Method for detecting glyphosate by using copper monatomic coordination amino covalent organic framework nano-enzyme

Abstract

The invention discloses a method for detecting glyphosate by using a copper monatomic coordination amino covalent organic framework nano-enzyme, the copper monatomic coordination amino covalent organic framework nano-enzyme adopted in the method comprises an amino covalent organic framework, and Cu < 2 + > ions are distributed on a cavity and the surface of the amino covalent organic framework. The nano-enzyme adopted in the invention has the advantages of excellent peroxidase-like activity, high crystallinity, strong chemical stability and the like, can realize specific detection of glyphosate, has the advantages of simple process, convenience in operation, low cost, wide detection range, high detection sensitivity, high detection precision and the like, has the glyphosate detection concentration of 2-100 [mu] mol / L, and has a good application prospect. The detection limit is 0.193 mu mol / L, the method can be widely used for detecting glyphosate in the environment (such as soil or water), the concentration of glyphosate can be rapidly and accurately obtained, the use value is high, and the application prospect is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and specifically relates to a method for detecting glyphosate by utilizing a copper single atom coordinated amino group covalent organic framework nanoenzyme. Background Art

[0002] Currently, the main methods used to detect glyphosate in the environment include liquid chromatography-tandem mass spectrometry, electrochemical sensors, fluorescent probes, gas chromatography, and immunoassays. While these methods offer high sensitivity, they still have shortcomings in terms of equipment cost, analysis time, and operation methods, failing to meet detection needs. Nanozymes, as an emerging rapid detection technology, are highly favored by researchers due to their high stability, low cost, and ease of use. For pesticide detection, nanozymes with peroxidase activity have attracted considerable attention due to their broad application prospects and efficient catalytic performance. Furthermore, nanozymes with good biocompatibility can meet the diverse requirements of environmental testing and offer an effective approach to addressing these challenges.

[0003] Framework materials such as metal organic frameworks and covalent organic frameworks have good application prospects in nanoenzyme detection technology due to their advantages such as high specific surface area, periodic voids and structural diversity. For example, researchers have proposed a bimetallic porphyrin-based covalent organic framework COF. Fe / CoP-Ph The nanozyme-based cascade colorimetric sensor for the determination of malathion in real samples can be constructed by using a bimetallic porphyrin-based covalent organic framework (COF) without the need for destructive H2O2. Fe / CoP-Ph The nanozyme promotes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and increases its absorbance. Furthermore, trisodium 2-phospho-L-ascorbic acid (AAP) and acid phosphatase (ACP) are added to the sensing system. ACP catalyzes the hydrolysis of AAP to produce ascorbic acid (AA), thereby inhibiting the colorimetric reaction induced by TMB oxidation and reducing the colorimetric signal. Subsequently, in the presence of the serine enzyme inhibitor malathion, specific recognition occurs, inhibiting the activity of the serine residue in the ACP active site, resulting in a decrease in AA production. This allows the cascade colorimetric sensor to catalyze the oxidation of TMB and restore signal transmission, thereby enabling the determination of malathion in the sample. However, this cascade colorimetric sensor cannot be used to detect glyphosate. Furthermore, to date, there have been no reports on the detection of glyphosate using a copper single-atom-coordinated amino group covalent organic framework nanozyme. Therefore, the development of a copper single-atom coordinated amino covalent organic framework nanozyme with good glyphosate selectivity, strong peroxidase-like activity, high crystallinity, and strong chemical stability is particularly important for achieving sensitive detection of glyphosate herbicides. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a method for detecting glyphosate using copper single atom coordinated amino covalent organic framework nanozyme with simple process, convenient operation, low cost, wide detection range, high detection sensitivity and high detection accuracy.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A method for detecting glyphosate using a copper single-atom coordinated amino covalent organic framework nanozyme, wherein the copper single-atom coordinated amino covalent organic framework nanozyme is used to detect glyphosate; the copper single-atom coordinated amino covalent organic framework nanozyme comprises an amino covalent organic framework, and Cu is distributed in the cavity and on the surface of the amino covalent organic framework. 2+ ion.

[0007] The above method of using copper single atom coordinated amino covalent organic framework nanoenzyme to detect glyphosate is further improved. 2+ The mass ratio of the ions to the amino covalent organic framework is 0.13-0.83:1.

[0008] The above-mentioned method of detecting glyphosate using copper single-atom coordinated amino covalent organic framework nanozyme is further improved, wherein the copper single-atom coordinated amino covalent organic framework nanozyme is in the shape of a regularly arranged nanoflower; the particle size of the copper single-atom coordinated amino covalent organic framework nanozyme is 2μm to 5μm.

[0009] The above method of using copper single atom coordinated amino covalent organic framework nanoenzyme to detect glyphosate is further improved. 2+ The mass ratio of the ions to the amino covalent organic framework is 0.27-0.83:1.

[0010] The above-mentioned method of detecting glyphosate using copper single atom coordinated amino covalent organic framework nanoenzyme is further improved, wherein the amino covalent organic framework is prepared by reducing terephthalic acid and imine covalent organic framework as raw materials.

[0011] The above-mentioned method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanoenzyme is further improved, and the preparation method of the amino covalent organic framework comprises the following steps: (1.1) An imino covalent organic framework, terephthalic acid, and an organic solvent are mixed and stirred to obtain a mixed solution A; the mass ratio of the terephthalic acid to the imino covalent organic framework is 1 to 2:1; the ratio of the terephthalic acid to the organic solvent is 57.6 mg: 25 mL to 50 mL; the stirring temperature is 0°C to 10°C, and the stirring time is 10 min to 30 min.

[0012] (1.2) Add a reducing agent to the mixed solution A for reduction reaction, stir, wash, and dry to obtain an amino covalent organic framework; the ratio of the mixed solution A to the reducing agent is 5 mL to 2 mL: 0.05 g to 0.15 g; the reduction reaction is carried out at 0°C to 10°C; the reduction reaction time is 10 min to 30 min; and the stirring time is 8 h to 12 h.

[0013] The above-mentioned method of detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanoenzyme is further improved, wherein the imine covalent organic framework is prepared by a Schiff base reaction using 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzenetricarboxaldehyde as monomers.

[0014] The above-mentioned method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanoenzyme is further improved, and the preparation method of the imine covalent organic framework comprises the following steps: (2.1) Dissolve 1,3,5-tris(4-aminophenyl)benzene in an acetic acid solution to obtain solution A; dissolve 1,3,5-benzenetricarboxaldehyde in an acetic acid solution to obtain solution B; the mass ratio of 1,3,5-tris(4-aminophenyl)benzene to 1,3,5-benzenetricarboxaldehyde is 50-100:23-46; the ratio of 1,3,5-tris(4-aminophenyl)benzene to acetic acid solution in solution A is 50 mg:7.0 mL-12.4 mL; the ratio of 1,3,5-benzenetricarboxaldehyde to acetic acid solution in solution B is 23 mg:7.0 mL-12.4 mL; the concentration of the acetic acid solution is 3 mol / L; (2.2) Solution A and solution B obtained in step (2.1) are mixed to undergo a Schiff base reaction, washed, and dried to obtain an imine-based covalent organic framework; the Schiff base reaction time is 72 hours to 96 hours; and the drying time is 48 hours to 72 hours.

[0015] The above-mentioned method of detecting glyphosate using copper single atom coordinated amino covalent organic framework nanozyme is further improved. The copper single atom coordinated amino covalent organic framework nanozyme is prepared by stirring divalent copper salt, amino covalent organic framework and water as raw materials.

[0016] The above-mentioned method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme is further improved, and the preparation method of the copper single atom coordinated amino covalent organic framework nanozyme comprises the following steps: (3.1) Mix a divalent copper salt with water and sonicate to obtain solution C. Add the amino covalent organic framework to water to obtain solution D. (3.2) Solution D is sonicated, and solution C is added during the sonication process. The solution is stirred, centrifuged, washed, filtered, and dried to obtain a copper single-atom coordinated amino covalent organic framework nanozyme.

[0017] The above-mentioned method for detecting glyphosate using copper single-atom coordinated amino covalent organic framework nanozyme is further improved. In step (3.1), the mass volume ratio of divalent copper salt to water in solution C is 25 mg~75 mg:15 mL~30 mL; the divalent copper salt is copper nitrate trihydrate; the mass volume ratio of amino covalent organic framework to water in solution D is 90 mg:15 mL~30 mL; and the ultrasonic time is 15 min~30 min.

[0018] The above-mentioned method for detecting glyphosate using copper single atom coordinated amino covalent organic framework nanoenzyme is further improved. In step (3.2), the ultrasonic time is 15 minutes to 30 minutes, the stirring time is 12 hours to 24 hours, the drying temperature is 60°C to 80°C, and the drying time is 12 hours to 24 hours.

[0019] The above-mentioned method of detecting glyphosate using copper single-atom coordinated amino covalent organic framework nanozyme is further improved by using copper single-atom coordinated amino covalent organic framework nanozyme to detect glyphosate in water or soil; The detection of glyphosate in water using a copper single atom coordinated amino covalent organic framework nanozyme includes the following steps: (4.1) mixing the copper single atom coordinated amino covalent organic framework nanozyme and glyphosate wastewater to react and obtain solution E; (4.2) adding p-phenylenediamine solution and hydrogen peroxide solution to the solution E obtained in step (4.1) to react, and detecting the absorbance intensity of the mixed solution; (4.3) Based on the absorbance intensity of the mixed solution and the linear equation between the absorbance intensity and glyphosate concentration in the glyphosate solution, the concentration of glyphosate in the glyphosate wastewater is calculated, thereby realizing the detection of glyphosate in the wastewater.

[0020] The above-mentioned method for detecting glyphosate using copper single-atom coordinated amino covalent organic framework nanozyme is further improved, and when using copper single-atom coordinated amino covalent organic framework nanozyme to detect glyphosate in soil, it includes the following steps: (5.1) Prepare soil extract from glyphosate-containing soil; (5.2) mixing the copper single atom coordinated amino covalent organic framework nanozyme and the soil extract to react and obtain a solution F; (5.3) Add p-phenylenediamine solution and hydrogen peroxide solution to the solution F obtained in step (5.2) to react, and measure the absorbance intensity of the mixed solution; (5.4) Based on the absorbance intensity of the mixed solution and the linear equation between the absorbance intensity and glyphosate concentration in the glyphosate solution, the concentration of glyphosate in the soil extract is calculated, thereby enabling the detection of glyphosate in the soil.

[0021] The above-mentioned method for detecting glyphosate using copper single-atom coordinated amino covalent organic framework nanozyme is further improved. In step (4.1), the copper single-atom coordinated amino covalent organic framework nanozyme is mixed with glyphosate wastewater in the form of a copper single-atom coordinated amino covalent organic framework nanozyme solution, and the volume ratio of the copper single-atom coordinated amino covalent organic framework nanozyme solution to the glyphosate wastewater is 1:5; the copper single-atom coordinated amino covalent organic framework nanozyme solution is prepared by mixing the copper single-atom coordinated amino covalent organic framework nanozyme and NaAc-HAc buffer solution; the concentration of the copper single-atom coordinated amino covalent organic framework nanozyme solution is ≤100 μg / mL, and the concentration of glyphosate in the glyphosate wastewater is 5 μmol / L~15 μmol / L; the reaction is carried out at a temperature of 30°C~40°C; and the reaction time is 10min~30min.

[0022] The above-mentioned method for detecting glyphosate using copper single atom coordinated amino covalent organic framework nanozyme is further improved. In step (4.2), the volume ratio of the E solution to the p-phenylenediamine solution is 6:1; the concentration of the p-phenylenediamine solution is 1 mmol / L to 3 mmol / L; the volume ratio of the E solution to the hydrogen peroxide solution is 6:1; the concentration of the hydrogen peroxide solution is 0.1 mmol / L to 1 mmol / L; the reaction is carried out at a temperature of 30°C to 40°C; and the reaction time is 10 min to 30 min.

[0023] The above-mentioned method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme is further improved. In step (4.3), the linear equation of the absorbance intensity and glyphosate concentration in the glyphosate solution is shown in formula (1), as follows: y=0.00191×x+0.04069(1); In formula (1), y is the absorbance intensity of glyphosate solution, x is the concentration of glyphosate in glyphosate solution, the unit is μmol / L, and the correlation coefficient is R 2 =0.9942.

[0024] The above-mentioned method for detecting glyphosate using copper single-atom coordinated amino covalent organic framework nanoenzyme is further improved. In step (5.1), the soil extract is prepared by the following method: mixing glyphosate-containing soil with acetonitrile, shaking at a speed of 200 rpm for 30 minutes, centrifuging at a speed of 5000 rpm for 10 minutes, and collecting the supernatant to obtain a soil extract.

[0025] The above-mentioned method for detecting glyphosate using copper single-atom coordinated amino covalent organic framework nanozyme is further improved. In step (5.2), the copper single-atom coordinated amino covalent organic framework nanozyme is mixed with the soil extract in the form of a copper single-atom coordinated amino covalent organic framework nanozyme solution, and the volume ratio of the copper single-atom coordinated amino covalent organic framework nanozyme solution to the soil extract is 1:5; the copper single-atom coordinated amino covalent organic framework nanozyme solution is prepared by mixing the copper single-atom coordinated amino covalent organic framework nanozyme and NaAc-HAc buffer solution; the concentration of the copper single-atom coordinated amino covalent organic framework nanozyme solution is ≤100 μg / mL, and the concentration of glyphosate in the soil extract is 5 μmol / L~15 μmol / L; the reaction is carried out at a temperature of 30°C~40°C; and the reaction time is 10min~30min; The above-mentioned method for detecting glyphosate using copper single atom coordinated amino covalent organic framework nanozyme is further improved. In step (5.3), the volume ratio of the F solution to the p-phenylenediamine solution is 6:1; the concentration of the p-phenylenediamine solution is 2 mmol / L; the volume ratio of the F solution to the hydrogen peroxide solution is 6:1; the concentration of the hydrogen peroxide solution is 0.1 mmol / L to 1 mmol / L; the reaction is carried out at a temperature of 30°C to 40°C; and the reaction time is 10 min to 30 min.

[0026] The above-mentioned method for detecting glyphosate using copper single atom coordinated amino covalent organic framework nanozyme is further improved. In step (5.4), the linear equation of the absorbance intensity and glyphosate concentration in the glyphosate solution is shown in formula (1).

[0027] Compared with the prior art, the advantages of the present invention are: (1) In view of the shortcomings of existing covalent organic framework nanozymes such as good selectivity for glyphosate, strong peroxidase-like activity, high crystallinity, and strong chemical stability, as well as the resulting defects in the detection of glyphosate, the present invention creatively provides a method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme. The copper single atom coordinated amino covalent organic framework nanozyme comprises an amino covalent organic framework, and Cu is distributed in the cavity and on the surface of the amino covalent organic framework. 2+Compared with conventional covalent organic frameworks, the copper single atom coordinated amino covalent organic framework nanozyme of the present invention uses amino covalent organic framework as a carrier, has stronger chemical stability, can solve the problem of easy structural collapse under extreme pH conditions, and is more suitable for the field of analytical sensing. At the same time, it has a higher specific surface area and periodic pores, which can provide more active sites for the coordination of copper single atoms, thereby being able to 2+ The ions are uniformly and stably fixed on the cavity and surface of the amino covalent organic framework, making more Cu 2+ The ions are exposed on the outside of the amino covalent organic framework, which has the advantages of good selectivity for glyphosate, strong peroxidase-like activity, high crystallinity, and strong chemical stability. On this basis, the copper single atom coordinated amino covalent organic framework nanozyme is used to detect glyphosate. On the one hand, the copper single atom coordinated amino covalent organic framework nanozyme can be used to efficiently catalyze hydrogen peroxide and oxidize the chromogenic substrate to form an identifiable substance. On the other hand, when glyphosate is present in the system, the Cu in the copper single atom coordinated amino covalent organic framework nanozyme 2+ Ions have a strong complexing effect on the -P-OH group in glyphosate. At this time, the copper single atom coordinated amino covalent organic framework nanozyme can highly selectively adsorb glyphosate on its surface and coat the surface Cu 2+ ions, which deteriorate the peroxidase activity of the copper single-atom coordinated amino covalent organic framework nanozyme, making it difficult for the chromogenic substrate in the system to be oxidized, and then it is difficult to produce identifiable substances. Based on this, a linear relationship between the absorbance intensity and the glyphosate concentration in the glyphosate solution is established. By detecting the absorbance intensity of the glyphosate solution to be tested and utilizing the above linear relationship, the concentration of glyphosate in the glufosinate solution to be tested is quickly and accurately obtained. The method has the advantages of simple process, convenient operation, low cost, wide detection range, high detection sensitivity, and high detection accuracy. The detection concentration of glyphosate is 2μmol / L~100μmol / L, and the detection limit is 0.193μmol / L. It can be widely used for the detection of glyphosate in the environment (such as soil or water bodies), with high use value and good application prospects.

[0028] (2) In the present invention, by optimizing the copper single atom coordinated amino covalent organic framework nanozyme Cu 2+ The mass ratio of ions to amino covalent organic frameworks is 0.13 to 0.83:1, especially 0.55:1, which can ensure that the nanozyme has both excellent metal atom utilization and efficient catalytic activity, thus being more conducive to the specific detection of glyphosate.

[0029] (3) In the present invention, the amino covalent organic framework used is prepared by reducing terephthalic acid and imine covalent organic framework as raw materials, and presents a regular rod-like morphology. It is an emerging nanozyme material with good biocompatibility. At the same time, the amino covalent organic framework has higher crystallinity and chemical stability, which can realize the reuse of copper single atom coordinated amino covalent organic framework nanozyme without causing secondary pollution.

[0030] (4) In the present invention, the copper single atom coordinated amino covalent organic framework nanozyme is prepared by stirring divalent copper salt, amino covalent organic framework and water as raw materials. Specifically, divalent copper salt and amino covalent organic framework are used as raw materials and water is used as solvent. The copper ions are chelated by N, O-chelating sites to form Cu 2+ Uniform and robust anchoring within the cavities and surfaces of the amino covalent organic framework (ACCF) yields a copper single-atom-coordinated ACCF nanozyme with excellent glyphosate selectivity, strong peroxidase-like activity, high crystallinity, and strong chemical stability. This preparation method offers advantages such as simplicity, ease of operation, and low cost, making it suitable for large-scale production and industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a scanning electron microscope image of the amino covalent organic framework (COF300-AR) prepared in Example 1 of the present invention.

[0032] Figure 2 This is a transmission electron micrograph of the amino covalent organic framework (COF300-AR) prepared in Example 1 of the present invention.

[0033] Figure 3 This is a scanning electron microscope image of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) prepared in Example 1 of the present invention.

[0034] Figure 4 This is a transmission electron micrograph of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) prepared in Example 1 of the present invention.

[0035] Figure 5 This is the XPS energy spectrum of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) prepared in Example 1 of the present invention.

[0036] Figure 6These are the XRD patterns of the amino covalent organic framework (COF300-AR) and different metal single-atom coordinated amino covalent organic framework nanozymes (Cu@COF300-AR, Ni@COF300-AR, Co@COF300-AR, and Zn@COF300-AR) prepared in Example 1 of the present invention.

[0037] Figure 7 This is the ultraviolet absorption spectrum of the chromogenic substrate o-phenylenediamine catalyzed by the amino covalent organic framework (COF300-AR) and different metal single-atom coordinated amino covalent organic framework nanozymes (Cu@COF300-AR, Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) in Example 1 of the present invention.

[0038] Figure 8 For different Cu in Example 1 of the present invention 2+ Ultraviolet absorption spectra of the chromogenic substrate o-phenylenediamine catalyzed by the coordinated copper single atom-coordinated amino covalent organic framework nanozyme (0.05 mM, 0.1 mM, 0.2 mM and 0.3 mM).

[0039] Figure 9 This is the ultraviolet absorption spectrum of the chromogenic substrate o-phenylenediamine catalyzed by copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) solutions with different concentrations in Example 1 of the present invention.

[0040] Figure 10 This is a diagram showing the relative activity of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) in Example 1 of the present invention in catalyzing the chromogenic substrate o-phenylenediamine under different pH conditions.

[0041] Figure 11 This is a diagram showing the selectivity effect of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) on glyphosate in Example 1 of the present invention.

[0042] Figure 12 This is the ultraviolet absorption spectrum of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) after mixing with glyphosate standard solutions of different concentrations in Example 1 of the present invention.

[0043] Figure 13 This is a working curve of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) in Example 1 of the present invention at different concentrations of glyphosate at 450nm.

[0044] Figure 14This is the ultraviolet absorption spectrum of different metal single-atom coordinated amino covalent organic framework nanozymes (Cu@COF300-AR, Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) after mixing with glyphosate solution in Example 1 of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the scope of protection of the present invention is not limited thereby.

[0046] In the following examples of the present invention, unless otherwise specified, the materials and instruments used are commercially available, the equipment used is conventional equipment, and the data obtained are the average values ​​of more than three repeated experiments.

[0047] Example 1: A method for detecting glyphosate using a copper single-atom coordinated amino covalent organic framework nanozyme, specifically: using a copper single-atom coordinated amino covalent organic framework nanozyme to detect glyphosate in water or soil.

[0048] In this embodiment, the detection of glyphosate in water using a copper single atom coordinated amino covalent organic framework nanozyme includes the following steps: S11. 0.010 g of copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) was placed in a 50 mL beaker, and NaAc-HAc buffer solution (pH = 4) was added. The mixture was stirred with a glass plate to evenly mix the copper single atom coordinated amino covalent organic framework nanozyme and the buffer solution. The mixture was transferred to a 100 mL volumetric flask, and the beaker was washed three times with NaAc-HAc buffer solution. The washing solution was transferred to a volumetric flask to make up the volume, and a copper single atom coordinated amino covalent organic framework nanozyme solution with a concentration of 100 μg / mL was obtained, which was recorded as Cu@COF300-AR nanozyme solution. 100 μL The Cu@COF300-AR nanozyme solution was mixed with 500 μL of glyphosate wastewater with different concentrations (as shown in Table 1) and reacted at 37°C for 15 min. Then, 100 μL of o-phenylenediamine (2 mmol / L) and 100 μL of hydrogen peroxide (1 mmol / L) were added to the mixed solution and reacted at 37°C for 15 min to obtain a mixed solution. The absorbance intensity of the mixed solution at 450 nm was detected using an ultraviolet spectrophotometer.

[0049] S12. According to the absorbance intensity of the mixed solution, combined with the linear equation of the absorbance intensity and glyphosate concentration in the glyphosate solution, the concentration of glyphosate in the glyphosate wastewater is calculated to achieve the detection of glyphosate in the wastewater, as shown in Table 1.

[0050] In this embodiment, the detection of glyphosate in soil using a copper single atom coordinated amino covalent organic framework nanozyme includes the following steps: S21. Preparation of soil extract Three soil samples containing different concentrations of glyphosate (as shown in Table 1) were weighed on a precision analytical balance, 1 g each, and placed in 25 mL centrifuge tubes. 4 mL of acetonitrile was added and mechanically shaken at 200 rpm for 30 min. The samples were then centrifuged at 5000 rpm for 10 min. The supernatant was collected to obtain soil extracts containing different concentrations of glyphosate, which were then stored in a 4°C refrigerator for later use.

[0051] S22. A 100 μg / mL copper single-atom coordinated amino covalent organic framework nanozyme solution (Cu@COF300-AR nanozyme solution) was used to test soil extracts containing different concentrations of glyphosate. Specifically: (a) 100 μL of Cu@COF300-AR nanozyme solution was mixed with 500 μL of soil extract containing different concentrations of glyphosate and reacted at 37°C for 15 min. 100 μL of o-phenylenediamine (2 mmol / L) and 100 μL of hydrogen peroxide (1 mmol / L) were then added to the mixed solution and reacted at 37°C for 15 min to obtain a mixed solution. The absorbance intensity of the mixed solution at 450 nm was detected using a UV spectrophotometer.

[0052] (b) Based on the absorbance intensity of the mixed solution and the linear equation between the absorbance intensity and glyphosate concentration in the glyphosate solution, the concentration of glyphosate in the soil extract is calculated to detect glyphosate in the soil, as shown in Table 1.

[0053] In this embodiment, different Cu 2+ The effect of the coordination amount of copper single atom coordinated amino covalent organic framework nanozyme (0.05 mM, 0.1 mM and 0.3 mM) on the detection of glyphosate in water was studied. 2+ The coordination amount of copper single atom coordinated amino covalent organic framework nanozyme (0.05 mM, 0.1 mM and 0.3 mM) was used to replace Cu@COF300-AR for the detection of glyphosate in water, and other conditions were the same. 2+ Catalytic effect of the chromogenic substrate o-phenylenediamine on the catalytic effect of the amino covalent organic framework nanozyme with a coordinated amount of copper single atom (0.05 mM, 0.1 mM, 0.2 mM and 0.3 mM).

[0054] In this example, the effect of different concentrations of copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) solutions on the detection of glyphosate in water was also investigated. Specifically, glyphosate in water was detected using copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) solutions at concentrations of 2 μg / mL, 4 μg / mL, 6 μg / mL, 7 μg / mL, 10 μg / mL, 20 μg / mL, 40 μg / mL, 80 μg / mL, and 100 μg / mL, with other conditions being the same. At the same time, the catalytic effect of different concentrations of copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) solutions on the chromogenic substrate o-phenylenediamine was also investigated.

[0055] In this example, the effect of the copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) on the detection of glyphosate in water with different pH values ​​was also investigated. Specifically, the copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) was used to detect glyphosate in water with pH values ​​of 4, 5, 6, 7, 8, and 9, with other conditions being the same. At the same time, the catalytic effect of the copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) on the chromogenic substrate o-phenylenediamine at pH values ​​of 4, 5, 6, 7, 8, and 9 was also investigated.

[0056] In this example, the effects of other different metal atom-coordinated amino covalent organic framework nanozymes (Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) on the detection of glyphosate in water were also investigated. Specifically, Ni@COF300-AR, Co@COF300-AR, and Zn@COF300-AR were used to replace Cu@COF300-AR, respectively, for the detection of glyphosate in water, with other conditions being the same. At the same time, the catalytic effects of different metal atom-coordinated amino covalent organic framework nanozymes (Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR, and Cu@COF300-AR) on the chromogenic substrate o-phenylenediamine were also investigated.

[0057] In this embodiment, the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) comprises an amino covalent organic framework, in which Cu is distributed in the cavity and on the surface of the amino covalent organic framework. 2+ ions, including Cu 2+ The mass ratio of ions to amino covalent organic frameworks is 0.55:1, and the amino covalent organic framework is a staggered rod-like structure.

[0058] In this embodiment, the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) used is a more regularly arranged nanoflower with a particle size of 2μm to 5μm.

[0059] In this embodiment, the amino covalent organic framework used is COF300-AR, which is prepared by reducing terephthalic acid and an imine covalent organic framework as raw materials. Specifically, the preparation method of the amino covalent organic framework includes the following steps: (1.1) Mix 90 mg of the imine-based covalent organic framework, 57.6 mg of terephthalic acid, and 25 mL of methanol and stir at 0°C for 15 min to obtain a mixture A.

[0060] (1.2) To 25 mL of mixed solution A, 0.5 g of sodium borohydride (the sodium borohydride can be added in small amounts several times) was added for reduction reaction. Specifically, the mixture was stirred at 0°C for 60 min. After the reaction was complete, the reduction product was stirred at room temperature for 10 h. The product was then washed by centrifugation three times with ethanol and three times with deionized water, and dried in a vacuum oven for 12 h to obtain an amino covalent organic framework, designated as COF300-AR.

[0061] In this embodiment, the imino-based covalent organic framework is prepared by using 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzenetricarboxaldehyde as monomers through a Schiff base reaction. Specifically, the preparation method of the imino-based covalent organic framework includes the following steps: (2.1) Dissolve 50 mg of 1,3,5-tris(4-aminophenyl)benzene in 7.0 mL of 3 mol / L acetic acid to obtain solution A. Dissolve 23 mg of 1,3,5-benzenetricarboxaldehyde in 7.0 mL of 3 mol / L acetic acid to obtain solution B.

[0062] (2.2) Solution A and solution B obtained in step (2.1) were mixed and subjected to a Schiff base reaction for 72 h. The mixture was then centrifuged and washed three times with ethanol and deionized water, and dried in a vacuum oven for 12 h to obtain an imine-based covalent organic framework, designated as COF300.

[0063] In this embodiment, the copper single atom coordinated amino covalent organic framework nanozyme used is prepared by stirring a divalent copper salt, an amino covalent organic framework, and water as raw materials. Specifically, the preparation method of the copper single atom coordinated amino covalent organic framework nanozyme includes the following steps: (3.1) Mix 50 mg of copper nitrate trihydrate with 15 mL of water and sonicate for 15 min to obtain solution C. Add 90 mg of amino covalent organic framework (COF300-AR) to 15 mL of water to obtain solution D.

[0064] (3.2) Solution D was sonicated for 30 min. During the sonication process, solution C was added, and the solution was covered with a sealing film and magnetically stirred for 12 h. The solution was then centrifuged and washed three times with deionized water and dried in a vacuum drying oven at 70 °C for 12 h to obtain a copper single atom coordinated amino covalent organic framework nanozyme, which was designated as Cu@COF300-AR.

[0065] In this embodiment, the copper single atom coordinated amino covalent organic framework nanozyme (0.05 mM, 0.1 mM and 0.3 mM) used is basically the same as the copper single atom coordinated amino covalent organic framework nanozyme (0.2 mM Cu@COF300-AR). The only difference is that the copper single atom coordinated amino covalent organic framework nanozyme (0.05 mM, 0.1 mM and 0.3 mM) in the copper single atom coordinated amino covalent organic framework nanozyme is 2+ The mass ratios of ions to amino covalent organic frameworks are 0.13:1, 0.27:1 and 0.83:1, respectively.

[0066] In this embodiment, different Cu 2+ The preparation method of the copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) with a coordinated amount of copper single-atom coordinated amino covalent organic framework nanozyme (0.05 mM, 0.1 mM and 0.3 mM) is basically the same as that of the copper single-atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR). The only difference is that the amount of copper nitrate trihydrate used in the preparation method of the copper single-atom coordinated amino covalent organic framework nanozyme (0.05 mM, 0.1 mM and 0.3 mM) is 12.5 mg, 25 mg and 75 mg, respectively.

[0067] In this embodiment, the other different metal atom coordinated amino covalent organic framework nanozymes (Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) used are respectively called nickel single atom coordinated amino covalent organic framework nanozyme, cobalt single atom coordinated amino covalent organic framework nanozyme, and zinc single atom coordinated amino covalent organic framework nanozyme. They are basically the same as copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR). The only difference is that the metal ions in the other different metal single atom coordinated amino covalent organic framework nanozymes (Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) are respectively Ni 2+ 、Co 3+ 、Zn 2+ .

[0068] In this embodiment, the preparation methods of other different metal atom coordinated amino covalent organic framework nanozymes (Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) and copper single atom coordinated amino covalent organic framework nanozymes (Cu@COF300-AR) are basically the same, with the only difference being that in the preparation methods of other different metal single atom coordinated amino covalent organic framework nanozymes (Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR), nickel nitrate hexahydrate, cobalt nitrate hexahydrate, and zinc nitrate hexahydrate are used in turn instead of copper nitrate trihydrate.

[0069] Figure 1 This is a scanning electron microscope image of the amino covalent organic framework (COF300-AR) prepared in Example 1 of the present invention.

[0070] Figure 2 This is a transmission electron micrograph of the amino covalent organic framework (COF300-AR) prepared in Example 1 of the present invention.

[0071] Depend on Figures 1 and 2 It can be seen that the amino covalent organic framework (COF300-AR) sample prepared by the present invention is a staggered rod-like structure, and its transmission electron microscope image shows stacked sheet-like structural ripples.

[0072] Figure 3 This is a scanning electron microscope image of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) prepared in Example 1 of the present invention.

[0073] Figure 4 This is a transmission electron micrograph of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) prepared in Example 1 of the present invention.

[0074] Figure 5 This is the XPS energy spectrum of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) prepared in Example 1 of the present invention.

[0075] Depend on Figures 3 to 5 It can be seen that the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) of the present invention is a more regularly arranged nanoflower with good crystallinity. It contains four elements: Cu, C, O and N. 2+ Evenly distributed in the cavity and surface of COF300-AR, with a particle size of 2μm~5μm.

[0076] Figure 6The XRD patterns of the amino covalent organic framework (COF300-AR) and different metal single-atom coordinated amino covalent organic framework nanozymes (Cu@COF300-AR, Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) prepared in Example 1 of the present invention are shown in FIG. Figure 6 It can be seen that COF300-AR has crystal diffraction peaks representing (200), (220), (240), (341), (611) and (152) at 6.82°, 8.58°, 14.02°, 17.64°, 20.62° and 24.36°, confirming the π-π stacking structure of COF300-AR. 3+ 、Zn 2+ 、Ni 2+ and Cu 2+ When coordinated with COF300-AR respectively, no additional peaks were observed in the corresponding XRD patterns, indicating that the introduction of metal single atoms does not change the crystal structure of COF300-AR.

[0077] Figure 7 The following is a graph showing the UV absorption spectra of the chromogenic substrate o-phenylenediamine catalyzed by the amino covalent organic framework (COF300-AR) and different metal single-atom coordinated amino covalent organic framework nanozymes (Cu@COF300-AR, Ni@COF300-AR, Co@COF300-AR, and Zn@COF300-AR) in Example 1 of the present invention. Under the catalysis of COF300-AR and Cu / Co / Ni / Zn@COF300-AR, the o-phenylenediamine (OPD) reaction solution exhibited a distinct absorption peak at 450nm. This indicates that the added nanozyme oxidized o-phenylenediamine, producing 2,3-diaminobenzimidazole with a discernible absorption peak. The absorbance intensity of each nanozyme in o-phenylenediamine follows the order of Cu@COF300-AR>Ni@COF300-AR>Co@COF300-AR>COF300-AR>Zn@COF300-AR, which indicates that Cu@COF300-AR has stronger peroxidase-like activity.

[0078] Figure 8 For different Cu in Example 1 of the present invention 2+ UV absorption spectra of the coordinated copper single atom-coordinated amino covalent organic framework nanozymes (0.05 mM, 0.1 mM, 0.2 mM and 0.3 mM). Figure 8 In the experiment, 0.2mM corresponds to Cu@COF300-AR. Figure 8 It can be seen that when Cu 2+ When the mass ratio of Fe ions to amino covalent organic framework is greater than 0.13:1, that is, Fe 3+When the mass ratio of copper ions to imine-based covalent organic frameworks is 0.13-0.83:1, the corresponding copper single-atom coordinated amino-based covalent organic framework nanozymes have a good catalytic effect on o-phenylenediamine, especially Cu 2+ When the mass ratio of ions to amino covalent organic frameworks is 0.55:1, that is, the coordination amount of Cu@COF300-AR is 0.2 mM, the catalytic effect of o-phenylenediamine is the highest, which is the optimal coordination amount.

[0079] Figure 9 This is the ultraviolet absorption spectrum of the chromogenic substrate o-phenylenediamine catalyzed by copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) solutions with different concentrations in Example 1 of the present invention.

[0080] like Figure 9 As shown in the data, when copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) was used to detect glyphosate, its catalytic effect on o-phenylenediamine increased with the increase of concentration, that is, when the concentration was 100 μg / mL, Cu@COF300-AR had the best catalytic effect on o-phenylenediamine.

[0081] Figure 10 The relative activity of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) in Example 1 of the present invention in catalyzing the chromogenic substrate o-phenylenediamine under different pH conditions is shown in FIG. Figure 10 As shown in the figure, under the conditions of pH 4-9, the relative activity of Cu@COF300-AR for the catalytic effect of o-phenylenediamine remains above 90%, indicating that it is suitable for use in acidic and alkaline environments and has good chemical stability.

[0082] In this embodiment, the method for constructing a linear equation of the absorbance intensity and glyphosate concentration in the glyphosate solution used includes the following steps: (1) Preparation of glyphosate and solution Weigh 0.169g of glyphosate into a 500mL beaker on a precision analytical balance. Dissolve it in distilled water and transfer it to a 1L volumetric flask. Rinse the beaker three times with distilled water, transfer the washings to the flask, and adjust the volume to obtain a 1000μmol / L glyphosate standard solution. Dilute the prepared 1000μmol / L glyphosate solution with distilled water in dilution steps of 10-100 to obtain 2-100μmol / L glyphosate solutions.

[0083] Follow the same steps to prepare 100 μmol / L dinotefuran, thiamethoxam, Mg 2+ , K + 、Na + , ascorbic acid, alanine, and histidine solutions.

[0084] (2) Detection of glyphosate standard solution Thirty centrifuge tubes with 2 mL graduations were prepared. 100 μL of Cu@COF300-AR (100 μg / mL) and 500 μL of glyphosate standard solutions of varying concentrations were added to each tube and incubated at 37°C for 15 minutes. 100 μL of o-phenylenediamine (2 mmol / L) and 100 μL of hydrogen peroxide (1 mmol / L) were then added to the mixed solution and incubated at 37°C for 15 minutes. The absorbance intensity of the Cu@COF300-AR nanozyme solution at different glyphosate concentrations was scanned using a UV spectrophotometer at wavelengths between 350 nm and 550 nm to obtain absorption spectra, enabling glyphosate detection.

[0085] The absorbance intensity of the mixed solution at a wavelength of 450 nm was used as the ordinate, and the concentration of the glyphosate solution was used as the abscissa. A scatter plot was drawn and fitted to obtain the glyphosate test working curve, which is the linear equation of the absorbance intensity in the glyphosate solution and the concentration of glyphosate, as shown in formula (1).

[0086] y=0.00191× x+0.04069(1); In formula (1), y is the absorbance intensity of glyphosate solution, x is the concentration of glyphosate in glyphosate solution, and the unit is μmol / L. In formula (1), the detection concentration is 2μmol / L to 100μmol / L, the detection limit is 0.193μmol / L, and the correlation coefficient is R 2 =0.9942.

[0087] Under the same conditions, the effects of 100 μmol / L dinotefuran, thiamethoxam, and Mg 2+ , K + 、Na + , ascorbic acid, alanine and histidine solution interferences and 100 μmol / L glyphosate were determined.

[0088] Figure 11 This is a graph showing the selectivity of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) on glyphosate in Example 1 of the present invention. Figure 11 As shown in the results, the inhibitory effect of the interfering substances on the Cu@COF300-AR nanozyme is not obvious, while the addition of glyphosate significantly inhibits the catalytic oxidation of o-phenylenediamine by the Cu@COF300-AR nanozyme, which indicates that the Cu@COF300-AR nanozyme of the present invention has good selectivity for glyphosate.

[0089] Figure 12This is the ultraviolet absorption spectrum of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) after mixing with glyphosate standard solutions of different concentrations in Example 1 of the present invention.

[0090] Figure 13 This is a working curve of the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) in Example 1 of the present invention at different concentrations of glyphosate at 450nm.

[0091] Combine Figures 12 and 13 It can be seen that the working curve of the Cu@COF300-AR nanozyme prepared in the present invention for detecting glyphosate has a good linear relationship, and its absorbance intensity decreases with the increase of glyphosate concentration.

[0092] Figure 14 This is the ultraviolet absorption spectrum of different metal single-atom coordinated amino covalent organic framework nanozymes (Cu@COF300-AR, Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) after mixing with glyphosate solution in Example 1 of the present invention.

[0093] Depend on Figure 14 It can be seen that compared with the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) of the present invention, the absorbance of other metal single atom coordinated amino covalent organic framework nanozymes (Ni@COF300-AR, Co@COF300-AR, Zn@COF300-AR) mixed with 100 μM glyphosate is lower, and it is difficult to form a linear relationship with different concentrations of glyphosate. Effective detection of glyphosate cannot be achieved.

[0094] As can be seen from Table 1, the copper single atom coordinated amino covalent organic framework nanozyme (Cu@COF300-AR) of the present invention can be well used to detect glyphosate in water or soil, and the detection accuracy is very high, indicating that the copper single atom coordinated amino covalent organic framework nanozyme of the present invention has the potential to be used as a new type of glyphosate detection agent.

[0095] Table 1 Glyphosate detection and recovery results in various samples

[0096] The above results demonstrate that the copper single-atom coordinated amino covalent organic framework nanozyme of the present invention can quickly and accurately determine the concentration of glyphosate in a glufosinate solution. It exhibits advantages such as simple process, convenient operation, low cost, a wide detection range, high sensitivity, and high detection accuracy. The detection range for glyphosate is 2 μmol / L to 100 μmol / L, with a detection limit of 0.193 μmol / L. This nanozyme is widely applicable for the detection of glyphosate in environmental environments (such as soil or water), demonstrating its high value and promising application prospects. Furthermore, when detecting glyphosate in wastewater or soil, no extensive sample pretreatment is required.

[0097] The above description is only a preferred embodiment of the present invention and does not constitute any formal limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme, characterized in that: Glyphosate is detected by using a copper single atom coordinated amino covalent organic framework nanozyme; the copper single atom coordinated amino covalent organic framework nanozyme comprises an amino covalent organic framework, and Cu is distributed in the cavity and on the surface of the amino covalent organic framework. 2+ ion.

2. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 1, characterized in that: The Cu 2+ The mass ratio of ions to the amino covalent organic framework is 0.13 to 0.83:1; the copper single atom coordinated amino covalent organic framework nanozyme is in the shape of a regularly arranged nanoflower; the particle size of the copper single atom coordinated amino covalent organic framework nanozyme is 2 μm to 5 μm.

3. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 2, characterized in that: The Cu 2+ The mass ratio of the ions to the amino covalent organic framework is 0.27-0.83:

1.

4. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 3, characterized in that: The amino covalent organic framework is prepared by reducing terephthalic acid and imine covalent organic framework as raw materials. The preparation method of the amino covalent organic framework comprises the following steps: (1.1) Mixing an imino covalent organic framework, terephthalic acid, and an organic solvent, and stirring to obtain a mixed solution A; the mass ratio of the terephthalic acid to the imino covalent organic framework is 1 to 2:1; the ratio of the terephthalic acid to the organic solvent is 57.6 mg: 25 mL to 50 mL; the stirring temperature is 0°C to 10°C, and the stirring time is 10 min to 30 min; (1.2) Add a reducing agent to the mixed solution A for reduction reaction, stir, wash, and dry to obtain an amino covalent organic framework; the ratio of the mixed solution A to the reducing agent is 5 mL to 2 mL: 0.05 g to 0.15 g; the reduction reaction is carried out at 0°C to 10°C; the reduction reaction time is 10 min to 30 min; and the stirring time is 8 h to 12 h.

5. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 4, characterized in that: The imino-based covalent organic framework is prepared by using 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzenetricarboxaldehyde as monomers through a Schiff base reaction. The preparation method of the imino-based covalent organic framework comprises the following steps: (2.1) Dissolve 1,3,5-tris(4-aminophenyl)benzene in an acetic acid solution to obtain solution A; dissolve 1,3,5-benzenetricarboxaldehyde in an acetic acid solution to obtain solution B; the mass ratio of 1,3,5-tris(4-aminophenyl)benzene to 1,3,5-benzenetricarboxaldehyde is 50-100:23-46; the ratio of 1,3,5-tris(4-aminophenyl)benzene to acetic acid solution in solution A is 50 mg:7.0 mL-12.4 mL; the ratio of 1,3,5-benzenetricarboxaldehyde to acetic acid solution in solution B is 23 mg:7.0 mL-12.4 mL; the concentration of the acetic acid solution is 3 mol / L; (2.2) Solution A and solution B obtained in step (2.1) are mixed to undergo a Schiff base reaction, washed, and dried to obtain an imine-based covalent organic framework; the Schiff base reaction time is 72 hours to 96 hours; and the drying time is 48 hours to 72 hours.

6. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 3, characterized in that: The copper single atom coordinated amino covalent organic framework nanozyme is prepared by stirring divalent copper salt, amino covalent organic framework, and water as raw materials; the preparation method of the copper single atom coordinated amino covalent organic framework nanozyme comprises the following steps: (3.1) Mix a divalent copper salt with water and sonicate to obtain solution C. Add the amino covalent organic framework to water to obtain solution D. (3.2) Solution D is sonicated, and solution C is added during the sonication process. The solution is stirred, centrifuged, washed, filtered, and dried to obtain a copper single-atom coordinated amino covalent organic framework nanozyme.

7. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 6, characterized in that: In step (3.1), the mass volume ratio of the divalent copper salt to water in the solution C is 25 mg to 75 mg: 15 mL to 30 mL; the divalent copper salt is copper nitrate trihydrate; the mass volume ratio of the amino covalent organic framework to water in the solution D is 90 mg: 15 mL to 30 mL; and the ultrasonication time is 15 min to 30 min. In step (3.2), the ultrasonication time is 15 min to 30 min, the stirring time is 12 h to 24 h, the drying temperature is 60° C. to 80° C., and the drying time is 12 h to 24 h.

8. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to any one of claims 1 to 7, characterized in that: A copper single-atom coordinated amino covalent organic framework nanozyme was used to detect glyphosate in water or soil. The detection of glyphosate in water using a copper single atom coordinated amino covalent organic framework nanozyme includes the following steps: (4.1) mixing the copper single atom coordinated amino covalent organic framework nanozyme and glyphosate wastewater to react and obtain solution E; (4.2) adding p-phenylenediamine solution and hydrogen peroxide solution to the solution E obtained in step (4.1) to react, and detecting the absorbance intensity of the mixed solution; (4.3) Based on the absorbance intensity of the mixed solution and the linear equation between the absorbance intensity and glyphosate concentration in the glyphosate solution, the concentration of glyphosate in the glyphosate wastewater is calculated, thereby enabling the detection of glyphosate in the wastewater. The detection of glyphosate in soil using a copper single atom coordinated amino covalent organic framework nanozyme includes the following steps: (5.1) Prepare soil extract from glyphosate-containing soil; (5.2) mixing the copper single atom coordinated amino covalent organic framework nanozyme and the soil extract to react and obtain a solution F; (5.3) Add p-phenylenediamine solution and hydrogen peroxide solution to the solution F obtained in step (5.2) to react, and measure the absorbance intensity of the mixed solution; (5.4) Based on the absorbance intensity of the mixed solution and the linear equation between the absorbance intensity and glyphosate concentration in the glyphosate solution, the concentration of glyphosate in the soil extract is calculated, thereby enabling the detection of glyphosate in the soil.

9. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 8, characterized in that: In step (4.1), the copper single-atom coordinated amino covalent organic framework nanozyme is mixed with glyphosate wastewater in the form of a copper single-atom coordinated amino covalent organic framework nanozyme solution, and the volume ratio of the copper single-atom coordinated amino covalent organic framework nanozyme solution to the glyphosate wastewater is 1:5; the copper single-atom coordinated amino covalent organic framework nanozyme solution is prepared by mixing the copper single-atom coordinated amino covalent organic framework nanozyme and a NaAc-HAc buffer solution; the concentration of the copper single-atom coordinated amino covalent organic framework nanozyme solution is ≤100 μg / mL, and the concentration of glyphosate in the glyphosate wastewater is 5 μmol / L~15 μmol / L; the reaction is carried out at a temperature of 30°C~40°C; and the reaction time is 10min~30min; In step (4.2), the volume ratio of the E solution to the p-phenylenediamine solution is 6:1; the concentration of the p-phenylenediamine solution is 1 mmol / L to 3 mmol / L; the volume ratio of the E solution to the hydrogen peroxide solution is 6:1; the concentration of the hydrogen peroxide solution is 0.1 mmol / L to 1 mmol / L; the reaction is carried out at a temperature of 30°C to 40°C; and the reaction time is 10 min to 30 min; In step (4.3), the linear equation of the absorbance intensity and glyphosate concentration in the glyphosate solution is shown in formula (1), as follows: y=0.00191×x+0.04069(1); In formula (1), y is the absorbance intensity of glyphosate solution, x is the concentration of glyphosate in glyphosate solution, the unit is μmol / L, and the correlation coefficient is R 2 =0.9942.

10. The method for detecting glyphosate using a copper single atom coordinated amino covalent organic framework nanozyme according to claim 8, characterized in that: In step (5.1), the soil extract is prepared by the following method: mixing glyphosate-containing soil with acetonitrile, shaking at a rotation speed of 200 rpm for 30 minutes, centrifuging at a rotation speed of 5000 rpm for 10 minutes, and collecting the supernatant to obtain a soil extract; In step (5.2), the copper single-atom coordinated amino covalent organic framework nanozyme is mixed with the soil extract in the form of a copper single-atom coordinated amino covalent organic framework nanozyme solution, and the volume ratio of the copper single-atom coordinated amino covalent organic framework nanozyme solution to the soil extract is 1:5; the copper single-atom coordinated amino covalent organic framework nanozyme solution is prepared by mixing the copper single-atom coordinated amino covalent organic framework nanozyme and a NaAc-HAc buffer solution; the concentration of the copper single-atom coordinated amino covalent organic framework nanozyme solution is ≤100 μg / mL, and the concentration of glyphosate in the soil extract is 5 μmol / L to 15 μmol / L; the reaction is carried out at a temperature of 30°C to 40°C; and the reaction time is 10 min to 30 min; In step (5.3), the volume ratio of the F solution to the p-phenylenediamine solution is 6:1; the concentration of the p-phenylenediamine solution is 2 mmol / L; the volume ratio of the F solution to the hydrogen peroxide solution is 6:1; the concentration of the hydrogen peroxide solution is 0.1 mmol / L to 1 mmol / L; the reaction is carried out at a temperature of 30°C to 40°C; and the reaction time is 10 min to 30 min; In step (5.4), the linear equation of the absorbance intensity and glyphosate concentration in the glyphosate solution is shown in formula (1).

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