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

Abstract

The invention discloses an aggregation-induced emission-metal-organic framework probe which is prepared by taking copper hydroxide 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 diazinon by using a fluorescence sensing system constructed based on the aggregation-induced emission-metal-organic framework probe. The aggregation-induced emission-metal-organic framework probe is extremely low in background fluorescence, background signal interference during diazinon detection can be reduced, and sensitivity is improved. Meanwhile, enzyme mediation is introduced to serve as a controllable recognition element, specific and sensitive detection of diazinon is achieved, and the detection limit is 0.14 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 diazinon detection, and has a wide application prospect.

Description

Technical Field

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

[0002] Organophosphorus pesticides such as diazinon, as important substitutes for organochlorine pesticides, play a key role in the prevention and control of agricultural pests and diseases in modern agriculture due to their economy and broad-spectrum insecticidal properties. However, based on the potential toxicity and environmental persistence of diazinon, the World Health Organization has classified it as a class II moderately hazardous compound. Therefore, there is an urgent need to develop a rapid, efficient, and convenient method for detecting diazinon, which can also respond to the growing public demand for food safety and environmental protection. Although researchers have established a mature system based on traditional detection technologies such as chromatography and mass spectrometry, these methods generally have limitations such as complex operation, high cost, and time-consuming, prompting researchers to seek more efficient and economical alternative solutions. In recent years, fluorescence analysis has shown excellent application prospects in the field of pesticide detection due to its advantages such as low cost, rapid response, high sensitivity, and visualization.

[0003] Among many fluorescence detection mechanisms, the aggregation-induced emission (AIE) phenomenon is particularly remarkable: such fluorescent molecules have weak fluorescence in the solution state, but significantly enhanced fluorescence in the aqueous phase aggregated state. This "aggregation-enhanced" effect stems from the restriction of intramolecular motion and vibration. With the development of metal-organic framework (MOFs) materials, by combining AIE luminophores as organic ligands with metal centers through coordination bonds, an AIE-MOFs composite system with both AIE characteristics and MOFs advantages has been successfully constructed. Such materials not only inherit the characteristics of MOFs such as high specific surface area, adjustable pore size, rich active sites, and strong stability, but also enhance the AIE performance through the structure-aggregation synergistic effect, significantly improving the luminescence efficiency and signal regulation ability in the aqueous environment. These characteristics have attracted much attention to AIE-MOFs in the fields of bioimaging, light-emitting devices, and biosensing. However, existing AIE-MOFs are mostly based on a simple "on-off" detection mode, and target recognition is achieved through energy transfer, which has defects such as insufficient selectivity and limited sensitivity. Therefore, introducing a molecular switch recognition element into AIE-MOFs to construct a controllable fluorescence recognition system has become the key to improving selectivity. Summary of the Invention

[0004] The object of the present invention is to provide a fluorescence sensing system based on an aggregation-induced emission-metal-organic framework (AIE-MOF) probe, which innovatively realizes the targeted detection and sensitive analysis of the organophosphorus pesticide diazinon. The core technology of this system lies in: precisely designing a metal-organic framework material with AIE characteristics as a signal carrier, and ingeniously constructing an "enzyme inhibition-fluorescence response" detection mechanism.

[0005] The object of the present invention is achieved by the following technical solutions:

[0006] An aggregation-induced emission-metal-organic framework (AIE-MOF) probe (denoted as Cu-TCPE) is prepared by a one-pot solvothermal method using copper hydroxide as the metal center and 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene (H4TCPE) as the organic ligand.

[0007] Preferably, the aggregation-induced emission-metal-organic framework probe is prepared by mixing copper hydroxide, 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene, and N,N-dimethylformamide (DMF), adding an appropriate amount of acetic acid to adjust the pore size, mixing evenly, and reacting at a temperature of 100 - 140 °C for 10 - 16 hours; after the reaction, centrifuging, discarding the supernatant, and washing the precipitate with DMF to obtain the aggregation-induced emission-metal-organic framework probe.

[0008] Another object of the present invention is to provide a preparation method of an aggregation-induced emission-metal-organic framework (AIE-MOF) probe, including: mixing copper hydroxide, 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene (H4TCPE), and DMF, adding an appropriate amount of acetic acid, mixing evenly, and reacting at a temperature of 100 - 140 °C for 10 - 16 hours; after the reaction, centrifuging, discarding the supernatant, and washing the precipitate with DMF to obtain the aggregation-induced emission-metal-organic framework (AIE-MOF) probe.

[0009] The molar ratio of copper hydroxide to 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene is 6:1 - 1:1, preferably 2:1.

[0010] The dosage ratio of acetic acid to 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene is 1:200 - 1:300 mL / mg.

[0011] The mass-volume ratio of 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene to N,N-dimethylformamide is 15:1 - 10:1 mg / mL.

[0012] Specifically, a method for preparing an aggregation-induced emission-metal-organic framework (AIE-MOF) probe includes: dispersing copper hydroxide in DMF to obtain a copper hydroxide dispersion; dissolving 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene in DMF to obtain a 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene solution; mixing the copper hydroxide dispersion and the 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene solution, adding an appropriate amount of acetic acid, mixing evenly, and reacting at a temperature of 100-140 °C for 10-16 hours; after the reaction, centrifuging, discarding the supernatant, and washing the precipitate with DMF to obtain an aggregation-induced emission-metal-organic framework probe.

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

[0014] Step (1): Disperse the AIE-MOF probe in DMF and dilute it with ultrapure water to obtain an AIE-MOF probe dispersion, or disperse the AIE-MOF probe in ultrapure water to obtain an AIE-MOF probe dispersion;

[0015] Step (2): Construct a fluorescence sensing system: Add different concentrations of diazinon methanol or aqueous solution and glutathione peroxidase aqueous solution to a phosphate buffer solution (PBS), incubate at a temperature of 35-40 °C for 40-60 minutes, then add glutathione aqueous solution and hydrogen peroxide aqueous solution to the reaction system, react at a temperature of 35-40 °C for 60-80 minutes, and finally add the AIE-MOF probe dispersion and ultrapure water to the reaction system, react at a temperature of 35-40 °C for 20-40 minutes to obtain a detection system. Use a multi-label detection system, with an excitation wavelength of 372 nm, measure the fluorescence intensity of the detection system at 478 nm, use the concentration of diazinon or its log value as the abscissa, and the fluorescence intensity at 478 nm as the ordinate to establish a diazinon standard curve;

[0016] Step (3): Sample detection; According to the fluorescence intensity of the unknown diazinon concentration test sample measured in step (2) at an excitation wavelength of 372 nm at 478 nm, substitute the fluorescence intensity into the diazinon standard curve in step (2) to obtain the concentration of diazinon in the test sample.

[0017] In step (1), preferably, disperse the AIE-MOF probe in DMF and dilute it 30 times with ultrapure water to obtain an AIE-MOF probe dispersion.

[0018] In step (2), the pH of the phosphate buffer solution is 6.5-7.4, preferably pH 7.0.

[0019] In the detection system described above, the final concentration of the enzyme activity of glutathione peroxidase is 20 - 40 mU·mL -1 , preferably 30 mU·mL -1 ; the final concentration of glutathione is 0.15 - 0.3 mM, preferably 0.2 mM; the final concentration of hydrogen peroxide is 0.15 - 0.3 mM, preferably 0.2 mM; the final concentration of the AIE-MOF probe is 20 - 50 mg·L -1 , preferably 25 mg·L -1 ; the final concentration of diazinon is 0.001 - 0.2 mg·L -1 , and diazinon has good linearity within the range of 0.001 - 0.2 mg·L -1 .

[0020] Preferably, the volume ratio of the phosphate buffer solution, diazinon methanol or aqueous solution, glutathione peroxidase aqueous solution, glutathione aqueous solution, hydrogen peroxide aqueous solution, ultrapure water and AIE-MOF probe dispersion is 2:1:2:2:2:9:2.

[0021] Preferably, for the construction of the fluorescence sensing system: add diazinon methanol solutions with different concentrations and glutathione peroxidase aqueous solution to the phosphate buffer solution, incubate at a temperature of 35 - 40 °C for 40 - 60 minutes, then add glutathione aqueous solution and hydrogen peroxide aqueous solution to the reaction system, react at a temperature of 35 - 40 °C for 60 - 80 minutes, and finally add the AIE-MOF probe dispersion and ultrapure water to the reaction system, react at a temperature of 35 - 40 °C for 20 - 40 minutes to obtain the detection system.

[0022] More preferably, for the construction of the fluorescence sensing system: add diazinon methanol solutions with different concentrations and glutathione peroxidase aqueous solution to the phosphate buffer solution, incubate at a temperature of 37 °C for 40 minutes, then add glutathione aqueous solution and hydrogen peroxide aqueous solution to the reaction system, react at a temperature of 37 °C for 60 minutes, and finally add the AIE-MOF probe dispersion and ultrapure water to the reaction system, react at a temperature of 37 °C for 30 minutes to obtain the detection system.

[0023] In step (3), for the detection of the sample: add the sample to be tested and glutathione peroxidase aqueous solution to the phosphate buffer solution (PBS), incubate at a temperature of 35 - 40 °C for 40 - 60 minutes, then add glutathione aqueous solution and hydrogen peroxide aqueous solution to the reaction system, react at a temperature of 35 - 40 °C for 60 - 80 minutes, and finally add the AIE-MOF probe dispersion and ultrapure water to the reaction system, react at a temperature of 35 - 40 °C for 20 - 40 minutes to obtain the detection system.

[0024] Preferably, the construction of the fluorescence sensing system is as follows: Add the sample to be tested and an aqueous solution of glutathione peroxidase to a phosphate buffer solution, incubate at 37 °C for 40 minutes, then add an aqueous solution of glutathione and an aqueous solution of hydrogen peroxide to the reaction system, react at 37 °C for 60 minutes, and finally add the AIE-MOF probe dispersion and ultrapure water to the reaction system, and react at 37 °C for 30 minutes to obtain the detection system.

[0025] Preferably, the volume ratio of the phosphate buffer solution, the sample to be tested, the aqueous solution of glutathione peroxidase, the aqueous solution of glutathione, the aqueous solution of hydrogen peroxide, the ultrapure water, and the AIE-MOF probe dispersion is 2:1:2:2:2:9:2.

[0026] In the detection system, the final concentration of the enzyme activity of glutathione peroxidase is 20 - 40 mU·mL -1 , preferably 30 mU·mL -1 ; the final concentration of glutathione is 0.15 - 0.3 mM, preferably 0.2 mM; the final concentration of hydrogen peroxide is 0.15 - 0.3 mM, preferably 0.2 mM; the final concentration of the AIE-MOF probe is 20 - 50 mg·L -1 , preferably 25 mg·L -1 .

[0027] The sample to be tested is a crop that may be contaminated with diazinon and is a sample obtained through conventional pretreatment in the art.

[0028] Another object of the present invention is to provide a method for detecting glutathione peroxidase based on the fluorescence sensing system constructed with the AIE-MOF probe, comprising the following steps:

[0029] Step (1), Disperse the AIE-MOF probe in DMF and dilute it with ultrapure water to obtain the AIE-MOF probe dispersion, or disperse the AIE-MOF probe in ultrapure water to obtain the AIE-MOF probe dispersion;

[0030] Step (2), Construct the fluorescence sensing system: Add an aqueous solution of glutathione peroxidase with different enzyme activities, an aqueous solution of glutathione, and an aqueous solution of hydrogen peroxide to a phosphate buffer solution (PBS), incubate at 35 - 40 °C for 40 - 60 minutes, add the AIE-MOF probe dispersion and ultrapure water to the reaction system, and react at 35 - 40 °C for 20 - 40 minutes to obtain the detection system; Use a multi-label detection system, with 372 nm as the excitation wavelength, measure the fluorescence intensity of the detection system at 478 nm, use the enzyme activity of glutathione peroxidase as the abscissa, and the fluorescence intensity at 478 nm as the ordinate to establish a standard curve of glutathione peroxidase;

[0031] Step (3), sample detection: According to step (2), measure the fluorescence intensity of the unknown glutathione peroxidase sample to be tested at 478 nm when the excitation wavelength is 372 nm, and substitute the fluorescence intensity into the glutathione peroxidase standard curve in step (2) to obtain the concentration of glutathione peroxidase in the sample to be tested.

[0032] In step (1), preferably, the AIE-MOF probe is dispersed in DMF and diluted 30 times with ultrapure water to obtain an AIE-MOF probe dispersion.

[0033] In step (2), the pH of the phosphate buffer solution is 6.5 - 7.4, preferably pH 7.0.

[0034] In the detection system described above, the final concentration of glutathione is 0.15 - 0.3 mM, preferably 0.2 mM; the final concentration of hydrogen peroxide is 0.15 - 0.3 mM, preferably 0.2 mM; the final concentration of the AIE-MOF probe is 20 - 50 mg·L -1 , preferably 25 mg·L -1 ; the final concentration of the enzyme activity of glutathione peroxidase is 0.1 - 30 mU·mL -1 . Glutathione peroxidase has good linearity in the range of 0.1 - 30 mU·mL -1 .

[0035] Preferably, the volume ratio of the phosphate buffer solution, the glutathione peroxidase aqueous solution, the glutathione aqueous solution, the hydrogen peroxide aqueous solution, the ultrapure water, and the AIE-MOF probe dispersion is 1:1:1:1:5:1.

[0036] Preferably, the construction of the fluorescence sensing system: Add the glutathione peroxidase aqueous solution, the glutathione aqueous solution, and the hydrogen peroxide aqueous solution with different enzyme activities to the phosphate buffer solution, incubate at 37 °C for 60 minutes, add the AIE-MOF probe dispersion and ultrapure water to the reaction system, and react at 37 °C for 30 minutes to obtain a detection system.

[0037] In step (3), the sample detection is as follows: Add the sample to be tested, the glutathione aqueous solution, and the hydrogen peroxide aqueous solution to the phosphate buffer solution, incubate at 35 - 40 °C for 60 - 80 minutes, add the AIE-MOF probe dispersion and ultrapure water to the reaction system, and react at 35 - 40 °C for 20 - 40 minutes to obtain a detection system; use a multi-label detection system, with 372 nm as the excitation wavelength, and measure the fluorescence intensity of the detection system at 478 nm.

[0038] Preferably, the sample detection is as follows: Add the sample to be tested, an aqueous glutathione solution, and an aqueous hydrogen peroxide solution to a phosphate buffer solution, and incubate at 37 °C for 60 minutes; Add the AIE-MOF probe dispersion and ultrapure water to the reaction system, and react at 37 °C for 30 minutes to obtain a detection system.

[0039] The volume ratio of the phosphate buffer solution, the sample to be tested, the aqueous glutathione solution, the aqueous hydrogen peroxide solution, the ultrapure water, and the AIE-MOF probe dispersion is 1:1:1:1:5:1.

[0040] The pH of the phosphate buffer solution is 6.5 to 7.4, preferably pH 7.0.

[0041] In the detection system, the final concentration of glutathione is 0.15 to 0.3 mM, preferably 0.2 mM; the final concentration of hydrogen peroxide is 0.15 to 0.3 mM, preferably 0.2 mM; the final concentration of the AIE-MOF probe is 20 to 50 mg·L -1 , preferably 25 mg·L -1 .

[0042] The preparation process of the AIE-MOF probe of the present invention is as Figure 1 shown. Using copper hydroxide as the metal node and the capping agent, and non-aggregated 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene as the organic ligand, the AIE-MOF probe is prepared by a one-pot solvothermal method. The fluorescence of the AIE ligand in the AIE-MOF probe is quenched by the electron transfer induced by Cu(II), providing a low background fluorescence.

[0043] The working principle of the present invention is as Figure 2As shown in the figure. In an organic solvent (DMF), the fluorescence of the non-aggregated AIE molecules is quenched by the electron transfer induced by Cu(II), resulting in a low fluorescence background of AIE-MOF. In the presence of glutathione (GSH), Cu(II) in AIE-MOF is reduced to Cu(I), promoting the dissociation of the AIE-MOF framework and releasing the AIE molecules into water. The AIE molecules re-aggregate in aqueous solution to form aggregates, significantly enhancing the fluorescence caused by AIE (AIE-MOF / GSH). When GSH is oxidized by glutathione peroxidase (GPx) (AIE-MOF / GSH / GPx), due to the limited cleavage of the AIE-MOF framework, the aggregation-induced emission of AIE molecules is weakened. At the same time, diazinon inhibits the catalytic activity of GPx and hinders the consumption of GSH by GPx, enabling GSH to continue to react with AIE-MOF and restore fluorescence (AIE-MOF / GSH / GPx / diazinon). Therefore, the AIE-MOF / GSH system provides a sensitive and highly selective method for detecting diazinon by converting the inhibitory effect of diazinon on GPx into a fluorescence signal.

[0044] Based on the unique fluorescence enhancement characteristics of AIE molecules, combined with the structural designability and high porosity advantages of MOF materials, the present invention innovatively constructs an AIE-MOF probe with a stable crystalline structure. Through a coordination-driven self-assembly strategy, this probe realizes the efficient loading of AIE molecules in the MOF framework, effectively solving the "aggregation-induced quenching" problem caused by molecular dispersion in traditional fluorescence probes. Compared with the existing detection methods for diazinon, the aggregation-induced emission-metal-organic framework probe of the present invention exhibits advantages such as high sensitivity, high selectivity, rapid response, stability, and simplicity in diazinon detection, and has broad application prospects. The present invention has the following advantages:

[0045] 1. The present invention utilizes the high specific surface area of MOF materials and combines with an aqueous detection system, significantly reducing the detection cost. It does not require complex instruments and cumbersome procedures, and is suitable for large-scale production and on-site applications; compared with the traditional preparation methods of fluorescence sensors, the operation of the present invention is more convenient and the cost is lower.

[0046] 2. The present invention utilizes the fluorescence characteristics of the AIE-MOF probe to regulate the fluorescence signal through the interaction between Cu(II) and the AIE ligand; in the presence of diazinon, the fluorescence signal is significantly enhanced, and the detection limit is 0.14 ng·mL -1 , lower than the maximum residue limit (100 ng·mL -1 ) stipulated by the Ministry of Agriculture and Rural Affairs of China, enabling highly sensitive detection of diazinon.

[0047] 3. The AIE-MOF probe of the present invention achieves fluorescence quenching through Cu(II)-induced electron transfer in the initial state, with extremely low background fluorescence, which can reduce the interference of background signals during the detection of diazinon and improve the sensitivity; this characteristic effectively solves the problem of high background signals in existing fluorescence detection methods and significantly improves the signal-to-noise ratio.

[0048] 4. The present invention introduces enzyme-mediated as a controllable recognition element. The AIE-MOF probe utilizes the specific inhibitory effect of diazinon on glutathione peroxidase (GPx) to convert the presence of diazinon into a fluorescence signal, realizing the specific detection of diazinon; compared with traditional detection methods, the present invention has higher selectivity and anti-interference ability. Brief Description of the Drawings

[0049] Figure 1 It is a schematic diagram for the preparation of the AIE-MOF probe.

[0050] Figure 2 It is a schematic diagram of the application of the AIE-MOF probe for detecting diazinon (a) and the working principle diagram of the fluorescence sensing system based on the AIE-MOF probe for detecting diazinon (b).

[0051] Figure 3 It is a characterization diagram of the AIE-MOF probe; among them, a is the transmission electron microscope (TEM) image of the AIE-MOF probe; b is the X-ray diffraction (XRD) pattern of the AIE-MOF probe; c is the Fourier transform infrared (FT-IR) spectrum of the AIE-MOF probe; d is the ultraviolet-visible (UV-Vis) spectrum of the AIE-MOF probe and H4TCPE.

[0052] Figure 4 It is a relationship diagram between the fluorescence intensity of the AIE-MOF / GSH system and the activity of glutathione peroxidase; among them, a is the fluorescence spectrum diagram of the AIE-MOF / GSH system with the activity of glutathione peroxidase (final concentrations of 0, 0.1, 0.5, 1, 5, 10, 20, and 30 mU·mL -1 )

[0053] Figure 5 It is a relationship diagram between the fluorescence intensity of the AIE-MOF / GSH / GPx / diazinon system and the concentration of diazinon; among them, a is the AIE-MOF / GSH / GPx / diazinon system with the concentration of diazinon (final concentrations of 0, 0.001, 0.005, 0.01, 0.05, 0.1, and 0.2 mg·L -1) Fluorescence spectra under [conditions]; b is the linear relationship diagram between the fluorescence intensity of the AIE-MOF / GSH / GPx / diazinon system and the log value of the diazinon concentration.

[0054] Figure 6 shows the accumulation amount of diazinon in rice determined by HPLC method and fluorescence sensing system; among them, a is the accumulation amount of diazinon in the above-ground tissues of rice; b is the accumulation amount of diazinon in the roots of rice.

[0055] Figure 7 shows the relationship between the fluorescence intensity of the AIE-MOF / GSH / GPx system at 478 nm and the incubation time.

[0056] Figure 8 shows the results of the investigation on the selectivity and anti-interference ability of the AIE-MOF probe; among them, a is the change in fluorescence intensity of nitenpyram, atrazine, fenitrothion, dufulin, chlorpyrifos and diazinon (final concentrations are all 0.1 mg·L -1 ); b is the fluorescence intensity of the AIE-MOF / GSH / GPx system before (gray) and after (blue) adding diazinon (final concentration is 0.1 mg·L -1 ), and the interfering substances include Na + , K + , Mg 2+ , Zn 2+ , Ca 2+ , Cl - and SO4 2- (final concentrations are all 50 μM). Specific implementation methods

[0057] Example 1

[0058] As Figure 1 , the AIE-MOF probe is prepared by a one-pot solvent method, and the steps are as follows:

[0059] Add sodium hydroxide aqueous solution (0.4 mL, 1.0 mol·L -1 ) to copper nitrate aqueous solution (0.4 mL, 0.55 mol·L -1) After fully reacting at room temperature, the supernatant was removed by centrifugation, and the resulting precipitate was fresh copper hydroxide. Copper hydroxide (19.5 mg, 0.2 mmol) was dispersed in 3 mL of DMF to obtain a copper hydroxide dispersion; 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene (50.9 mg, 0.1 mmol) was dissolved in 1 mL of DMF to obtain a 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene solution. The copper hydroxide dispersion and the 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene solution were mixed together, and then 0.2 mL of acetic acid was added and mixed well; the mixture was placed in a PTFE liner of an autoclave and heated to 120 °C, and reacted at 120 °C for 12 hours. After the reaction was completed, it was cooled to room temperature and centrifuged at 80000 rpm for 10 minutes. The supernatant was discarded, and the precipitate was washed with DMF to remove unreacted raw materials and generated by-products, and washed three times in total. At this time, new DMF was added, and there was no color change in the DMF, and the AIE-MOF probe was obtained. The AIE-MOF probe was a bright blue crystal. The AIE-MOF probe was suspended in DMF, and the concentration was about 7.5 mg·mL -1 .

[0060] The prepared AIE-MOF probe was characterized.

[0061] The transmission electron microscope (TEM) image of the AIE-MOF probe showed that the AIE-MOF presented a unique spindle-shaped structure with a diameter of about 390 nm( Figure 3 a). In the X-ray diffraction pattern of the AIE-MOF probe, the peaks observed at 2θ of 10.2°, 12.0° and 20.4° corresponded to the (110), (020) and (220) crystal planes respectively. There was no diffraction peak of Cu(OH)2 in the XRD pattern of AIE-MOF, indicating that Cu(OH)2 was completely converted into AIE-MOF, confirming the existence of the crystal structure of the AIE-MOF probe( Figure 3 b). In the Fourier transform infrared (FT-IR) spectrum of the AIE-MOF probe, the strong peak at 1600 cm -1 and the medium peak at 1394 cm -1 corresponded to the asymmetric stretching vibration and symmetric stretching vibration of the carboxylate group respectively, indicating that the carboxylate group coordinated with Cu 2+ c). It can be seen from the ultraviolet-visible light spectrum (UV-Vis) of the AIE-MOF probe that H4TCPE had a broad absorption band from 290 nm to 600 nm, while the AIE-MOF showed an obvious absorption peak at 372 nm, indicating that the spectrum had a significant shift( Figure 3 c). Figure 3d). In addition, the absorption band of H4TCPE extends into the visible light region, which is a characteristic not possessed by AIE-MOF chromophores, indicating that the self-aggregation behavior of the TCPE ligand is restricted by the framework.

[0062] The above characterizations all prove that the AIE-MOF probe of the present invention has been successfully prepared.

[0063] Example 2

[0064] A method for detecting glutathione peroxidase by a fluorescence sensing system based on an AIE-MOF probe, comprising the following steps:

[0065] Step (1): Prepare the AIE-MOF probe according to Example 1, suspend the AIE-MOF probe in DMF at a concentration of about 7.5 mg·mL -1 , and then dilute it 30 times with ultrapure water to obtain an AIE-MOF probe dispersion with a concentration of 250 mg·L -1 ;

[0066] Step (2): Construct a fluorescence sensing system: Prepare glutathione peroxidase solutions with different enzyme activities (0, 1, 5, 10, 50, 100, 200, 300 mU·mL -1 ), glutathione solution (2 mM), and hydrogen peroxide solution (2 mM) respectively with ultrapure water; Add 20 μL of glutathione peroxidase aqueous solutions with different concentrations (0, 1, 5, 10, 50, 100, 200, 300 mU·mL -1 ), 20 μL of glutathione aqueous solution (2 mM), and 20 μL of hydrogen peroxide aqueous solution (2 mM) to 20 μL of phosphate buffer solution (PBS, 5 mM, pH = 7.0), incubate at 37 °C for 60 minutes; Subsequently, add 20 μL of the AIE-MOF probe dispersion (250 mg·L -1 ) and 100 μL of ultrapure water to the reaction system, react at 37 °C for 30 minutes to obtain the AIE-MOF / GSH system, use a multi-label detection system, with 372 nm as the excitation wavelength, measure the fluorescence intensity of the AIE-MOF / GSH system at 478 nm ( Figure 4 a), with the glutathione peroxidase enzyme activity (C GPx ) as the abscissa and the fluorescence intensity (F) at 478 nm as the ordinate, establish a standard curve for glutathione peroxidase ( Figure 4 b): F = 1.07464×10 7 -225227C GPx (R 2 = 0.999), showing a good linear relationship in the range of 0 - 30 mUmL -1 ;

[0067] Step (3), detecting glutathione peroxidase in the sample based on the fluorescence sensing system; for the test sample with unknown glutathione peroxidase activity measured in step (2), the fluorescence intensity at 478 nm when the excitation wavelength is 372 nm, the specific method is: adding 20 μL of the test sample, 20 μL of glutathione aqueous solution (2 mM), and 20 μL of hydrogen peroxide aqueous solution (2 mM) to 20 μL of phosphate buffer solution (5 mM, pH = 7.0), incubating at 37 °C for 60 minutes; then adding 20 μL of AIE-MOF probe dispersion (250 mg·L -1 ) and 100 μL of ultrapure water to the reaction system, reacting at 37 °C for 30 minutes to obtain the AIE-MOF / GSH system, using a multi-label detection system, with 372 nm as the excitation wavelength, measuring the fluorescence intensity of the AIE-MOF / GSH system at 478 nm; substituting the fluorescence intensity into the glutathione peroxidase standard curve in step (2) to obtain the concentration of glutathione peroxidase in the test sample.

[0068] Example 3

[0069] An addition recovery experiment for detecting diazinon based on a fluorescence sensing system constructed with an AIE-MOF probe, including the following steps:

[0070] Step (1), preparing the AIE-MOF probe according to Example 1, suspending the AIE-MOF probe in DMF, and then diluting it with ultrapure water to obtain an AIE-MOF probe dispersion with a concentration of 250 mg·L -1 ;

[0071] Step (2), constructing the fluorescence sensing system: preparing methanol solutions of diazinon with different concentrations (0, 0.02, 0.10, 0.2, 1, 2, 4 mg·mL -1 ) with methanol, preparing glutathione peroxidase aqueous solutions (0.3 U·mL -1 ), glutathione aqueous solutions (2 mM), and hydrogen peroxide aqueous solutions (2 mM) with ultrapure water respectively; adding 10 μL of methanol solutions of diazinon with different concentrations (0, 0.02, 0.10, 0.2, 1, 2, 4 mg·L -1 ), 20 μL of glutathione peroxidase aqueous solution (0.3 U·mL -1 ) to 20 μL of phosphate buffer solution (PBS, 5 mM, pH = 7.0), reacting at 37 °C for 40 minutes, then adding 20 μL of glutathione aqueous solution (2 mM) and 20 μL of hydrogen peroxide aqueous solution (2 mM), incubating at 37 °C for 60 minutes; then adding 20 μL of the AIE-MOF probe dispersion (250 mg·L -1) and 90 μL of ultrapure water, react at 37 °C for 30 minutes to obtain the AIE-MOF / GSH / GPx / diazinon system. Using a multi-label detection system, with an excitation wavelength of 372 nm, measure the fluorescence intensity of the AIE-MOF / GSH / GPx / diazinon system at 478 nm ( Figure 5 a), with the logarithm value of the concentration of diazinon (C diazinon ) as the abscissa and the fluorescence intensity at 478 nm as the ordinate, establish the diazinon standard curve ( Figure 5 b); the linear equation is F = 1.39344×10 7 + 3283970×log C diazinon (R 2 = 0.999);

[0072] Step (3), conduct the addition and recovery experiment of diazinon in rice samples: Divide the rice samples into the above-ground part and the root part, and grind them into powder form respectively through liquid nitrogen; weigh 2 g of the above-ground part or root powder, and then drop 100 μL of 0.2, 2, 20 mg·L -1 diazinon methanol solution (that is, add standard concentrations of 0.01, 0.1, and 1.0 mg·kg -1 diazinon to the samples respectively), shake evenly, and let stand for 30 minutes; extract with an acetonitrile-water mixed solvent (10 mL of acetonitrile, 5 mL of water) at room temperature for 1 hour, add 2 g of sodium chloride and continue to extract by shaking for 8 minutes, centrifuge at 4000×g for 8 minutes, take a part of the supernatant, transfer it into a centrifuge tube containing 80 mg of CNWBOND HC-C18 QuEChERS special ultra-clean filler, shake for 2 minutes, centrifuge at low speed for 2 minutes, and filter through a 0.22 μm organic filter membrane to obtain the addition and recovery test sample of diazinon added;

[0073] Step (4), add 10 μL of the addition and recovery test sample of diazinon, 20 μL of glutathione peroxidase aqueous solution (0.3 U·mL -1 ) to 20 μL of phosphate buffer solution (5 mM, pH = 7.0), react at 37 °C for 40 minutes, then add glutathione aqueous solution (20 μL, 2 mM) and hydrogen peroxide aqueous solution (20 μL, 2 mM), incubate at 37 °C for 60 minutes, add 20 μL of AIE-MOF probe dispersion (250 mg L -1) and 90 μL of ultrapure water, react at 37 °C for 30 minutes to obtain the AIE-MOF / GSH / GPx / diazinon system. Using a multi-label detection system, with an excitation wavelength of 372 nm, record the fluorescence intensity of the AIE-MOF / GSH / GPx / diazinon system at 478 nm. Substitute the fluorescence intensity into the diazinon standard curve in step (2) to obtain the concentration of diazinon 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 is kept within 6.62%, and these results highlight the advantages of the AIE-MOF / GSH / GPx / diazinon system being reliable and highly sensitive.

[0074] Table 1. Recovery rate of diazinon added in rice samples

[0075]

[0076]

[0077] Example 4

[0078] A method for detecting the accumulation amount of diazinon in crops based on a fluorescence sensing system constructed with an AIE-MOF probe, comprising the following steps:

[0079] Step (1): Prepare the AIE-MOF probe according to Example 1. Suspend the AIE-MOF probe in DMF and then dilute it with ultrapure water to obtain an AIE-MOF probe dispersion with a concentration of 250 mg·L -1 .

[0080] Step (2): Construct a fluorescence sensing system according to step (2) of Example 3: Add 10 μL of methanol solutions of diazinon with different concentrations (0, 0.02, 0.10, 0.2, 1, 2, 4 mg·L -1 ) and 20 μL of glutathione peroxidase aqueous solution (0.3 U mL -1 ) into 20 μL of phosphate buffer solution (PBS, 5 mM, pH = 7.0), react at 37 °C for 40 minutes, then add 20 μL of glutathione aqueous solution (2 mM) and 20 μL of hydrogen peroxide aqueous solution (2 mM), and incubate at 37 °C for 60 minutes; subsequently, add 20 μL of the AIE-MOF probe dispersion (250 mg·L -1) and 90 μL of ultrapure water, react at 37 °C for 30 minutes to obtain the AIE-MOF / GSH / GPx / diazinon system. Using a multi-label detection system, with an excitation wavelength of 372 nm, measure the fluorescence intensity of the AIE-MOF / GSH / GPx / diazinon system at 478 nm. Taking the logarithm value of the diazinon concentration as the abscissa and the fluorescence intensity at 478 nm as the ordinate, establish a diazinon standard curve;

[0081] Step (3): Taking the detection of diazinon in rice as an example, after disinfecting and sterilizing rice seeds, germinate them in an incubator (set with a day / night temperature cycle of 30 °C / 25 °C and a light / dark cycle of 14 hours / 10 hours) for 2 days; after germination, under the same temperature and light conditions, culture the seeds in 1 / 2 strength Hoagland nutrient solution for 8 days (change the water every 2 days); then add a diazinon solution to the nutrient solution so that the final concentrations of diazinon in the nutrient solution are 0.1, 0.2, 0.5, 1.0 mg·L -1 , culture for 6 days (change the water every 2 days); divide the rice plants into above-ground parts and roots, and grind them into powder form through liquid nitrogen respectively; weigh 2 g of the above-ground part or root powder, add an acetonitrile-water mixed solvent (10 mL of acetonitrile, 5 mL of water), shake and extract at room temperature for 1 hour, then add 2 g of sodium chloride and continue to extract for 8 minutes, centrifuge at 4000×g for 8 minutes, take the supernatant, take a part of the supernatant, transfer it into a centrifuge tube containing 80 mg of CNWBOND HC-C18 QuEChERS special ultra-clean filler, shake for 2 minutes, centrifuge at low speed for 2 minutes, and filter through a 0.22 μm organic filter membrane to obtain a test sample with an unknown diazinon concentration;

[0082] Step (4): Add 10 μL of the test sample with an unknown diazinon concentration and 20 μL of an aqueous glutathione peroxidase solution (0.3 U·mL -1 ) to 20 μL of phosphate buffer solution (5 mM, pH = 7.0), react at 37 °C for 40 minutes, then add 20 μL of an aqueous glutathione solution (2 mM) and 20 μL of an aqueous hydrogen peroxide solution (2 mM), incubate at 37 °C for 60 minutes; subsequently, add 20 μL of the AIE-MOF probe dispersion (250 mg·L -1 ) and 90 μL of ultrapure water, react at 37 °C for 30 minutes to obtain the AIE-MOF / GSH / GPx / diazinon system. Record the fluorescence intensity of the AIE-MOF / GSH / GPx / diazinon system at 478 nm at an excitation wavelength of 372 nm, substitute the fluorescence intensity into the diazinon standard curve in step (2) to obtain the concentration of diazinon in the test sample, and compare it with the result measured by high performance liquid chromatography. The results are as Figure 6as shown (a is the above-ground part, b is the root). Compared with high-performance liquid chromatography, the method of the present invention is easy to operate, can detect in large quantities, and only requires a small amount of solvent, which is more environmentally friendly.

[0083] The high-performance liquid chromatography conditions were as follows: the chromatographic column was C18 (250 mm × 4.6 mm), the mobile phase was acetonitrile: water (45:55, volume ratio), and the flow rate was 1 mL min -1 , and the detection wavelength was 220 nm.

[0084] Example 5

[0085] Optimization of the incubation time of glutathione peroxidase with glutathione

[0086] Add 20 μL of glutathione peroxidase aqueous solution (0.3 U·mL -1 ), 20 μL of glutathione aqueous solution (2 mM), and 20 μL of hydrogen peroxide aqueous solution (2 mM) to 20 μL of phosphate buffer solution (5 mM, pH = 7.0), and incubate at 37 °C for 0, 5, 10, 20, 30, 40, 60, 80 minutes respectively; then add 20 μL of AIE-MOF probe dispersion (250 mg·L -1 ) and 100 μL of ultrapure water to the reaction system, and react at 37 °C for 30 minutes to obtain the AIE-MOF / GSH / GPx system. Using 372 nm as the excitation wavelength, record the fluorescence intensity of the AIE-MOF / GSH / GPx system at 478 nm.

[0087] The results are shown in Figure 7 , indicating that when glutathione peroxidase reacts with glutathione for 60 minutes, the fluorescence intensity of the AIE-MOF / GSH / GPx / system reaches the minimum value, and with the increase of the reaction time, the fluorescence intensity no longer changes; therefore, the incubation time of glutathione peroxidase with glutathione is selected as 60 minutes as the optimal condition.

[0088] Example 6

[0089] Investigate the selectivity of the AIE-MOF / GSH / GPx / system to diazinon

[0090] Add 20 μL of glutathione peroxidase aqueous solution (0.3 U·mL -1 ) and 10 μL of methanol solution of diazinon or other pesticides (nitenpyram, atrazine, fenitrothion, dufulin, and chlorpyrifos) (the pesticide concentration is 2 mg·L -1), 10 μL of methanol was used instead of the methanol solution of diazinon as a control, and they were incubated at 37 °C for 40 minutes respectively. Then, 20 μL of glutathione aqueous solution (2 mM) and 20 μL of hydrogen peroxide aqueous solution (2 mM) were added, and the mixture was incubated at 37 °C for 60 minutes. Subsequently, 20 μL of the AIE-MOF probe dispersion (250 mg·L -1 ) and 90 μL of ultrapure water were added, and the reaction was carried out at 37 °C for 20 minutes to obtain the AIE-MOF / GSH / GPx / pesticide system. Then, with an excitation wavelength of 372 nm, the fluorescence intensity of the AIE-MOF / GSH / GPx / pesticide system at 478 nm was recorded.

[0091] The results are shown in Figure 8 a. Compared with the fluorescence intensity of diazinon, the effects of the above five control pesticides on the AIE-MOF / GSH / GPx system were relatively weak. The results indicated that the AIE-MOF / GSH / GPx system had good selectivity for diazinon.

[0092] Example 7

[0093] Investigate the anti-ion interference ability of the AIE-MOF / GSH / GPx and AIE-MOF / GSH / GPx / diazinon systems

[0094] In 20 μL of phosphate buffer solution (5 mM, pH = 7.0), 20 μL of glutathione peroxidase aqueous solution (0.3 U·mL -1 ), 20 μL of glutathione aqueous solution (2 mM) and 20 μL of hydrogen peroxide (2 mM) were added. Then, 10 μL of interfering ions (Na + , K + , Mg 2+ , Zn 2+ , Ca 2+ , Cl - or SO4 2- ) aqueous solution (the concentration of interfering ions was 1 mM for all) were added. 10 μL of ultrapure water was used instead of the interfering ion aqueous solution as a blank control (Blank), and the mixture was incubated at 37 °C for 60 minutes. Subsequently, 20 μL of the AIE-MOF probe dispersion (250 mg·L -1 ) and 90 μL of ultrapure water were added, and the reaction was carried out at 37 °C for 30 minutes to obtain the AIE-MOF / GSH / GPx system. With an excitation wavelength of 372 nm, the fluorescence intensity of the AIE-MOF / GSH / GPx system at 478 nm was recorded.

[0095] In 20 μL of phosphate buffer solution (5 mM, pH = 7.0), 20 μL of glutathione peroxidase aqueous solution (0.3 U·mL-1 ), incubated with 10 μL of methanol solution of diazinon (2 mg·L -1 ) at 37 °C for 60 minutes, added 20 μL of glutathione aqueous solution (2 mM) and 20 μL of hydrogen peroxide aqueous solution (2 mM), then added 10 μL of interfering ions (Na + , K + , Mg 2+ , Zn 2+ , Ca 2+ , Cl - or SO4 2- ) aqueous solution (the concentration of interfering ions was 1 mM each), replaced the interfering ion aqueous solution with 10 μL of ultrapure water as a blank control (Blank), and incubated at 37 °C for 60 minutes; then added 20 μL of AIE-MOF probe dispersion (250 mg·L -1 ) and 80 μL of ultrapure water to the reaction system, and reacted at 37 °C for 30 minutes to obtain the AIE-MOF / GSH / GPx / diazinon system. Using 372 nm as the excitation wavelength, the fluorescence intensity of the AIE-MOF / GSH / GPx / diazinon system at 478 nm was recorded.

[0096] The results are shown in Figure 8 b. In the AIE-MOF / GSH / GPx system, compared with the blank group, the signal change rates caused by these interfering ions were all lower than 2.8%. In the AIE-MOF / GSH / GPx / diazinon system, even in the presence of various interfering ions, the fluorescence intensity response of the AIE-MOF / GSH / GPx / diazinon system to diazinon was not affected. The above results confirmed that the AIE-MOF / GSH / GPx / diazinon system had good anti-ion interference ability.

Claims

1. An aggregation-induced emission-metal-organic framework probe, characterized in that: It is prepared by a one-pot solvothermal method with copper hydroxide 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 mixing copper hydroxide, 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene and DMF, dropping an appropriate amount of acetic acid, mixing, and reacting at a temperature of 100-140°C for 10-16 hours; after the reaction is completed, centrifuging, discarding the supernatant, and washing the precipitate with DMF to obtain the aggregation-induced emission-metal-organic framework probe; wherein the molar ratio of the copper hydroxide to the 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene is 6:1-1:1; the dosage ratio of the acetic acid to the 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene is 1:200-1:300 mL / mg; and the mass-to-volume ratio of the 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene to DMF is 15:1-10:1 mg / mL.

3. A method for detecting diazinon using a fluorescence sensing system constructed based on 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 DMF 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 diazinon methanol or aqueous solution and glutathione peroxidase aqueous solution to a phosphate buffer solution, incubating at a temperature of 35-40° C. for 40-60 minutes, then adding a glutathione aqueous solution and a hydrogen peroxide aqueous solution to the reaction system, reacting at a temperature of 35-40° C. for 60-80 minutes, finally adding an aggregation-induced emission-metal-organic framework probe dispersion and ultrapure water to the reaction system, reacting at a temperature of 35-40° C. for 20-40 minutes, obtaining a detection system, taking 372 nm as an excitation wavelength, measuring the fluorescence intensity of the detection system at 478 nm, taking the concentration of diazinon or its log value as the horizontal coordinate, and taking the fluorescence intensity at 478 nm as the vertical coordinate, and establishing a diazinon standard curve; Step (3), sample testing; according to step (2), the fluorescence intensity of the sample to be tested with unknown diazinon concentration at an excitation wavelength of 372nm at 478nm is measured, and the fluorescence intensity is substituted into the diazinon standard curve of step (2) to obtain the concentration of diazinon in the sample to be tested.

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

0.

5. The method for detecting diazinon according to claim 3, characterized in that: In step (2), in the detection system, the final concentration of glutathione peroxidase activity is 20-40 mU·mL -1 , preferably 30 mU·mL -1 The final concentration of glutathione is 0.15-0.3 mM, preferably 0.2 mM; the final concentration of hydrogen peroxide is 0.15-0.3 mM, preferably 0.2 mM; the final concentration of the aggregation-induced emission-metal-organic framework probe is 20-50 mg·L -1 , preferably 25 mg·L -1 The final concentration of diazinon is 0.001-0.2 mg·L -1 .

6. The method for detecting diazinon according to claim 3, characterized in that: In step (2), the fluorescent sensing system is constructed as follows: adding different concentrations of diazinon methanol solution and glutathione peroxidase aqueous solution to a phosphate buffer solution, incubating at a temperature of 35-40°C for 40-60 minutes, then adding glutathione aqueous solution and hydrogen peroxide aqueous solution to the reaction system, reacting at a temperature of 35-40°C for 60-80 minutes, and finally adding aggregation-induced emission-metal-organic framework probe dispersion and ultrapure water to the reaction system, reacting at a temperature of 35-40°C for 20-40 minutes to obtain a detection system.

7. The method for detecting diazinon according to claim 3 or 6, characterized in that: In step (2), the fluorescent sensing system is constructed as follows: different concentrations of diazinon methanol solution and glutathione peroxidase aqueous solution are added to the phosphate buffer solution, and the mixture is incubated at 37°C for 40 minutes. Then, glutathione aqueous solution and hydrogen peroxide aqueous solution are added to the reaction system, and the mixture is reacted at 37°C for 60 minutes. Finally, aggregation-induced emission-metal-organic framework probe dispersion and ultrapure water are added to the reaction system, and the mixture is reacted at 37°C for 30 minutes to obtain a detection system.

8. A method for detecting glutathione peroxidase 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 DMF 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 glutathione peroxidase aqueous solution with different enzyme activities, glutathione aqueous solution and hydrogen peroxide aqueous solution to a phosphate buffer solution, incubating at a temperature of 35 to 40° C. for 60 to 80 minutes, adding an aggregation-induced emission-metal-organic framework probe dispersion and ultrapure water to the reaction system, reacting at a temperature of 35 to 40° C. for 20 to 40 minutes, and obtaining a detection system; using 372 nm as an excitation wavelength, measuring the fluorescence intensity of the detection system at 478 nm, using the enzyme activity of glutathione peroxidase as the horizontal coordinate and the fluorescence intensity at 478 nm as the vertical coordinate, and establishing a glutathione peroxidase standard curve; Step (3), sample detection: According to step (2), the fluorescence intensity of the unknown glutathione peroxidase test sample at 478 nm when the excitation wavelength is 372 nm is measured, and the fluorescence intensity is substituted into the glutathione peroxidase standard curve of step (2) to obtain the concentration of glutathione peroxidase in the test sample.

9. The method for detecting glutathione peroxidase according to claim 8, characterized in that: In step (2), the pH of the phosphate buffer solution is 6.5 to 7.4, preferably 7.

0.

10. The method for detecting glutathione peroxidase according to claim 8, characterized in that: In step (2), in the detection system, the final concentration of glutathione is 0.15-0.3 mM, preferably 0.2 mM; the final concentration of hydrogen peroxide is 0.15-0.3 mM, preferably 0.2 mM; the final concentration of the aggregation-induced emission-metal-organic framework probe is 20-50 mg·L -1 , preferably 25 mg·L -1 The final concentration of glutathione peroxidase activity is 0.1~30mU·mL -1 .

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