MOFs-based mixed matrix membrane for field visual quantitative detection of nitenpyram as well as preparation method and application of MOFs-based mixed matrix membrane

Abstract

The invention belongs to the field of materials and detection, and provides an MOFs (Metal-Organic Frameworks)-based mixed matrix membrane for visually and quantitatively detecting nitenpyram on site as well as a preparation method and application of the MOFs-based mixed matrix membrane. A stable luminescent Zn-MOF (1) material is doped into a polymethyl methacrylate (PMMA) adhesive to successfully prepare a mixed matrix film (1 (at) PMMA). The mixed matrix membrane has the excellent luminescence characteristic of Zn-MOF (1) and the flexibility and good processability of PMMA, and shows high sensitivity, strong anti-interference performance, recoverability and visual detection capability on nitenpyram (NTP). Meanwhile, the 1-coated PMMA mixed matrix membrane is combined with a smart phone, a portable smart phone auxiliary fluorescent sensing platform is constructed, the platform can realize on-site visual quantitative detection of NTP, and the convenience and accuracy of food safety monitoring are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the field of materials and detection, and particularly relates to a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram, and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] In recent years, food safety issues have become increasingly prominent due to the frequent occurrence of foodborne diseases and have become a global concern. Among the many factors that threaten food safety, the problem of pesticide residues is particularly prominent and poses a serious threat to human health. As a new and highly efficient neonicotinoid insecticide, nitenpyram (NTP) has been widely used in agricultural production due to its good systemic absorption, strong penetration and broad insecticide spectrum, especially in the prevention and control of pests such as aphids, planthoppers and leafhoppers. However, with the increasing use of NTP worldwide, its residue problem has become increasingly serious. Although NTP is less toxic than previous generations of pesticides, its good water solubility and slow degradation in the natural environment (half-life of up to 415 days) cause it to accumulate in the environment, causing serious harm to human health. Therefore, the development of a method that can accurately detect NTP residues in food in real time on site is of vital importance to ensure food safety and maintain public health.

[0004] At present, common detection methods include high performance liquid chromatography (HPLC), liquid chromatography-tandem mass spectrometry (LC-MS / MS), capillary electrophoresis chromatography (CEC) and surface enhanced Raman spectroscopy (SERS). However, these methods have complex sample pretreatment, long analysis time, and require complex and expensive instruments and professional technicians, which limits their portability and on-site real-time detection applications. Fluorescence sensing detection has the characteristics of low cost, fast response speed, and simple operation, and is suitable for on-site real-time detection. In addition, it is more convenient to observe the change of fluorescence color by naked eye. However, it is difficult for the human eye to distinguish tiny color changes, which affects the sensitivity of naked eye detection. Smartphones have attracted widespread attention as intelligent tools for quantitative analysis due to their excellent image processing and data processing capabilities. Smartphones combined with fluorescence sensing detection methods can convert luminescent colors into digital information, achieving better sensitivity and accuracy than naked eye detection, and have been used for on-site visual quantitative detection.

[0005] Among fluorescent sensor materials, metal organic framework materials (MOFs), as a crystalline material, have attracted extensive attention in fluorescent sensing detection applications due to their unique fluorescent properties, adjustable structures, and easily modified functional sites. However, the poor solubility of MOFs crystals makes it difficult to disperse evenly in the analyte solution, resulting in insufficient contact between MOFs and analytes, resulting in low sensitivity and poor accuracy. In addition, MOFs crystal particles are difficult to recover from the solution, limiting their recyclability and cyclic detection applications. Therefore, adopting some methods to solve the dispersibility and recyclability of MOFs in solution is crucial to improving the accuracy and cyclic detection capabilities of fluorescent detection. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram and its preparation method and application. The present invention evenly disperses MOFs crystals in a polymer matrix, combines the excellent flexibility, processability and mechanical stability of the polymer with the good luminescent sensing detection ability of MOFs, and the obtained MOFs-based mixed matrix membrane has the advantages of portability, simple operation, fast detection speed and convenient recycling. Using a smartphone to assist the MOFs-based mixed matrix membrane can realize NTP on-site visual quantitative detection.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides a method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram, comprising:

[0009] Zn-MOF was prepared by solvothermal method with zinc ion as metal center and 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid as organic ligand;

[0010] Dispersing the Zn-MOF in an organic solvent, adding polymethyl methacrylate, and mixing well to obtain a mixed solution;

[0011] The mixed solution is coated on a substrate and dried to obtain the product.

[0012] In some embodiments, the zinc salt is zinc nitrate hexahydrate.

[0013] In some embodiments, the mass ratio of zinc salt to 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid is 23.8-29.7:27.7-34.6.

[0014] In some embodiments, the solvent used in the solvothermal method is a mixed solution of dimethyl sulfoxide and water.

[0015] In some embodiments, the reaction conditions of the solvothermal method are 130° C.-140° C. for 60-72 hours.

[0016] In some embodiments, the mass ratio of the Zn-MOF to polymethyl methacrylate is 0.005-0.015:0.1.

[0017] In some embodiments, the organic solvent is dichloromethane.

[0018] In some embodiments, the drying condition is drying at room temperature for more than 12 hours.

[0019] The second aspect of the present invention provides a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram prepared by the above method.

[0020] The third aspect of the present invention provides the use of the above-mentioned MOFs-based mixed matrix membrane in on-site visual quantitative detection of nitenpyram.

[0021] Beneficial Effects of the Invention

[0022] (1) The present invention uniformly incorporates MOFs crystals into a polymer matrix to prepare a MOFs-based mixed matrix membrane, combining the excellent flexibility, processability and mechanical stability of the polymer with the good luminescent sensing detection ability of MOFs. The MOFs-based mixed matrix membrane as a fluorescent sensor has the advantages of portability, simple operation, fast detection speed and convenient recycling, making it suitable for on-site naked eye detection. The present invention uses a smartphone-assisted MOFs-based mixed matrix membrane to achieve on-site visual quantitative detection of NTP.

[0023] (2) The preparation method of the present invention is simple, practical and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 This is the structural diagram of Zn-MOF (1).

[0026] Figure 2 This is a photograph of 1@PMMA mixed matrix membrane with a Zn-MOF (1) loading of 0 to 15 wt% under 365 nm ultraviolet light irradiation.

[0027] Figure 3 Scanning electron microscope (SEM) images of 1@PMMA (0wt%, 5wt%, 10wt%, 15wt%).

[0028] Figure 4 Distortion diagrams of pure PMMA and 1@PMMA (10wt%).

[0029] Figure 5 This is a bar graph comparing the fluorescence responses of 1@PMMA (10wt%) to different neonicotinoid insecticides.

[0030] Figure 6 Fluorescence spectra of 1@PMMA (10wt%) to NTP solutions of different concentrations.

[0031] Figure 7 It is a curve graph of the fluorescence intensity I0 / I of 1@PMMA (10wt%) and the NTP concentration. The inset is the Stern-Volmer linear graph of the fluorescence intensity I0 / I of 1@PMMA (10wt%) and the NTP concentration ([NTP]≤90.9μM).

[0032] Figure 8 This is the fluorescence response time diagram of 1@PMMA (10wt%) detecting NTP.

[0033] Fig. 9 This is the anti-interference detection diagram of 1@PMMA (10wt%) to NTP.

[0034] Fig.10 This is the cyclic regeneration detection diagram of 1@PMMA (10wt%) to NTP.

[0035] Fig.11 The fluorescence excitation spectrum of 1@PMMA (10wt%) and the ultraviolet absorption spectrum of neonicotinoid insecticides.

[0036] Fig.12 This is the fluorescence color diagram of 1@PMMA (10wt%) mixed matrix membrane immersed in NTP solutions of different concentrations under 365nm ultraviolet light.

[0037] Fig.13 For I mean Linear relationship between the concentration of NTP. DETAILED DESCRIPTION

[0038] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0039] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0040] Example 1

[0041] 0.9 g of 4-(4-pyridyl)benzaldehyde and 0.9 g of 5-aminophthalic acid were dissolved in anhydrous ethanol solvent. Under N2 protection, the reaction mixture was reacted at 80°C for 12 h. The reaction solution was then poured into ice water for cooling. The generated white solid was filtered out, washed with ether and water, and dried to obtain 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid.

[0042] Example 2

[0043] Synthesis of MOF materials: 29.7 mg of zinc nitrate hexahydrate and 34.6 mg of 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid were dissolved in a mixed solvent consisting of 3.0 mL of dimethyl sulfoxide and 1.0 mL of water, and ultrasonic treatment was performed until the mixture was uniformly mixed. The mixture was placed in a stainless steel reactor lined with polytetrafluoroethylene, and then reacted at 130°C for 72 h, and then cooled to room temperature at a constant rate of 5°C / h to obtain transparent block crystals. The product was filtered and washed with a mixed solution of dimethyl sulfoxide and water (v / v=3:1), dried at room temperature, and collected to obtain Zn-MOF (1) with a yield of about 80%.

[0044] Example 3

[0045] Synthesis of MOF materials: 23.8 mg of zinc nitrate hexahydrate and 34.6 mg of 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid were dissolved in a mixed solvent consisting of 3.0 mL of dimethyl sulfoxide and 1.0 mL of water, and ultrasonic treatment was performed until the mixture was uniformly mixed. The mixture was placed in a stainless steel reactor lined with polytetrafluoroethylene, and then reacted at 130°C for 72 h, and then cooled to room temperature at a constant rate of 5°C / h to obtain transparent block crystals. The product was filtered and washed with a mixed solution of dimethyl sulfoxide and water (v / v=3:1), dried at room temperature, and collected to obtain Zn-MOF (1) with a yield of about 65%.

[0046] Example 4

[0047] Synthesis of MOF materials: 29.7 mg of zinc nitrate hexahydrate and 27.7 mg of 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid were dissolved in a mixed solvent consisting of 3.0 mL of dimethyl sulfoxide and 1.0 mL of water, and ultrasonic treatment was performed until the mixture was uniformly mixed. The mixture was placed in a stainless steel reactor lined with polytetrafluoroethylene, and then reacted at 130°C for 72 h, and then cooled to room temperature at a constant rate of 5°C / h to obtain transparent block crystals. The product was filtered and washed with a mixed solution of dimethyl sulfoxide and water (v / v=3:1), dried at room temperature, and collected to obtain Zn-MOF (1) with a yield of about 68%.

[0048] Example 5

[0049] Synthesis of MOF materials: 29.7 mg of zinc nitrate hexahydrate and 34.6 mg of 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid were dissolved in a mixed solvent consisting of 3.0 mL of dimethyl sulfoxide and 1.0 mL of water, and ultrasonic treatment was performed until the mixture was uniformly mixed. The mixture was placed in a stainless steel reactor lined with polytetrafluoroethylene, and then reacted at 140°C for 72 h, and then cooled to room temperature at a constant rate of 5°C / h to obtain transparent block crystals. The product was filtered and washed with a mixed solution of dimethyl sulfoxide and water (v / v=3:1), dried at room temperature, and collected to obtain Zn-MOF (1) with a yield of about 71%.

[0050] Example 6

[0051] Synthesis of MOF materials: 29.7 mg of zinc nitrate hexahydrate and 34.6 mg of 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid were dissolved in a mixed solvent consisting of 3.0 mL of dimethyl sulfoxide and 1.0 mL of water, and ultrasonic treatment was performed until the mixture was uniformly mixed. The mixture was placed in a stainless steel reactor lined with polytetrafluoroethylene, and then reacted at a constant temperature of 130°C for 60 h, and then cooled to room temperature at a constant rate of 5°C / h to obtain transparent block crystals. The product was filtered and washed with a mixed solution of dimethyl sulfoxide and water (v / v=3:1), dried at room temperature, and collected to obtain Zn-MOF (1) with a yield of about 75%.

[0052] Example 7

[0053] Preparation of pure PMMA film material: Add polymethyl methacrylate (PMMA, 0.1 g) into 5 mL of dichloromethane and stir for 30 min. Spread 2 mL of the mixed PMMA solution evenly on a glass plate and then dry at room temperature for 12 h to obtain a pure PMMA film, i.e.: 1@PMMA (0 wt%).

[0054] Example 8

[0055] Preparation of mixed matrix membrane material: The Zn-MOF (1) sample powder (5 mg) prepared in Example 1 was dispersed in 5 mL of dichloromethane, and evenly dispersed by ultrasonication at 0°C, and polymethyl methacrylate (PMMA, 0.1 g) was added and stirred to mix evenly until a well-dispersed solution was formed. The mixed solution was then evenly coated on a glass plate and dried at room temperature for 12 h to obtain a mixed matrix membrane 1@PMMA (5 wt%).

[0056] Example 9

[0057] The difference from Example 3 is that the Zn-MOF (1) sample powder (10 mg) was dispersed in 5 mL of dichloromethane to obtain a mixed matrix membrane 1@PMMA (10 wt %).

[0058] Example 10

[0059] The difference from Example 3 is that the Zn-MOF (1) sample powder (15 mg) was dispersed in 5 mL of dichloromethane to obtain a mixed matrix membrane 1@PMMA (15 wt %).

[0060] Embodiment 11

[0061] The color changes of the prepared pure PMMA film and 1@PMMA (5wt%, 10wt%, 15wt%) mixed matrix film under 365nm ultraviolet light were observed. Figure 2 As shown, the 1@PMMA mixed matrix membranes with different loading amounts exhibited obvious blue fluorescence under 365nm ultraviolet light. As the loading amount of Zn-MOF (1) continued to increase, the luminescence intensity of the 1@PMMA mixed matrix membrane gradually increased, indicating that its luminescence source came from Zn-MOF (1). In addition, the morphological characteristics of pure PMMA membranes and 1@PMMA mixed matrix membranes with different loading amounts (5wt%, 10wt%, 15wt%) were characterized by scanning electron microscopy (SEM). Figure 3 As shown in the figure, the morphology of the 1@PMMA (5wt%, 10wt%) mixed matrix membrane is similar to that of the pure PMMA membrane, indicating that the crystalline powder particles of Zn-MOF (1) have been successfully coated and evenly distributed in the PMMA matrix, and no obvious aggregation phenomenon was observed. However, the surface of 1@PMMA (15wt%) is relatively rough, and the crystalline powder particles of 1 are aggregated and exposed on the surface of the mixed matrix membrane. This result shows that the high loading amount of 1@PMMA (15wt%) is not suitable as a fluorescent sensor. Figure 4 As shown in the figure, compared with pure PMMA film, 1@PMMA (10wt%) also exhibits excellent flexibility and mechanical strength, indicating that the mixed matrix film can be used as a portable fluorescent sensor for field detection applications. Therefore, 1@PMMA (10wt%) was selected for subsequent experiments.

[0062] Example 12

[0063] The 1@PMMA (10 wt%) mixed matrix membrane (2 cm × 1 cm) was placed in a cuvette containing 1 mL of distilled water, and 200 μL of 1.0 × 10 -3 mol / L nitenpyram (NTP), imidacloprid (IDP), clothianidin (CTD), dinotefuran (DNF), thiamethoxam (TMX), acetamiprid (AAP) and thiacloprid (TCP), and the changes in their fluorescence intensity were measured. Figure 5As shown, 1@PMMA (10wt%) exhibits different degrees of fluorescence quenching for different neonicotinoid insecticides, among which the NTP quenching effect is the most significant, and the quenching effects of other neonicotinoid insecticides are relatively weak. The experimental results show that the mixed matrix membrane has good fluorescence detection ability for NTP.

[0064] Example 13

[0065] In order to study the fluorescence detection ability of 1@PMMA (10 wt %) mixed matrix membrane for NTP in detail, the 1@PMMA (10 wt %) mixed matrix membrane (2 cm × 1 cm) was placed in a cuvette containing 1 mL of distilled water, and its emission spectrum was measured. Then, 20, 40, 60, 80, 100, 120, 140, 160, 180, and 200 μL of NTP solution (1.0 × 10 -3 mol / L) in the above dispersion and measure the changes in fluorescence intensity. The test results show that Figure 6 As shown in Figure 2, the fluorescence intensity of the 1@PMMA (10wt%) mixed matrix membrane gradually decreases with the continuous increase of NTP concentration. When 200μL NTP solution is added, the quenching degree reaches 83.7%. The fluorescence quenching effect can also be (SV) Equation: I0 / I=K SV [A]+1, where I0 and I are the fluorescence intensity of 1@PMMA (10 wt%) mixed matrix membrane without and with NTP, respectively, and K SV is the quenching constant (M -1 ), [A] is the molar concentration of NTP. In the low concentration range, the relationship between I0 / I and NFZ concentration conforms to the SV equation, and the K of NTP SV The value is 1.7×10 4 M -1 As the NTP concentration increases, the SV graph deviates from the original linearity ( Figure 7 In addition, the limit of detection (LOD) was calculated to be 0.17 ppm according to the equation LOD=3σ / k (σ: standard deviation of 7 blank fluorescence intensities, k: slope of the calibration curve), showing high sensitivity.

[0066] Embodiment 14

[0067] The fluorescence response time of 1@PMMA (10wt%) mixed matrix membrane for NTP detection was tested. The 1@PMMA (10wt%) mixed matrix membrane was placed in a cuvette containing 1 mL of distilled water, and then 200 μL of NTP solution (1.0×10 -3 mol / L), and the fluorescence intensity change of the mixed matrix membrane after adding NTP was monitored in real time using a fluorescence spectrometer. Figure 8 As shown in the figure, the fluorescence intensity of the 1@PMMA (10wt%) mixed matrix membrane decreased significantly within 5 seconds and remained stable over time. This result proves that the 1@PMMA (10wt%) mixed matrix membrane exhibits a fast fluorescence response speed to NTP and also shows that it has good stability during the response process. This feature is conducive to the real-time detection of NTP, effectively shortening the detection time, improving the detection efficiency, and ensuring the accuracy and reliability of the detection results.

[0068] Embodiment 15

[0069] In order to evaluate the detection performance of 1@PMMA (10wt%) mixed matrix membrane in complex environments, especially its anti-interference ability to other neonicotinoid insecticides, 1@PMMA (10wt%) mixed matrix membrane was placed in 200 μL solutions of other neonicotinoid insecticides (1.0×10 -3 mol / L), and then add 200 μL NTP solution (1.0×10 -3 mol / L), and then the fluorescence intensity of the mixed matrix membrane was measured. Fig. 9 As shown in the figure, in the presence of other neonicotinoid insecticides, the fluorescence quenching effect of 1@PMMA (10wt%) mixed matrix membrane on NTP did not change significantly, indicating that the mixed matrix membrane has good anti-interference ability for NTP detection in a complex environment. This property is of great significance for improving the accuracy and reliability of NTP detection.

[0070] Example 16

[0071] First, the 1@PMMA (10 wt%) mixed matrix membrane after NTP detection in Example 8 was soaked in distilled water and cleaned by ultrasonic for 3 times. The membrane was dried and recovered for later use. The recycled 1@PMMA (10 wt%) mixed matrix membrane was placed in a cuvette containing 1 mL of distilled water, and its initial fluorescence intensity was measured using a fluorescence spectrometer. Subsequently, 200 μL of 1.0×10 -3 mol / L NTP solution, and then measure its fluorescence intensity. Fig.10 As shown in the figure, the fluorescence intensity change of the recycled 1@PMMA (10wt%) mixed matrix membrane before and after the addition of NTP is almost the same as that of the newly prepared 1@PMMA (10wt%) mixed matrix membrane. The above experimental process was repeated 5 times, and no obvious fluorescence intensity change was found, indicating that the mixed matrix membrane has the advantages of good repeatability and recyclability, which will greatly reduce the detection cost and improve the detection efficiency.

[0072] Embodiment 17

[0073] Fluorescence detection mechanism analysis: The UV absorption spectra of neonicotinoids were measured and compared with the fluorescence excitation spectra of 1@PMMA (10wt%) mixed matrix membranes. Fig.11 ), only the UV absorption spectrum of NTP has an obvious overlapping area with the fluorescence excitation spectrum of 1@PMMA (10wt%) mixed matrix membrane. It is speculated that the fluorescence quenching mechanism of NTP can be attributed to the inner filter effect (IFE), indicating that there is a competitive absorption of the excitation light between NTP and 1@PMMA (10wt%) mixed matrix membrane.

[0074] Embodiment 18

[0075] In order to realize the on-site visual detection of NTP by 1@PMMA (10wt%) mixed matrix membrane, under the irradiation of 365nm ultraviolet light, 1@PMMA (10wt%) mixed matrix membrane exhibits bright blue fluorescence, which makes it possible to observe with the naked eye. Fig.12 As shown in Figure 2, when the mixed matrix membrane is immersed in solutions containing different concentrations of NTP, its luminescent color gradually changes from bright blue to darker as the concentration of NTP increases. However, due to differences in individual perception, even with the corresponding color card as a reference, there is still a certain uncertainty in the assessment of color changes by the naked eye.

[0076] In order to overcome this limitation, the present invention has developed a smartphone-assisted mixed matrix membrane fluorescence sensor, which aims to achieve accurate and on-site quantitative detection of NTP. Specifically, the 1@PMMA (10wt%) mixed matrix membrane soaked in NTP solutions of different concentrations is placed under 365nm ultraviolet light, and the Identify Colors application installed on the smartphone is used for identification and analysis. The color signal of the captured luminescent photo is converted into a digital RGB value, and the RGB value is further converted into a grayscale value (I) according to the formula I = 0.299R + 0.587G + 0.114B. In order to further improve the detection accuracy, the formula I is used. mean =(I blank -I test ) / I blank To calculate the relative gray value I mean , and use this to conduct quantitative analysis. Fig.13 As shown, in the range of NTP concentration from 0 to 100 μM, I mean The value showed a good linear relationship with the NTP concentration. This result shows that the smartphone-assisted 1@PMMA (10wt%) mixed matrix membrane fluorescence sensor can be used as a portable fluorescence sensing platform to achieve on-site visual quantitative detection and analysis of NTP.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram, characterized in that: include: Zn-MOF was prepared by solvothermal method with zinc ion as metal center and 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid as organic ligand; Dispersing the Zn-MOF in an organic solvent, adding polymethyl methacrylate, and mixing well to obtain a mixed solution; The mixed solution is coated on a substrate and dried to obtain the product.

2. The method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram according to claim 1, characterized in that: The zinc salt is zinc nitrate hexahydrate.

3. The method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram according to claim 1, characterized in that: The mass ratio of zinc salt to 5-((4-(pyridin-4-yl)benzylidene)amino)isophthalic acid is 23.8-29.7:27.7-34.

6.

4. The method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram according to claim 1, characterized in that: The solvent used in the solvothermal method is a mixed solution of dimethyl sulfoxide and water.

5. The method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram according to claim 1, characterized in that: The reaction conditions of the solvothermal method are 130° C.-140° C. for 60-72 hours.

6. The method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram according to claim 1, characterized in that: The mass ratio of the Zn-MOF to polymethyl methacrylate is 0.005-0.015:0.

1.

7. The method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram according to claim 1, characterized in that: The organic solvent is dichloromethane.

8. The method for preparing a MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram according to claim 1, characterized in that: The drying condition is drying at room temperature for more than 12 hours.

9. A MOFs-based mixed matrix membrane for on-site visual quantitative detection of nitenpyram prepared by the method according to any one of claims 1 to 8.

10. Use of the MOFs-based mixed matrix membrane according to claim 9 in on-site visual quantitative detection of nitenpyram.

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