Application of bimetal Pt / Co nano-enzyme in instant and portable detection of malathion

Abstract

The invention belongs to the field of environment detection, and particularly relates to application of bimetal Pt / Co nano-enzyme to instant portable detection of malathion. The bimetallic Pt / Co nano-enzyme for malathion detection is ZIF-67NF loaded with Pt nanoparticles and has peroxidase activity, nucleotide can enhance the peroxidase activity of the bimetallic Pt / Co nano-enzyme under an alkaline condition, a colorimetric reaction is started by combining the inhibition effect of malathion on alkaline phosphatase and the decomposition effect of the alkaline phosphatase on the nucleotide, and the sensitivity of malathion detection is improved. The method is used for detecting malathion, has the advantages of low detection cost, instantaneity, accuracy and the like, and provides a new method for detecting malathion.

Description

Technical Field

[0001] This invention belongs to the field of environmental monitoring, specifically relating to the application and method of a bimetallic Pt / Co nanozyme for the instantaneous and portable detection of malathion. Background Technology

[0002] Visual sensing is a method of determining the concentration of an analyte by reading the color change signal accompanying a physical or chemical change with the naked eye. It can also use ultraviolet-visible spectroscopy or fluorescence spectroscopy to read the signal change, obtaining accurate results without the need for other complex instruments. Visual sensing has significant advantages such as simple operation, low cost, and good practicality, and has attracted increasing attention in fields such as in vitro detection, environmental monitoring, and food detection, prompting extensive research by researchers. Traditional visualization sensing methods based on organic dye molecules have drawbacks such as limited color change and low sensitivity, which greatly restricts the further application of visualization sensing. Therefore, developing more accurate and faster visualization sensing methods has become a hot topic in current visualization sensing research.

[0003] Malathion, an organophosphorus pesticide, is widely used in agriculture and public health, but its various hazards and limitations have become key bottlenecks restricting its safe use. In terms of environmental ecology, it is highly toxic to aquatic organisms and pollinating insects such as bees, disrupting the ecological balance. In public health and agriculture, improper use can lead to occupational exposure risks, excessive residues in agricultural products, and has already caused significant resistance in various pests, creating a vicious cycle of "decreasing effectiveness - increased dosage." In light of this, global regulations are becoming increasingly stringent, with its registration on some crops being revoked or restricted, and maximum residue limits being continuously tightened. Therefore, simple and rapid detection of malathion in aquatic ecosystems is receiving increasing attention.

[0004] For example, CN120665257A discloses a nanosilver-modified covalent organic framework composite material, its preparation method and application, and an electrochemical aptamer sensor, using an electrochemical aptamer sensor based on the nanosilver-modified covalent organic framework composite material for the detection of malathion. CN120891054A discloses an electrochemical sensing platform for detecting lead ions and malathion, its preparation method and detection method, using a triple-stranded DNA complex and gold nanoparticle electrodes for electrochemical detection of malathion. CN118663294A discloses the application of FeCo-NC bimetallic single-atom nanozyme in the detection of malathion, achieving colorimetric detection of malathion based on FeCo-NC bimetallic single-atom nanozyme, AA2P, ACP, and a chromogenic substrate. Summary of the Invention

[0005] This invention provides a rapid, low-cost, and highly specific detection method for malathion using a bimetallic Pt / Co nanozyme.

[0006] The technical solution of this invention is as follows: a bimetallic Pt / Co nanozyme is used for the instantaneous and portable detection of malathion. When used for malathion detection, alkaline phosphatase and nucleotides, a chromogenic agent and H2O2, and a buffer solution are also used; or a bimetallic Pt / Co nanozyme is used to prepare a product for instantaneous and portable detection of malathion, the product further containing alkaline phosphatase and nucleotides; further still, it also contains a chromogenic agent and H2O2; even further, it also contains a buffer solution; the product includes, but is not limited to, reagents, test strips, components, devices, or equipment. The nucleotides are selected from any one or any combination of ATP, ADP, CTP, and GTP, preferably ATP or CTP, and more preferably ATP. The chromogenic agent is selected from any one or any combination of TMB, ADOS, ADPS, HDAOS, ABTS, DAB, and OPD, preferably TMB. The pH of the buffer solution is 4-8, preferably 8, and the buffer solution is selected from any one of phosphate buffer, Tris-HCl buffer, HEPES buffer, borate buffer, citrate buffer, barbiturate buffer, carbonate buffer, acetate buffer, and succinate buffer, preferably phosphate buffer or Tris-HCl buffer.

[0007] The bimetallic Pt / Co nanozyme of the present invention is ZIF-67NF loaded with Pt nanoparticles. ZIF-67NF is shaped like a nanoflower and has a particle size of 600±20nm, preferably 600nm. Pt nanoparticles are attached to the "petals" of the ZIF-67NF nanoflower and have a particle size of 2-4nm. That is, the bimetallic Pt / Co nanozyme (ZIF-67NF@Pt) presents the shape of a nanoflower as a whole, and Pt nanoparticles with a particle size of 600±20nm, preferably 600nm, are attached to the "petals" of the nanoflower. The bimetallic Pt / Co nanozyme of this invention is prepared by the following steps: ZIF-67NF and Pt nanoparticles are stirred and mixed in a solution to allow for complete reaction, thereby obtaining ZIF-67NF@Pt. Specifically, mechanical stirring is used at a speed of 750 rpm for 6-7 hours. After complete reaction, the precipitate is collected by centrifugation, washed three times each with ethanol and water, and dried at 60-65℃ to obtain the bimetallic Pt / Co nanozyme (ZIF-67NF@Pt).

[0008] The preparation of ZIF-67NF includes: dispersing cobalt nitrate hexahydrate and 2-methylimidazole in methanol, mixing thoroughly, and aging at room temperature to obtain the product.

[0009] The molar ratio of cobalt nitrate hexahydrate to 2-methylimidazole is 0.9-2:1, preferably 1-1.5:1, and more preferably 1:1; the concentration of 2-methylimidazole is 0.02-0.06 mol / L, preferably 0.04-0.05 mol / L, and more preferably 0.049-0.05 mol / L.

[0010] The room temperature aging process lasts for 10-15 hours.

[0011] After the room temperature aging process is completed, the precipitate is collected by centrifugation, washed with methanol, and dried at 60~65℃ to obtain ZIF-67NF.

[0012] The preparation of the Pt nanoparticles includes: adding sodium borohydride to water containing a mixture of polyvinylpyrrolidone and chloroplatinic acid, and allowing it to react fully to obtain Pt NPs.

[0013] In the reaction system, the molar ratio of chloroplatinic acid, polyvinylpyrrolidone, and sodium borohydride is 1:1-1.5:4-6, preferably 1:1-1.5:4.5-5, and more preferably 1:1.2-1.3:4.6-4.7; the concentration of chloroplatinic acid is 0.8-2 mmol / L, preferably 1-1.5 mmol / L, and more preferably 1.2-1.3 mmol / L.

[0014] The bimetallic Pt / Co nanozyme of the present invention is simple to synthesize, easy to operate, and has high catalytic activity sites.

[0015] This invention provides a portable, on-the-fly product for detecting malathion, containing the bimetallic Pt / Co nanozyme described above. Further, it also contains alkaline phosphatase and nucleotides. Even further, it contains TMB and H2O2. Even further, it contains a buffer solution. The product includes, but is not limited to, reagents, test strips, components, devices, or equipment. The nucleotides are selected from any one or any combination of ATP, ADP, CTP, and GTP, preferably ATP or CTP, and more preferably ATP. The chromogenic agent is selected from any one or any combination of TMB, ADOS, ADPS, HDAOS, ABTS, DAB, and OPD, preferably TMB. The buffer solution has a pH of 4-8, preferably pH 8, and is selected from any one of phosphate buffer, Tris-HCl buffer, HEPES buffer, borate buffer, citrate buffer, barbiturate buffer, carbonate buffer, acetate buffer, and succinate buffer, preferably phosphate buffer or Tris-HCl buffer.

[0016] The present invention also provides a method for instant and portable detection of malathion, comprising the following steps: mixing the sample to be tested with alkaline phosphatase (ALP), incubating at 37°C for 30 minutes, then adding nucleotides and incubating at 37°C for 60 minutes, then adding the bimetallic Pt / Co nanozyme of the present invention and incubating at room temperature (37°C) for 30 minutes, then adding buffer, chromogenic agent and H2O2, reacting for 10 minutes, and collecting the absorbance at 652 nm for qualitative and / or quantitative detection of malathion in the sample to be tested; Alternatively, the supernatant after the reaction is complete can be dropped onto the colorimetric test strip platform, and an image of the colorimetric test strip platform can be acquired. Based on the color signal intensity of the image, qualitative and / or quantitative detection of malathion in the sample can be performed.

[0017] The pH of the buffer solution is 4-8, preferably 8, and the buffer solution is selected from any one of phosphate buffer, Tris-HCl buffer, HEPES buffer, borate buffer, citrate buffer, barbiturate buffer, carbonate buffer, acetate buffer, and succinate buffer, preferably phosphate buffer or Tris-HCl buffer.

[0018] The concentration of the bimetallic Pt / Co nanozyme described above in this invention is 10 μg / mL.

[0019] The concentration of the nucleotide is 10 mM, and the nucleotide is selected from any one or any combination of ATP, ADP, CTP, and GTP, preferably ATP or CTP, and more preferably ATP.

[0020] The colorimetric agent is selected from any one or any combination of TMB, ADOS, ADPS, HDAOS, ABTS, DAB, and OPD, with TMB being preferred.

[0021] This invention provides a novel method for the detection of malathion. This method uses ZIF-67NF loaded with Pt nanoparticles as a bimetallic Pt / Co nanozyme. The binding of the bimetallic Pt / Co nanozyme to the MOF matrix via nucleotides (especially ATP) triggers the decomposition of the Pt nanoparticles, releasing them and enhancing their peroxidase activity over a wide pH range (pH 4-8, especially in alkaline environments), thus initiating the colorimetric reaction. Alkaline phosphatase decomposes nucleotides (especially ATP), closing the activated colorimetric channel. Malathion, however, inhibits alkaline phosphatase activity. When malathion is present, the colorimetric signal is reactivated, allowing for the immediate and portable detection of malathion. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the colorimetric detection principle based on nanozymes of the present invention.

[0023] Figure 2 The images show the SEM, TEM, and EDS mapping characterization of ZIF-67NF of the present invention, revealing the microstructure of the prepared ZIF-67NF.

[0024] Figure 3 The images show the SEM, TEM, and EDS mapping characterization of the ZIF-67NF@Pt nanozyme of this invention, revealing its microstructure.

[0025] Figure 4 The image shows the ATP response of ZIF-67NF@Pt and the UV-Vis absorption spectrum of ZIF-67NF@Pt catalyzing the oxidation of TMBox in the presence and absence of ATP.

[0026] Figure 5 Effects of ATP-modified ZIF-67NF@Pt on the activity of ZIF-67NF@Pt peroxidases at different pH values.

[0027] Figure 6 The absorbance relationship between ATP concentration and the peroxidase-like activity of ZIF-67NF@Pt is shown. Figure 7 The effect of ATP analogs on the activity of ZIF-67NF@Pt peroxidases.

[0028] Figure 8 In diagram A, the UV-Vis absorption spectra correspond to different concentrations of ALP. In diagram B, the relationship between relative UV absorbance and ALP concentration is shown. Figure 7 The illustration in section B is a linear relationship diagram.

[0029] Figure 9 A: UV-Vis absorption spectra of ZIF-67NF@Pt + TMB + H2O2, ZIF-67NF@Pt + TMB + H2O2 + ATP, ZIF-67NF@Pt + TMB + H2O2 + ATP + ALP, ZIF-67NF@Pt + TMB + H2O2 + ATP + ALP + Mal (malathion); B: UV-Vis absorption spectra of malathion at different concentrations; C: UV-Vis absorption spectrum changes of malathion at 652 nm at different concentrations; D: R / B relationship of malathion at different concentrations.

[0030] Figure 10 A specificity analysis diagram of the colorimetric sensing strategy. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0032] The present invention will be further described below with reference to the embodiments: Figure 1 This is a schematic diagram of the principle of a bimetallic Pt / Co nanozyme for instantaneous and portable detection of malathion according to the present invention.

[0033] Malathion, an organophosphorus pesticide, can inhibit the activity of ALP, thereby preventing alkaline phosphatase (ALP) from breaking down ATP. When the target substance (malathion) is present, adenosine triphosphate (ATP) triggers the decomposition of the MOF matrix to release Pt nanoparticles, which utilize their enhanced peroxidase activity to generate a colorimetric activation reaction. When malathion is absent, alkaline phosphatase (ALP) breaks down ATP, and the colorimetric signal weakens.

[0034] Example 1: Synthesis of nanozyme ZIF-67NF@Pt Co(NO3)2·6H2O (1.455 g) was dissolved in 50 mL of methanol to form a pink solution, named Sample A. 2-MI (0.4105 g) was dissolved in 50 mL of methanol to form a clear solution, named Sample B. The liquid from Sample B was added to Sample A. After thorough mixing, the mixture was aged at room temperature for 12 hours. The resulting brown precipitate was collected by centrifugation (10000 rpm, 5 min), washed three times with methanol, and dried at 60 °C. The obtained product was named ZIF-67 NF, and the microstructure of ZIF-67 NF is as follows. Figure 2 As shown.

[0035] Synthesis of Platinum Nanoparticles (Pt NPs): Pt NPs were synthesized using a direct reduction method. 51.4 mg of polyvinylpyrrolidone (PVP) was added to a flask, followed by 45 mL of deionized water, and then 5 mL of 20 mM chloroplatinic acid (H₂PtCl₆). Under vigorous stirring, 30 mL of 15.5 mM NaBH₄ was added. After stirring for 3 h, Pt NPs were obtained and stored at 4 °C.

[0036] ZIF-67NF@Pt Synthesis: 20 mL of Pt NPs were added dropwise to 30 mL of 1 mg / mL ZIF-67 NF solution, and stirred at room temperature for 6 h. The mixture was centrifuged and washed three times each with deionized water and anhydrous ethanol, and dried at 60 °C for later use.

[0037] The structure of ZIF-67NF@Pt prepared in Example 1 is shown below. Figure 3 . Figure 3 The microstructure of the prepared nanozyme ZIF-67NF@Pt is shown in the SEM image. Figure 3 As shown, the bimetallic Pt / Co nanozyme exhibits the shape of a nanoflower, with Pt nanoparticles attached to the "petals" of the nanoflower.

[0038] Example 2: ATP-regulated peroxidase activity Add 10 mM ATP and ZIF-67NF@Pt (10 μg / mL) to a centrifuge tube and incubate at 25 °C for 30 minutes. Then add 10 mM Tris-HCl buffer (pH 8.0), 0.2 mM TMB, and 1 mM H2O2, and react at room temperature for 10 minutes. Finally, measure the absorption spectrum of the supernatant using a UV-Vis spectrophotometer in wavelength mode. Figure 4 As shown, the addition of ATP effectively enhances the catalytic efficiency of nanozymes.

[0039] Example 3: Effect of ATP-modified ZIF-67NF@Pt on the activity of ZIF-67NF@Pt peroxidases at different pH levels. Add 10 mM ATP and ZIF-67NF@Pt (10 μg / mL) to a centrifuge tube and incubate at 25 °C for 30 minutes. Then add 10 mM buffer solutions of different pH values, 0.2 mM TMB, and 1 mM H2O2, and react at room temperature for 10 minutes. Finally, measure the absorbance of the supernatant at 652 nm using a UV-Vis spectrophotometer in wavelength mode. Figure 5 As shown, although the catalytic performance is better under acidic conditions, the absorbance is strongest in the presence of ATP under alkaline conditions. Since the reaction of ALP decomposing ATP depends on alkaline conditions, pH 8 is selected as the optimal reaction condition.

[0040] ZIF-67NF@Pt (10 μg / mL), 0.2 mM TMB, and 1 mM H2O2 were added to 10 mM buffer solutions of different pH values. The solutions were then reacted at room temperature for 10 minutes. Finally, the absorbance of the supernatant at 652 nm was measured using a UV-Vis spectrophotometer in wavelength mode. Figure 5 As shown, the catalytic performance is optimal under acidic conditions at pH 4.

[0041] Therefore, during the property investigation of ZIF-67NF@Pt, it was found that its enzyme activity was almost non-existent in neutral and alkaline environments. The phosphate groups of adenosine compounds can coordinate and bind firmly to the active metal sites on the nanozyme surface, thereby effectively enhancing the catalytic efficiency of the nanozyme. Therefore, by modifying the ZIF-67NF@Pt interface with ATP, a breakthrough in enzyme activity can be achieved in alkaline environments, expanding the application of this material in alkaline conditions.

[0042] Example 4: Absorbance relationship between different ATP concentrations and the peroxidase-like activity of ZIF-67NF@Pt Add different concentrations of ATP and ZIF-67NF@Pt (10 μg / mL) to centrifuge tubes and incubate at 25 °C for 30 minutes. Then add 10 mM Tris-HCl buffer (pH 8.0), 0.2 mM TMB, and 1 mM H2O2, and react at room temperature for 10 minutes. Finally, measure the absorbance of the supernatant at 652 nm using a UV-Vis spectrophotometer in wavelength mode. Figure 6 As shown, the activity of peroxidase-like enzymes increases with increasing ATP concentration, and tends to saturate after reaching 10 mM.

[0043] Example 5: Effect of ATP analogs on the activity of ZIF-67NF@Pt peroxidases Different ATP analogs (10 mM) and ZIF-67NF@Pt (10 μg / mL) were added to centrifuge tubes and incubated at 25 °C for 30 minutes. Then, 10 mM Tris-HCl buffer (pH 8.0), 0.2 mM TMB, and 1 mM H2O2 were added, and the mixture was reacted at room temperature for 10 minutes. Finally, the absorbance of the supernatant at 652 nm was measured using a UV-Vis spectrophotometer in wavelength mode. Figure 7 The material exhibits optimal peroxidase-like activity in response to ATP.

[0044] Example 6: A linear relationship exists between ALP concentration and absorbance ratio. 3 μL of the 1 mg / mL ZIF-67NF@Pt solution prepared in Example 1 was added to 10 μL of 300 mM ATP solution, and the reaction was carried out at room temperature for 0.5 hours to obtain ZIF-67NF@Pt-ATP.

[0045] The ZIF-67NF@Pt-ATP prepared above was added to Tris HCl (10 mM, pH 8.0), followed by 6 μL of 10 mM TMB and 30 μL of 10 mM hydrogen peroxide solution. The mixture was reacted at 37 °C for 10 min, and the absorbance value A0 of the mixed solution at 652 nm was measured. First, 10 μL of alkaline phosphatase (ALP) with different activities was mixed with nucleotides (ATP) and incubated at 37°C for 60 minutes. Then, ZIF-67NF@Pt was added and incubated at room temperature (37°C) for 30 minutes. Tris HCl (10 mM, pH 8.0) was then added, followed by 6 μL of 10 mM TMB and 30 μL of 10 mM hydrogen peroxide solution. The mixture was reacted at 37°C for 10 minutes, and the absorbance value A of the mixed solution at 652 nm was measured.

[0046] As ATP is gradually hydrolyzed, the peroxidase-like activity of nanozymes gradually decreases. Absorbance (A0-A) showed a linear correlation with ALP concentration, and the alkaline phosphatase concentration range that could be measured was 1–100 mU / mL, with a limit of detection of 0.56 mU / mL. See the results below. Figure 8 .

[0047] Example 7: Real-time and portable detection of malathion using bimetallic Pt / Co nanozymes Malathion (100 μM) and alkaline phosphatase (ALP) were mixed and incubated at 37°C for 30 minutes. Then, adenosine triphosphate (ATP) was added to the reaction system, and the mixture was incubated at 37°C for 60 minutes. Next, ZIF-67NF@Pt was added to the above solution and incubated at room temperature for 30 minutes. Finally, Tris HCl (10 mM, pH 8.0), 6 μL of 10 mM TMB, and 30 μL of 10 mM H₂O₂ were added to the above reaction solution. After reacting for 10 minutes, the absorbance of the supernatant at 652 nm was measured using a UV-Vis spectrophotometer. Figure 9 As shown in Figure A, after the addition of malathion, UV-Vis spectrophotometry showed an increase in peroxidase-like activity.

[0048] Mix different concentrations of malathion and alkaline phosphatase (50 mU / mL), incubate at 37°C for 30 minutes, and then proceed with the same steps as above. Figure 9 As shown in Figure B, the UV-Vis spectrophotometer indicates that the activity of peroxidase-like enzymes gradually increases with the increase of malathion concentration.

[0049] Meanwhile, the intensity of the UV-Vis spectrophotometer showed a linear correlation with the concentration of malathion, allowing for the determination of malathion concentrations ranging from 0.1 to 100 μM, with a detection limit of 2.73 μM. (See attached results). Figure 9 C.

[0050] Simultaneously, the solution after the reaction was completed was centrifuged (10000 rpm, 1 min), and then 80 μL of the supernatant was dropped onto the prepared colorimetric platform paper. After waiting for 10 min at room temperature, an image of the colorimetric platform was captured using a smartphone camera, and quantitative detection of different concentrations of target analytes was achieved based on the color signal intensity. Figure 9 As shown in D, R / B is linearly correlated with malathion concentration, and the concentration range of malathion can be measured from 0.1 to 100 μM, with a detection limit of 1.13 μM.

[0051] Example 8: Specificity of Bimetallic Pt / Co Nanozymes for Instantaneous Portable Detection of Malathion Malathion and different interfering agents were mixed with alkaline phosphatase (50 mU / mL) and incubated at 37°C for 30 minutes. Then, adenosine triphosphate (ATP, 10 mM) was added to the reaction system, and the mixture was incubated at 37°C for 60 minutes. Next, ZIF-67NF@Pt was added to the above solution and incubated at room temperature for 30 minutes. Finally, Tris HCl (10 mM, pH 8.0), 6 μL of 10 mM TMB, and 30 μL of 10 mM H₂O₂ were added to the above reaction solution. After reacting for 10 minutes, the absorbance of the supernatant at 652 nm was measured using a UV-Vis spectrophotometer. Figure 10 As shown in Figure A, the UV-Vis spectrophotometer indicates that the peroxidase-like activity of the malathion-containing enzyme is the highest, demonstrating good specificity.

[0052] After mixing malathion and various interfering agents, mix with alkaline phosphatase (50 mU / mL), and then proceed as before. Figure 10 As shown in Figure B, the UV-Vis spectrophotometer indicates that the peroxidase-like activities are similar, thus demonstrating good specificity under mixed conditions.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will recognize that the present invention can be appropriately modified and varied. Therefore, this application is not limited to the specific embodiments disclosed and described above, and any modifications, equivalent substitutions, improvements, etc., made to this application should be included within the protection scope of the present invention.

Claims

1. A bimetallic Pt / Co nanosensor for instant portable detection of malathion or for preparing a product for instant portable detection of malathion.

2. Use according to claim 1, characterized in that, The product further comprises alkaline phosphatase and nucleotides.

3. Use according to claim 2, characterized in that, The product further comprises a chromogenic agent and H2O2.

4. Use according to claim 1, characterized in that, The bimetallic Pt / Co nanosensor is ZIF-67 NF loaded with Pt nanoparticles, the ZIF-67 NF is in the shape of nanoflower, the particle size of the ZIF-67 NF is 600±20 nm, and the Pt nanoparticles are attached to the petals of the ZIF-67 NF nanoflower, and the particle size of the Pt nanoparticles is 2-4 nm.

5. A product for the instant portable detection of malathion, characterized in that it comprises: The bimetallic Pt / Co nanosensor is ZIF-67 NF loaded with Pt nanoparticles, the ZIF-67 NF is in the shape of nanoflower, the particle size of the ZIF-67 NF is 600±20 nm, and the Pt nanoparticles are attached to the petals of the ZIF-67 NF nanoflower, and the particle size of the Pt nanoparticles is 2-4 nm.

6. A product for the instant portable detection of malathion according to claim 5, characterized in that, The product further comprises alkaline phosphatase and nucleotides.

7. A product for the instant portable detection of malathion according to claim 5, characterized in that, The product further comprises a chromogenic agent and H2O2.

8. A method for the instant portable detection of malathion, characterized in that, The steps include: The sample to be tested and alkaline phosphatase are mixed, incubated at 37°C for 30 minutes, then nucleotides are added and incubated at 37°C for 60 minutes, then the bimetallic Pt / Co nanosensor is added, incubated at room temperature for 30 minutes, then buffer, chromogenic agent and H2O2 are added, reacted for 10 minutes, and the absorbance at 652 nm is collected for qualitative and / or quantitative detection of malathion in the sample to be tested; Or the supernatant after the reaction is added dropwise on a chromogenic test paper platform, an image of the chromogenic test paper platform is collected, and the color signal intensity of the image is used for qualitative and / or quantitative detection of malathion in the sample to be tested.

9. The method of claim 8, wherein, The pH of the buffer is 4-8, and the buffer is selected from any one of phosphate buffer, Tris-HCl buffer, HEPES buffer, borate buffer, citrate buffer, barbituric acid buffer, carbonate buffer, acetate buffer, and succinate buffer.

10. The method of claim 8, wherein, The nucleotides are selected from any one or any combination of ATP, ADP, CTP, and GTP. The chromogenic agent is selected from any one or any combination of TMB, ADOS, ADPS, HDAOS, ABTS, DAB, and OPD.

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