CN-116609302-B - Preparation method and application of paper-based sensor for detecting ammonia gas

Abstract

The invention belongs to the technical field of nano science and fluorescence sensing, and particularly relates to a preparation method and application of a paper-based sensor for detecting ammonia gas. Firstly preparing Zn (PA) (BPE), absorbing ammonia by utilizing a Zn (PA) (BPE) surface porous structure to improve the reaction sensitivity to ammonia, then embedding the ammonia with CNQDs through Zn (PA) (BPE) to form Zn (PA) @ CNQDs ratio type fluorescent substance, finally dissolving the Zn (PA) @ CNQDs ratio type fluorescent substance in ultrapure water to obtain a solution, dripping the solution on filter paper, and loading the solution on the filter paper by nitrogen blowing to obtain the ratio type fluorescent paper-based sensor. The invention utilizes Zn (PA) (BPE) and CNQDs to embed and form the ratio type fluorescent paper-based sensor, which not only ensures that CNQDs are more stable, but also improves the background anti-interference capability for detecting ammonia gas, has higher selectivity and sensitivity, and has good application prospect in the process of detecting the spoilage of meat products.

Inventors

• HUANG XIAOWEI
• HU XUETAO
• SHEN TINGTING
• SUN WEI
• ZOU XIAOBO
• LI ZHIHUA
• SHI JIYONG
• ZHANG XINAI
• ZHANG NING
• ZHANG DI
• ZHAI XIAODONG

Assignees

• 江苏大学

Dates

Publication Date

20260512

Application Date

20230313

Claims (6)

1. 1. The preparation method of the paper-based sensor for detecting ammonia gas is characterized by comprising the following steps of: (1) Mixing Zn (NO 3 ) 2 ·6H 2 O and DMF, stirring to obtain a mixed solution, namely A solution, mixing pamoic acid, 1, 2-bis (4-pyridyl) ethane and ultrapure water to obtain a mixed solution, regulating the pH of the mixed solution to be alkaline by KOH, namely B solution, mixing the A solution and the B solution, putting the mixed solution into a high-pressure reaction kettle after ultrasonic treatment, heating for a period of time to obtain a solid substance, washing the solid substance by ultrapure water, and performing vacuum freeze drying to obtain solid powder, namely Zn (PA) (BPE); In the step (1), zn (the dosage ratio of NO 3 ) 2 ·6H 2 O to DMF is 15g:200mL; the dosage ratio of pamoic acid, 1, 2-bis (4-pyridyl) ethane and ultrapure water in the solution B is 1.6g: 1.5g: 400mL; the volume ratio of the solution A to the solution B is 1:5; the concentration of KOH is 1M, the alkaline pH is adjusted to 8, the ultrasonic time is 5min, and the heating time is 120 ℃ for 72h; (2) Mixing a certain amount of sodium citrate, ammonium chloride and water, adding Zn (PA) (BPE) obtained in the step (1), uniformly mixing, transferring to a high-pressure reaction kettle, placing the high-pressure reaction kettle in a baking oven for reaction, naturally cooling to room temperature after the reaction to obtain a mixture, placing the obtained mixture into a dialysis membrane, placing the dialysis solution for a period of time for purification so as to remove unreacted precursor substances, naturally depositing the purified mixture, collecting precipitate, and freeze-drying the precipitate to obtain solid powder, namely Zn (PA) @ CNQDs ratio fluorescent substance; The dosage of Zn (PA) (BPE), sodium citrate, ammonium chloride and water in the step (2) is 20g to 10g to 53g to 500mL; (3) Dissolving Zn (PA) @ CNQDs ratio fluorescent material prepared in the step (2) in ultrapure water to obtain Zn (PA) @ CNQDs solution, then dripping the Zn (PA) @ CNQDs solution on filter paper, and drying and loading the Zn (PA) @ CNQDs solution on the filter paper by nitrogen blowing to obtain a ratio fluorescent paper-based sensor, namely the paper-based sensor for detecting ammonia gas; the ratio of Zn (PA) @ CNQDs in the step (3) is 1.5 mg/1-128 mL.
2. 2. The method for manufacturing a paper-based sensor for detecting ammonia gas according to claim 1, wherein the reaction condition in the oven in the step (2) is 180 ℃ for 4 hours, the molecular weight of the dialysis membrane is 1000Da, the dialysate is ultrapure water, distilled water or deionized water, and the standing time is 24 hours.
3. 3. The method for producing a paper-based sensor for detecting ammonia gas according to claim 1, wherein the amount of Zn (PA) @ CNQDs ratio type fluorescent substance used in step (3) is 1.5 mg/16 mL with respect to ultrapure water.
4. 4. The method for preparing a paper-based sensor for detecting ammonia gas according to claim 1, wherein the Zn (PA) @ CNQDs solution in the step (3) is dripped on filter paper in an amount of 15-20 μl of Zn (PA) @ CNQDs solution per cm 2 of filter paper.
5. 5. Use of a paper-based sensor for detecting ammonia gas prepared according to the method of any one of claims 1-4 for ammonia gas detection, characterized by the steps of: (1) Setting ammonia water solutions with different concentrations and the ratio type fluorescent paper-based sensor under the same closed environment condition, wherein one concentration ammonia water solution corresponds to one ratio type fluorescent paper-based sensor, after reacting for a period of time, calculating ammonia gas concentration in gas phase according to Henry's law, calculating G/B ratio in RGB value of the corresponding paper-based sensor, and then correspondingly establishing a standard curve according to the ammonia gas concentration and the G/B ratio; (2) And (3) detecting an unknown sample, namely placing the sample liquid to be detected and the ratio type fluorescent paper-based sensor under the same closed environment condition, reacting for a period of time, calculating the G/B ratio in the RGB value of the paper-based sensor, and substituting the G/B ratio into the standard curve of the step (1) to realize the detection of the ammonia concentration.
6. 6. The application of the fluorescent paper-based sensor according to claim 5, wherein the concentration of the ammonia water solution in the step (1) is 0.1-0.6M, the temperature of the environmental conditions in the step (1) and the step (2) is 25 ℃, the reaction time is 24 hours, and the fluorescent paper-based sensor is placed adjacent to the ammonia water solution or the sample liquid to be detected.

Description

Preparation method and application of paper-based sensor for detecting ammonia gas Technical Field The invention belongs to the technical field of nano science and fluorescence sensing, and particularly relates to a preparation method and application of a paper-based sensor for detecting ammonia gas. Background Ammonia is a gas having a lower density than air and having a pungent odor and toxicity. It is produced by decarboxylation of amino acids in rotten animal tissue, commonly found in chicken and other foods containing high protein meats. Currently, common means for detecting ammonia gas and fatty amine gas include gas chromatography-mass spectrometry, electrochemical method, colorimetric method, high performance liquid chromatography and fluorescence detection method. However, these methods are often time consuming, laborious, complex to pre-process, and unsuitable for detection in complex storage environments. Among these detection methods, fluorescence detection of ammonia gas and aliphatic amine gas is simpler and more convenient. Coordination polymers are complexes with different properties that can be obtained by combining different metal ions with different organic ligands, which have a stable, porous three-dimensional structure. The porous cavity structure is provided with a plurality of reaction sites which can react with the detection object, and has the material characteristic of good stability. The nature of coordination polymers formed by combining different metal ions with organic ligands is also different, so that the complex is used as an ammonia and amine gas detection material and is a method which is widely applied at present. Meanwhile, compared with the enhanced fluorescence detection ammonia gas probe, the ratio type fluorescence probe has the characteristic of dual-wavelength emission, and the change of the wavelength ratio value is independent of the probe concentration and the light source intensity, so that the interference of other detection conditions can be greatly reduced. In the prior art, literature discloses a sensing material for ammonia gas detection and a preparation method and application thereof (CN 115452894A), in particular to a carbon dot fluorescent probe with low detection limit and high sensitivity, but the stability of the probe is insufficient. The patent 'an organic cuprous halide material for high-efficiency ammonia fluorescence detection and preparation and application thereof' (CN 115028188A) provides a fluorescence detection probe with high sensitivity and simple synthesis method, but the material used by the probe is based on the organic cuprous halide material and has certain biotoxicity in food spoilage detection. At present, most of materials used for ammonia gas sensing are organic conductive gas-sensitive materials, and the materials have the advantages of high sensitivity, but also have the problems of higher cost, poor selectivity, poor stability and the like. Therefore, the combination of the fluorescent probe and the paper base has important significance in developing a simple, rapid, accurate, portable and easy-to-operate biosensor. Disclosure of Invention Aiming at the defects of the existing ammonia fluorescence molecular probes, the invention provides the ratio fluorescence probe with high sensitivity and strong stability, on one hand, the ammonia is adsorbed by utilizing a Zn (PA) (BPE) surface porous structure, so that the reaction sensitivity to ammonia is increased, and on the other hand, the ratio fluorescence probe formed by embedding between Zn (PA) (BPE) and CNQDs not only ensures that the CNQDs are more stable, but also improves the background anti-interference capability for detecting ammonia gas. In order to achieve the above object, the present invention provides a method for manufacturing a paper-based sensor for detecting ammonia gas, comprising the steps of: (1) Preparing Zn (PA) (BPE), mixing Zn (NO 3)2·6H2 O and DMF, stirring to obtain a mixed solution A, mixing pamoic acid, 1, 2-bis (4-pyridyl) ethane and ultrapure water to obtain a mixed solution, regulating the pH of the mixed solution to be alkaline by KOH, marking the solution B as a solution at the moment, mixing the solution A and the solution B, putting the mixed solution A and the mixed solution B into a high-pressure reaction kettle after ultrasonic treatment, heating for a period of time to obtain a solid substance, washing the solid substance with ultrapure water, and performing vacuum freeze drying to obtain solid powder Zn (PA) (BPE); (2) Preparing Zn (PA) @ CNQDs ratio fluorescent material, namely mixing a certain amount of sodium citrate, ammonium chloride and water, adding Zn (PA) (BPE) powder obtained in the step (1), uniformly mixing, transferring to a high-pressure reaction kettle, placing the high-pressure reaction kettle in an oven for reaction, naturally cooling to room temperature to obtain a mixture, placing the obtained mixture into a dialysis mem