A functionalized metal organic framework sensing material reagent for detecting hydrazine

Abstract

The application provides a functionalized metal organic framework sensing material reagent for detecting solution hydrazine, the detection reagent is modified with 5-carboxyfluorescein on the organic ligand of a zirconium metal organic framework material, with the recognition reaction between hydrazine and the functionalized zirconium metal organic framework material, the 5-carboxyfluorescein is disconnected from the ligand, the defect state disappears, the blue fluorescence emission intensity of the original metal organic framework material is gradually recovered, and a new green fluorescence response signal is generated, so that the effect of detecting hydrazine is achieved. The detection reagent provided by the application can be used for qualitative detection of hydrazine in a water source, has the characteristics of simple operation, strong specificity, sensitive reaction, convenient use and low cost, and can provide an effective technical means for the identification of hydrazine-containing pollutants by environmental protection departments.

Description

Technical Field

[0001] This invention relates to a functionalized metal-organic framework sensing material reagent for detecting hydrazine. This reagent has a low detection limit, strong anti-interference ability and high sensitivity, and can achieve rapid and visual detection of hydrazine in solution. Background Technology

[0002] With the rapid development of the chemical and aerospace industries, the total amount of wastewater from hydrazine and its derivative propellants is increasing year by year. Hydrazine is a highly toxic hazardous chemical. As a neurotoxin, long-term exposure to hydrazine hydrate may cause cancer and mutations, and can worsen the central nervous system, respiratory system, liver, and kidneys. Some health organizations have classified hydrazine as a potential occupational hazard, which seriously affects people's health. Therefore, there is an urgent need to find a simple, easy-to-operate, and visually rapid method for the detection of hydrazine solutions.

[0003] Previously, the main methods reported domestically and internationally for the detection of hydrazine included high-performance gas / liquid chromatography, Raman spectroscopy, ion chromatography, electrophoresis, and electrochemical detection. However, these methods all have certain drawbacks, such as low time resolution, high labor costs for sample preparation, high requirements for instruments and equipment, and poor biocompatibility. Furthermore, these traditional methods suffer from poor sensitivity, slow response time, and complex processes, limiting their application in practice. Fluorescent probes based on functionalized metal-organic frameworks (MOFs) can achieve rapid and visual detection of hydrazine solutions, requiring no complex equipment or procedures, offering low cost, high sensitivity, short detection time, and ease of operation. Current reports on the detection of hydrazine using MOFs include the use of phthalimide-functionalized MOFs for selective detection of hydrazine via the Gabriel reaction. Dalton Transactions, 2019, 48, 12615- 12621 Another report mentions a lanthanide-functionalized metal-organic framework material used for the qualitative and quantitative analysis of hydrazine. This probe exhibits a luminescence quenching effect upon contact with hydrazine, and the mechanism is still unclear. RSC Advances, 2018, 8, 17471- 17476 ).

[0004] This invention develops a functionalized metal-organic framework (MOF) sensing material reagent for detecting hydrazine in solution. It primarily utilizes the defect states generated when zirconium-based MOFs are modified with 5-carboxyfluorescein, leading to a decrease in the fluorescence intensity of the functionalized MOF sensing material. Upon addition of hydrazine solution, these defect states disappear, and a new green fluorescence response signal is generated, thus achieving the detection of hydrazine. This functionalized MOF reagent for detecting hydrazine in solution based on the defect state principle is readily available, simple to prepare, lightweight and portable, and exhibits high selectivity, showing great potential for wide application. Summary of the Invention

[0005] The purpose of this invention is to provide a functionalized metal-organic framework (MOF) sensing material reagent for detecting hydrazine in solution. This reagent modifies a zirconium-based MOF with 5-carboxyfluorescein, causing hybridization between the highest occupied molecular frontier (HOM) and lowest unoccupied molecular frontier (UFF) orbitals (LOMs) of the MOF, which were originally entirely contributed by the ligand after photoexcitation. This results in new HOMs and UFFs coupled to the ligand within the original pair of molecular orbitals, representing hole and electron defect states, respectively. This causes a decrease in the intensity of the blue fluorescence emission of the MOF. However, as a recognition reaction occurs between hydrazine and the functionalized zirconium-based MOF, the 5-carboxyfluorescein dissociates from the ligand, the defect states disappear, and the blue fluorescence emission intensity of the MOF gradually recovers. Simultaneously, a new green fluorescence response signal is generated, thus achieving the detection of hydrazine. The detection reagent described in this invention can be used for the qualitative detection of hydrazine in water sources. It features simple operation, high specificity, sensitive reaction, convenient use, and low cost, and can provide an effective technical means for environmental protection departments to identify hydrazine-containing pollutants.

[0006] The present invention discloses a functionalized metal-organic framework sensing material reagent for detecting hydrazine in solution. This reagent comprises a fluorescent probe prepared from a zirconium-based metal-organic framework material and a functionalized 5-carboxyfluorescein group, and an N,N-dimethylformamide solution, and is prepared according to the following steps: Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050-0.0100 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b, dissolve it in 10 ml of N,N-dimethylformamide, and sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of hydrazine: d. Take the hydrazine solution to be tested and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. The generation and disappearance of defect states in the zirconium-based metal-organic framework material modified with hydrazine and 5-carboxyfluorescein will release the fluorescence of 5-carboxyfluorescein at 528 nm, thereby confirming the presence of hydrazine.

[0007] This invention discloses a fluorescent 5-carboxyfluorescein-modified zirconium-based metal-organic framework (MOF) reagent for detecting hydrazine. The reagent targets hydrazine in a water source and is formulated at room temperature using a zirconium-based MOF modified with 5-carboxyfluorescein and N,N-dimethylformamide. A sample is collected using a pipette and placed in a test vial. The reagent is then added to the vial containing the sample, where it reacts to produce a green fluorescent substance, thus confirming the presence of hydrazine.

[0008] The present invention provides a reagent for detecting hydrazine in solution by means of a zirconium-based metal-organic framework material modified with 5-carboxyfluorescein, with a detection limit of 0.315 nM.

[0009] Fluorescence detection of hydrazine: Use a pipette to draw a small amount of the analyte hydrazine and drop it into the test bottle. Add the detection reagent from the brown bottle and observe under a 365 nm UV lamp to see if the green fluorescence signal of the sample solution and the detection reagent increases after the reaction, thus confirming the presence of hydrazine. Attached Figure Description

[0010] Figure 1 The diagram shows the response of the zirconium-based metal-organic framework material reagent modified with fluorescent 5-carboxyfluorescein to hydrazine before and after the invention. Figure 1 The image on the left shows the blue fluorescence of a zirconium-based metal-organic framework material reagent modified with 5-carboxyfluorescein at 365 nm under a UV lamp. Figure 1 The image on the right shows the green fluorescence of a zirconium-based metal-organic framework material modified with 5-carboxyfluorescein at 365 nm under a UV lamp after the reagent was added to a hydrazine solution.

[0011] Figure 2 These are the detection results of Examples 1-6 of the present invention. Detailed Implementation Example 1

[0012] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0100 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of unknown solutions: d. Take an acrylamide solution containing the unknown analyte and add it to a test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is blue, it proves that the sample in the test bottle does not contain hydrazine. Example 2

[0013] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0100 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of unknown solutions: d. Take a urea solution containing the unknown analyte and add it to a test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is blue, it proves that the sample in the test bottle does not contain hydrazine. Example 3

[0014] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of unknown solutions: d. Take a thiourea solution containing the unknown analyte and add it to a test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is blue, it proves that the sample in the test bottle does not contain hydrazine. Example 4

[0015] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of unknown solutions: d. Take a solution containing the unknown analyte nickel chloride and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is blue, it proves that the sample in the test bottle does not contain hydrazine. Example 5

[0016] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050-0.0100 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b, dissolve it in 10 ml of N,N-dimethylformamide, and sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of unknown solutions: d. Take a solution containing the unknown analyte barium chloride and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is blue, it proves that the sample in the test bottle does not contain hydrazine. Example 6

[0017] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of copper chloride dihydrate solution: d. Take copper chloride dihydrate solution and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is green, it proves that the sample in the test bottle contains hydrazine. Example 7

[0018] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of anhydrous calcium chloride solution: d. Take anhydrous calcium chloride solution and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is green, it proves that the sample in the test bottle contains hydrazine. Example 8

[0019] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of sodium thiosulfate solution: d. Take sodium thiosulfate solution and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is green, it proves that the sample in the test bottle contains hydrazine. Example 9

[0020] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of copper sulfate solution: d. Take copper sulfate solution and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is green, it proves that the sample in the test bottle contains hydrazine. Example 10

[0021] Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide. Add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes. Place the reactor in an oven preheated to 120°C and react for 2 hours. Then, wash the reaction solution three times with N,N-dimethylformamide by centrifugation. Place the precipitate in a vacuum drying oven at 60°C and dry for 24 hours to obtain the product, zirconium-based metal-organic framework material. b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050 g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b and dissolve it in 10 ml of N,N-dimethylformamide. Sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of boric acid solution: d. Take boric acid solution and add it to the test bottle containing the detection reagent obtained in step c at a volume ratio of 1:1. Immediately observe the fluorescence change in the test bottle using a 365 nm ultraviolet lamp. If the fluorescence in the test bottle is green, it proves that the sample in the test bottle contains hydrazine.

Claims

1. A method for detecting hydrazine based on functionalized metal-organic framework sensing materials, characterized in that... The reagent consists of a probe prepared from a zirconium-based metal-organic framework material and a functionalized 5-carboxyfluorescein group, and an N,N-dimethylformamide solution. The specific operation is performed according to the following steps: Preparation of detection reagents: a. Dissolve 0.0420 g of zirconium chloride and 0.1785 g of 2-hydroxyterephthalic acid in a 30 ml polyvinyl fluoride reactor containing 13.5 ml of N,N-dimethylformamide, add 12.8 ml of acetic acid and 0.5 ml of deionized water, and stir at 800 rpm for 10 minutes; place the reactor in an oven preheated to 120°C and react for 2 hours; then wash the reaction solution three times with N,N-dimethylformamide by centrifugation, and dry the precipitate in a vacuum drying oven at 60°C for 24 hours to obtain the product, zirconium-based metal-organic framework material; b. Dissolve 0.1000 g of the zirconium-based metal-organic framework material obtained in step a and 0.0500 g of 5-carboxyfluorescein in a 250 ml round-bottom flask containing 80 ml of N,N-dimethylformamide, add 8 ml of 10 mM sodium hydroxide ethanol solution, and react at 40 °C for 24 hours; then centrifuge and wash with N,N-dimethylformamide solution until the supernatant is free of fluorescence, and dry the precipitate in a vacuum drying oven at 60 °C for 24 hours to obtain the product 5-carboxyfluorescein modified zirconium-based metal-organic framework material, wherein the sodium hydroxide ethanol solution is prepared by dissolving 0.0200 g of sodium hydroxide in 50 ml of anhydrous ethanol; c. At room temperature, weigh 0.0050-0.0100g of 5-carboxyfluorescein-modified zirconium-based metal-organic framework material obtained in step b, dissolve it in 10 ml of N,N-dimethylformamide, and sonicate until the mixture is homogeneous to obtain the functionalized metal-organic framework sensing material detection reagent. Encapsulate the detection reagent in a brown reagent bottle. Fluorescence detection of hydrazine: d. Take the hydrazine solution to be tested and add it to the test bottle containing the test reagent obtained in step c at a volume ratio of 1:

1. Due to the disappearance of the defect state in the zirconium-based metal-organic framework material modified with 5-carboxyfluorescein, its fluorescence at 450 nm gradually recovers and releases the green fluorescence of 5-carboxyfluorescein at 528 nm, thereby confirming the presence of hydrazine.

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