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CN-121991366-A - Preparation method of Co-MOF fluorescent material and application of Co-MOF fluorescent material in detection of volatile ammonia

CN121991366ACN 121991366 ACN121991366 ACN 121991366ACN-121991366-A

Abstract

The invention provides a preparation method of a Co-MOF fluorescent material and application thereof in detection of volatile ammonia. The preparation method comprises the steps of synthesizing a long-chain imidazole carboxylic acid rigid organic ligand with larger size through an amide condensation reaction of benzimidazole dicarboxylic acid and 3-aminobenzoic acid, and carrying out self-assembly reaction on the ligand and cobalt nitrate to obtain the Co-MOF compound. The Co-MOF fluorescent material can be used for detecting volatile ammonia. The fluorescent color of the Co-MOF fluorescent material is changed from blue to yellow-green after incubation with the volatile ammonia, and a standard curve can be drawn through different ratios of the concentration of the volatile ammonia to the measured fluorescent intensity, so that the rapid detection of the volatile ammonia is realized. The method can be used for quickly identifying the volatile ammonia through the preparation indication film, does not need to use a large instrument, is convenient to operate, and can quickly identify the freshness of agricultural products.

Inventors

  • LIU QINGJU
  • LUAN YUNXIA
  • JIA WENSHEN
  • WANG HUI
  • ZHAO FANG

Assignees

  • 北京市农林科学院

Dates

Publication Date
20260508
Application Date
20251120

Claims (10)

  1. 1. The preparation method of the Co-MOF fluorescent material is characterized by comprising the following steps: S1, adding benzimidazole-5, 6-dicarboxylic acid and 3-aminobenzoic acid into N, N-dimethylformamide, dissolving, stirring and mixing, heating, stirring and reacting to obtain white precipitate, centrifuging, washing and drying to obtain a white product amide ligand 3-CPID; S2, dissolving 3-CPID and cobalt nitrate in a mixed solution of N, N-dimethylformamide and dimethyl sulfoxide, adding water and methanol for ultrasonic treatment, heating for reaction, centrifuging, washing the precipitate, and drying to obtain the Co-MOF fluorescent material.
  2. 2. The preparation method according to claim 1, wherein in the step S1, benzimidazole-5, 6-dicarboxylic acid and 3-aminobenzoic acid are added according to a molar ratio of 1:1, and the amount of N, N-dimethylformamide is added according to a volume mass ratio of 10-20 mL:1 g of N, N-dimethylformamide to benzimidazole-5, 6-dicarboxylic acid; The temperature of the heating reaction is 110-150 ℃ and the reaction time is 8-12 h.
  3. 3. The preparation method according to claim 1, wherein in the step S1, the centrifugal speed is 6000-10000 rpm, the centrifugal time is 5-15 min, the washing is performed by using N, N-dimethylformamide and then ethanol, and the drying condition is that the drying is performed in a vacuum drying oven at 50-80 ℃ for 10-12 h.
  4. 4. The preparation method of claim 1, wherein in the step S2, the amide ligand and cobalt nitrate are added according to a molar ratio of 1:0.5-2, N, N-dimethylformamide, dimethyl sulfoxide, water and methanol are added according to a volume ratio of 1-3:2-5:0.5-2:1, the N, N-dimethylformamide is added according to a volume mass ratio of 1 L:20-200 g, the ultrasonic time is 10-30 min, the heating reaction temperature is 90-130 ℃, and the reaction time is 20-30 h.
  5. 5. The preparation method according to claim 1, wherein in the step S2, the centrifugal speed is 6000-10000 rpm, the centrifugal time is 3-15 min, the washing is performed by using N, N-dimethylformamide and then ethanol, and the drying condition is that the drying is performed in a vacuum drying oven at 50-80 ℃ for 10-12 h.
  6. 6. Use of the Co-MOF fluorescent material obtained by the preparation method of any one of claims 1 to 5 for preparing a volatile ammonia detection reagent.
  7. 7. Use of the Co-MOF fluorescent material obtained by the preparation method of any one of claims 1 to 5 in detection of volatile ammonia.
  8. 8. Use of a Co-MOF fluorescent material obtained by the method of any one of claims 1 to 5 for the preparation of an indicator film for the detection of volatile ammonia.
  9. 9. Use of a Co-MOF fluorescent material obtained by the method of any one of claims 1 to 5 for the preparation of a film for detecting shrimp freshness.
  10. 10. A method of detecting volatile ammonia comprising the steps of: A. Dissolving the Co-MOF fluorescent material obtained by the preparation method of any one of claims 1-5 in water to prepare a fluorescent probe aqueous solution, and respectively exposing the fluorescent probe aqueous solution to volatile ammonia gas with different concentrations and gas to be detected for incubation; B. Measuring the fluorescence intensity of the solution after incubation at excitation wavelength 365 nm and emission wavelength 410 nm and 520 nm, drawing a standard curve according to the ratio F 520 /F 410 of the concentration of the volatile ammonia gas to the fluorescence intensity corresponding to the concentration of the volatile ammonia gas, and substituting the fluorescence intensity of the gas to be measured into the standard curve to obtain the concentration of the volatile ammonia in the gas to be measured.

Description

Preparation method of Co-MOF fluorescent material and application of Co-MOF fluorescent material in detection of volatile ammonia Technical Field The invention belongs to the technical field of chemical sensors, and particularly relates to a preparation method of a Co-MOF fluorescent material and application of the Co-MOF fluorescent material in detection of volatile ammonia. Background Food safety is a major issue in the world of public health, and is increasingly being highly appreciated by the society. Statistics of the world health organization show that up to 42 tens of thousands of deaths each year are caused by consumption of contaminated food worldwide. Shrimp, which is a source of high quality protein, is an important component in the human dietary structure. However, during the storage and transportation process, shrimps are susceptible to enzymolysis and microbial action to produce Biogenic Amine (BAs) toxic substances and the like. Excessive intake of these biogenic amines may cause symptoms such as hypotension, allergic reactions, headache, and the like, and even shock or death in severe cases. Therefore, the establishment of an effective shrimp freshness monitoring system has important significance for guaranteeing the health of consumers. The traditional method for detecting the freshness of the shrimps mainly depends on the determination of volatile ammonia, but the method has the limitations of complex pretreatment of samples, long time consumption, strong destructiveness and the like. Although electrochemical methods, gas chromatography, liquid chromatography and other technologies can be used for detecting volatile ammonia, the methods also face the problems of complex pretreatment, long analysis period, high equipment cost and the like, and the requirements of rapid and real-time monitoring of the freshness of the shrimps are difficult to meet. Under the background of increasingly severe food safety situations, it is particularly important to develop a simple, rapid, visual and efficient detection technology. In recent years, the fluorescence sensor has wide application prospect in the fields of biomedicine, food analysis and the like by virtue of the advantages of rapid response, high sensitivity, convenient operation, excellent selectivity and the like, and provides a new technical approach for solving the problems. Therefore, it is necessary to develop a fluorescent sensing platform which is rapid and nondestructive, does not need sample pretreatment and complex instruments, and can directly interpret the detection result by naked eyes, thereby realizing convenient measurement of the volatile ammonia content. Disclosure of Invention In order to solve the technical problems, the invention provides a preparation method of a Co-MOF fluorescent material and application thereof in detecting volatile ammonia, and in particular, the Co-MOF fluorescent material can be used for detecting volatile organic substances in agricultural products. In order to achieve the above purpose, the invention adopts the following technical scheme: A preparation method of a Co-MOF fluorescent material comprises the following steps: S1, adding benzimidazole-5, 6-dicarboxylic acid and 3-aminobenzoic acid into N, N-dimethylformamide, dissolving, stirring and mixing, heating, stirring and reacting to obtain white precipitate, centrifuging, washing and drying to obtain a white product amide ligand 3-CPID; S2, dissolving 3-CPID and cobalt nitrate in a mixed solution of N, N-dimethylformamide and dimethyl sulfoxide, adding water and methanol for ultrasonic treatment, heating for reaction, centrifuging, washing the precipitate, and drying to obtain the Co-MOF fluorescent material. In the preparation method, in the step S1, preferably, the benzimidazole-5, 6-dicarboxylic acid and the 3-aminobenzoic acid are added according to a molar ratio of 1:1, and the N, N-dimethylformamide is used in an amount such that the volume/mass ratio of the N, N-dimethylformamide to the benzimidazole-5, 6-dicarboxylic acid is 10-20 ml/1 g. In the preparation method, in the step S1, the heating reaction temperature is preferably 110-150 ℃ and the reaction time is preferably 8-12 h. In the preparation method, in the step S1, preferably, the centrifugal speed is 6000-10000 rpm, the centrifugal time is 5-15 min, the washing is performed by using N, N-dimethylformamide and then ethanol, and the drying condition is that the drying is performed for 10-12 h at 50-80 ℃ in a vacuum drying oven. In the preparation method, in the step S2, preferably, the amide ligand and the cobalt nitrate are added according to a molar ratio of 1:0.5-2, the N, N-dimethylformamide, the dimethyl sulfoxide, the water and the methanol are added according to a volume ratio of 1-3:2-5:0.5-2:1, and the N, N-dimethylformamide is added according to a volume mass ratio of 1 l:20-200 g. Further, the amide ligand and the cobalt nitrate are added according to a molar ratio of 1:1,