Aggregation-induced emission-metal-organic framework probe and method for detecting chlorpyrifos

Abstract

The invention discloses an aggregation-induced emission-metal-organic framework probe which is prepared by taking manganese chloride tetrahydrate as a metal center and 1, 1, 2, 2-tetra (4-carboxybenzene) ethylene as an organic ligand through a one-pot solvothermal method. The invention discloses a method for detecting chlorpyrifos based on a fluorescence sensing system constructed by the aggregation-induced emission-metal-organic framework probe. The aggregation-induced emission-metal-organic framework probe disclosed by the invention has a low-fluorescence background, background signal interference during detection of chlorpyrifos can be reduced, and the sensitivity is improved. Meanwhile, enzyme mediation is introduced to serve as a controllable recognition element, specific and sensitive detection of chlorpyrifos is achieved, and the detection limit is 3.79 ng mL <-1 >. The aggregation-induced emission-metal-organic framework probe disclosed by the invention shows the advantages of high sensitivity, high selectivity, quick response, stability, simplicity and convenience in operation and the like in chlorpyrifos detection, and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of analysis and detection, and relates to an aggregation-induced emission-metal-organic framework (AIE-MOF) probe and a method for detecting ascorbic acid oxidase by a fluorescence sensing system constructed based on the aggregation-induced emission-metal-organic framework probe, and a method for detecting chlorpyrifos by a fluorescence sensing system constructed based on the aggregation-induced emission-metal-organic framework probe. Background Art

[0002] Organophosphorus pesticides (OPs) are essential for agricultural pest control, productivity improvement and economic benefits. Chlorpyrifos is a highly effective, broad-spectrum organophosphorus insecticide that plays an important role in agriculture. However, due to the widespread application and long-term overuse of chlorpyrifos, it has also led to serious environmental pollution and various health problems. Therefore, if a simple and sensitive chlorpyrifos detection method can be established, it can play a vital role in protecting the ecological environment and human health. Traditional chromatographic detection methods can effectively detect chlorpyrifos, but the detection equipment used is expensive and the detection process is time-consuming. It also requires well-trained staff and professional operation. Therefore, people are still working to develop simpler, more cost-effective and more reliable alternative methods to detect chlorpyrifos. Fluorescence technology has been praised for its sensitivity, convenience and cost-effectiveness, and has been widely adopted and become an effective method for detecting pesticides.

[0003] Metal-organic frameworks (MOFs), as a class of porous crystalline materials, are suitable for catalysis, gas storage, photocatalytic degradation, and sensor analysis due to their high specific surface area, adjustable porosity, and stable structure. The aggregation-induced emission (AIE) phenomenon is characterized by organic molecules showing weak or negligible fluorescence in solution, but strong fluorescence emission when aggregated. This property gives AIE materials the advantages of high signal-to-noise ratio and low background interference in fluorescence detection. By combining AIE molecules with MOFs, an efficient fluorescence sensor was constructed by utilizing the high specific surface area, physicochemical stability, adjustable pore size, and metal active sites of MOFs.

[0004] However, the signal output mode of existing AIE-MOF technology is relatively single, usually adopting an "on to off" signal output mode, which has a high background signal and limits the further improvement of sensitivity. Summary of the invention

[0005] The purpose of the present invention is to provide an aggregation-induced emission-metal-organic framework (AIE-MOF) probe, and to construct a fluorescence sensing system based on the AIE-MOF probe, which can be used for targeted and controllable fluorescence detection of chlorpyrifos. The fluorescence sensing system can achieve sensitive detection of chlorpyrifos by converting the inhibitory effect of chlorpyrifos on ascorbate oxidase into an AIE fluorescence signal, while having cost-effectiveness and environmental protection potential.

[0006] The purpose of the present invention is to be achieved through the following technical solutions:

[0007] An aggregation-induced emission-metal-organic framework (AIE-MOF) probe is prepared by a one-pot solvothermal method with manganese chloride tetrahydrate as the metal center and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene (H4TCPE) as the organic ligand.

[0008] Preferably, the aggregation-induced emission-metal-organic framework probe is prepared by dissolving manganese chloride tetrahydrate and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene in N,N-diethylacetamide, adding an appropriate amount of acetic acid to adjust the pore size, mixing, and reacting at a temperature of 100 to 120° C. for 12 to 16 hours; after the reaction is completed, centrifuging, discarding the supernatant, and washing the precipitate with acetonitrile to obtain an aggregation-induced emission-metal-organic framework probe.

[0009] Another object of the present invention is to provide a method for preparing an aggregation-induced emission-metal-organic framework (AIE-MOF) probe, comprising: dissolving manganese chloride tetrahydrate and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene (H4TCPE) in N,N-diethylacetamide, adding an appropriate amount of acetic acid, mixing, and reacting at a temperature of 100 to 120°C for 12 to 16 hours; after the reaction is completed, centrifuging, discarding the supernatant, and washing the precipitate with acetonitrile to obtain an aggregation-induced emission-metal-organic framework (AIE-MOF) probe.

[0010] The molar ratio of the manganese chloride tetrahydrate to 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene is 5:1-5.15:1.

[0011] The dosage ratio of the acetic acid to 1,1,2,2-tetra(4-carboxyphenyl)ethylene is 1:20-1:30 mL / mg.

[0012] The mass volume ratio of the 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene and N,N-diethylacetamide is 10:1-5:1 mg / mL.

[0013] Another object of the present invention is to provide a method for detecting ascorbate oxidase based on a fluorescence sensing system constructed based on the AIE-MOF probe, comprising the following steps:

[0014] Step (1), dispersing the AIE-MOF probe in acetonitrile and diluting it with ultrapure water to obtain an AIE-MOF probe dispersion, or dispersing the AIE-MOF probe in ultrapure water to obtain an AIE-MOF probe dispersion;

[0015] Step (2), constructing a fluorescence sensing system: adding ascorbate oxidase aqueous solution and ascorbic acid aqueous solution with different enzyme activities and ultrapure water to phosphate buffered saline (PBS), incubating at a temperature of 35-40°C for 30-50 minutes, adding AIE-MOF probe dispersion to the reaction system, reacting at a temperature of 35-40°C for 15-30 minutes, and obtaining a detection system; using a multi-label detection system, with 348nm as the excitation wavelength, measuring the fluorescence intensity of the detection system at 427nm, with the enzyme activity of ascorbate oxidase or its log value as the horizontal coordinate, and the fluorescence intensity at 427nm as the vertical coordinate, to establish an ascorbate oxidase standard curve;

[0016] Step (3), sample detection: According to step (2), the fluorescence intensity of the unknown ascorbate oxidase test sample at 427 nm when the excitation wavelength is 348 nm is measured, and the fluorescence intensity is substituted into the ascorbate oxidase standard curve of step (2) to obtain the concentration of ascorbate oxidase in the test sample.

[0017] In step (1), preferably, the AIE-MOF probe is dispersed in acetonitrile and diluted 4 times with ultrapure water to obtain an AIE-MOF probe dispersion.

[0018] In step (2), the pH of the phosphate buffered saline solution is 6.5-7.4, preferably pH 7.

[0019] In the detection system, the final concentration of ascorbic acid is 0.5-1.5 mM, preferably 1 mM; the final concentration of the AIE-MOF probe is 50-100 mg·L -1 , preferably 62.5 mg·L -1 ; The final concentration of ascorbate oxidase is 0.001~0.8U·mL -1 Ascorbic acid oxidase is 0.001~0.8U mL -1 It has good linearity within the range.

[0020] Preferably, the volume ratio of the phosphate buffered saline solution, the ascorbate oxidase aqueous solution, the ascorbic acid aqueous solution, the ultrapure water and the AIE-MOF probe dispersion is 1:1:1:6:1.

[0021] Preferably, the fluorescent sensing system is constructed as follows: an aqueous solution of ascorbic acid oxidase with different enzyme activities and an aqueous solution of ascorbic acid and ultrapure water are added to a phosphate buffered saline solution, incubated at 37°C for 40 minutes, an AIE-MOF probe dispersion is added to the reaction system, and the reaction is carried out at 37°C for 20 minutes to obtain a detection system.

[0022] In step (3), the sample detection is as follows: adding the sample to be tested, ascorbic acid aqueous solution and ultrapure water to a phosphate buffered saline solution, incubating at a temperature of 35 to 40° C. for 30 to 50 minutes, adding an AIE-MOF probe dispersion to the reaction system, reacting at a temperature of 35 to 40° C. for 15 to 30 minutes, and obtaining a detection system; using a multi-label detection system, with 348 nm as the excitation wavelength, and measuring the fluorescence intensity of the detection system at 427 nm.

[0023] Preferably, the sample detection is as follows: adding the sample to be tested, ascorbic acid aqueous solution and ultrapure water to a phosphate buffered saline solution, and incubating at a temperature of 37°C for 40 minutes; adding an AIE-MOF probe dispersion to the reaction system, reacting at a temperature of 37°C for 20 minutes, to obtain a detection system.

[0024] The volume ratio of the phosphate buffered saline solution, the sample to be tested, the ascorbic acid aqueous solution, the ultrapure water and the AIE-MOF probe dispersion is 1:1:1:6:1.

[0025] The pH of the phosphate buffered saline solution is 6.5-7.4, preferably pH 7.

[0026] In the detection system, the final concentration of ascorbic acid is 0.5-1.5 mM, preferably 1 mM; the final concentration of the AIE-MOF probe is 50-100 mg·L -1 , preferably 62.5 mg·L -1 .

[0027] Another object of the present invention is to provide a method for detecting chlorpyrifos using a fluorescence sensing system constructed based on the AIE-MOF probe, comprising the following steps:

[0028] Step (1), dispersing the AIE-MOF probe in acetonitrile and diluting it with ultrapure water to obtain an AIE-MOF probe dispersion, or dispersing the AIE-MOF probe in ultrapure water to obtain an AIE-MOF probe dispersion;

[0029] Step (2), constructing a fluorescence sensing system: adding different concentrations of chlorpyrifos methanol or aqueous solution and ascorbate oxidase aqueous solution to a phosphate buffered saline solution (PBS), incubating at a temperature of 35-40° C. for 50-80 minutes, then adding ascorbic acid aqueous solution and ultrapure water to the reaction system, reacting at a temperature of 35-40° C. for 15-40 minutes, finally adding an AIE-MOF probe dispersion to the reaction system, reacting at a temperature of 35-40° C. for 15-30 minutes, obtaining a detection system, using a multi-label detection system, taking 348 nm as an excitation wavelength, measuring the fluorescence intensity of the detection system at 427 nm, taking the concentration of chlorpyrifos or its log value as the horizontal coordinate, and taking the fluorescence intensity at 427 nm as the vertical coordinate, to establish a chlorpyrifos standard curve;

[0030] Step (3), sample testing: according to step (2), the fluorescence intensity of the sample to be tested with unknown chlorpyrifos concentration at 427 nm when the excitation wavelength is 348 nm is measured, and the fluorescence intensity is substituted into the chlorpyrifos standard curve of step (2) to obtain the concentration of chlorpyrifos in the sample to be tested.

[0031] In step (1), preferably, the AIE-MOF probe is dispersed in acetonitrile and diluted 4 times with ultrapure water to obtain an AIE-MOF probe dispersion.

[0032] In step (2), the pH of the phosphate buffered saline solution is 6.5-7.4, preferably pH 7.

[0033] In the detection system, the enzyme activity of ascorbic acid oxidase is 0.1-0.8 U·mL -1 , preferably 0.2 U·mL -1 The final concentration of ascorbic acid is 0.5-1.5 mM, preferably 1 mM; the final concentration of the AIE-MOF probe is 50-100 mg·L -1 , preferably 62.5 mg·L -1 The final concentration of chlorpyrifos is 0.005-5 mg·L -1 , chlorpyrifos is 0.005~5mg·L -1 It has good linearity within the range.

[0034] Preferably, the volume ratio of the phosphate buffered saline solution, the chlorpyrifos methanol solution, the ascorbate oxidase aqueous solution, the ascorbic acid aqueous solution, the ultrapure water and the AIE-MOF probe dispersion is 1:1:1:1:5:1.

[0035] Preferably, the fluorescent sensing system is constructed as follows: adding different concentrations of chlorpyrifos methanol solution and ascorbic acid oxidase aqueous solution to a phosphate buffered saline solution, incubating at a temperature of 35-40°C for 60-80 minutes, then adding ascorbic acid aqueous solution and ultrapure water to the reaction system, reacting at a temperature of 35-40°C for 15-40 minutes, and finally adding an AIE-MOF probe dispersion to the reaction system, reacting at a temperature of 35-40°C for 15-40 minutes to obtain a detection system.

[0036] More preferably, the fluorescent sensing system is constructed as follows: adding different concentrations of chlorpyrifos methanol solution and ascorbate oxidase aqueous solution to a phosphate buffered saline solution, incubating at 37°C for 60 minutes, then adding ascorbic acid aqueous solution and ultrapure water to the reaction system, reacting at 37°C for 40 minutes, and finally adding AIE-MOF probe dispersion to the reaction system, reacting at 37°C for 20 minutes to obtain a detection system.

[0037] In step (3), preferably, the sample detection is as follows: adding the sample to be tested and the ascorbic acid oxidase aqueous solution to a phosphate buffered saline solution (PBS), incubating at a temperature of 35 to 40°C for 50 to 80 minutes, then adding the ascorbic acid aqueous solution and ultrapure water to the reaction system, reacting at a temperature of 35 to 40°C for 15 to 40 minutes, and finally adding the AIE-MOF probe dispersion to the reaction system, reacting at a temperature of 35 to 40°C for 15 to 30 minutes to obtain a detection system.

[0038] Preferably, the fluorescent sensing system is constructed as follows: the sample to be tested and the ascorbic acid oxidase aqueous solution are added to the phosphate buffered saline solution, incubated at a temperature of 35-40°C for 60-80 minutes, then the ascorbic acid aqueous solution and ultrapure water are added to the reaction system, reacted at a temperature of 35-40°C for 15-40 minutes, and finally the AIE-MOF probe dispersion is added to the reaction system, reacted at a temperature of 35-40°C for 15-40 minutes to obtain a detection system.

[0039] More preferably, the fluorescent sensing system is constructed as follows: the sample to be tested and the ascorbic acid oxidase aqueous solution are added to the phosphate buffered saline solution, incubated at 37°C for 60 minutes, then the ascorbic acid aqueous solution and ultrapure water are added to the reaction system, reacted at 37°C for 40 minutes, and finally the AIE-MOF probe dispersion is added to the reaction system, reacted at 37°C for 20 minutes to obtain a detection system.

[0040] Preferably, the volume ratio of the phosphate buffered saline solution, the sample to be tested, the ascorbate oxidase aqueous solution, the ascorbic acid aqueous solution, the ultrapure water and the AIE-MOF probe dispersion is 1:1:1:1:5:1.

[0041] The samples to be tested are samples of crops, food, water samples, soil, etc. that may be contaminated by chlorpyrifos, obtained through conventional pretreatment in the art.

[0042] The preparation process of the AIE-MOF probe of the present invention is as follows Figure 1 As shown in the figure, the AIE-MOF probe was prepared by a one-pot solvothermal method using Mn clusters as metal nodes and capping agents and non-aggregated 1,1,2,2-tetra(4-carboxyphenyl)ethylene as organic ligands. The fluorescence of the AIE ligand in the AIE-MOF probe is due to The FRET is quenched by Mn(III), providing lower background fluorescence.

[0043] The working principle of the present invention is as follows Figure 2 When in an organic solvent (N,N-diethylacetamide), the fluorescence of non-aggregated AIE molecules is The resonance energy transfer (FRET) is quenched by Mn(III), resulting in a low fluorescence background of AIE-MOF (AIE-MOF). In the presence of ascorbic acid (AA), Mn(III) in AIE-MOF is reduced to Mn(II), which promotes the dissociation of the AIE-MOF skeleton and releases the AIE molecules into water. The AIE molecules re-aggregate to form aggregates in aqueous solution, which significantly enhances the fluorescence caused by AIE (AIE-MOF / AA). When AA is oxidized by ascorbate oxidase (AAox) (AIE-MOF / AA / AAox), the fluorescence recovery and aggregate emission of AIE molecules are weakened due to the limited delocalization of Mn(III) and the cleavage of the AIE-MOF skeleton. At the same time, chlorpyrifos hinders the consumption of AA by AAox by inhibiting the catalytic activity of AAox, allowing AA to continue to react with AIE-MOF and recover fluorescence (AIE-MOF / AA / AAox / chlorpyrifos). Therefore, the AIE-MOF / AA system provides a sensitive and highly selective method for the detection of chlorpyrifos by converting the inhibitory effect of chlorpyrifos on AAox into a fluorescent signal.

[0044] Based on the excellent fluorescence emission advantages of AIE molecules and the structurally adjustable characteristics of MOF skeletons, the present invention prepares a structurally stable AIE-MOF probe, which not only ensures the formation of a stable MOF structure, but also effectively improves the loading efficiency of AIE molecules. At the same time, the introduction of enzyme mediation as a controllable recognition element can sensitively detect chlorpyrifos in crops, showing the advantages of high sensitivity, high selectivity, rapid response, stability and simple operation, and has broad application prospects. Compared with the existing chlorpyrifos detection method, the present invention has the following advantages:

[0045] 1. The present invention utilizes the fluorescence properties of the AIE-MOF probe to achieve regulation of the fluorescence signal through the interaction between Mn(III) and the AIE ligand; in the presence of chlorpyrifos, the fluorescence signal is significantly enhanced, and the detection limit is 3.79 ng·mL -1 , which is lower than the maximum residue limit stipulated by China (0.2 mg·L -1 ), which can achieve high-sensitivity detection of chlorpyrifos.

[0046] 2. The AIE-MOF probe of the present invention is in the initial state by The resonance energy transfer (FRET) mechanism achieves fluorescence quenching, and the background fluorescence is extremely low, which can reduce the background signal interference when detecting chlorpyrifos and improve the sensitivity. This feature effectively solves the problem of high background signal in existing fluorescence detection methods and significantly improves the signal-to-noise ratio.

[0047] 3. The AIE-MOF probe of the present invention utilizes the specific inhibitory effect of chlorpyrifos on ascorbic acid oxidase (AAox) to convert the presence of chlorpyrifos into a fluorescent signal, thereby achieving specific detection of chlorpyrifos; compared with traditional detection methods, the present invention has higher selectivity and anti-interference ability.

[0048] 4. The manganese element released by the AIE-MOF probe of the present invention is beneficial to plant growth and can improve the stress resistance and yield of plants; compared with existing detection methods, the present invention not only reduces pollution to the environment, but also has cost-effectiveness and environmental protection potential.

[0049] 5. The AIE-MOF probe preparation method of the present invention is simple, does not require complex instruments and equipment and cumbersome steps, and is suitable for large-scale production and field application; compared with the traditional fluorescence sensor preparation method, the operation of the present invention is simpler and the cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Schematic diagram of the preparation of AIE-MOF probe.

[0051] Figure 2 Schematic diagram of the application of AIE-MOF probe to detect chlorpyrifos (A) and the working principle diagram of the fluorescence sensing system based on AIE-MOF probe to detect chlorpyrifos (B).

[0052] Figure 3is a characterization diagram of the AIE-MOF probe; wherein, A is the transmission electron microscope (TEM) image of the AIE-MOF probe; B is the particle size distribution diagram of the AIE-MOF probe; C is the X-ray diffraction diagram of the AIE-MOF probe, AIE-MOF is the X-ray diffraction diagram of the AIE-MOF probe, and Simulated AIE-MOF is the simulation data of the AIE-MOF probe; D is the Fourier transform infrared (FT-IR) spectrum of the AIE-MOF probe; E is the full X-ray photoelectron spectroscopy (XPS) spectrum of the AIE-MOF probe; and F is the fine X-ray photoelectron spectroscopy (XPS) spectrum of the AIE-MOF probe.

[0053] Figure 4 Figure 2 is the relationship between the fluorescence intensity of the AIE-MOF / AA system and the ascorbate oxidase activity; A is the fluorescence intensity of the AIE-MOF / AA system and the ascorbate oxidase activity (0, 0.001, 0.005, 0.01, 0.05, 0.1, 0.5 and 0.8 U mL -1 ) under fluorescence spectrum; B is the linear relationship between the fluorescence intensity of AIE-MOF / AA system and the ascorbic acid oxidase activity.

[0054] Figure 5 : The relationship between the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system and the chlorpyrifos concentration; A is the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system and the chlorpyrifos concentration (0, 0.005, 0.01, 0.05, 0.1, 0.5, 1 and 5 mg L -1 ) under the fluorescence spectrum; B is the linear relationship between the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system and the chlorpyrifos concentration.

[0055] Figure 6 The accumulation amount of chlorpyrifos in wheat was determined by HPLC method and fluorescence sensing system; wherein, A is the accumulation amount of chlorpyrifos in the aboveground tissues of wheat; and B is the accumulation amount of chlorpyrifos in the roots of wheat.

[0056] Figure 7 This is a diagram showing the optimization results of the detection conditions of the AIE-MOF probe; wherein A is the relationship between the fluorescence signal change rate ((F0-F) / F0) of chlorpyrifos and the activity of AAox for the AIE-MOF / AA / AAox / chlorpyrifos system; and B is the relationship between the 427nm fluorescence intensity and reaction time of the AIE-MOF / AA / AAox / chlorpyrifos system.

[0057] Figure 8The selectivity and anti-interference ability of the AIE-MOF probe are investigated in Figure 2. A represents atrazine, carbaryl, diazinon, fenitrothion, pyridazine, malathion, and chlorpyrifos (the final concentrations are all 1 mg·L -1 ); B is the fluorescence intensity change of AIE-MOF / AA / AAOx system after adding 1 mg L -1 Fluorescence intensity before (gray) and after (orange) chlorpyrifos, interfering substances including Na + , K + Mg 2+ 、Zn 2+ , Ca 2+ , Cl - and SO4 2- (50μM). DETAILED DESCRIPTION

[0058] Example 1

[0059] like Figure 1 , the AIE-MOF probe was prepared by a one-pot solvent method, the steps are as follows:

[0060] Manganese chloride tetrahydrate (50 mg) and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene (25 mg) were dissolved in 7.5 mL N,N-diethylacetamide, and 1 mL acetic acid was added and mixed; the mixture was placed in a polytetrafluoroethylene-lined autoclave, heated to 120°C, and reacted at 120°C for 16 hours. After the reaction was completed, it was cooled to room temperature and centrifuged at 10000 rpm for 10 minutes. The supernatant was discarded, and the precipitate was washed with acetonitrile to remove unreacted raw materials and generated by-products. The precipitate was washed three times in total. At this time, new acetonitrile was added. The acetonitrile did not change color, and the AIE-MOF probe was obtained. The AIE-MOF probe was light yellow needle-shaped crystals. The AIE-MOF probe was suspended in acetonitrile at a concentration of about 2.5 mg mL -1 .

[0061] The prepared AIE-MOF probe was characterized.

[0062] Transmission electron microscopy (TEM) images of the AIE-MOF probe show that the AIE-MOF probe is a hexagonal sheet with a diameter of about 500 nm ( Figure 3 A), which is consistent with the 620 nm diameter obtained by dynamic light scattering (DLS) analysis ( Figure 3 B). In the X-ray diffraction pattern of the AIE-MOF probe, the peaks observed at 2θ of approximately 6.9°, 9.7°, 14.1°, and 17.1° correspond to the (110), (200), (002), and (202) crystal planes, respectively, which are consistent with the simulation data ( Figure 3C), confirming the existence of the crystal structure of the AIE-MOF probe. The Fourier transform infrared (FT-IR) spectrum of the AIE-MOF probe shows a characteristic peak of the organic ligand H4TCPE at 1600 cm -1 and 1546cm -1 The strong peak at 1359cm -1 There is a medium peak at 1398cm -1 The strong peak at is the CO-Mn stretching vibration, indicating the existence of metal ion-carboxylate coordination bond ( Figure 3 D). Full X-ray photoelectron spectroscopy (XPS) spectrum of the AIE-MOF probe ( Figure 3 E) and X-ray photoelectron spectroscopy (XPS) fine spectra ( Figure 3 F) It can be seen that divalent and trivalent manganese coexist in the AIE-MOF probe.

[0063] The above characterizations all prove that the present invention successfully prepared the AIE-MOF probe.

[0064] Example 2

[0065] A method for detecting ascorbate oxidase based on a fluorescence sensing system constructed based on an AIE-MOF probe comprises the following steps:

[0066] Step (1), prepare the AIE-MOF probe according to Example 1, and suspend the AIE-MOF probe in acetonitrile at a concentration of about 2.5 mg mL -1 , and then diluted 4 times with ultrapure water to obtain a concentration of 625 mg·L -1 AIE-MOF probe dispersion;

[0067] Step (2), constructing a fluorescence sensing system: using ultrapure water to prepare ascorbic acid oxidase solutions with different enzyme activities (0, 0.01, 0.05, 0.1, 0.5, 1, 5, 8 U·mL -1 ), ascorbic acid solution (10 mM); different concentrations of ascorbate oxidase solution (20 μL, 0, 0.01, 0.05, 0.1, 0.5, 1, 5, 8 U·mL) were added to phosphate buffered saline (PBS, 20 μL, 10 mM, pH = 7.0) -1 ), ascorbic acid solution (20 μL, 10 mM) and ultrapure water (120 μL) were incubated at 37 °C for 40 min. Then, the AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), reacted at 37°C for 20 minutes to obtain the AIE-MOF / AA system, and a multi-label detection system was used to measure the fluorescence intensity of the AIE-MOF / AA system at 427 nm with an excitation wavelength of 348 nm ( Figure 4 A), ascorbate oxidase activity (C AAox ) as the horizontal axis, and the fluorescence intensity (F) at 427 nm as the vertical axis to establish the ascorbic acid oxidase standard curve ( Figure 4 B): F=1343685-3117963×logC AAox (R 2 =0.999), 0~0.8U mL -1 It has a good linear relationship within the range;

[0068] Step (3), detecting ascorbic acid oxidase in the sample based on the fluorescence sensing system; according to step (2), the fluorescence intensity of the unknown ascorbic acid oxidase activity at 427 nm is measured when the excitation wavelength is 348 nm, and the specific method is: adding the sample to be tested (20 μL), ascorbic acid solution (20 μL, 10 mM) and ultrapure water (120 μL) to a phosphate buffered saline solution (20 μL, 10 Mm, pH = 7.0), and incubating at 37°C for 40 minutes; then adding the AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), react at 37° C. for 20 minutes to obtain an AIE-MOF / AA system, and use a multi-label detection system with 348 nm as an excitation wavelength to measure the fluorescence intensity of the AIE-MOF / AA system at 427 nm; substitute the fluorescence intensity into the ascorbate oxidase standard curve of step (2) to obtain the concentration of ascorbate oxidase in the sample to be tested.

[0069] Example 3

[0070] A fluorescence sensing system based on AIE-MOF probe is used to detect the addition and recovery of chlorpyrifos, comprising the following steps:

[0071] Step (1), prepare the AIE-MOF probe according to Example 1, suspend the AIE-MOF probe in acetonitrile, and then dilute it with ultrapure water to obtain a concentration of 625 mg·L -1 AIE-MOF probe dispersion;

[0072] Step (2), constructing a fluorescence sensing system: methanol solutions of chlorpyrifos with different concentrations (0, 0.05, 0.1, 0.5, 1, 5, 50 mg mL -1 ), and ultrapure water was used to prepare ascorbic acid oxidase aqueous solution (2 U mL -1 ), ascorbic acid aqueous solution (10 mM); different concentrations of chlorpyrifos methanol solution (20 μL, 0, 0.05, 0.1, 0.5, 1, 5, 50 mg·L) were added to phosphate buffered saline (PBS, 20 μL, 10 mM, pH = 7.0)-1 ), ascorbate oxidase aqueous solution (20 μL, 2 U mL -1 ), reacted at 37°C for 60 min, then added ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL), and incubated at 37°C for 40 min; then added the dispersion of AIE-MOF probe (20 μL, 625 mg·L -1 ), reacted at 37°C for 20 minutes to obtain the AIE-MOF / AA / AAox / chlorpyrifos system, and the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system at 427 nm was measured using a multi-label detection system with an excitation wavelength of 348 nm ( Figure 5 A), the concentration of chlorpyrifos (C chlorpyrifos ) as the horizontal axis, and the fluorescence intensity at 427 nm as the vertical axis to establish a chlorpyrifos standard curve ( Figure 5 B); the linear equation is F = 8733676 + 2036536 × log C chlorpyrifos (R 2 =0.998);

[0073] Step (3), conducting a chlorpyrifos addition and recovery experiment in wheat samples: the wheat samples were divided into aerial parts and roots, and ground into powders respectively using liquid nitrogen; 2 g of aerial parts / root powders were weighed, and then 2, 5, and 10 mg·L of chlorpyrifos were added to the powders respectively; -1 Chlorpyrifos methanol solution (100 μL, i.e., spiked into the sample at concentrations of 0.1, 0.5, and 1.0 mg kg -1 of chlorpyrifos), shake evenly, and let stand for 30 minutes; use acetonitrile-water mixed solvent (10mL acetonitrile, 5mL water) to shake and extract at room temperature for 1 hour, centrifuge at 4000×g for 8 minutes, take the supernatant, take part of the supernatant, dilute 5 times with water, transfer to a centrifuge tube filled with 80mg CNWBONDHC-C18 QuEChERS special ultra-clean filler, shake for 2 minutes, centrifuge at low speed for 2 minutes, pass through a 0.22μm organic filter membrane, and obtain the added recovery test sample with chlorpyrifos added;

[0074] Step (4), add chlorpyrifos recovery sample (20 μL), ascorbate oxidase aqueous solution (20 μL, 2 U·mL) to phosphate buffered saline (20 μL, 10 Mm, pH = 7.0) -1 ), reacted at 37°C for 60 min, then added ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL), incubated at 37°C for 40 min, and added AIE-MOF probe (20 μL, 625 mg L -1) dispersion, react at 37°C for 20 minutes to obtain an AIE-MOF / AA / AAox / chlorpyrifos system, use a multi-label detection system, use 348nm as the excitation wavelength, record the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system at 427nm, substitute the fluorescence intensity into the chlorpyrifos standard curve of step (2) to obtain the concentration of chlorpyrifos in the sample to be tested; calculate the recovery rate in the actual sample, and the recovery rate results are shown in Table 1. The RSD of all measurements was kept within 5.75%, and these results highlight the advantages of the AIE-MOF / AA / AAox / chlorpyrifos system with reliability and high sensitivity.

[0075] Table 1. Recovery of chlorpyrifos in wheat samples

[0076]

[0077] Example 4

[0078] A method for detecting the accumulation of chlorpyrifos in crops using a fluorescence sensing system based on an AIE-MOF probe comprises the following steps:

[0079] Step (1), prepare the AIE-MOF probe according to Example 1, suspend the AIE-MOF probe in acetonitrile, and then dilute it with ultrapure water to obtain a concentration of 625 mg·L -1 AIE-MOF probe dispersion;

[0080] Step (2), construct a fluorescence sensing system according to step (2) of Example 3: add different concentrations of methanol solution of chlorpyrifos (20 μL, 0, 0.05, 0.1, 0.5, 1, 5, 50 mg·L) to phosphate buffered saline (PBS, 20 μL, 10 mM, pH = 7.0); -1 ), ascorbate oxidase aqueous solution (20 μL, 2 U mL -1 ), reacted at 37°C for 60 min, then added ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL), incubated at 37°C for 40 min; then added AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), reacting at 37° C. for 20 minutes to obtain an AIE-MOF / AA / AAox / chlorpyrifos system, using a multi-label detection system, with 348 nm as an excitation wavelength, to measure the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system at 427 nm, with the log value of the chlorpyrifos concentration as the abscissa and the fluorescence intensity at 427 nm as the ordinate, to establish a chlorpyrifos standard curve;

[0081] Step (3), taking the detection of chlorpyrifos in wheat as an example, the wheat seeds were disinfected and sterilized, and then germinated in an incubator (with a temperature cycle of 30°C / 25°C and a light / dark cycle of 14 hours / 10 hours) for 24 hours; after germination, the seeds were cultured in a 1 / 2 concentration Hoagland nutrient solution for 10 days under the same temperature and light conditions (with water changed every 2 days); then, chlorpyrifos solution was added to the nutrient solution, so that the final concentrations of chlorpyrifos in the nutrient solution were 0, 0.2, 0.6, 1.0, and 1.4 mg·L, respectively. -1 , cultured for 6 days (changing water every 2 days); the wheat plants were divided into aerial parts and roots, and ground into powders respectively by liquid nitrogen; 2 g of aerial parts / root powder was weighed, added into acetonitrile-water mixed solvent (10 mL acetonitrile, 5 mL water), and extracted by shaking for 1 hour at room temperature, and then 2 g sodium chloride was added, and the extraction was continued for 15 minutes, centrifuged at 4000×g for 8 minutes, and the supernatant was taken, and part of the supernatant was diluted 5 times with water, and transferred into a centrifuge tube containing 80 mg CNWBOND HC-C18 QuEChERS special ultra-clean filler, shaken for 2 minutes, centrifuged at low speed for 2 minutes, and filtered through a 0.22 μm organic filter membrane to obtain a sample with an unknown chlorpyrifos concentration;

[0082] Step (4), add the sample to be tested (20 μL) with unknown chlorpyrifos concentration and ascorbate oxidase aqueous solution (20 μL, 2 U·mL) to phosphate buffered saline (20 μL, 10 mM, pH=7.0). -1 ), reacted at 37°C for 60 min, then added ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL), and incubated at 37°C for 40 min; then added AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), react at 37° C. for 20 minutes to obtain an AIE-MOF / AA / AAox / chlorpyrifos system, record the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system at 427 nm with an excitation wavelength of 348 nm, substitute the fluorescence intensity into the chlorpyrifos standard curve of step (2) to obtain the concentration of chlorpyrifos in the sample to be tested, and compare it with the result measured by high performance liquid chromatography. The result is as follows: Figure 6 As shown (A is the above-ground part, B is the root). Compared with the high performance liquid chromatography method, the method of the present invention is simple to operate, can be used for large-scale detection, and only requires a small amount of solvent, which is more environmentally friendly.

[0083] The HPLC conditions were as follows: the chromatographic column was C18 (250 mm × 4.6 mm), the mobile phase was acetonitrile: water (55:45, volume ratio), and the flow rate was 1 mL min -1 , the detection wavelength is 230nm.

[0084] Example 5

[0085] Optimization of detection conditions for fluorescence sensing systems based on AIE-MOF probes

[0086] Different concentrations of ascorbate oxidase aqueous solution (20 μL, 1, 2, 5, 8 U·mL) were added to phosphate buffered saline (20 μL, 10 mM, pH = 7.0). -1 ) and methanol (20 μL) were incubated at 37°C for 60 min. Then, ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL) were added and incubated at 37°C for 40 min. Then, AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), react at 37°C for 20 minutes to obtain the AIE-MOF / AA / AAox system, and then record the fluorescence intensity of the AIE-MOF / AA / AAox system at 427 nm under an excitation wavelength of 348 nm, which is recorded as F0.

[0087] Different concentrations of ascorbate oxidase aqueous solution (20 μL, 1, 2, 5, 8 U·mL) were added to phosphate buffered saline (20 μL, 10 mM, pH = 7.0). -1 ) and a methanol solution of chlorpyrifos (20 μL, 50 mg·L -1 ), incubated at 37°C for 60 min; then added ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL), incubated at 37°C for 40 min; then added AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), react at 37°C for 20 minutes to obtain the AIE-MOF / AA / AAox / chlorpyrifos system, and then record the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system at 427 nm under an excitation wavelength of 348 nm, denoted as F.

[0088] The fluorescence signal change ratio ((F-F0) / F0) of the AIE-MOF / AA / AAox / chlorpyrifos system was calculated.

[0089] Results Figure 7 A, indicating that: when the ascorbic acid oxidase activity is 0.2U·mL -1 When the fluorescence signal change ratio of the AIE-MOF / AA / AAox / chlorpyrifos system reached the maximum value, the ascorbate oxidase activity of 0.2 U·mL was finally selected. -1 For the best conditions.

[0090] Example 6

[0091] Optimization of the reaction time of ascorbate oxidase and chlorpyrifos

[0092] Ascorbate oxidase aqueous solution (20 μL, 2 U mL -1 ) and a methanol solution of chlorpyrifos (20 μL, 50 mg·L -1 ), incubated at 37°C for 0, 5, 10, 20, 30, 40, 60, and 80 min, respectively; then, ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL) were added, and incubated at 37°C for 40 min; then, the AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), reacted at 37°C for 20 minutes to obtain the AIE-MOF / AA / AAox / chlorpyrifos system, with 348 nm as the excitation wavelength, and the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system at 427 nm was recorded.

[0093] Results Figure 7 B, indicating that when ascorbate oxidase reacts with chlorpyrifos for 60 minutes, the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system reaches a maximum value, and the fluorescence intensity no longer increases with the increase of reaction time; therefore, the reaction time of ascorbate oxidase and chlorpyrifos is selected as 60 minutes as the optimal condition.

[0094] Example 7

[0095] Investigating the selectivity of the AIE-MOF / AA / AAox system for chlorpyrifos

[0096] Ascorbate oxidase aqueous solution (20 μL, 2 U mL -1 ) and other pesticides (atrazine, carbaryl, diazinon, fenitrothion, pyridaphenthion, malathion) or methanol solution of chlorpyrifos (20 μL, the pesticide concentration is 10 mg·L -1 ), incubated at 37°C for 60 min, then added ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (100 μL), and incubated at 37°C for 40 min; then added AIE-MOF probe dispersion (20 μL, 625 mg·L -1), react at 37°C for 20 minutes to obtain the AIE-MOF / AA / AAox / pesticide system, and then record the fluorescence intensity F of the AIE-MOF / AA / AAox / pesticide system at 427nm with an excitation wavelength of 348nm. At the same time, record the fluorescence intensity F0 of the AIE-MOF / AA / AAox system without adding pesticides at 427nm with an excitation wavelength of 348nm.

[0097] Results Figure 8 A. Compared with the ΔF of chlorpyrifos (ΔF = F-F0), the above six control pesticides have relatively weak effects on the AIE-MOF / AA / AAox system. The signal change caused by chlorpyrifos is more than 5 times that of atrazine, fenitrothion and malathion, while the signal changes caused by carbaryl and diazinon are only about 6.76% and 7.30% of chlorpyrifos, respectively. In addition, the response of the sensing system to pyridazithion, which has a similar structure to chlorpyrifos, is only 32.25% of that of chlorpyrifos. The above results show that the AIE-MOF / AA / AAox system has good selectivity for chlorpyrifos.

[0098] Example 8

[0099] Investigation of the anti-ion interference ability of AIE-MOF / AA / AAox and AIE-MOF / AA / AAox / chlorpyrifos systems

[0100] Ascorbate oxidase aqueous solution (20 μL, 2 U mL -1 ) and methanol (20 μL), incubated at 37°C for 60 min, added ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (90 μL), and then added Na + ,K + Mg 2+ ,Zn 2+ ,Ca 2+ ,Cl - or SO4 2- The aqueous solution (10 μL, 1 mM) was incubated at 37 °C for 40 min. Then, the AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), react at 37°C for 20 minutes to obtain the AIE-MOF / AA / AAox system, take 348 nm as the excitation wavelength, and record the fluorescence intensity of the AIE-MOF / AA / AAox system at 427 nm.

[0101] Ascorbate oxidase aqueous solution (20 μL, 2 U mL -1) and a methanol solution of chlorpyrifos (20 μL, 10 mg·L -1 ), incubate at 37°C for 60 min, add ascorbic acid aqueous solution (20 μL, 10 mM) and ultrapure water (90 μL), then add Na + ,K + Mg 2+ ,Zn 2+ ,Ca 2+ ,Cl - or SO4 2- The aqueous solution (10 μL, 1 mM) was incubated at 37 °C for 40 min. Then, the AIE-MOF probe dispersion (20 μL, 625 mg·L -1 ), reacted at 37°C for 20 minutes to obtain the AIE-MOF / AA / AAox / chlorpyrifos system, with 348 nm as the excitation wavelength, and the fluorescence intensity of the AIE-MOF / AA / AAox / chlorpyrifos system at 427 nm was recorded.

[0102] Results Figure 8 B, In the AIE-MOF / AA / AAox system, the signal change rate caused by these interfering ions was less than 3.9% compared with the blank group. In the AIE-MOF / AA / AAox / chlorpyrifos system, even in the presence of various interfering ions, the fluorescence intensity response of the AIE-MOF / AA / AAox / chlorpyrifos system to chlorpyrifos was not affected. The above results confirm that the AIE-MOF / AA / AAox / chlorpyrifos system has good resistance to ion interference.

Claims

1. An aggregation-induced emission-metal-organic framework probe, characterized in that: It is prepared by a one-pot solvothermal method with manganese chloride tetrahydrate as the metal center and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene as the organic ligand.

2. The aggregation-induced emission-metal-organic framework probe according to claim 1, characterized in that: The aggregation-induced emission-metal-organic framework probe is prepared by dissolving manganese chloride tetrahydrate and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene in N,N-diethylacetamide, dropping an appropriate amount of acetic acid, mixing, and reacting at a temperature of 100-120°C for 12-16 hours; after the reaction is completed, centrifuging, discarding the supernatant, and washing the precipitate with acetonitrile to obtain the aggregation-induced emission-metal-organic framework probe; wherein the molar ratio of manganese chloride tetrahydrate and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene is 5:1-5.15:1; the dosage ratio of acetic acid and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene is 1:20-1:30 mL / mg; and the mass-to-volume ratio of 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene and N,N-diethylacetamide is 10:1-5:1 mg / mL.

3. A method for detecting ascorbate oxidase based on the fluorescence sensing system constructed by the aggregation-induced emission-metal-organic framework probe according to claim 1, characterized in that: The steps include: Step (1), dispersing the aggregation-induced emission-metal-organic framework probe in acetonitrile and diluting it with ultrapure water to obtain an aggregation-induced emission-metal-organic framework probe dispersion, or dispersing the aggregation-induced emission-metal-organic framework probe in ultrapure water to obtain an aggregation-induced emission-metal-organic framework probe dispersion; Step (2), constructing a fluorescence sensing system: adding ascorbate oxidase aqueous solution and ascorbic acid aqueous solution with different enzyme activities and ultrapure water to a phosphate buffered saline solution, incubating at a temperature of 35 to 40° C. for 30 to 50 minutes, adding an aggregation-induced emission-metal-organic framework probe dispersion to the reaction system, reacting at a temperature of 35 to 40° C. for 15 to 30 minutes, and obtaining a detection system; using 348 nm as an excitation wavelength, measuring the fluorescence intensity of the detection system at 427 nm, using the enzyme activity of ascorbate oxidase or its log value as the horizontal coordinate, and using the fluorescence intensity at 427 nm as the vertical coordinate, to establish an ascorbate oxidase standard curve; Step (3), sample detection: According to step (2), the fluorescence intensity of the unknown ascorbate oxidase test sample at 427 nm when the excitation wavelength is 348 nm is measured, and the fluorescence intensity is substituted into the ascorbate oxidase standard curve of step (2) to obtain the concentration of ascorbate oxidase in the test sample.

4. The method for detecting ascorbate oxidase according to claim 3, characterized in that: In step (2), the pH of the phosphate buffered saline solution is 6.5-7.4, preferably pH 7.

5. The method for detecting ascorbic acid oxidase according to claim 3, characterized in that: In step (2), in the detection system, the final concentration of ascorbic acid is 0.5-1.5 mM, preferably 1 mM; the final concentration of the aggregation-induced emission-metal-organic framework probe is 50-100 mg·L -1 , preferably 62.5 mg·L -1 ; The final concentration of ascorbate oxidase is 0.001~0.8U·mL -1 .

6. A method for detecting chlorpyrifos based on the fluorescence sensing system constructed by the aggregation-induced emission-metal-organic framework probe according to claim 1, characterized in that: The steps include: Step (1), dispersing the aggregation-induced emission-metal-organic framework probe in acetonitrile and diluting it with ultrapure water to obtain an aggregation-induced emission-metal-organic framework probe dispersion, or dispersing the aggregation-induced emission-metal-organic framework probe in ultrapure water to obtain an aggregation-induced emission-metal-organic framework probe dispersion; Step (2), constructing a fluorescence sensing system: adding different concentrations of chlorpyrifos methanol or aqueous solution and ascorbate oxidase aqueous solution to a phosphate buffered saline solution (PBS), incubating at a temperature of 35 to 40° C. for 50 to 80 minutes, then adding ascorbic acid aqueous solution and ultrapure water to the reaction system, reacting at a temperature of 35 to 40° C. for 15 to 40 minutes, finally adding an aggregation-induced emission-metal-organic framework probe dispersion to the reaction system, reacting at a temperature of 35 to 40° C. for 15 to 30 minutes, obtaining a detection system, taking 348 nm as an excitation wavelength, measuring the fluorescence intensity of the detection system at 427 nm, taking the concentration of chlorpyrifos or its log value as the horizontal coordinate, and taking the fluorescence intensity at 427 nm as the vertical coordinate, and establishing a chlorpyrifos standard curve; Step (3), sample testing; according to step (2), the fluorescence intensity of the sample to be tested with unknown chlorpyrifos concentration at 427 nm when the excitation wavelength is 348 nm is measured, and the fluorescence intensity value is substituted into the chlorpyrifos standard curve of step (2) to obtain the concentration of chlorpyrifos in the sample to be tested.

7. The method for detecting chlorpyrifos according to claim 6, characterized in that: In step (2), the pH of the phosphate buffered saline solution is 6.5-7.4, preferably pH 7.

8. The method for detecting chlorpyrifos according to claim 6, characterized in that: In step (2), in the detection system, the enzyme activity of ascorbic acid oxidase is 0.1 to 0.8 U·mL -1 , preferably 0.2 U·mL -1 The final concentration of ascorbic acid is 0.5-1.5 mM, preferably 1 mM; the final concentration of the aggregation-induced emission-metal-organic framework probe is 50-100 mg·L -1 , preferably 62.5 mg·L -1 The final concentration of chlorpyrifos is 0.005-5 mg·L -1 .

9. The method for detecting chlorpyrifos according to claim 6, characterized in that: In step (2), the fluorescent sensing system is constructed as follows: adding different concentrations of chlorpyrifos methanol solution and ascorbate oxidase aqueous solution to a phosphate buffered saline solution, incubating at a temperature of 35 to 40°C for 60 to 80 minutes, then adding ascorbic acid aqueous solution and ultrapure water to the reaction system, reacting at a temperature of 35 to 40°C for 15 to 40 minutes, and finally adding an AIE-MOF probe dispersion to the reaction system, reacting at a temperature of 35 to 40°C for 15 to 40 minutes to obtain a detection system.

10. The method for detecting chlorpyrifos according to claim 6 or 9, characterized in that: In step (2), the fluorescent sensing system is constructed as follows: adding different concentrations of chlorpyrifos methanol solution and ascorbate oxidase aqueous solution to a phosphate buffered saline solution, incubating at a temperature of 37°C for 60 minutes, then adding ascorbic acid aqueous solution and ultrapure water to the reaction system, reacting at a temperature of 37°C for 40 minutes, and finally adding an AIE-MOF probe dispersion to the reaction system, reacting at 37°C for 20 minutes to obtain a detection system.

Images