Modified indoxacarb nano pesticide and preparation method thereof

Abstract

The invention discloses a modified indoxacarb nano pesticide and a preparation method thereof, the pesticide comprises a carrier, a loaded indoxacarb active compound and oxidized sodium alginate grafted on the carrier, the carrier is an amino-containing iron-based metal organic framework material, and the aldehyde group of the oxidized sodium alginate and the amino group on the carrier material are subjected to a Schiff base reaction to obtain the modified indoxacarb nano pesticide. Grafting on a carrier; the preparation method comprises the following steps: (1) loading an indoxacarb active compound on an amino-containing iron-based metal organic framework material; and (2) adding the carrier loaded with the pesticide in the step (1) and oxidized sodium alginate into a solvent, and grafting the oxidized sodium alginate onto an iron-based metal organic framework through Schiff base reaction to obtain the modified indoxacarb nano pesticide. According to the invention, the indoxacarb active compound is loaded on the iron-based metal organic framework material, and the iron-based metal organic framework material is further modified by using the oxidized sodium alginate, so that the stability of the indoxacarb active compound and the adhesiveness of the indoxacarb active compound on plant leaf surfaces are improved.

Description

Technical Field

[0001] The invention relates to the field of pesticides, and in particular to a modified indoxacarb nanopesticide and a preparation method thereof. Background Art

[0002] Indoxacarb is a common insecticide for controlling lepidopteran pests, mainly acting as contact and stomach poisons. Currently, it is mainly used in agriculture in the form of synthetic suspension concentrates, water dispersants and emulsifiable concentrates. In order to improve the efficacy of the original drug, it is necessary to add a certain amount of pesticide adjuvants, functional compounds or emulsifiers to the solution to reduce the surface tension of the solution and increase the amount of solution deposited on the target surface.

[0003] Although the hydrophobicity of droplets on target crops can be improved and the utilization rate of pesticides can be increased by making reasonable emulsifiers and formulations, most of these pesticide formulations are chemicals that are difficult to dissolve in water, have poor stability, are easy to decompose, and are not resistant to rain erosion; during the application process, due to weather and application methods, most pesticides fail to reach the target crops and flow into the ecosystem, thus causing environmental and cost problems, which in turn increases production costs. Summary of the invention

[0004] Purpose of the invention: The first purpose of the invention is to provide a modified indoxacarb nanopesticide that improves the stability of the original indoxacarb and its adhesion on plant leaves; the second purpose of the invention is to provide a method for preparing the modified indoxacarb nanopesticide.

[0005] Technical solution: The modified indoxacarb nanopesticide described in the present invention includes a carrier, a loaded indoxacarb original drug (IND) and oxidized sodium alginate (OSA) grafted on the carrier, wherein the carrier is an iron-based metal organic framework material () containing amino groups, and the aldehyde group of the oxidized sodium alginate reacts with the amino group on the carrier material to undergo a Schiff base reaction, thereby being grafted on the carrier.

[0006] Preferably, the organic ligand of the amino-containing iron-based metal organic framework material is aminoterephthalic acid. Further preferably, the mass ratio of the amino-containing iron-based metal organic framework material to indoxacarb original drug is (5:4) to (4:3); the molar ratio of the iron-based metal organic framework material loaded with indoxacarb original drug to oxidized sodium alginate is (4:5) to (5:6).

[0007] The preparation method of the modified indoxacarb nanopesticide of the present invention comprises the following steps:

[0008] (1) loading the indoxacarb technical onto an amino-containing iron-based metal organic framework material;

[0009] (2) adding the drug-loaded carrier and oxidized sodium alginate in step (1) into a solvent, grafting the oxidized sodium alginate onto the iron-based metal organic framework through a Schiff base reaction, and obtaining a modified indoxacarb nanopesticide.

[0010] Preferably, in step (1), the method for loading the indoxacarb technical onto the amino-containing iron-based metal-organic framework material is: dispersing the iron-based metal-organic framework material and the indoxacarb technical in a solvent, allowing the indoxacarb technical to enter the voids of the iron-based metal-organic framework material, and then freeze-drying to obtain the iron-based metal-organic framework material loaded with the indoxacarb technical.

[0011] Preferably, in step (1), the preparation method of the iron-based metal organic framework material is: using aminoterephthalic acid as an organic ligand, dimethylformamide as a solvent and iron salt to synthesize an amino-containing iron-based metal organic framework material (MIL-101-NH2) by a hydrothermal method, wherein the molar ratio of aminoterephthalic acid as an organic ligand to iron in the iron salt is (1:1) to (1:6), the reaction temperature is 90 to 130°C, and the reaction time is 20 to 48 hours.

[0012] The structural formula of the MIL-101-NH2 is:

[0013]

[0014] Preferably, in step (2), the reaction temperature is 20-40°C.

[0015] Preferably, in step (2), the solvent is an ethanol solution or a DMF solution.

[0016] Preferably, in step (2), the preparation method of the oxidized sodium alginate is: (1) fully dissolving sodium alginate in deionized water; (2) adding sodium periodate to the sodium alginate solution, and causing an oxidation reaction at 20 to 30° C. in the dark; (3) terminating the reaction, washing multiple times, centrifuging, dialyzing, and freeze-drying.

[0017] Preferably, the termination reaction is to terminate the reaction after the color of the ethylene glycol solution becomes darker.

[0018] Preferably, the reaction time is 4 to 5 hours.

[0019] Invention mechanism:

[0020] The rise of nanopesticides provides new solutions for the controllable design of pesticide formulations, precise delivery of pesticides to targets, and sustainable development of agriculture. Metal-organic framework materials have large specific surface area, abundant internal pores, controllable synthesis routes, easy surface modification, and good biocompatibility. Therefore, metal-organic framework materials are selected as carriers of pesticides to design nanopesticides with stimuli-responsive controlled release.

[0021] The present invention uses an amino-containing iron-based metal organic framework material as a carrier, loads the indoxacarb original drug, and then uses oxidized sodium alginate to modify the drug-loaded iron-based metal organic framework material using a Schiff base reaction, and then forms a chemically cross-linked hydrogel, which is coated on the surface. Sodium alginate is a natural polysaccharide with good interface affinity. It is used to modify the iron-based metal organic framework material to enhance the interface affinity of the material and improve the adhesion of nano pesticide particles to plant leaves.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) by loading the indoxacarb technical onto the iron-based metal organic framework material and further modifying the iron-based metal organic framework material with oxidized sodium alginate, the stability of the indoxacarb technical and the adhesion to the plant leaf surface are improved; (2) by utilizing the Schiff base reaction to graft the oxidized sodium alginate onto the iron-based metal organic framework, the synthesized material has low density, large specific surface area, high porosity, high crystallinity and high functionalization; (3) the preparation method is simple, easy to synthesize, low in production cost, easy to implement and convenient to realize industrialization; (4) the product prepared by the method is easy to purify and has a high yield; the solvent used for precipitating the product and the solvent used for washing the product can be recovered by atmospheric distillation, thereby reducing the use of solvents and the pollution to the environment caused by sewage discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 XRD diagrams of the modified indoxacarb nanopesticide prepared in Example 1 and the materials of Comparative Examples 1 to 3;

[0024] Figure 2 FTIR images of the modified indoxacarb nanopesticide prepared in Example 1 and the materials of Comparative Examples 1 to 3;

[0025] Figure 3 TG graphs of the modified indoxacarb nanopesticide prepared in Example 1 and the materials of Comparative Examples 1 and 2;

[0026] Figure 4 The modified indoxacarb nanopesticide prepared in Example 1 was tested for the sustained release of indoxacarb at different pH values;

[0027] Figure 5 The water contact angle diagram of the modified indoxacarb nanopesticide prepared in Example 1 and the indoxacarb original pesticide after spraying on corn leaves;

[0028] Figure 6 The Zeta potential data test graphs of the modified indoxacarb nanopesticide prepared in Example 1 and the materials of Comparative Examples 1 and 2;

[0029] Figure 7Inverted fluorescence microscope images of the modified indoxacarb nanopesticide prepared in Example 1 sprayed on corn leaves under white light and fluorescence fields before and after simulated rain scouring. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below in conjunction with embodiments.

[0031] Example 1

[0032] The modified indoxacarb nanopesticide of the present invention comprises the following steps:

[0033] (1) Preparation of iron-based MOF materials

[0034] Aminoterephthalic acid and ferric chloride hexahydrate were dispersed in dimethylformamide at a molar ratio of 1:2, and after being fully stirred and dissolved, they were added into a reactor and reacted at 110°C for 24 hours. After being cooled to room temperature, the mixture was washed with ethanol several times, centrifuged, and vacuum dried to obtain the amino-containing iron-based MOF material MIL-101-NH2.

[0035] (2) Preparation of oxidized sodium alginate

[0036] Sodium alginate was fully dissolved in deionized water to obtain a sodium alginate solution with a mass fraction of 2%, and then sodium periodate was added to the sodium alginate solution at a molar ratio of 2:3. The reaction was carried out under light-proof conditions for 4 hours, and then 2 ml of ethylene glycol was added to terminate the reaction. Ethanol was added to precipitate it, and it was washed several times until the supernatant became clear, centrifuged 2 to 3 times, dialyzed, and then freeze-dried and stored in a vacuum dryer to obtain oxidized sodium alginate.

[0037] (3) Preparation of drug-loaded iron-based MOF materials

[0038] The MIL-101-NH2 material prepared in step (1) and indoxacarb are dispersed in a 30% by mass ethanol solution at a mass ratio of 5:4, and ultrasonically dispersed evenly to allow indoxacarb to enter the pores of the MOF material so that indoxacarb can be loaded to the maximum extent. The drug-loaded iron-based MOF material is obtained by freeze-drying.

[0039] (4) Grafted oxidized sodium alginate

[0040] The drug-loaded iron-based MOF material and oxidized sodium alginate prepared in step (3) were dispersed in a 30% by mass ethanol solution at a mass ratio of 5:6, ultrasonicated for 30 minutes at 30°C, and magnetically stirred in a beaker for reaction for 2 hours to obtain the modified indoxacarb nanopesticide MIL-IND-OSA.

[0041] Example 2

[0042] The modified indoxacarb nanopesticide of the present invention comprises the following steps:

[0043] (1) Preparation of iron-based MOF materials

[0044] Aminoterephthalic acid and ferric chloride hexahydrate were dispersed in dimethylformamide in a molar ratio of 1:2. After being fully stirred and dissolved, they were added into a reactor and reacted at 110°C for 24 hours. After being cooled to room temperature, they were washed with ethanol several times, centrifuged, and vacuum dried to obtain the amino-containing iron-based MOF material MIL-101-NH2.

[0045] (2) Preparation of oxidized sodium alginate

[0046] Sodium alginate was fully dissolved in deionized water to obtain a sodium alginate solution with a mass fraction of 2%, and then sodium periodate was added to the sodium alginate solution at a molar ratio of 2:3. The reaction was carried out under light-proof conditions for 4 hours, and then 2 ml of ethylene glycol was added to terminate the reaction. Ethanol was added to precipitate it, and it was washed several times until the supernatant became clear, centrifuged 2 to 3 times, dialyzed, and then freeze-dried and stored in a vacuum dryer to obtain oxidized sodium alginate.

[0047] (3) Preparation of drug-loaded iron-based MOF materials

[0048] The MIL-101-NH2 material prepared in step (1) and indoxacarb are dispersed in a 30% by mass ethanol solution at a mass ratio of 4:3, and ultrasonically dispersed evenly to allow indoxacarb to enter the pores of the MOF material so that indoxacarb can be loaded to the maximum extent. The drug-loaded iron-based MOF material is obtained by freeze-drying.

[0049] (4) Grafted oxidized sodium alginate

[0050] The drug-loaded iron-based MOF material and oxidized sodium alginate prepared in step (3) were dispersed in a 30% by mass ethanol solution at a mass ratio of 5:6, ultrasonicated for 30 minutes at 30°C, and magnetically stirred in a beaker for reaction for 2 hours to obtain the modified indoxacarb nanopesticide MIL-IND-OSA.

[0051] Example 3

[0052] The modified indoxacarb nanopesticide of the present invention comprises the following steps:

[0053] (1) Preparation of iron-based MOF materials

[0054] Aminoterephthalic acid and ferric chloride hexahydrate were dispersed in dimethylformamide in a molar ratio of 1:2. After being fully stirred and dissolved, they were added into a reactor and reacted at 110°C for 24 hours. After being cooled to room temperature, they were washed with ethanol several times, centrifuged, and vacuum dried to obtain the amino-containing iron-based MOF material MIL-101-NH2.

[0055] (2) Preparation of oxidized sodium alginate

[0056] Sodium alginate was fully dissolved in deionized water to obtain a sodium alginate solution with a mass fraction of 1%, and then ultrasonicated for 30 minutes, and sodium periodate was added to the sodium alginate solution at a molar ratio of 2:3; the reaction was carried out under light-proof conditions for 4 hours, and then 2 ml of ethylene glycol was added to terminate the reaction. Ethanol was added to precipitate it, and it was washed several times until the supernatant became clear, centrifuged 2 to 3 times, dialyzed, and then freeze-dried and stored in a vacuum dryer to obtain the successfully prepared oxidized sodium alginate.

[0057] (3) Preparation of drug-loaded iron-based MOF materials

[0058] The MIL-101-NH2 material prepared in step (1) and indoxacarb are dispersed in a 30% by mass ethanol solution at a mass ratio of 5:4, and ultrasonically dispersed evenly to allow indoxacarb to enter the pores of the MOF material so that indoxacarb can be loaded to the maximum extent. The drug-loaded iron-based MOF material is obtained by freeze-drying.

[0059] (4) Grafted oxidized sodium alginate

[0060] The drug-loaded iron-based MOF material prepared in step (3) and oxidized sodium alginate were dispersed in a 30% ethanol solution at a mass ratio of 5:6, ultrasonicated for 30 minutes at 30°C, and magnetically stirred in a beaker for reaction for 2 hours to obtain the modified indoxacarb nanopesticide MIL-IND-OSA.

[0061] Example 4

[0062] The modified indoxacarb nanopesticide of the present invention comprises the following steps:

[0063] (1) Preparation of iron-based MOF materials

[0064] Aminoterephthalic acid and ferric chloride hexahydrate were dispersed in dimethylformamide in a molar ratio of 1:2. After being fully stirred and dissolved, they were added into a reactor and reacted at 110°C for 24 hours. After being cooled to room temperature, they were washed with ethanol several times, centrifuged, and vacuum dried to obtain the amino-containing iron-based MOF material MIL-101-NH2.

[0065] (2) Preparation of oxidized sodium alginate

[0066] Sodium alginate was fully dissolved in deionized water to obtain a sodium alginate solution with a mass fraction of 2%, and then the solution was ultrasonicated for 30 minutes, and sodium periodate was added to the sodium alginate solution at a molar ratio of 2:3; the reaction was carried out under light-proof conditions for 4 hours, and then 2 ml of ethylene glycol was added to terminate the reaction. Ethanol was added to precipitate it, and it was washed several times until the supernatant became clear, centrifuged 2 to 3 times, dialyzed, and then freeze-dried and stored in a vacuum dryer to obtain the successfully prepared oxidized sodium alginate.

[0067] (3) Preparation of drug-loaded iron-based MOF materials

[0068] The MIL-101-NH2 material prepared in step (1) and indoxacarb are dispersed in a 30% by mass ethanol solution at a mass ratio of 5:4 and dispersed evenly by ultrasonication. The purpose of ultrasonication is to make the MOF material more dispersed and allow indoxacarb to enter the pores of the MOF material so that indoxacarb can be loaded to the maximum extent. The drug-loaded iron-based MOF material is obtained by freeze-drying.

[0069] (4) Grafted oxidized sodium alginate

[0070] The drug-loaded iron-based MOF material prepared in step (3) and oxidized sodium alginate were dispersed in a 30% by mass ethanol solution at a mass ratio of 4:5, ultrasonicated for 30 minutes at 30°C, and magnetically stirred in a beaker for reaction for 2 hours to obtain the modified indoxacarb nanopesticide MIL-IND-OSA.

[0071] Example 5

[0072] The modified indoxacarb nanopesticide of the present invention comprises the following steps:

[0073] (1) Preparation of iron-based MOF materials

[0074] Aminoterephthalic acid and ferric chloride hexahydrate were dispersed in dimethylformamide in a molar ratio of 1:2. After being fully stirred and dissolved, they were added into a reactor and reacted at 110°C for 24 hours. After being cooled to room temperature, they were washed with ethanol several times, centrifuged, and vacuum dried to obtain the amino-containing iron-based MOF material MIL-101-NH2.

[0075] (2) Preparation of oxidized sodium alginate

[0076] Sodium alginate was fully dissolved in deionized water to obtain a sodium alginate solution with a mass fraction of 2%, and then the solution was ultrasonicated for 30 minutes, and sodium periodate was added to the sodium alginate solution at a molar ratio of 2:3; the reaction was carried out under light-proof conditions for 4 hours, and then 2 ml of ethylene glycol was added to terminate the reaction. Ethanol was added to precipitate it, and it was washed several times until the supernatant became clear, centrifuged 2 to 3 times, dialyzed, and then freeze-dried and stored in a vacuum dryer to obtain the successfully prepared oxidized sodium alginate.

[0077] (3) Preparation of drug-loaded iron-based MOF materials

[0078] The MIL-101-NH2 material prepared in step (1) and indoxacarb are dispersed in a 30% by mass ethanol solution at a molar ratio of 4:3, and ultrasonically dispersed evenly to allow indoxacarb to enter the pores of the MOF material, so that indoxacarb can be loaded to the maximum extent, and freeze-dried to obtain the drug-loaded iron-based MOF material.

[0079] (4) Grafted oxidized sodium alginate

[0080] The drug-loaded iron-based MOF material prepared in step (3) and oxidized sodium alginate were dispersed in a 30% ethanol solution at a molar ratio of 4:5, ultrasonicated for 30 min at 30° C., and magnetically stirred in a beaker for 2 h to obtain the modified indoxacarb nanopesticide MIL-IND-OSA.

[0081] Comparative Example 1

[0082] No treatment was performed on the original indoxacarb (IND).

[0083] Comparative Example 2

[0084] On the basis of Example 1, only steps (1) and (3) were performed to obtain the drug-loaded iron-based MOF material MIL-IND.

[0085] Comparative Example 3

[0086] On the basis of Example 1, only step (1) was performed to obtain the amino-containing iron-based MOF material MIL-101-NH2.

[0087] Structural characterization

[0088] The modified indoxacarb nanopesticide prepared in Example 1 was characterized, and the results were as follows: Figure 1 and Figure 2 shown.

[0089] Depend on Figure 1 It can be obtained that the characteristic peak positions of MIL-IND-OSA prepared in Example 1 are mainly at 8.61°, 12.54°, and 21.7°, indicating that an iron-based metal organic framework material modified by oxidized sodium alginate has been formed.

[0090] Depend on Figure 2 It can be seen that the characteristic peaks of OSA, MIL and indoxacarb can be found on the absorption peak of MIL-IND-OSA, indicating that the material was successfully synthesized.

[0091] Performance Testing

[0092] (1) Thermal stability test

[0093] The thermal stability of the nanopesticides of Example 1, Comparative Example 1 and Comparative Example 2 was tested. The results are as follows: Figure 3 shown.

[0094] Figure 3 It can be seen that compared with the original drug and the nanopesticide of indoxacarb loaded on the iron-based MOF carrier not modified with sodium alginate, MIL-IND-OSA has the highest stability.

[0095] (2) pH-responsive controlled release performance test

[0096] The controlled release performance of MIL-IND-OSA prepared in Example 1 was tested at different pH values.

[0097] Test method: Under the conditions of pH 5, 7, and 9, 30% ethanol solution was used as the dialysate, 5 mL of 1 mg / mL MIL-IND-OSA nanoformulation was taken and placed in a dialysis bag (8000-14000 kDa), and the release rate of the original drug IND of the MIL-IND-OSA nano sustained-release agent was explored within 0, 1, 2, 4...240 hours. Each time, 4 mL of the permeate was taken for UV test on a UV spectrophotometer. The test results are as follows: Figure 4 shown.

[0098] Depend on Figure 4 It can be obtained that the release rate of MIL-IND-OSA prepared in Example 1 is improved at different pH values ​​compared with neutral pH; the release rate is highest under pH = 9. This may be because the strength of the nanogel is weakened under alkaline conditions, and the structure of the outermost coated oxidized sodium alginate is gradually destroyed, which is beneficial to the hydrolysis of the Schiff base compound generated by the reaction of MIL-101-NH2 and the grafted oxidized sodium alginate Schiff base, thereby facilitating the release of indoxacarb on the metal organic framework.

[0099] (3) Leaf wetting performance test

[0100] The wetting properties of MIL-IND-OSA prepared in Example 1 and the indoxacarb technical material of Comparative Example 1 were tested.

[0101] Test method: Use a fully automatic contact angle meter (DSA30S, GmbH, Germany) measured the water contact angle of 1 mg / mL MIL-IND-OSA and IND on corn leaves. Fresh corn leaves were repeatedly rinsed with deionized water three times, and after natural drying, the flat parts were cut and attached to a glass slide and placed on the operating table. 3 μL MIL-IND-OSA and IND were dropped on the corn leaves each time, and the contact angle was recorded every 2 minutes. Each sample was tested three times. The test results are shown in Figure 5 shown.

[0102] Depend on Figure 5 It can be seen that compared with the original drug, the leaf wettability of MIL-IND-OSA is greatly enhanced, so that the pesticide droplets sprayed on the plant leaves can be better spread out, increasing the effective area, and the pesticide droplets are not easy to leave the leaf surface under the action of wind and gravity, thereby increasing the utilization rate of pesticides and reducing spraying losses.

[0103] (4) Zeta potential

[0104] The Zeta potential of the MIL-IND-OSA prepared in Example 1 and the nanopesticides prepared in Comparative Examples 1 and 2 were tested.

[0105] Test method: Use a Zeta potential meter (NANO ZS90, Malvern, UK) to measure the Zeta potential of 1mg / L IL-IND-OSA, MIL-IND and IND. Dilute the prepared solution to 1mg / L, sonicate for 20 minutes, and after uniform dispersion, select water as the solvent to test the Zeta potential of the materials. The test results are as follows: Figure 6 shown.

[0106] Depend on Figure 6 It can be obtained that the potentials of the nanopesticides obtained in Example 1, Comparative Example 1, and Comparative Example 2 are 45 mV, 4.95 mV, and 19.8 mV, respectively. It can be seen that compared with the original indoxacarb and the nanopesticide loaded with indoxacarb on the iron-based MOF carrier not modified with sodium alginate, the MIL-IND-OSA system prepared in Example 1 is the most stable.

[0107] (5) Test on the retention rate of nanopesticides on plant leaves

[0108] The retention capacity of MIL-IND-OSA prepared in Example 1 and indoxacarb technical of Comparative Example 1 sprayed on corn leaves was tested on an inverted fluorescence microscope (Ti-S, Nikon, Japan).

[0109] Test method: Select corn leaves of basically the same size and width, soak them in anhydrous ethanol, rinse them with pure water, dry them in a ventilated place for later use, prepare 2ml of 1mg / mL OSA-MIL-IND pesticide preparation and 1mg / mL Rhodamine Red B mixed solution and 2mL of 1mg / mL IND and 1mg / mL Rhodamine Red B mixed solution, spray them evenly on the corn leaves with a spray bottle, place them in a petri dish covered with filter paper and dry them in a ventilated place for later use, and use pure water to simulate rainwater scouring. Observe the images of the original drug and the preparation before and after simulated rainwater scouring under white light and fluorescence field of an inverted fluorescence microscope.

[0110] Depend on Figure 7 It can be obtained that the MIL-IND-OSA prepared in Example 1 ( Figure 7 a~d) Compared with indoxacarb original drug ( Figure 7 e~h), when sprayed directly on plant leaves, a large amount of MIL-IND-OSA and indoxacarb technical can be observed to remain under both bright field and fluorescent field conditions; after simulated rain scouring, most of MIL-IND-OSA is retained on the leaves, while the amount of indoxacarb technical remains is very small.

Claims

1. A modified indoxacarb nanopesticide, characterized in that: The invention comprises a carrier, a loaded indoxacarb original drug and oxidized sodium alginate grafted on the carrier. The carrier is an iron-based metal organic framework material containing amino groups. The aldehyde groups of the oxidized sodium alginate react with the amino groups on the carrier material to generate a Schiff base reaction, thereby being grafted on the carrier.

2. The modified indoxacarb nanopesticide according to claim 1, characterized in that: The organic ligand of the amino-containing iron-based metal organic framework material is aminoterephthalic acid.

3. The modified indoxacarb nanopesticide according to claim 2, characterized in that: The mass ratio of the amino-containing iron-based metal organic framework material to the indoxacarb original drug is (5:4) to (4:3).

4. The modified indoxacarb nanopesticide according to claim 2, characterized in that: The mass ratio of the iron-based metal organic framework material loaded with indoxacarb technical to oxidized sodium alginate is (4:5) to (5:6).

5. A method for preparing the modified indoxacarb nanopesticide according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) loading the indoxacarb technical onto an amino-containing iron-based metal organic framework material; (2) adding the drug-loaded carrier and oxidized sodium alginate in step (1) into a solvent, grafting the oxidized sodium alginate onto the iron-based metal organic framework through a Schiff base reaction, and obtaining a modified indoxacarb nanopesticide.

6. The method for preparing the modified indoxacarb nanopesticide according to claim 5, characterized in that: In step (2), the reaction temperature is 20-40°C.

7. The method for preparing the modified indoxacarb nanopesticide according to claim 5, characterized in that: In step (1), the method for loading the indoxacarb technical onto the amino-containing iron-based metal organic framework material is as follows: dispersing the iron-based metal organic framework material and the indoxacarb technical in a solvent, allowing the indoxacarb technical to enter the voids of the iron-based metal organic framework material, and then freeze-drying to obtain the iron-based metal organic framework material loaded with the indoxacarb technical.

8. The method for preparing the modified indoxacarb nanopesticide according to claim 5, characterized in that: In step (2), the solvent is an ethanol solution or a DMF solution.

9. The method for preparing the modified indoxacarb nanopesticide according to claim 5, characterized in that: The preparation method of the amino-containing iron-based metal organic framework material is as follows: the amino-containing iron-based metal organic framework material is synthesized by a hydrothermal method using aminoterephthalic acid as an organic ligand, dimethylformamide as a solvent and iron salt, wherein the molar ratio of the aminoterephthalic acid as an organic ligand to the iron in the iron salt is (1:1) to (1:6), the reaction temperature is 90 to 130°C, and the reaction time is 20 to 48 hours.

10. The method for preparing the modified indoxacarb nanopesticide according to claim 5, characterized in that: The preparation method of the oxidized sodium alginate is: (1) Dissolve sodium alginate in deionized water; (2) adding sodium periodate to the sodium alginate solution to cause an oxidation reaction at 20-30° C. in the dark; (3) Terminate the reaction, wash multiple times, centrifuge, dialyze, and freeze-dry.

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