Method for detecting pyrethroid pesticide residues in agricultural products
By doping CsPbBr3 quantum dots with Ta and performing bilayer modification, combined with sulfobutyl ether-β-cyclodextrin bridging, the prepared working electrode solves the problem of insufficient stability of CsPbBr3 quantum dots, and realizes the detection of cypermethrin with high sensitivity and high accuracy.
Patent Information
- Application Number
- CN202511649410.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-12
- Publication Date
- 2026-03-06
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The environmental sensitivity of CsPbBr3 quantum dots leads to poor stability, which affects their sensitivity and accuracy as a cypermethrin detector in the working electrode.
By doping CsPbBr3 quantum dots with Ta and modifying them with a bilayer of zinc sulfide and silicon dioxide, a Ta-CsPbBr3@ZnS@SiO2 composite material was formed. This composite material was then combined with sulfobutyl ether-β-cyclodextrin to bridge the SiO2 surface, thus preparing a working electrode that enhances its stability and fluorescence quantum yield. Furthermore, the detection accuracy was improved by the specific inclusion complex of sulfobutyl ether-β-cyclodextrin and cypermethrin.
It significantly improved the sensitivity and accuracy of cypermethrin detection, enhanced the electrochemiluminescence intensity, lowered the detection limit, and improved overall stability.
Smart Images
Figure CN121612967A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of pesticide residue detection technology, specifically relating to a method for detecting pyrethroid pesticide residues in agricultural products. Background Technology
[0002] In agriculture, pyrethroid pesticides are widely used to control pests on various crops. However, these pesticides leave residues in the environment and crops after use, causing negative environmental impacts and posing risks to human health. Therefore, the analysis and detection of pyrethroid pesticide residues are particularly necessary.
[0003] Electrochemiluminescence (ECL) technology has become a hot research area for the analysis and detection of pyrethroid pesticide residues due to its ease of operation and significant cost-effectiveness. This technology typically uses luminol, ruthenium bipyridine, and quantum dots as luminescent materials. CsPbBr3 quantum dots, as an inorganic luminescent material highly sensitive to the external environment, can achieve a photoluminescence quantum yield of over 80%, exhibiting a narrow emission half-width and tunable emission characteristics. However, the environmental sensitivity of CsPbBr3 quantum dots leads to poor stability, which in turn affects the stability of its fluorescence quantum yield. This characteristic limits the sensitivity and accuracy of CsPbBr3 quantum dots as a cypermethrin detector in the working electrode. Summary of the Invention
[0004] The purpose of this invention is to provide a method for detecting pyrethroid pesticide residues in agricultural products, so as to solve the above-mentioned technical problems.
[0005] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows: A method for detecting pyrethroid pesticide residues in agricultural products, comprising the following steps: S1, The concentration prepared is 1×10 -11 mol / L, 1×10 -10 mol / L, 1×10 -9 mol / L, 1×10 -8 mol / L, 1×10 -7 mol / L, 1×10 -6 mol / L, 1×10 -5 mol / L and 1×10 -4 A standard solution of pyrethroid pesticides at mol / L was used. The electrochemiluminescence intensity of each standard solution of pyrethroid pesticides was measured using a three-electrode system. A linear equation was established with the logarithm of the concentration of the standard solution of pyrethroid pesticides as the abscissa and the electrochemiluminescence intensity as the ordinate. S2. Using a three-electrode system, the electrochemiluminescence intensity of the test solution containing pyrethroid pesticides is measured, and the concentration of pyrethroid pesticides in the test solution is calculated based on the linear equation. The three-electrode system includes: a phosphate buffer containing a ruthenium terpyridine-labeled antibody and tripropylamine co-reactant as the electrolyte, Ag / AgCl as the reference electrode, platinum wire as the auxiliary electrode, and a working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE.
[0006] As a further improvement, the specific preparation method of the working electrode is as follows: the glassy carbon electrode is polished sequentially with aluminum oxide powder with particle sizes of 1.0 μm, 0.3 μm, and 0.05 μm, and then ultrasonically cleaned alternately with anhydrous ethanol and ultrapure water, and dried with nitrogen gas; the composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD is uniformly dispersed in a polypyrrole solution to obtain an electrolyte, and then the electrode is placed in the electrolyte. A voltage of 0.01~0.8V is applied to the electrode, and electropolymerization is carried out by cyclic voltammetry at a scanning speed of 80mV / s for 15 cycles. The electrode is removed, and the unpolymerized composite material and polypyrrole are washed away with deionized water. The electrode is then dried under an infrared lamp at 50°C to obtain the working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE made of the composite material.
[0007] As a further improvement, the specific preparation method of the composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD is as follows: Sulfobutyl ether-β-cyclodextrin is dissolved in 0.01 mol / L phosphate buffer solution, and sonicated to form a sulfobutyl ether-β-cyclodextrin solution. The temperature is raised to 37℃, and the Ta-CsPbBr3@ZnS@SiO2-TDI dispersion is uniformly mixed with the sulfobutyl ether-β-cyclodextrin solution. After reacting at 37℃ in the dark for 6 hours, the mixture is dialyzed with deionized water for 24 hours to obtain the composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD. The volume ratio of the Ta-CsPbBr3@ZnS@SiO2-TDI dispersion to the sulfobutyl ether-β-cyclodextrin solution is 1~1.6:1; the concentration of the sulfobutyl ether-β-cyclodextrin solution is 20 g / L.
[0008] As a further improvement, the specific preparation method of the Ta-CsPbBr3@ZnS@SiO2-TDI dispersion is as follows: Ta-CsPbBr3@ZnS@SiO2-NH2 is dispersed in 0.01 mol / L phosphate buffer to obtain the Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion; at room temperature, toluene-2,4-diisocyanate is added dropwise to anhydrous N,N-dimethylformamide to obtain a toluene-2,4-diisocyanate solution; then, the toluene-2,4-diisocyanate solution is... -2,4-diisocyanate solution was added dropwise to Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion, and the reaction was carried out in the dark for 2 h. After centrifugation and washing, the precipitate was dispersed in phosphate buffer to obtain Ta-CsPbBr3@ZnS@SiO2-TDI dispersion; the concentration of Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion was 2 g / L, and the volume ratio of toluene-2,4-diisocyanate to anhydrous N,N-dimethylformamide was 1~1.5:20.
[0009] As a further improvement, the specific preparation method of Ta-CsPbBr3@ZnS@SiO2-NH2 is as follows: Ta-CsPbBr3@ZnS@SiO2 is added to anhydrous ethanol and ultrasonically stirred at 30°C for 2 hours. Then, 3-aminopropyltriethoxysilane and 25wt% ammonia are added, nitrogen gas is introduced, and the mixture is heated to 70°C and stirred for 4 hours. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, filtered, and the precipitate is washed three times with anhydrous ethanol and vacuum dried at 65°C for 24 hours to obtain Ta-CsPbBr3@ZnS@SiO2-NH2. The mass ratio of Ta-CsPbBr3@ZnS@SiO2 to 3-aminopropyltriethoxysilane is 1:0.37~0.5, and the volume ratio of anhydrous ethanol to 25wt% ammonia is 375:23.
[0010] As a further improvement, the specific preparation method of Ta-CsPbBr3@ZnS@SiO2 is as follows: Ta-CsPbBr3@ZnS is dispersed in anhydrous ethanol, then tetramethoxysilane is quickly added, stirred evenly, ammonium hydroxide solution is added dropwise, stirring is continued for 30 min, and the mixture is allowed to stand for 24 h to obtain Ta-CsPbBr3@ZnS@SiO2; the volume ratio of anhydrous ethanol, tetramethoxysilane and ammonium hydroxide solution is 100:1~2:0.1~0.2, and the concentration of Ta-CsPbBr3@ZnS in n-hexane is 0.2 g / mL.
[0011] As a further improvement, the specific preparation method of Ta-CsPbBr3@ZnS is as follows: zinc stearate is added to the Ta-CsPbBr3 nanocrystal solution, stirred at 300 rpm for 5 min, dodecyl mercaptan is added, and stirred thoroughly at 1500 rpm for 10 min. The above solution is heated under vacuum at 120℃ for 20 min, and then cooled to room temperature to obtain a Ta-CsPbBr3@ZnS nanocrystal mixed solution. Hexane is added to the Ta-CsPbBr3@ZnS nanocrystal mixed solution, washed and centrifuged, the precipitate is filtered and dried to obtain Ta-CsPbBr3@ZnS. The concentration of zinc stearate in the Ta-CsPbBr3 nanocrystal solution is 16.2857 g / L, and the volume ratio of the Ta-CsPbBr3 nanocrystal solution to dodecyl mercaptan is 7:3~5.
[0012] As a further improvement, the specific preparation method of Ta-CsPbBr3 is as follows: Cesium carbonate, octadecene, and oleic acid are uniformly mixed to obtain a cesium carbonate solution; lead bromide, tantalum pentabromide, and octadecene are then uniformly mixed to obtain a dispersion; nitrogen gas is introduced into the cesium carbonate solution, and the mixture is stirred at 500 rpm for 1 h at 120 °C to obtain a cesium oleate precursor solution; nitrogen gas is introduced into the dispersion, and the mixture is stirred at 500 rpm for 1 h at 120 °C; oleylamine and oleic acid are rapidly added to the dispersion, the temperature is raised to 180 °C, and the temperature is maintained for 5 min; then the cesium oleate precursor solution is rapidly added, and after reacting for 60 s, the mixture is rapidly transferred to an ice-water bath at 0~4 °C and cooled for 2 h until the reaction is complete to obtain a Ta-CsPbBr3 nanocrystal solution; the mass ratio of cesium carbonate, lead bromide, and tantalum pentabromide is 15.376:73.4:8~12.
[0013] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: This invention provides a method for detecting pyrethroid pesticide residues in agricultural products, which involves doping Ta into CsPbBr3 quantum dots. 5+ With higher stable valence states and stronger bonding ability, it can more effectively passivate lattice defects and enhance lattice energy, thereby significantly reducing material toxicity while greatly improving its thermal stability and chemical stability against ion migration. Further modification of Ta-CsPbBr3 with zinc sulfide and silicon dioxide sequentially yields a double-layered Ta-CsPbBr3@ZnS@SiO2, which increases quantum yield. Reduced defects lead to higher irradiation recombination efficiency, improving the fluorescence quantum yield of Ta-CsPbBr3@ZnS@SiO2 and directly enhancing ECL luminescence intensity. The double-layer coating also enables the quantum dots to withstand redox stress during electrochemical cycling, improving overall stability and maintaining stable ECL signal output, thus enhancing the sensitivity for detecting cypermethrin.
[0014] Amination treatment was performed on the surface of Ta-CsPbBr3@ZnS@SiO2 quantum dots, and sulfobutyl ether-β-cyclodextrin was bridged to the SiO2 surface using toluene-2,4-diisocyanate as a linker to prepare a working electrode of the Ta-CsPbBr3@ZnS@SiO2-SBE-β-CD composite material. The cavity of sulfobutyl ether-β-cyclodextrin forms a specific inclusion complex with the benzene ring of cypermethrin through hydrophobic interactions, forming a host-guest complex. This selective recognition gives the working electrode a high affinity for cypermethrin, improving the overall detection accuracy. The sulfonic acid groups of sulfobutyl ether-β-cyclodextrin and the cyano groups of cypermethrin enhance the binding energy through electrostatic interactions, lowering the detection limit. Toluene-2,4-diisocyanate, as a linker, covalently binds to the surface of SiO2 through its amino groups, while its isocyanate groups react with the hydroxyl groups of sulfobutyl ether-β-cyclodextrin to form a stable bridging structure, which shortens the electron transport path. Its rigid structure can reduce molecular chain entanglement, ensure unobstructed electron transfer channels, further amplify the signal response, and accelerate charge injection in the ECL reaction. Attached Figure Description
[0015] Figure 1 The graph shows the linear equation between the logarithm of the concentration of the standard solution of cypermethrin pesticide and the corresponding electrochemiluminescence intensity. Figure 2 Selectivity analysis of cypermethrin on the working electrode made of composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD; Figure 3 Transmission electron microscope image of the composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD. Detailed Implementation
[0016] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.
[0017] Example 1: A method for preparing a working electrode, comprising the following steps: S1. Weigh 81.4 mg of cesium carbonate solid powder and mix it evenly with 4 mL of octadecene and 0.5 mL of oleic acid to obtain a cesium carbonate solution; then weigh 73.4 mg of lead bromide solid powder, 8 mg of tantalum pentabromide solid powder and mix them evenly with 10 mL of octadecene to obtain a dispersion; introduce nitrogen gas into the cesium carbonate solution and stir at 500 rpm for 1 h at 120 °C to remove water and gas, to obtain a cesium oleate precursor solution; introduce nitrogen gas into the dispersion and stir at 500 rpm for 1 h at 120 °C to remove water and gas; quickly add 1.5 mL of oleylamine and 1 mL of oleic acid to the dispersion, heat to 180 °C and keep warm for 5 min, then quickly add 0.85 mL of the cesium oleate precursor solution, react for 60 s, and then quickly transfer it to an ice-water bath at 0~4 °C for cooling for 2 h until the reaction is complete to obtain a Ta-CsPbBr3 nanocrystal solution.
[0018] S2. Add 114 mg of zinc stearate to 7 mL of Ta-CsPbBr3 nanocrystal solution and stir at 300 rpm for 5 min to fully dissolve the zinc stearate. Then add 3 mL of dodecanethiol as a sulfur precursor and stir thoroughly at 1500 rpm with nitrogen gas for 10 min. Heat the above solution under vacuum at 120 °C for 20 min and then wait for it to cool to room temperature to obtain a Ta-CsPbBr3@ZnS nanocrystal mixed solution. Add 5 mL of n-hexane to the prepared mixed solution and centrifuge at 12000 rpm for 10 min. Remove the supernatant after centrifugation, retain the precipitate, filter and dry the precipitate to obtain Ta-CsPbBr3@ZnS.
[0019] S3. Disperse 1g Ta-CsPbBr3@ZnS in 5mL of anhydrous ethanol, quickly add 50μL of tetramethoxysilane, stir at 300rpm for 30min, then add 5μL of ammonium hydroxide solution dropwise, stir at 300rpm for 30min, and let stand for 24h to obtain Ta-CsPbBr3@ZnS@SiO2.
[0020] S4. Add 5g of Ta-CsPbBr3@ZnS@SiO2 to 375mL of anhydrous ethanol and sonicate at 30℃ for 2h to ensure uniform dispersion. Then add 1.85g of 3-aminopropyltriethoxysilane and 23mL of 25wt% ammonia solution, purge with nitrogen, heat to 70℃, and stir at 500rpm for 4h. After cooling to room temperature, centrifuge the reaction mixture at 10000rpm for 30min, remove the supernatant, wash the lower precipitate with anhydrous ethanol, and filter. Repeat the centrifugation and washing process three times. Place the filtered precipitate in a vacuum oven at 65℃ and dry for 24h to obtain Ta-CsPbBr3@ZnS@SiO2-NH2.
[0021] S5. Disperse 10 mg of Ta-CsPbBr3@ZnS@SiO2-NH2 in 5 mL of 0.01 mol / L phosphate buffer (pH 7.4) to obtain a Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion. Add 10 μL of toluene-2,4-diisocyanate dropwise to 200 μL of anhydrous N,N-dimethylformamide at room temperature and 300 rpm to obtain a toluene-2,4-diisocyanate solution. Then, add the entire toluene-2,4-diisocyanate solution dropwise to the Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion. Incubate in the dark for 2 h. After centrifugation at 14000 rpm for 15 min, wash three times with phosphate buffer to remove the supernatant and free toluene-2,4-diisocyanate. Disperse the precipitate in 5 mL of phosphate buffer solution. A Ta-CsPbBr3@ZnS@SiO2-TDI dispersion was obtained in phosphate buffer.
[0022] S6. Dissolve 100 mg of sulfobutyl ether-β-cyclodextrin (SBE-β-CD) in 5 mL of 0.01 mol / L phosphate buffer (pH 7.4), and sonicate at 100 W for 5 min to aid dissolution. Preheat the solution to 37 °C. Mix 5 mL of Ta-CsPbBr3@ZnS@SiO2-TDI dispersion with 5 mL of sulfobutyl ether-β-cyclodextrin solution. React at 400 rpm and 37 °C in the dark for 6 h. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 12 kDa and dialyze against deionized water for 24 h, changing the water every 6 h to remove free sulfobutyl ether-β-cyclodextrin and small molecule impurities, yielding Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD. The transmission electron microscope image of Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD is shown below. Figure 3 As shown.
[0023] S7. After polishing the glassy carbon electrode with aluminum oxide powder of particle sizes of 1.0μm, 0.3μm, and 0.05μm, it was then ultrasonically cleaned alternately with anhydrous ethanol and ultrapure water, and dried with nitrogen. 5mg of Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD was dissolved in 10mL of 0.2mol / L polypyrrole solution and uniformly dispersed to obtain an electrolyte. The electrode was then placed in the electrolyte, and a voltage of 0.01~0.8 V was applied to the electrode. Electropolymerization was carried out by cyclic voltammetry at a scan rate of 80mV / s for 15 cycles. The electrode was then removed, and the unpolymerized composite material and polypyrrole were washed away with deionized water. The electrode was then dried under an infrared lamp at 50℃ to obtain the working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE prepared from the composite material.
[0024] Example 2: A method for preparing a working electrode, comprising the following steps: S1. Weigh 81.4 mg of cesium carbonate solid powder and mix it evenly with 4 mL of octadecene and 0.5 mL of oleic acid to obtain a cesium carbonate solution; then weigh 73.4 mg of lead bromide solid powder, 10 mg of tantalum pentabromide solid powder and mix them evenly with 10 mL of octadecene to obtain a dispersion; introduce nitrogen gas into the cesium carbonate solution and stir at 500 rpm for 1 h at 120 °C to remove water and gas, to obtain a cesium oleate precursor solution; introduce nitrogen gas into the dispersion and stir at 500 rpm for 1 h at 120 °C to remove water and gas; quickly add 1.5 mL of oleylamine and 1 mL of oleic acid to the dispersion, heat to 180 °C and keep warm for 5 min, then quickly add 0.85 mL of the cesium oleate precursor solution, react for 60 s, and then quickly transfer it to an ice-water bath at 0~4 °C for cooling for 2 h until the reaction is complete to obtain a Ta-CsPbBr3 nanocrystal solution.
[0025] S2. Add 114 mg of zinc stearate to 7 mL of Ta-CsPbBr3 nanocrystal solution and stir at 300 rpm for 5 min to fully dissolve the zinc stearate. Then add 4 mL of dodecanethiol as a sulfur precursor and stir thoroughly at 1500 rpm with nitrogen gas for 10 min. Heat the above solution under vacuum at 120 °C for 20 min and then wait for it to cool to room temperature to obtain a Ta-CsPbBr3@ZnS nanocrystal mixed solution. Add 5 mL of n-hexane to the prepared mixed solution and centrifuge at 12000 rpm for 10 min. Remove the supernatant after centrifugation, retain the precipitate, filter and dry the precipitate to obtain Ta-CsPbBr3@ZnS.
[0026] S3. Disperse 1g Ta-CsPbBr3@ZnS in 5mL of anhydrous ethanol, quickly add 75μL of tetramethoxysilane, stir at 300rpm for 30min, then add 7.5μL of ammonium hydroxide solution dropwise, stir at 300rpm for 30min, and let stand for 24h to obtain Ta-CsPbBr3@ZnS@SiO2.
[0027] S4. Add 5g of Ta-CsPbBr3@ZnS@SiO2 to 375mL of anhydrous ethanol and sonicate at 30℃ for 2h to ensure uniform dispersion. Then add 2.2g of 3-aminopropyltriethoxysilane and 23mL of 25wt% ammonia solution, purge with nitrogen, heat to 70℃, and stir at 500rpm for 4h. After cooling to room temperature, centrifuge the reaction mixture at 10000rpm for 30min, remove the supernatant, wash the lower precipitate with anhydrous ethanol, and filter. Repeat the centrifugation and washing process three times. Place the filtered precipitate in a vacuum oven at 65℃ and dry for 24h to obtain Ta-CsPbBr3@ZnS@SiO2-NH2.
[0028] S4. Add 5g of Ta-CsPbBr3@ZnS@SiO2 to 375mL of anhydrous ethanol and sonicate at 30℃ for 2h to ensure uniform dispersion. Then add 2.2g of 3-aminopropyltriethoxysilane and 23mL of 25wt% ammonia solution, purge with nitrogen, heat to 70℃, and stir at 500rpm for 4h. After cooling to room temperature, centrifuge the reaction mixture at 10000rpm for 30min, remove the supernatant, wash the lower precipitate with anhydrous ethanol, and filter. Repeat the centrifugation and washing process three times. Place the filtered precipitate in a vacuum oven at 65℃ and dry for 24h to obtain Ta-CsPbBr3@ZnS@SiO2-NH2.
[0029] S5. Disperse 10 mg of Ta-CsPbBr3@ZnS@SiO2-NH2 in 5 mL of 0.01 mol / L phosphate buffer (pH 7.4) to obtain a Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion. Add 13 μL of toluene-2,4-diisocyanate dropwise to 200 μL of anhydrous N,N-dimethylformamide at room temperature and 300 rpm to obtain a toluene-2,4-diisocyanate solution. Then, add the entire toluene-2,4-diisocyanate solution dropwise to the Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion. Incubate in the dark for 2 h. After centrifugation at 14000 rpm for 15 min, wash three times with phosphate buffer to remove the supernatant and free toluene-2,4-diisocyanate. Disperse the precipitate in 5 mL of phosphate buffer solution. A Ta-CsPbBr3@ZnS@SiO2-TDI dispersion was obtained in phosphate buffer.
[0030] S6. Dissolve 100 mg of sulfobutyl ether-β-cyclodextrin (SBE-β-CD) in 5 mL of 0.01 mol / L phosphate buffer (pH 7.4), sonicate at 100 W for 5 min to aid dissolution, preheat to 37 °C, and mix 6.5 mL of Ta-CsPbBr3@ZnS@SiO2-TDI dispersion with 5 mL of sulfobutyl ether-β-cyclodextrin solution. React at 400 rpm and 37 °C in the dark for 6 h. Then, transfer the reaction solution into a dialysis bag with a molecular weight cutoff of 12 kDa and dialyze with deionized water for 24 h, changing the water every 6 h to remove free sulfobutyl ether-β-cyclodextrin and small molecule impurities, to obtain Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD.
[0031] S7. After polishing the glassy carbon electrode with aluminum oxide powder of particle sizes of 1.0μm, 0.3μm, and 0.05μm, it was then ultrasonically cleaned alternately with anhydrous ethanol and ultrapure water, and dried with nitrogen. 5mg of Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD was dissolved in 10mL of 0.2mol / L polypyrrole solution and uniformly dispersed to obtain an electrolyte. The electrode was then placed in the electrolyte, and a voltage of 0.01~0.8 V was applied to the electrode. Electropolymerization was carried out by cyclic voltammetry at a scan rate of 80mV / s for 15 cycles. The electrode was then removed, and the unpolymerized composite material and polypyrrole were washed away with deionized water. The electrode was then dried under an infrared lamp at 50℃ to obtain the working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE prepared from the composite material.
[0032] Example 3: A method for preparing a working electrode, comprising the following steps: S1. Weigh 81.4 mg of cesium carbonate solid powder and mix it evenly with 4 mL of octadecene and 0.5 mL of oleic acid to obtain a cesium carbonate solution; then weigh 73.4 mg of lead bromide solid powder, 12 mg of tantalum pentabromide solid powder and mix them evenly with 10 mL of octadecene to obtain a dispersion; introduce nitrogen gas into the cesium carbonate solution and stir at 500 rpm for 1 h at 120 °C to remove water and gas, to obtain a cesium oleate precursor solution; introduce nitrogen gas into the dispersion and stir at 500 rpm for 1 h at 120 °C to remove water and gas; quickly add 1.5 mL of oleylamine and 1 mL of oleic acid to the dispersion, heat to 180 °C and keep warm for 5 min, then quickly add 0.85 mL of the cesium oleate precursor solution, react for 60 s, and then quickly transfer it to an ice-water bath at 0~4 °C for 2 h until the reaction is complete to obtain a Ta-CsPbBr3 nanocrystal solution.
[0033] S2. Add 114 mg of zinc stearate to 7 mL of Ta-CsPbBr3 nanocrystal solution and stir at 300 rpm for 5 min to fully dissolve the zinc stearate. Then add 5 mL of dodecanethiol as a sulfur precursor and stir thoroughly at 1500 rpm with nitrogen gas for 10 min. Heat the above solution under vacuum at 120 °C for 20 min and then wait for it to cool to room temperature to obtain a Ta-CsPbBr3@ZnS nanocrystal mixed solution. Add 5 mL of n-hexane to the prepared mixed solution and centrifuge at 12000 rpm for 10 min. Remove the supernatant after centrifugation, retain the precipitate, filter and dry the precipitate to obtain Ta-CsPbBr3@ZnS.
[0034] S3. Disperse 1g Ta-CsPbBr3@ZnS in 5mL of anhydrous ethanol, quickly add 100μL of tetramethoxysilane, stir at 300rpm for 30min, then add 10μL of ammonium hydroxide solution dropwise, stir at 300rpm for 30min, and let stand for 24h to obtain Ta-CsPbBr3@ZnS@SiO2.
[0035] S4. Add 5g of Ta-CsPbBr3@ZnS@SiO2 to 375mL of anhydrous ethanol and sonicate at 30℃ for 2h to disperse it evenly. Then add 2.5g of 3-aminopropyltriethoxysilane and 23mL of 25wt% ammonia water, purge with nitrogen, heat to 70℃, and stir at 500rpm for 4h. After cooling to room temperature, centrifuge the reaction mixture at 10000rpm for 30min, remove the supernatant, wash the lower precipitate with anhydrous ethanol and filter. Repeat the centrifugation and washing operation 3 times. Place the filtered precipitate in a vacuum oven at 65℃ and dry for 24h to obtain Ta-CsPbBr3@ZnS@SiO2-NH2.
[0036] S5. Disperse 10 mg of Ta-CsPbBr3@ZnS@SiO2-NH2 in 5 mL of 0.01 mol / L phosphate buffer (pH 7.4) to obtain a Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion. Add 15 μL of toluene-2,4-diisocyanate dropwise to 200 μL of anhydrous N,N-dimethylformamide at room temperature and 300 rpm to obtain a toluene-2,4-diisocyanate solution. Then, add the entire toluene-2,4-diisocyanate solution dropwise to the Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion and react in the dark for 2 h. After centrifugation at 14000 rpm for 15 min, wash three times with phosphate buffer to remove the supernatant and free toluene-2,4-diisocyanate. Disperse the precipitate in 5 mL of phosphate buffer solution. A Ta-CsPbBr3@ZnS@SiO2-TDI dispersion was obtained in phosphate buffer.
[0037] S6. Dissolve 100 mg of sulfobutyl ether-β-cyclodextrin (SBE-β-CD) in 5 mL of 0.01 mol / L phosphate buffer (pH 7.4), sonicate at 100 W for 5 min to aid dissolution, preheat to 37 °C, mix 8 mL of Ta-CsPbBr3@ZnS@SiO2-TDI dispersion with 5 mL of sulfobutyl ether-β-cyclodextrin solution, react at 400 rpm and 37 °C in the dark for 6 h, then transfer the reaction solution into a dialysis bag with a molecular weight cutoff of 12 kDa and dialyze with deionized water for 24 h, changing the water every 6 h to remove free sulfobutyl ether-β-cyclodextrin and small molecule impurities, to obtain Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD.
[0038] S7. After polishing the glassy carbon electrode with aluminum oxide powder of particle sizes of 1.0μm, 0.3μm, and 0.05μm, it was then ultrasonically cleaned alternately with anhydrous ethanol and ultrapure water, and dried with nitrogen. 5mg of Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD was dissolved in 10mL of 0.2mol / L polypyrrole solution and uniformly dispersed to obtain an electrolyte. The electrode was then placed in the electrolyte, and a voltage of 0.01~0.8 V was applied to the electrode. Electropolymerization was carried out by cyclic voltammetry at a scan rate of 80mV / s for 15 cycles. The electrode was then removed, and the unpolymerized composite material and polypyrrole were washed away with deionized water. The electrode was then dried under an infrared lamp at 50℃ to obtain the working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE prepared from the composite material.
[0039] Comparative Example 1: Compared with Example 1, Comparative Example 1 did not bridge sulfonyl ether-β-cyclodextrin on the SiO2 surface, and included the following steps: S1. Weigh 81.4 mg of cesium carbonate solid powder and mix it evenly with 4 mL of octadecene and 0.5 mL of oleic acid to obtain a cesium carbonate solution; then weigh 73.4 mg of lead bromide solid powder, 10 mg of tantalum pentabromide solid powder and mix them evenly with 10 mL of octadecene to obtain a dispersion; introduce nitrogen gas into the cesium carbonate solution and stir at 500 rpm for 1 h at 120 °C to remove water and gas, to obtain a cesium oleate precursor solution; introduce nitrogen gas into the dispersion and stir at 500 rpm for 1 h at 120 °C to remove water and gas; quickly add 1.5 mL of oleylamine and 1 mL of oleic acid to the dispersion, heat to 180 °C and keep warm for 5 min, then quickly add 0.85 mL of the cesium oleate precursor solution, react for 60 s, and then quickly transfer it to an ice-water bath at 0~4 °C for cooling for 2 h until the reaction is complete to obtain a Ta-CsPbBr3 nanocrystal solution.
[0040] S2. Add 114 mg of zinc stearate to 7 mL of Ta-CsPbBr3 nanocrystal solution and stir at 300 rpm for 5 min to fully dissolve the zinc stearate. Then add 3 mL of dodecanethiol as a sulfur precursor and stir thoroughly at 1500 rpm with nitrogen gas for 10 min. Heat the above solution under vacuum at 120 °C for 20 min and then wait for it to cool to room temperature to obtain a Ta-CsPbBr3@ZnS nanocrystal mixed solution. Add 5 mL of n-hexane to the prepared mixed solution and centrifuge at 12000 rpm for 10 min. Remove the supernatant after centrifugation, retain the precipitate, filter and dry the precipitate to obtain Ta-CsPbBr3@ZnS.
[0041] S3. Disperse 1g Ta-CsPbBr3@ZnS in 5mL of anhydrous ethanol, quickly add 50μL of tetramethoxysilane, stir at 300rpm for 30min, then add 5μL of ammonium hydroxide solution dropwise, stir at 300rpm for 30min, and let stand for 24h to obtain Ta-CsPbBr3@ZnS@SiO2.
[0042] S4. After polishing the glassy carbon electrode with aluminum oxide powder of 1.0μm, 0.3μm, and 0.05μm particle sizes, it was then ultrasonically cleaned alternately with anhydrous ethanol and ultrapure water, and dried with nitrogen. 5mg of Ta-CsPbBr3@ZnS@SiO2 was dissolved in 10mL of 0.2mol / L polypyrrole solution and uniformly dispersed to obtain an electrolyte. The electrode was then placed in the electrolyte, and a voltage of 0.01~0.8 V was applied to the electrode. Electropolymerization was carried out by cyclic voltammetry at a scan rate of 80mV / s for 15 cycles. The electrode was then removed, and the unpolymerized composite material and polypyrrole were washed away with deionized water. The electrode was then dried under an infrared lamp at 50℃ to obtain the electrode PPY-Ta-CsPbBr3@ZnS@SiO2 / GCE prepared from the composite material.
[0043] Comparative Example 2: Compared with Example 1, Comparative Example 2 did not add Ta element during the preparation of CsPbBr3 nanocrystals, nor did it bridge sulfonyl ether-β-cyclodextrin on the SiO2 surface, and included the following steps: S1. Weigh 81.4 mg of cesium carbonate solid powder and mix it evenly with 4 mL of octadecene and 0.5 mL of oleic acid to obtain a cesium carbonate solution; weigh 73.4 mg of lead bromide solid powder and mix it evenly with 10 mL of octadecene to obtain a dispersion; introduce nitrogen gas into the cesium carbonate solution and stir at 500 rpm for 1 h at 120 °C to remove water and gas, to obtain a cesium oleate precursor solution; introduce nitrogen gas into the dispersion and stir at 500 rpm for 1 h at 120 °C to remove water and gas; quickly add 1.5 mL of oleylamine and 1 mL of oleic acid to the dispersion, heat to 180 °C, keep warm for 5 min, then quickly add 0.85 mL of the cesium oleate precursor solution, react for 60 s, and then quickly transfer it to an ice-water bath at 0~4 °C for cooling for 2 h until the reaction is complete, to obtain a CsPbBr3 nanocrystal solution.
[0044] S2. The glassy carbon electrode was polished sequentially with aluminum oxide powders of 1.0 μm, 0.3 μm, and 0.05 μm particle sizes, followed by alternating ultrasonic cleaning with anhydrous ethanol and ultrapure water, and then dried with nitrogen. 5 mg of CsPbBr3 was dissolved in 10 mL of 0.2 mol / L polypyrrole solution and uniformly dispersed to obtain an electrolyte. The electrode was then placed in the electrolyte, and a voltage of 0-0.8 V was applied to the electrode. Electropolymerization was performed by cyclic voltammetry at a scan rate of 80 mV / s for 15 cycles. The electrode was then removed, and unpolymerized CsPbBr3 nanocrystals and polypyrrole were washed away with deionized water. The electrode was then dried under an infrared lamp at 50 °C to obtain the working electrode PPY-CsPbBr3 / GCE.
[0045] Performance testing: The stability of the working electrodes prepared in Examples 1-3 and Comparative Examples 1-2 was tested by means of: testing the quantum yield of the working electrodes and then placing them at 21 mW / cm². 2 Irradiated with blue light for 3 days to test its quantum yield.
[0046] The instrument used in this invention for quantum yield testing is the Hamamatsu Absolute Quantum Yield Testing System.
[0047] The retention rate of quantum yield (%) = quantum yield after blue light irradiation / quantum yield before blue light irradiation × 100%.
[0048] The test results are shown in Table 1.
[0049] Table 1: Results of Quantum Yield Retention Test
[0050] As shown in Table 1, the working electrodes prepared in Examples 1-3 all maintained a quantum yield retention rate of over 96.3% after blue light irradiation, exhibiting good stability. In contrast, the working electrodes prepared in Comparative Examples 1 and 2 showed relatively low quantum yield retention rates, especially Comparative Example 2, whose quantum yield retention rate was only 17%, indicating poor stability. This is because in Examples 1-3, ZnS, SiO2, and SBE-β-CD were sequentially coated onto the surface of Ta-CsPbBr3 nanocrystals through a multi-step reaction, and polypyrrole was modified onto the electrode surface through electropolymerization, forming a composite structure. This structure effectively improved the stability of the working electrodes. In Comparative Example 2, however, no Ta doping, ZnS, SiO2, or SBE-β-CD coating was performed, resulting in the worst stability. In summary, the working electrode preparation method provided by this invention has the advantages of simple operation and good stability, and can play an important role in practical applications.
[0051] Example 4: A method for detecting pyrethroid pesticide residues in agricultural products, comprising the following steps: The concentration to be prepared is 1×10 -11 mol / L, 1×10 -10 mol / L, 1×10 -9 mol / L, 1×10 -8 mol / L, 1×10 - 7 mol / L, 1×10 -6 mol / L, 1×10 -5 mol / L and 1×10 -4A standard solution of pyrethroid pesticides at mol / L was used. The electrochemiluminescence (ECL) intensity of each standard solution of pyrethroid pesticides was measured using a three-electrode system. A linear equation between the logarithm of the concentration of the standard solution of pyrethroid pesticides and the corresponding ECL intensity was established with the logarithm of the concentration of the standard solution of pyrethroid pesticides as the abscissa and the corresponding ECL intensity as the ordinate. A three-electrode system was used to determine the ECL intensity of a test solution containing pyrethroid pesticides. The concentration of pyrethroid pesticides in the test solution could then be calculated based on the linear equation described above. The three-electrode system included a system containing ruthenium terpyridine (Ru(bpy)3). 2+ The electrolyte was phosphate-buffered saline (PBS) containing the antibody-labeled antibody and tripropylamine (TPA), the reference electrode was Ag / AgCl, the auxiliary electrode was platinum wire, and the working electrode was PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE. In an electrochemiluminescence cell containing 1 mL of 0.2 mol / L phosphate-buffered saline (pH 7.5), 32 μL of a 10 mmol / L solution of ruthenium terpyridine and 200 μL of a 100 μmol / L solution of tripropylamine (TPA) were added, followed by 768 μL of deionized water. The mixture was thoroughly mixed to obtain a solution with a concentration of 0.16 mmol / L ruthenium terpyridine and 10 μmol / L tripropylamine. The electrochemiluminescence signal of the mixed solution was scanned using a three-electrode system at a voltage of 0.2V~1.25V, a scan rate of 100mV / s, and a photomultiplier tube voltage of 700V, to obtain the luminescence signal of the mixed solution of terpyridine ruthenium and tripropylamine.
[0052] Taking cypermethrin (CP) pesticide residue as an example, the agricultural product sample was washed with distilled water, chopped, and juiced using a blender. The juice was then diluted with 10 mL of phosphate buffer, centrifuged, and the supernatant was collected. The pretreated supernatant was added to 10 mL of 0.1 mol / L phosphate buffer (pH 7.5). The experiment was performed using the standard spiking method, with three parallel determinations.
[0053] The results are as follows Figure 1 As shown, in this invention, the change in electrochemiluminescence intensity (ΔI) of the working electrode is related to the logarithm of the cypermethrin concentration within 1.0 × 10⁻⁶. -11 ~1.0×10 -4 A significant linear relationship is observed within the mol / L range. This linear relationship can be expressed by the linear equation ΔI = 16832 + 1515lg. c CP The linear correlation coefficient reached 0.9971. Using a signal-to-noise ratio (S / N) of 3 as the criterion for the detection limit, the detection limit of this method is 2.95 × 10⁻⁶. -11mol / L. Compared with the prior art, the working electrode in this invention has a wider detection range and a significantly lower detection limit, thereby achieving higher detection sensitivity.
[0054] To assess the selectivity of the working electrode, a concentration of 5 × 10⁻⁶ was selected. -10 Several compounds with similar biological activity to cypermethrin at mol / L, as well as cypermethrin pesticides at equivalent concentrations, were investigated. These included indoxacarb (INC), chlorpyrifos (CPR), procymidone (PCM), malathion (MAT), and quizalofop-P-ethyl (QFE), which were used as interfering agents in the experiments. Independent detection of cypermethrin pesticide residues at equivalent concentrations was conducted.
[0055] The results show that the working electrode prepared in this invention exhibits a significant response change to cypermethrin pesticide residues. Furthermore, a comparison of the detection results of a mixed solution of cypermethrin containing equal concentrations of interfering substances and a single solution of cypermethrin pesticide residues revealed no significant differences. The results are as follows... Figure 2 As shown, the working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE exhibits excellent selectivity and accuracy.
[0056] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A method for detecting residues of pyrethroid insecticides in agricultural products, characterized by, Comprising the following steps: S1, the preparation concentration is 1×10 -11 mol / L, 1×10 -10 mol / L, 1×10 -9 mol / L, 1×10 -8 mol / L, 1×10 - 7 mol / L, 1×10 -6 mol / L, 1×10 -5 mol / L and 1×10 -4 mol / L pyrethroid pesticide standard solution, using a three-electrode system, the electrochemiluminescence intensity of each pyrethroid pesticide standard solution is determined, the logarithm of the concentration of the pyrethroid pesticide standard solution is taken as the horizontal coordinate, and the electrochemiluminescence intensity is taken as the vertical coordinate, and a linear equation is established. S2, using a three-electrode system, measuring the electrochemiluminescence intensity of the test solution containing pyrethroid pesticides, and calculating the concentration of pyrethroid pesticides in the test solution according to the linear equation; The three-electrode system comprises: using a phosphate buffer solution containing a trispyridine ruthenium labeled antibody and a tripropylamine co-reactant as an electrolyte, Ag / AgCl as a reference electrode, a platinum wire as an auxiliary electrode, and a working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE.
2. The method according to claim 1, wherein the method is characterized by, The specific preparation method of the working electrode is: sequentially polishing the glassy carbon electrode with aluminum oxide powder with particle sizes of 1.0 μm, 0.3 μm and 0.05 μm, and then cleaning with anhydrous ethanol and ultrapure water alternately, and blowing dry with nitrogen; the composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD is uniformly dispersed in a polypyrrole solution to obtain an electrolyte, and then the electrode is placed in the electrolyte, a voltage of 0.01-0.8V is applied to the electrode, and the cyclic voltammetry method is used to cycle 15 times at a scan speed of 80mV / s, the electrode is taken out, the unaggregated composite material and polypyrrole are washed away with deionized water, and the electrode is baked at 50℃ under an infrared lamp to obtain the working electrode PPY-Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD / GCE made of the composite material.
3. The method according to claim 2, wherein the method is characterized by, The specific preparation method of the composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD is: dissolving sulfobutyl ether-β-cyclodextrin in 0.01 mol / L phosphate buffer solution, ultrasonic, forming a sulfobutyl ether-β-cyclodextrin solution, heating to 37℃, uniformly mixing Ta-CsPbBr3@ZnS@SiO2-TDI dispersion liquid with sulfobutyl ether-β-cyclodextrin solution, reacting at 37℃ in the dark for 6h, and then dialyzing with deionized water for 24h to obtain the composite material Ta-CsPbBr3@ZnS@SiO2@SBE-β-CD; the volume ratio of the Ta-CsPbBr3@ZnS@SiO2-TDI dispersion liquid to the sulfobutyl ether-β-cyclodextrin solution is 1-1.6:1; the concentration of the sulfobutyl ether-β-cyclodextrin solution is 20g / L.
4. The method according to claim 3, wherein the method is characterized by, The specific preparation method of the Ta-CsPbBr3@ZnS@SiO2-TDI dispersion liquid is as follows: dispersing Ta-CsPbBr3@ZnS@SiO2-NH2 in 0.01 mol / L phosphate buffer to obtain a Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion liquid; adding toluene-2,4-diisocyanate dropwise into anhydrous N,N-dimethylformamide at room temperature to obtain a toluene-2,4-diisocyanate solution, and then adding the toluene-2,4-diisocyanate solution dropwise into the Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion liquid, and reacting for 2 hours in the dark, and then centrifuging and washing, and dispersing the precipitate in the phosphate buffer to obtain the Ta-CsPbBr3@ZnS@SiO2-TDI dispersion liquid; the concentration of the Ta-CsPbBr3@ZnS@SiO2-NH2 dispersion liquid is 2 g / L, and the volume ratio of the toluene-2,4-diisocyanate to the anhydrous N,N-dimethylformamide is 1-1.5:
20.
5. The method according to claim 4, wherein the method is characterized by, The specific preparation method of the Ta-CsPbBr3@ZnS@SiO2-NH2 is as follows: adding Ta-CsPbBr3@ZnS@SiO2 into anhydrous ethanol, ultrasonically stirring at 30°C for 2 hours, then adding 3-aminopropyl triethoxysilane and 25wt% ammonia water, heating to 70°C under nitrogen, stirring for 4 hours, cooling to room temperature after the reaction, centrifuging, filtering, washing the precipitate with anhydrous ethanol for 3 times, and vacuum drying at 65°C for 24 hours to obtain Ta-CsPbBr3@ZnS@SiO2-NH2; the mass ratio of the Ta-CsPbBr3@ZnS@SiO2 to the 3-aminopropyl triethoxysilane is 1:0.37-0.5, and the volume ratio of the anhydrous ethanol to the 25wt% ammonia water is 375:
23.
6. The method according to claim 5, wherein the method is characterized by, The specific preparation method of the Ta-CsPbBr3@ZnS@SiO2 is as follows: dispersing Ta-CsPbBr3@ZnS in anhydrous ethanol, then quickly adding tetramethoxysilane, stirring uniformly, adding an ammonium hydroxide solution dropwise, continuing to stir for 30 minutes, and standing for 24 hours to obtain Ta-CsPbBr3@ZnS@SiO2; the volume ratio of the n-hexane, tetramethoxysilane and ammonium hydroxide solution is 100:1-2:0.1-0.2, and the concentration of the Ta-CsPbBr3@ZnS in the n-hexane is 0.2 g / mL.
7. The method according to claim 6, wherein the method is characterized by, The specific preparation method of the Ta-CsPbBr3@ZnS is as follows: zinc stearate is added into a Ta-CsPbBr3 nanocrystal solution, stirring is carried out at 300 rpm for 5 min, dodecanethiol is added, stirring is carried out at 1500 rpm for 10 min, the above solution is heated at 120 DEG C under vacuum for 20 min, cooling is carried out to room temperature, a Ta-CsPbBr3@ZnS nanocrystal mixed solution is prepared, n-hexane is added into the Ta-CsPbBr3@ZnS nanocrystal mixed solution, washing and centrifugation are carried out, the precipitate is suction filtered, drying is carried out, and the Ta-CsPbBr3@ZnS is obtained; the concentration of the zinc stearate in the Ta-CsPbBr3 nanocrystal solution is 16.2857 g / L, and the volume ratio of the Ta-CsPbBr3 nanocrystal solution to the dodecanethiol is 7:3~5.
8. The method according to claim 7, wherein the method is characterized by, The specific preparation method of the Ta-CsPbBr3 is as follows: cesium carbonate, octadecene and oleic acid are uniformly mixed to obtain a cesium carbonate solution; lead bromide and pentabromide are uniformly mixed with octadecene to obtain a dispersion liquid; nitrogen is introduced into the cesium carbonate solution, stirring is carried out at 500 rpm at 120 DEG C for 1 h, and a cesium oleate precursor solution is obtained; nitrogen is introduced into the dispersion liquid, stirring is carried out at 500 rpm at 120 DEG C for 1 h, the dispersion liquid is quickly added with oleylamine and oleic acid, the temperature is raised to 180 DEG C, and the temperature is kept for 5 min, the cesium oleate precursor solution is quickly added into the dispersion liquid, the reaction is carried out for 60 s, the reaction liquid is quickly moved into an ice water bath at 0~4 DEG C, and the temperature is kept for 2 h until the reaction is completed, and a Ta-CsPbBr3 nanocrystal solution is obtained; the mass ratio of the cesium carbonate, the lead bromide and the pentabromide is 15.376:73.4:8~12.