Method for visually and rapidly detecting carbosulfan by medium-entropy nano-enzyme and application of carbosulfan

Abstract

The invention provides a method for visually and rapidly detecting carbosulfan pesticide by using medium-entropy nano-enzyme and application of the medium-entropy nano-enzyme, and belongs to the technical field of analytical chemistry. On the basis of a metal ligand cross-linking strategy, the medium-entropy nano-enzyme FeCeCu MEzymes is synthesized through self-assembly of the chelating ability of dopamine phenolic hydroxyl and multi-metal ions of Fe < 3 + >, Ce < 3 + > and Cu < 2 + >, and the medium-entropy nano-enzyme FeCeCu MEzymes sensor is designed to be combined with a smart phone to realize rapid visual detection of carbosulfan; the rapid and visual carbosulfan detection method provided by the invention has the advantages of rapidness, high sensitivity, good selectivity, visual detection result and the like, and is simple and easy to operate and relatively low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical chemistry, and specifically relates to a method and application of a medium-entropy nanoenzyme for rapid visualization detection of carbosulfan pesticide. Background Art

[0002] Carbosulfan belongs to the carbamate pesticide class and has the advantages of high efficacy, easy decomposition and short residual period. It is widely used in crop pest control. However, the misuse of pesticides can contaminate food and water sources, leading to biological contamination in the food chain. In addition, carbosulfan pesticide is an environmental hormone substance that can inhibit the activity of acetylcholinesterase in the central nervous system and may cause deformities, mutations and cancer. Therefore, accurate determination of carbosulfan pesticide is particularly important for monitoring its environmental behavior and residues in food.

[0003] At present, common detection methods for carbosulfan pesticides include GC-MS, GC, HPLC, electrochemical method, fluorescence method, etc., but these methods have the disadvantages of cumbersome operation, expensive equipment, and high cost. So far, a fast, convenient and low-cost detection method is still needed. Among the many detection methods, nanozyme colorimetry is based on the relationship between the depth of solution color and absorbance for detection and analysis. The nanozyme colorimetric strategy combined with smartphones has been widely used in the detection field. It is characterized by visualization, low cost, simple operation, and portable on-site detection, which expands its practical application. Summary of the invention

[0004] In view of the defects mentioned in the background technology, the present invention aims to provide a visual rapid detection method and application of carbosulfan by a medium entropy nanozyme. The oxidase-like activity of the medium entropy nanozyme FeCeCu Mezymes of the present invention can generate free radicals from dissolved oxygen, and then catalyze the colorless 3,3'5,5'-tetramethylbenzidine TMB to generate blue TMBox for color development reaction. When different concentrations of carbosulfan are added to the medium entropy nanozyme FeCeCu Mezymes sensing system, under pH conditions, carbosulfan is hydrolyzed to generate -SH groups, which can work with the metal in the medium entropy nanozyme FeCeCu Mezymes to inhibit the generation of TMBox, thereby realizing the visual rapid detection of carbosulfan. The medium entropy nanozyme FeCeCu Mezymes of the present invention is simple to synthesize, and its colorimetric sensing detection method for carbosulfan is fast and convenient, and the results are intuitive and clear.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions: The present invention provides a method for rapidly detecting carbosulfan, which specifically comprises the following steps: S1: Ethylene glycol and water are mixed evenly, and ammonia water, dopamine hydrochloride, ferric nitrate nonahydrate, copper nitrate, and cerium nitrate hexahydrate are added in sequence and stirred evenly; after the reaction is completed, the obtained sample is washed, centrifuged, dried, and calcined to obtain the medium entropy nanozyme FeCeCu Mezymes; S2: Add carbosulfan and medium-entropy nanozymes FeCeCu Mezymes to HAc-NaAc acetic acid-sodium acetate buffer, incubate for 30 minutes, then add TMB, and visualize the solution after incubation.

[0006] Furthermore, in step S1, the volume ratio of ethylene glycol, water and ammonia solution is 8:5:0.3, the molar ratio of dopamine hydrochloride to ferric nitrate nonahydrate, copper nitrate and cerium nitrate hexahydrate is 6:1:1:1, and the mixture is stirred at 60°C for 11 h.

[0007] Furthermore, in step S2, the concentration of HAc-NaAc acetic acid-sodium acetate buffer was 0.1 M, pH = 4, and incubated at 37°C.

[0008] Furthermore, the visual detection in step S2 is ultraviolet spectrophotometer detection or smartphone RGB grayscale value extraction detection.

[0009] Furthermore, the ultraviolet spectrophotometer detects the absorbance of the solution at 652 nm, and a standard curve and a linear equation are obtained according to the absorbance change of carbosulfan at different concentrations.

[0010] Furthermore, the RGB grayscale value extraction detection includes the following steps: taking pictures of different concentrations of carbosulfan added to the medium-entropy nanozyme FeCeCu Mezymes sensing system, extracting the grayscale value of RGB in each picture, the ordinate of the linear equation is (G+B) / 2×R, and the abscissa is the concentration of carbosulfan, and the linear equation is obtained through the RGB values ​​and different concentrations of carbosulfan.

[0011] On the other hand, the present invention also provides a method for applying the visual detection method of carbosulfan pesticide in the above example to the rapid visual detection of pesticides.

[0012] Furthermore, carbofuran, dichlorvos, ethyl paraoxon, isocarbophos, thiamethoxam and glyphosate were added during the detection process for selective testing.

[0013] Furthermore, Na was added during the detection process. + , K + 、Al 3+ Mg 2+ , Mn 2+ , Ca 2+ 、Zn 2+ , Cu 2+Conduct anti-interference test.

[0014] Furthermore, it is applied to the visual rapid detection of carbosulfan pesticide in actual soil and water samples.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The medium entropy nanozyme FeCeCu Mezymes synthesized by the present invention has excellent oxidase-like activity, and a colorimetric sensor is constructed using the enzyme activity of the nanozyme to detect carbosulfan pesticide. The method is applied to the detection of carbosulfan pesticide, and has the advantages of convenient and fast operation, high detection sensitivity, and low cost.

[0016] 2. The FeCeCu Mezymes synthesized by the present invention has a detection range of 0.15µM-50µM for carbosulfan pesticide, with a detection limit of 0.13µM, and is selective for carbofuran, dichlorvos, ethyl paraoxon, isothiocarb, thiamethoxam, and glyphosate, which are similar in structure to carbosulfan pesticide, and is selective for common ions Na in solution. + , K + 、Al 3+ Mg 2+ , Mn 2+ , Ca 2 + 、Zn 2+ , Cu 2+ It has good anti-interference properties. It can be used to detect carbosulfan in soil and water sources, and combined with color changes, it can realize on-site instant detection of carbosulfan.

[0017] 3. The preparation method of the present invention is simple and convenient, has high detection sensitivity, low cost, and good anti-interference performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a scanning electron microscope image of the medium-entropy nanozyme FeCeCu Mezymes prepared under the conditions of Example 1; Figure 2 It is the oxidase-like activity diagram of the UV-visible absorption spectrum of the entropic nanozyme FeCeCu Mezymes in the present invention in different TMB concentration systems; Figure 3 The UV-visible spectra of the TMB-FeCeCu MEzymes system to which carbosulfan pesticide of different concentrations is added in the present invention; Figure 4 This is a linear relationship diagram of the concentration of carbosulfan detected by the medium entropy nanozyme FeCeCu Mezymes in the present invention; Figure 5Colorimetric photos and standard curves of different carbosulfan concentrations using a smartphone color analysis application for the present invention. Specific implementation methods To make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. If the specific conditions are not specified in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0020] Example 1: Preparation of medium entropy nanozymes FeCeCu Mezymes 1. In a clean three-necked flask, add 80 mL of ethylene glycol and 50 mL of water in turn and mix evenly, then add 3 mL of ammonia solution (mass fraction 28%), heat and stir to 60 ° C and stabilize for 10 min to obtain an ethylene glycol ammonia reaction system.

[0021] 2. First add 10 mL of 50 mg / mL dopamine hydrochloride solution to the ethylene glycol ammonia reaction system, and then slowly drop 10 mL of 17.7 mg / mL ferric nitrate nonahydrate solution, 10.6 mg / ml copper nitrate, and 19.0 mg / mL cerium nitrate hexahydrate in sequence. The reaction molar ratio of dopamine hydrochloride to ferric nitrate, copper nitrate, and cerium nitrate is 6:1:1:1. React for 11 hours to obtain the crude medium-entropy nanozyme FeCeCu Mezymes.

[0022] 3. The crude product of the medium-entropy nanozyme FeCeCu Mezymes was collected by centrifugation, washed three times with a mixed solution of ethanol and water in a volume ratio of 1:1, freeze-dried, and the obtained powder was calcined at 900°C for 7 h in a tubular furnace to obtain the medium-entropy nanozyme FeCeCu Mezymes sample.

[0023] Figure 1 This is a scanning electron microscope image (SEM) of the medium-entropy nanozyme FeCeCu Mezymes prepared under the conditions of Example 1; it can be seen from the figure that the medium-entropy nanozyme FeCeCu Mezymes particles have a single morphology and self-assemble into a flower ball shape.

[0024] Example 2: Study on the oxidase-like activity of the medium-entropy nanozyme FeCeCu Mezymes Prepare 50 mL of HAc-NaAc acetic acid-sodium acetate buffer with an ion concentration of 0.1 M and pH = 4, and 4 mL of 1 mM TMB; then extract 1900 μL and 100 μL from each and put them into cuvette No. 1. Draw 1900 μL of HAc-NaAc acetic acid-sodium acetate buffer and 100 μL of 1 mg / mL medium entropy nanozyme FeCeCu Mezymes into cuvette No. 2. Cuvette No. 3 is based on cuvette No. 1 and adds 100 μL of 1 mg / mL medium entropy nanozyme FeCeCu Mezymes. After incubation for 10 min, measure the absorption spectra of the three cuvettes at a wavelength of 300nm-800nm.

[0025] Figure 2 This is the oxidase-like activity diagram of the medium-entropy nanozyme FeCeCu Mezymes under the conditions of this example. It can be seen that the medium-entropy nanozyme FeCeCu Mezymes has high oxidase-like activity, which oxidizes the color developer TMB into blue TMBox.

[0026] Example 3: Detection of standard carbosulfan solution The TMB-FeCeCu MEzymes system and different concentrations of carbosulfan were added to HAc-NaAc acetic acid-sodium acetate buffer and incubated at 37°C for 30 minutes. TMB was added and then incubated for another 10 minutes. Finally, the relationship between the absorbance at 652 nm and different carbosulfan concentrations was studied.

[0027] Figure 3 This is the UV-visible spectrum of the TMB-FeCeCu MEzymes system with carbosulfan added. It can be seen from the figure that with the increase of carbosulfan concentration, the absorbance at a wavelength of 652 nm gradually decreases, showing a decrease in the degree of blue. Figure 4 This is the linear relationship diagram of the concentration of carbosulfan detected by the medium entropy nanozyme FeCeCu Mezymes, and the linear relationship formula is: y=-0.00972x+0.709(R 2 =0.997), where x is the concentration of carbosulfan, y is the absorbance of the solution, the detection range is 0.15-50µM, and the minimum detection limit is 0.13µM.

[0028] Example 4: Detection of Carbosulfan in Soil and Water Through the standard spike test, the standard solution of carbosulfan (6µM, 30µM, 50µM) was added to the extracts from soil and water sources, and then the test solution and the medium entropy nanozyme FeCeCu Mezymes were added to the HAc-NaAc acetic acid-sodium acetate buffer, incubated at 37°C for 30 minutes, and then incubated for another 10 minutes after adding TMB, and then the absorbance at 652 nm was measured using a UV spectrophotometer. The experimental results are shown in Table 1.

[0029] Table 1

[0030] From the analysis of the test results in Table 1, it can be seen that the detection results of the solution content after spiked soil and water source by this method are similar to those of standard large-scale instruments, indicating that the visual rapid detection of carbosulfan by the entropic nanozyme FeCeCu Mezymes of the present invention is feasible.

[0031] Example 5: Real-time detection of carbosulfan using R, G and B grayscale (RGB) color analysis program The medium-entropy nanozymes FeCeCu Mezymes and carbosulfan were added to HAc-NaAc acetic acid-sodium acetate buffer and incubated at 37°C for 30 minutes. After adding TMB, they were incubated for another 10 minutes. Photos were taken with a smartphone, and the grayscale averages of the R, G, and B components were extracted from the photos using a color analysis program.

[0032] Figure 5 The RGB colorimetric photos and standard curves of different concentrations of carbosulfan by smartphones. The linear relationship is as follows: y=-0.0385x+2.941(R 2 =0.992), and the LOD was calculated to be 0.14 µM.

[0033] The embodiments described above only express several preferred embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but are not intended to limit the present invention. It should be noted that for those skilled in the art, the present invention may also have various changes and modifications, and any modifications, equivalent substitutions, improvements, etc. made within the concept and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A visual detection method for carbosulfan pesticide, characterized in that: The following steps are involved: S1: Ethylene glycol and water are mixed evenly, and ammonia water, dopamine hydrochloride, ferric nitrate nonahydrate, copper nitrate, and cerium nitrate hexahydrate are added in sequence and stirred evenly; after the reaction is completed, the obtained sample is washed, centrifuged, dried, and calcined to obtain the medium entropy nanozyme FeCeCuMEzymes; S2: Add carbosulfan and FeCeCu Mezymes to HAc-NaAc acetic acid-sodium acetate buffer, incubate for 30 minutes, then add TMB, and visualize the solution after incubation for 10 minutes.

2. The method according to claim 1, characterized in that In step S1, the volume ratio of ethylene glycol, water and ammonia solution is 8:5:0.3, the molar ratio of dopamine hydrochloride to ferric nitrate nonahydrate, copper nitrate and cerium nitrate hexahydrate is 6:1:1:1, and the mixture is stirred at 60°C for 11 h.

3. The method according to claim 1, characterized in that In step S2, the concentration of HAc-NaAc acetic acid-sodium acetate buffer was 0.1 M, pH = 4, and incubated at 37°C.

4. The method according to claim 1, characterized in that The visual detection in S2 is UV spectrophotometer detection or smartphone RGB grayscale value extraction detection.

5. The method according to claim 4, characterized in that The ultraviolet spectrophotometer detection is to record the absorbance of the solution at 652 nm, and obtain a standard curve and a linear equation according to the absorbance changes of carbosulfan at different concentrations.

6. The method according to claim 4, characterized in that The smartphone RGB grayscale value extraction detection comprises the following steps: taking pictures of different concentrations of carbosulfan added to the medium-entropy nanozyme FeCeCu Mezymes sensing system, extracting the RGB grayscale value in each picture, the ordinate of the linear equation is (G+B) / 2×R, the abscissa is the concentration of carbosulfan, and the linear equation is obtained through the RGB values ​​and different concentrations of carbosulfan.

7. A method for using the method according to any one of claims 1 to 6 for rapid visual detection of carbosulfan.

8. The use according to claim 7, characterized in that: During the detection process, carbofuran, dichlorvos, ethyl paraoxon, isocarbophos, thiamethoxam and glyphosate were added for selective testing.

9. The use according to claim 7, characterized in that: Na was added during the detection process + , K + 、Al 3+ Mg 2+ , Mn 2+ , Ca 2 + 、Zn 2+ , Cu 2+ Perform an interference immunity test.

10. The use according to claim 7, characterized in that: Visual rapid detection of carbosulfan in actual soil and water samples.

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