071] e. The 5-50nm NH2-MIL-125 (Ti) nanosheets in step d are evenly dropped on the Al2O3 non-conductive substrate by spin coating to serve as a seed layer for growing an oriented NH2-MIL-125 (Ti) film;

[0072] f. Mix 18 ml of anhydrous DMF and 2 ml of anhydrous methanol, then add 0.2172 g of NH2-BDC and 0.21 ml of tetra-n-butyl titanate, and stir to mix evenly;

[0073] g. Place the seed layer containing the NH2-MIL-125 (Ti) film in step e into the solution in step f, place it in a polytetrafluoroethylene liner, and then place the liner in a stainless steel autoclave, place the autoclave in an oven, and heat at 150°C for 72 hours. After the reaction is completed, wash it with methanol to obtain a continuous preferentially oriented NH2-MIL-125 (Ti) film, the scanning electron microscope image of which is shown in the following figure Figure 5 Its PXRD pattern is shown as Figure 6 shown.

[0074] Example 6

[0075] The above chemical resistance type sensor is used to detect the atmosphere of nitro explosives. The specific detection method is as follows:

[0076] S1. 5 mg NH2-MIL-125 (Ti) powder in Example 3 was dissolved in methanol and stirred for 24 h to prepare a paste sample;

[0077] S2. Connect gold wires to the two ends of the interdigital electrodes on the Al2O3 substrate with silver glue and place them at 80℃ for 2h;

[0078] S3. Dropping the paste sample in step a onto the substrate in step b, drying at 80°C, to obtain a chemical resistance sensor for detecting nitro explosive atmosphere;

[0079] S4. The device was connected to a Keithley source meter, dry air was introduced, aged at 5V for 12h, and then used for the detection of nitro explosive atmosphere;

[0080] S5. 2 g of PA powder was placed in a U-shaped glass tube, dry air was introduced into both ends, and the tube was heated at 80°C for 24 h to remove the adsorbed water vapor. The tube was then sealed and pre-enriched at room temperature for 24 h to obtain 0.97 ppb of PA vapor.

[0081] S6. Pass the steam in step e into the device in step d, and use Keithley source meter to monitor the current change caused by passing into PA. The test device is as follows Figure 8 The response of the chemical resistance sensor to the PA atmosphere is shown in Fig. 9 As shown, the response to 0.97 ppb of PA was 42%.

[0082] Example 7

[0083] The above chemical resistance type sensor is used to detect the atmosphere of nitro explosives. The specific detection method is as follows:

[0084] a. The NH2-MOF powder in Example 3 was dissolved in methanol and stirred for 24 h until the sample became a paste;

[0085] b. Connect gold wires to the two ends of the interdigital electrodes based on AL2O3 with silver glue and place them at 80℃ for 2h;

[0086] c. Apply the paste sample in step a to the substrate in step b, and place it at room temperature to dry naturally. A chemical resistance sensor for detecting nitro explosive atmosphere is obtained;

[0087] d. The device was connected to a Keithley source meter, dry air was introduced, aged at 5 V for 12 h, and then used for the detection of nitro explosive atmosphere;

[0088] e. 2g PA powder was placed in a U-shaped glass tube, dry air was introduced into both ends, and the tube was heated at 80℃ for 24 hours to exhaust the adsorbed water vapor. Then the tube was sealed and pre-enriched at 40℃ for 24 hours to obtain PA vapor with a concentration of 7.3ppb.

[0089] f. Pass the steam in step e into the device in step d, and use a Keithley source meter to monitor the current change caused by the passage of PA. The response of the chemical resistance sensor test to the PA atmosphere is as follows Fig.10 As shown, the response to 7.3 ppb of PA was 230%.

[0090] Example 8

[0091] The above chemical resistance type sensor is used to detect the atmosphere of nitro explosives. The specific detection method is as follows:

[0092] a. The NH2-MOF powder in Example 3 was dissolved in methanol and stirred for 24 h until the sample became a paste;

[0093] b. Connect gold wires to the two ends of the interdigital electrodes based on AL2O3 with silver glue and place them at 80℃ for 2h;

[0094] c. Apply the paste sample in step a dropwise on the substrate in step b, place it at room temperature and allow it to dry naturally. A chemical resistance sensor for detecting nitro explosive atmosphere is obtained;

[0095] d. The device was connected to a Keithley source meter, dry air was introduced, aged at 5 V for 12 h, and then used for the detection of nitro explosive atmosphere;

[0096] e. 2g PA powder was placed in a U-shaped glass tube, dry air was introduced into both ends, and the tube was heated at 80℃ for 24 hours to exhaust the adsorbed water vapor. Then the tube was sealed and pre-enriched at 60℃ for 24 hours to obtain PA vapor with a concentration of 82ppb.

[0097] f. Pass the steam in step e into the device in step d, and use a Keithley source meter to monitor the current change caused by the passage of PA. The response of the chemical resistance sensor test to the PA atmosphere is as follows Fig.11 As shown, the response to 82 ppb of PA was 372%.

[0098] Example 9

[0099] The above chemical resistance type sensor is used to detect the atmosphere of nitro explosives. The specific detection method is as follows:

[0100] a. The preferentially oriented continuous NH2-MOF film (ie, NH2-MIL-125 (Ti) film) grown directly on the Al2O3 non-conductive substrate in Example 5 is evaporated onto a gold electrode.

[0101] b. The two ends were connected with silver glue and gold wire, and placed at 80°C for 2h to obtain a chemical resistance sensor for detecting nitro explosive atmosphere;

[0102] c. Connect the device to a Keithley source meter, introduce dry air, age it at 5V for 12h, and then use it to detect nitro explosive atmospheres;

[0103] d. 2g PA powder was placed in a U-shaped glass tube, dry air was introduced into both ends, and the tube was heated at 80℃ for 24 hours to exhaust the adsorbed water vapor. Then the tube was sealed and pre-enriched at room temperature for 24 hours to obtain PA vapor with a concentration of 0.97ppb.

[0104] e. Pass the steam in step d into the device in step b, and use Keithley source meter to monitor the current change caused by the introduction of PA. The chemical resistance sensor test responds to PA atmosphere, and the response value to 0.97ppb PA is significantly higher than that of the thick film device with NH2-MIL-125 disordered particle accumulation, and the response speed and recovery speed are significantly improved.

[0105] Comparative Example 1

[0106] The synthesis of NH2-MOF material for chemical resistance type sensor to detect nitro explosive atmosphere includes the following steps:

[0107] a. Take 60 ml of DMF and 0.19 ml of water and mix them evenly, then dissolve 0.1 mmol of NH2-BDC in the mixed solvent and sonicate for 5 min to completely dissolve it.

[0108] b. Quickly add 1.029 mmol zirconium tetrachloride to solution a and stir evenly.

[0109] c. Transfer solution b into a polytetrafluoroethylene liner, then put it into a stainless steel autoclave, put it into an oven at 120°C for 24 hours, then take it out to prepare a mixed solution;

[0110] d. The mixed solution in step c was washed by centrifugation with methanol and dried at 80 ° C for 12 h to obtain NH2-UIO-66 (Zr), such as Figure 7 Shown is the PXRD of the synthesized NH2-UiO-66(Zr).

[0111] Comparative Example 2

[0112] The above chemical resistance type sensor is used to detect the atmosphere of nitro explosives. The specific detection method is as follows:

[0113] a. The NH2-UiO-66 (Zr) powder in Comparative Example 1 was dissolved in methanol and stirred for 24 hours until the sample became a paste;

[0114] b. Connect gold wires to both ends of the silver-palladium interdigitated electrodes based on AL2O3 with silver glue and place them at 80℃ for 2h;

[0115] c. Apply the paste sample in step a on the substrate in step b, place it at room temperature and let it dry naturally. A chemical resistance sensor for detecting nitro explosive atmosphere is obtained;

[0116] d. The device was connected to a Keithley source meter, dry air was introduced, aged at 5 V for 12 h, and then used for the detection of nitro explosive atmosphere;

[0117] e. 2g PA powder was placed in a U-shaped glass tube, dry air was introduced into both ends, and the tube was heated at 80℃ for 24 hours to exhaust the adsorbed water vapor. Then the tube was sealed and pre-enriched at room temperature for 24 hours to obtain PA vapor with a concentration of 0.97ppb.

[0118] f. Pass the steam in step e into the device in step d, and use a Keithley source meter to monitor the current change caused by the introduction of PA. The material has a significant response to 0.97 ppb PA even at room temperature.

[0119] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a chemical resistance sensor using an amino-functionalized metal organic framework material, characterized in that: The specific steps are: S1: Preparation of amino-functionalized metal organic framework NH2-MIL-125(Ti) nanosheet powder; S2: dissolving NH2-MIL-125 (Ti) nanosheet powder in an organic solvent to prepare a paste, and then uniformly coating the paste on a non-conductive substrate, wherein both ends of the non-conductive substrate are fixedly connected with wires, to prepare an NH2-MIL-125 (Ti) nanosheet thin film seed layer; dissolving an amino-containing organic ligand and a metal salt in a mixed solvent of anhydrous methanol and DMF to prepare a mixed solution, immersing the NH2-MIL-125 (Ti) nanosheet thin film seed layer in the mixed solution, and heating to prepare a chemical resistance sensor; the metal in the metal salt is titanium; Chemical resistance sensors are used to detect nitro explosive atmospheres.

2. The method according to claim 1, characterized in that The non-conductive substrate is one of an AL2O3 substrate, a sapphire substrate, a carrier substrate, a polytetrafluoroethylene substrate, a quartz substrate, and a PDMS substrate.

3. The method according to claim 1, characterized in that The specific preparation steps of the amino-functionalized metal organic framework powder in step S1 are: dissolving the amino-containing organic ligand and the metal salt in a mixed solvent of anhydrous methanol and DMF, mixing evenly, heating for reaction, and drying to prepare NH2-MIL-125(Ti) powder; The volume ratio of anhydrous methanol and DMF is (1-9): (9-1); The molar ratio of the amino-containing organic ligand to the metal salt is (20-1):

1.

4. The method according to claim 3, characterized in that The specific surface area of ​​NH2-MIL-125(Ti) is 1000-3000 m 2 g -1 , pore size is 0.2-2 nm; In step S1, the heating temperature is 100-220°C; the heating time is 15-96 h; the drying temperature is 80-150°C, and the drying time is 12-48 h.

5. The method according to claim 3, characterized in that: The amino-containing organic ligand is diaminoterephthalic acid NH2-BDC.

6. A chemical resistance sensor prepared by the method according to any one of claims 1 to 5.

7. Use of the chemical resistance sensor according to claim 6, characterized in that: Applied to the detection of nitro explosive atmosphere, the specific detection method is as follows: The chemical resistance sensor is connected to a power source and energized to apply voltage to detect nitro explosive vapor.

8. The use according to claim 7, characterized in that: The nitro explosive is TNT, DNT, PA, RDX or its derivatives.

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