Schiff base enhanced dual catalytic copper cluster enzyme, its preparation method and application in degrading and determining atrazine

Abstract

The application discloses a Schiff base enhanced double-catalytic copper cluster enzyme, a preparation method thereof and application of the Schiff base enhanced double-catalytic copper cluster enzyme in degradation and determination of atrazine. The Schiff base enhanced double-catalytic copper cluster enzyme is a copper cluster material modified by a Schiff base formed by 4,6-diamino-2-mercapto pyrimidine and p-xylene dialdehyde. The Schiff base and the copper cluster have the effect of catalytically degrading atrazine, and can emit different colors of fluorescence; the Schiff base enhances the catalytic activity of the copper cluster enzyme. The Schiff base modified copper cluster enzyme not only has the function of double-catalytically degrading atrazine, but also has the function of displaying the content of atrazine by ratio fluorescence.

Description

Technical Field

[0001] This invention belongs to the field of catalysis and luminescence analysis technology, specifically relating to Schiff base-enhanced dual-catalytic copper cluster enzymes, their preparation methods, and their application in the degradation and determination of atrazine. Background Technology

[0002] Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine, abbreviated as ATZ) is a triazine-based organic pesticide and is currently the most widely used agricultural herbicide globally. ATZ is carcinogenic and teratogenic to humans and animals, and the World Health Organization has classified it as an endocrine disrupting chemical (EDC) and a Group 3 carcinogen. Due to its high usage and long residual time, ATZ poses a threat to ecosystems and aquatic environments. Therefore, the degradation and detection of ATZ in the environment are of great significance.

[0003] Several methods for degrading atrazine have been reported. Chinese Patent Publication No. CN 116020473 A, 2023, Song Weifeng et al., "A catalyst for activating persulfate to degrade atrazine, its preparation method and application," discloses a method for catalytic degradation of atrazine using a catalyst activated by persulfate. Chinese Patent Publication No. CN 116162261 A, 2023, Wang Kun et al., "A method for preparing MOFs with light-regulated peroxidase-like activity and its application," discloses a method for degrading and detecting atrazine using MOFs with peroxidase-like activity. Chinese Patent Publication No. CN117019179A, 2023, Wang Dongbo et al., "A core-shell structured Bi2Se3 / Bi2O3@Bi nanocomposite photocatalyst, its preparation method and application," discloses a method for photodegrading atrazine using a nanocomposite photocatalyst. Chinese Patent Publication No. CN116004453 A, 2022, Sun Dongmei et al., A strain and fermentation broth for degrading atrazine and its application, discloses a method for degrading atrazine using Bacillus. Chinese Patent Publication No. CN110240232 A, 2019, Shi Huijie et al., A highly efficient photoelectrocatalytic oxidation method for removing atrazine, discloses a method for removing atrazine using photoelectrocatalytic oxidation. Chinese Patent Publication No. CN108503039 A, 2018, Yang Chunping et al., A method for degrading atrazine using Penicillium magnetic nanocomposite materials, discloses a method for degrading atrazine using a composite material formed by nano-Fe3O4 and Penicillium. Li Jiayi et al. reported a method for degrading atrazine in water using iron titanate-catalyzed ozone oxidation (Journal of Environmental Science, 2024, 44, 1-10). Xu Yuhang et al. reported a method for degrading atrazine in water using iron-doped bismuth oxychloride in photo-Fenton catalysis (Journal of Environmental Science, 2023, 43, 37-48). Several methods for detecting atrazine have been reported. The main methods for detecting ATZ include gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. Chinese Patent Publication No. CN 115015417 A, 2022, Qian Haiyan et al., "A Method for Determining Atrazine in Water Samples," discloses an extraction combined with high-performance liquid chromatography method for detecting atrazine. Chinese Patent Publication No. CN 116337974 A, Yan Pengcheng et al., "Preparation Method and Application of Co(II) / g-C3N4 Nanotube-Based Photoelectrochemical Aptamer Sensor," discloses a photoelectrochemical method for detecting atrazine. Although various degradation and detection technologies for atrazine have been reported, rapid, convenient, and low-cost methods for the degradation and detection of atrazine are urgently needed. Summary of the Invention

[0004] Purpose of the invention: The first technical problem to be solved by the present invention is to provide an artificial enzyme for the effective degradation and determination of atrazine, namely a Schiff base enhanced dual-catalytic copper cluster enzyme, which can both degrade atrazine by copper clusters and Schiff base and determine atrazine by proportional fluorescence.

[0005] The second technical problem to be solved by the present invention is to provide a simple and easy method for preparing a Schiff base-enhanced dual-catalytic copper cluster enzyme.

[0006] The third technical problem to be solved by this invention is to provide the application of this Schiff base-enhanced dual-catalytic copper cluster enzyme in the catalytic degradation or determination of atrazine.

[0007] The fourth technical problem to be solved by the present invention is to provide a method for the catalytic degradation of atrazine by such Schiff base-enhanced dual-catalytic copper cluster enzymes.

[0008] The fifth technical problem to be solved by the present invention is to provide this Schiff base-enhanced dual-catalytic copper cluster enzyme as a ratiometric fluorescent probe, and to provide a method for visually detecting atrazine content by means of changes in fluorescence color.

[0009] Technical solution: To solve the first technical problem mentioned above, the present invention provides a Schiff base-enhanced dual-catalytic copper cluster enzyme, wherein the Schiff base-enhanced dual-catalytic copper cluster enzyme is prepared by heating and reacting copper clusters with terephthalaldehyde solution, wherein the copper clusters are prepared by reacting an alkaline aqueous solution of 4,6-diamino-2-mercaptopyrimidine with copper ions.

[0010] The Schiff base-enhanced dual-catalytic copper cluster enzyme is a copper cluster material modified with a Schiff base formed from 4,6-diamino-2-mercaptopyrimidine and terephthalaldehyde.

[0011] The copper cluster is synthesized by reduction of 4,6-diamino-2-mercaptopyrimidine and copper ions with citric acid.

[0012] The copper clusters loaded with Schiff bases are obtained by reacting terephthalaldehyde with 4,6-diamino-2-mercaptopyrimidine on the surface of the copper clusters to form Schiff bases.

[0013] The particle size of the Schiff base-enhanced dual-catalytic copper cluster enzyme is 2–5 nm.

[0014] The Schiff base-enhanced dual-catalytic copper cluster enzyme possesses both copper cluster catalytic activity and Schiff base catalytic activity, making it a cluster enzyme with dual catalytic activity.

[0015] The Schiff base-enhanced dual-catalytic copper cluster enzyme described herein can degrade atrazine (ATZ).

[0016] The Schiff base-enhanced dual-catalytic copper cluster enzyme exhibits both the green luminescence of the Schiff base and the red luminescence of the copper cluster, making it a dual-fluorescent cluster enzyme.

[0017] The Schiff base-enhanced dual-catalytic copper cluster enzyme has a ratio fluorescence indicator function, which can indicate the content of atrazine by the change in the ratio of green fluorescence to red fluorescence intensity.

[0018] To solve the second technical problem mentioned above, the preparation method of the Schiff base-enhanced dual-catalytic copper cluster enzyme of the present invention includes the following steps:

[0019] (1) Preparation of copper cluster enzyme: copper ions are mixed with an alkaline aqueous solution of 4,6-diamino-2-mercaptopyrimidine to form a mixture, heated and stirred, and citric acid solution is added to react and a copper cluster solution is obtained;

[0020] (2) Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme: Add ethanol solution of terephthalaldehyde to the prepared copper cluster solution, heat and stir to react, and obtain Schiff base-enhanced dual-catalytic copper cluster enzyme solution.

[0021] The Schiff base-enhanced dual-catalytic copper cluster enzyme of the present invention comprises the following steps:

[0022] (1) Preparation of copper cluster enzyme: copper ions were mixed with an alkaline solution of 4,6-diamino-2-mercaptopyrimidine to form a mixture. The pH of the mixture was adjusted to 10-12 with sodium hydroxide solution. The mixture was heated and stirred, and citric acid solution was added dropwise. The mixture was reacted at 60°C for 6 hours. The precipitate was collected by centrifugation. The precipitate was washed with ethanol and then centrifuged. The precipitate was washed with water and then centrifuged again. The precipitate was ultrasonically dispersed in water to obtain copper cluster enzyme solution.

[0023] (2) Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme solution: The prepared copper cluster aqueous solution was mixed with the ethanol solution of terephthalaldehyde to form a mixture. The mixture was heated and stirred and reacted at 60°C for 6 hours. The precipitate was collected by centrifugation. The precipitate was washed with ethanol and then centrifuged. After washing with water, it was centrifuged again. The precipitate was ultrasonically dispersed in water to obtain the dual-catalytic copper cluster enzyme solution, which was stored at room temperature for later use.

[0024] In step (1), the molar ratio of 4,6-diamino-2-mercaptopyrimidine to copper ions in the mixture is 2 to 5:1.

[0025] In step (1), the concentration of sodium hydroxide is 1M and the concentration of the reducing agent citric acid solution is 0.5M.

[0026] In step (2), the molar ratio of terephthalaldehyde to 4,6-diamino-2-mercaptopyrimidine in the mixture is 1 to 2:1.

[0027] To address the third technical problem mentioned above, this invention provides an application of Schiff base-enhanced dual-catalytic copper cluster enzyme in the degradation or determination of atrazine.

[0028] To address the fourth technical problem mentioned above, this invention provides a method for the degradation of atrazine using a Schiff base-enhanced dual-catalytic copper cluster enzyme. The specific steps are as follows: a certain amount of the Schiff base-enhanced dual-catalytic copper cluster enzyme solution is added to a solution containing atrazine, mixed thoroughly, and the degradation efficiency of atrazine is determined based on the fluorescence change of atrazine.

[0029] To address the fifth technical problem mentioned above, this invention provides a method for determining atrazine using a Schiff base-enhanced dual-catalytic copper cluster enzyme ratio fluorescence assay. The specific steps are as follows: First, a certain amount of the Schiff base-enhanced dual-catalytic copper cluster enzyme solution is added to a series of atrazine standard solutions of known concentrations. The mixture is stirred thoroughly and reacted. The fluorescence intensity of the solution at 710 nm and 500 nm is measured, and a working curve is plotted between the 710 nm / 500 nm ratio fluorescence and the concentration of the atrazine standard solution. Then, under the same conditions, the fluorescence ratio of atrazine in the sample solution at 710 nm / 500 nm is measured. Based on the working curve and the fluorescence ratio of the sample solution, the content of atrazine in the sample is obtained.

[0030] The concentration of the atrazine standard solution is 0–25 μM.

[0031] Beneficial effects: Compared with the prior art, the Schiff base-enhanced dual-catalytic copper cluster enzyme of the present invention has the following advantages:

[0032] 1) The Schiff base-enhanced dual-catalytic copper cluster enzyme of the present invention has dual catalytic activities of copper clusters and Schiff bases, and also has dual-color fluorescence emission function.

[0033] 2) The Schiff base-enhanced dual-catalytic copper cluster enzyme of the present invention can directly degrade atrazine without the participation of other reagents and can display the degradation efficiency with fluorescence, making it a multifunctional artificial enzyme.

[0034] 3) The Schiff base-enhanced dual-catalytic copper cluster enzyme of the present invention indicates the content of atrazine with ratio fluorescence, which has high sensitivity and is a sensitive and rapid method for atrazine determination.

[0035] 4) The preparation method of the Schiff base-enhanced dual-catalytic copper cluster enzyme of the present invention is simple and does not require complex organic synthesis. Attached Figure Description

[0036] Figure 1 Transmission electron microscope image of copper clusters CuNCs;

[0037] Figure 2 Fluorescence spectra of copper clusters (CuNCs);

[0038] Figure 3 Transmission electron microscopy image of Schiff base-enhanced dual-catalytic copper cluster enzymes SB-CuNCs;

[0039] Figure 4 Fluorescence spectra of Schiff base-enhanced dual-catalytic copper cluster enzymes SB-CuNCs;

[0040] Figure 5 Fluorescence spectra of atrazine degradation catalyzed by Schiff base-enhanced dual-catalytic copper cluster enzymes SB-CuNCs;

[0041] Figure 6 Fluorescence changes during the catalytic degradation of atrazine;

[0042] Figure 7 Working curve of atrazine fluorescence detection by Schiff base-enhanced dual-catalytic copper cluster enzyme SB-CuNCs. Detailed Implementation

[0043] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0044] Example 1: Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme

[0045] Preparation of copper clusters: 0.1 mmol of 4,6-diamino-2-mercaptopyrimidine was dissolved in 1 mL of sodium hydroxide (1 M) aqueous solution, and 200 μL of copper chloride aqueous solution (0.2 M) and 4 mL of water were added to form a mixed solution. The molar ratio of 4,6-diamino-2-mercaptopyrimidine to copper ions was 2.5:1. The mixture was heated and stirred in a heating mantle at 60 °C. 0.5 mL of citric acid aqueous solution (1 M) was added dropwise. After stirring for 6 h, the mixture was centrifuged at 8000 rpm / min for 10 min, the precipitate was collected and ultrasonically dispersed in 1 mL of water to obtain copper cluster solution CuNCs. Figure 1 This is a transmission electron microscope image of the prepared copper clusters, which are 2-3 nm in size. Figure 2 This is the fluorescence spectrum of the prepared copper clusters, with a maximum emission wavelength of 710 nm.

[0046] Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme: 1 mL of the above copper cluster solution was dissolved in 4 mL of water, and mixed with 1 mL of 0.2 M terephthalaldehyde ethanol solution and 4 mL of ethanol to form a mixed solution with a molar ratio of terephthalaldehyde:4,6-diamino-2-mercaptopyrimidine of 2:1. The solution was heated and stirred in a heating mantle at 60 °C. After about 6 h, the solution changed from pale yellow to yellow until it remained unchanged. The precipitate after vacuum drying to evaporate the solvent was ultrasonically dispersed in 1 mL of water to obtain the Schiff base-enhanced dual-catalytic copper cluster enzyme solution SB-CuNCs. Figure 3This is a transmission electron microscope (TEM) image of the prepared Schiff base-enhanced dual-catalytic copper cluster enzymes SB-CuNCs, with a particle size of 2-5 nm. Figure 4 The image shows the fluorescence spectrum of the prepared Schiff base-enhanced dual-catalytic copper cluster enzymes SB-CuNCs, with Schiff base emission at 500 nm.

[0047] Example 2: Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme

[0048] Preparation of copper clusters: 0.1 mmol of 4,6-diamino-2-mercaptopyrimidine was dissolved in 1 mL of 1 M sodium hydroxide aqueous solution. 100 μL of 0.2 M copper chloride aqueous solution and 4 mL of water were added to form a mixed solution, with a molar ratio of 4,6-diamino-2-mercaptopyrimidine to copper ions of 5:1. The mixture was heated and stirred at 60 °C. 0.5 mL of 1 M citric acid aqueous solution was added dropwise while stirring for 6 h. The mixture was centrifuged at 8000 rpm for 10 min, and the precipitate was collected and ultrasonically dispersed in 1 mL of water to obtain a copper cluster solution. The size of the copper clusters was 2-3 nm.

[0049] Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme: 1 mL of the above copper cluster solution was dissolved in 4 mL of water, and mixed with 1 mL of 0.2 M terephthalaldehyde ethanol solution and 4 mL of ethanol to form a mixed solution with a molar ratio of terephthalaldehyde:4,6-diamino-2-mercaptopyrimidine of 2:1. After heating and stirring at 60 °C for about 6 h, the solution changed from pale yellow to yellow until it remained unchanged. The precipitate after vacuum drying to evaporate the solvent was ultrasonically dispersed in 1 mL of water to obtain the Schiff base-enhanced dual-catalytic copper cluster enzyme solution. The particle size of the Schiff base-enhanced dual-catalytic copper cluster enzyme was 2-5 nm.

[0050] Example 3: Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme

[0051] Preparation of copper clusters: 0.1 mmol of 4,6-diamino-2-mercaptopyrimidine was dissolved in 1 mL of 1 M sodium hydroxide aqueous solution. 100 μL of 0.2 M copper chloride aqueous solution and 4 mL of water were added to form a mixed solution, with a molar ratio of 4,6-diamino-2-mercaptopyrimidine to copper ions of 5:1. The mixture was heated and stirred at 60 °C. 0.5 mL of 1 M citric acid aqueous solution was added dropwise while stirring for 6 h. The mixture was centrifuged at 8000 rpm for 10 min, and the precipitate was collected and ultrasonically dispersed in 1 mL of water to obtain a copper cluster solution. The size of the copper clusters was 2-3 nm.

[0052] Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme: 1 mL of the above copper cluster solution was dissolved in 4 mL of water, and mixed with 1 mL of 0.1 M terephthalaldehyde ethanol solution and 4 mL of ethanol to form a mixed solution with a molar ratio of terephthalaldehyde: 4,6-diamino-2-mercaptopyrimidine of 1:1. After heating and stirring at 60 °C for about 6 h, the solution changed from pale yellow to yellow until it remained unchanged. The precipitate after vacuum drying to evaporate the solvent was ultrasonically dispersed in 1 mL of water to obtain the Schiff base-enhanced dual-catalytic copper cluster enzyme solution. The particle size of the Schiff base-enhanced dual-catalytic copper cluster enzyme was 2-5 nm.

[0053] Example 4: Schiff base-enhanced dual-catalytic copper cluster enzyme dual-catalytic degradation of atrazine

[0054] 10 μL of the SB-CuNCs solution prepared in Example 1 was added to 1 mL of atrazine solution (20 mM, containing 50% ethanol v / v), and the fluorescence spectrum of ATZ was measured. Under the action of SB-CuNCs, the emission peak of ATZ at 384 nm gradually decreased, indicating that ATZ was degraded. Figure 5 ).

[0055] 0.1 mmol of 4,6-diamino-2-mercaptopyrimidine was dissolved in 1 mL of 1 M sodium hydroxide aqueous solution, and 4 mL of water was added to form a mixed solution. This mixed solution was then mixed with 1 mL of 0.2 M terephthalaldehyde ethanol solution and 4 mL of ethanol to form a 2:1 molar ratio of terephthalaldehyde to 4,6-diamino-2-mercaptopyrimidine. The solution was heated and stirred in a heating mantle at 60 °C for about 6 hours. After about 6 hours, the solution changed from pale yellow to yellow and then remained unchanged, yielding the Schiff base SB solution. 10 μL of the Schiff base SB solution or 10 μL of the copper cluster CuNCs solution prepared in the first step of Example 1 was added to 1 mL of ATZ (20 mM, containing 50% ethanol v / v). The fluorescence spectrum of ATZ was measured, and the emission peak of ATZ also decreased, indicating that SB or CuNCs had a catalytic effect on the degradation of ATZ. Figure 5 The degree of ATZ degradation is represented by changes in ATZ fluorescence intensity. Figure 6 This indicates that SB-CuNCs exhibit the strongest catalytic degradation activity for ATZ. Furthermore, SB not only catalyzes the degradation of ATZ but also enhances the catalytic activity of CuNCs.

[0056] Example 5: Schiff base-enhanced dual-catalytic copper cluster enzyme fluorescence assay for atrazine.

[0057] 0.5 mL of the Schiff base-enhanced dual-catalytic copper cluster enzyme SB-CuNCs prepared in Example 1 was added to 1.5 mL of water, followed by 10 μL of atrazine standard solutions of different concentrations. The mixture was thoroughly mixed to prepare a series of solutions containing atrazine concentrations of 0, 0.05, 0.2, 0.8, 2, 4, 7, 10, and 15 μM. After mixing for 20 minutes, the fluorescence intensity at 710 nm and 500 nm was measured under 365 nm excitation. With increasing atrazine concentration, the fluorescence intensity of the Schiff base-enhanced dual-catalytic copper cluster enzyme SB-CuNCs at the 500 nm fluorescence peak continuously decreased, while the fluorescence intensity at the 710 nm fluorescence peak continuously increased. Figure 7 The fluorescence ratio at 710 nm / 500 nm was linearly proportional to the concentration of atrazine, and the detection limit of atrazine was 0.05 μM.

[0058] Example 6: Schiff base-enhanced dual-catalytic copper cluster enzyme fluorescence assay for atrazine

[0059] Take 1 mL of fresh milk, centrifuge at 3000 rpm for 10 min to remove the upper fat layer, add 1 mL of isopropanol to the lower layer, centrifuge at 8000 rpm for 10 min, collect the supernatant, and dilute it 20 times with water to obtain the milk sample solution. Take two 1 mL aliquots of the milk sample solution and add standard atrazine solution to each, so that the atrazine concentrations in the two milk sample solutions are 0.5 μM and 5 μM respectively.

[0060] 0.5 mL of the Schiff base-enhanced dual-catalytic copper cluster enzyme SB-CuNCs prepared in Example 1 was added to 1.5 mL of water, followed by 10 μL of the above milk sample solution. The mixture was thoroughly mixed, and after 20 minutes, the fluorescence intensity at 710 nm and 500 nm was measured using 365 nm as the excitation wavelength. The recovery rate of atrazine was calculated based on the 710 nm / 500 nm fluorescence ratio and the amount of atrazine added.

[0061] Table 1. Determination results of ATZ in milk samples

[0062]

[0063] The results in Table 1 show that the method for determining atrazine using a Schiff base-enhanced dual-catalytic copper cluster enzyme has good accuracy.

Claims

1. A Schiff base-enhanced dual-catalytic copper cluster enzyme, characterized in that, The Schiff base-enhanced dual-catalytic copper cluster enzyme is prepared by heating a copper cluster with a terephthalaldehyde solution, wherein the copper cluster is prepared by reacting a 4,6-diamino-2-mercaptopyrimidine alkaline aqueous solution with copper ions; the preparation method of the Schiff base-enhanced dual-catalytic copper cluster enzyme includes the following steps: (1) Preparation of copper clusters: copper ions are mixed with an alkaline aqueous solution of 4,6-diamino-2-mercaptopyrimidine to form a mixture, heated and stirred, and citric acid solution is added to react and a copper cluster solution is obtained; (2) Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme: Add ethanol solution of terephthalaldehyde to the prepared copper cluster solution, heat and stir to react, and obtain Schiff base-enhanced dual-catalytic copper cluster enzyme solution. The pH value of the mixture in step (1) is 10~12, and the molar ratio of 4,6-diamino-2-mercaptopyrimidine to copper ions is 2~5:1; the molar ratio of terephthalaldehyde to 4,6-diamino-2-mercaptopyrimidine in step (2) is 1~2:

1.

2. The Schiff base-enhanced dual-catalytic copper cluster enzyme according to claim 1, characterized in that, The copper clusters have a particle size of 2-5 nm.

3. The method for preparing a Schiff base-enhanced dual-catalytic copper cluster enzyme according to any one of claims 1 to 2, characterized in that, Includes the following steps: (1) Preparation of copper clusters: copper ions are mixed with an alkaline aqueous solution of 4,6-diamino-2-mercaptopyrimidine to form a mixture, heated and stirred, and citric acid solution is added to react and a copper cluster solution is obtained; (2) Preparation of Schiff base-enhanced dual-catalytic copper cluster enzyme: Add ethanol solution of terephthalaldehyde to the prepared copper cluster solution, heat and stir to react, and obtain Schiff base-enhanced dual-catalytic copper cluster enzyme solution. The pH value of the mixture in step (1) is 10~12, and the molar ratio of 4,6-diamino-2-mercaptopyrimidine to copper ions is 2~5:1; the molar ratio of terephthalaldehyde to 4,6-diamino-2-mercaptopyrimidine in step (2) is 1~2:

1.

4. The application of the Schiff base-enhanced dual-catalytic copper cluster enzyme according to any one of claims 1 to 2 in the catalytic degradation of atrazine.

5. The application of the Schiff base-enhanced dual-catalytic copper cluster enzyme according to any one of claims 1 to 2 in the quantitative determination of atrazine.

6. A method for the degradation of atrazine by a Schiff base-enhanced dual-catalytic copper cluster enzyme, characterized in that, The specific steps are as follows: A certain amount of the Schiff base-enhanced dual-catalytic copper cluster enzyme solution according to any one of claims 1 to 2 is added to the solution containing atrazine, mixed evenly, and the degradation efficiency of atrazine is determined based on the fluorescence change of atrazine.

7. A method for determining atrazine using a Schiff base-enhanced dual-catalytic copper cluster enzyme, characterized in that, The specific steps are as follows: First, a certain amount of the Schiff base-enhanced dual-catalytic copper cluster enzyme solution according to any one of claims 1 to 2 is added to a series of atrazine standard solutions of known concentrations, mixed evenly and reacted, and the fluorescence intensity of the solution at 710 nm and 500 nm is measured. A working curve of the fluorescence ratio of 710 nm / 500 nm versus the concentration of the atrazine standard solution is plotted. Then, the content of atrazine in the sample can be detected based on the working curve and the fluorescence ratio of the sample to be tested.

8. The method according to claim 7, characterized in that, The concentration of the atrazine standard solution is 0~25μM.

9. The method according to claim 8, characterized in that, The samples to be tested include milk samples.

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