Fe3O4@mesoporous SiO2 drug-carrying system based on photothermal-pesticide synergistic insecticide and its preparation method

Abstract

The present invention relates to the application and development of nanotechnology in the field of pest control technology, and specifically to an Fe3O4@mesoporous SiO2 drug delivery system and preparation method based on photothermal-pesticide synergistic insecticide. The preparation method of the present application assembles mesoporous silica on the surface of magnetic spherical nano-Fe3O4 by a simple sol-gel method, uses undecyltrimethylammonium bromide as a template, and ethyl tetrasilicate as a silicon source. The reaction is carried out in a mixed solution of ammonia, ethanol, and water, and water is used as an etchant. The resulting product is filtered and dried to obtain an Fe3O4@mesoporous SiO2 nanocarrier. The nanocarrier has a mesoporous structure and a large specific surface area, which is conducive to loading hydrophobic pesticide molecules. In addition, the core Fe3O4 has photothermal conversion ability, which has good application prospects in the field of pest control, especially for photothermal and chemical pesticide synergistic insecticide.

Description

Technical Field

[0001] The present invention relates to the application and development of nanotechnology in the field of pest control technology, and specifically to a Fe3O4@mesoporous SiO2 drug-carrying system based on photothermal-pesticide synergistic insecticide and a preparation method thereof. Background Art

[0002] Major crop pests in my country are numerous and present severe damage, with frequent outbreaks posing a long-term threat to agricultural production and national food security. Pesticides continue to play an irreplaceable and important role in combating major agricultural pests. However, traditional pesticide formulations suffer from poor dispersibility and contain large amounts of chemical organic solvents and adjuvants. These lack affinity with plant surfaces, making them prone to splashing and loss. They also suffer from volatilization of active ingredients and susceptibility to degradation by light and microorganisms, leading to low pesticide utilization rates and short effective lifespans. Large amounts of pesticides are lost into the air, soil, and water, posing a serious threat to biodiversity, environmental safety, and even human health. Therefore, improving pesticide utilization through technological innovation will provide a technical foundation for continuously promoting pesticide reduction and efficiency improvements and green agricultural development in my country.

[0003] The development of nanotechnology and nanomaterials has provided new avenues for improving the utilization rate of pesticides and enhancing their effectiveness against pests. Encapsulating bioactive substances, such as pesticides, in nanocarrier materials not only increases their solubility, prevents rapid degradation, and promotes sustained and gradual release of the pesticide, but also effectively enhances the distribution and absorption penetration of the pesticide into target pests, significantly improving the pesticide's effectiveness against pests and diseases. Compared with conventional mesoporous silica, Fe3O4@mesoporous silica has a larger specific surface area and structural functionality, resulting in superior drug release performance. Furthermore, the Fe3O4 core exhibits a photothermal effect, converting near-infrared light into heat, thermally ablating cells and tissues and achieving photothermal insecticide. Therefore, the development of Fe3O4@mesoporous silica nanoparticle drug delivery systems with synergistic effects of photothermal and chemical pesticides has great potential for application. Summary of the Invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a method for preparing a Fe3O4@mesoporous SiO2 drug-carrying system based on photothermal-pesticide synergistic insecticide, comprising the following steps:

[0006] S1. Preparation of magnetic spherical nano-Fe3O4

[0007] Ferric chloride, sodium citrate and sodium acetate were added into a reaction kettle containing ethylene glycol solution and reacted at 220-225°C for 12 hours, and then washed and dried to obtain magnetic spherical nano-Fe3O4.

[0008] Preparation of S2, Fe3O4@mesoporous SiO2 nanocarriers

[0009] Using the sol-gel method, ethyl tetrasilicate, ammonia, water, ethanol, and the magnetic spherical nano-Fe3O4 obtained in step S1 were sequentially added to the reactor and reacted at 45°C for 6 hours. Then, using the self-template method, the template agent and ethyl tetrasilicate were stirred and reacted at 30-40°C for 24 hours. Finally, water was used as an etchant and the mixture was incubated in water at 60°C for 12 hours to obtain Fe3O4@mesoporous SiO2 nanocarriers.

[0010] Preparation of S3, Fe3O4@mesoporous SiO2 nano-drug delivery system

[0011] The active component of the insecticide was added to a reactor containing an ethanol solution, and then the Fe3O4@mesoporous SiO2 nanocarrier in step S2 was added. The reaction was carried out for 12 hours, the solvent was removed by centrifugation, and the mixture was vacuum dried to obtain the Fe3O4@mesoporous SiO2 nanodrug delivery system.

[0012] Furthermore, the mass ratio of ferric chloride, sodium citrate and sodium acetate is 1:0.3-0.4:2-2.5.

[0013] Furthermore, the mass ratio of ethyl tetrasilicate, ammonia water, water, ethanol and nano-Fe3O4 is 1:2-3:7-8:300-305:0.6-0.8.

[0014] Furthermore, the concentration of the ammonia water is 25-30%.

[0015] Furthermore, the template agent is undecyltrimethylammonium bromide or hexadecyltrimethylammonium bromide.

[0016] Furthermore, the reaction temperature of the self-template method in step S2 is 25° C., and the stirring speed is 300 rpm / min.

[0017] Furthermore, the active ingredient of the insecticide is emamectin benzoate.

[0018] Furthermore, the mass concentration of the insecticide active component is 10 mg / mL.

[0019] Furthermore, the mass of the Fe3O4@mesoporous SiO2 nanocarrier is 100-150 mg.

[0020] The Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide is prepared using the above-mentioned preparation method of the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide.

[0021] From the above description of the present invention, it can be seen that compared with the prior art, the present invention has the following beneficial effects:

[0022] The preparation method of the present application has simple steps and does not require sacrificial templates, surface protective agents or corrosive and toxic etchants.

[0023] The mesoporous SiO2 in this application has controllable pore size and uniform thickness, making it suitable for loading active pesticide molecules. The Fe3O4 core has good photothermal conversion efficiency, is recyclable, and has minimal toxic side effects, showing promising application prospects in pest control, particularly for synergistic insecticide applications involving photothermal and chemical pesticides. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a transmission electron microscope image of the magnetic spherical nano-Fe3O4 of the present invention;

[0025] Figure 2 This is a pore size distribution diagram of the Fe3O4@mesoporous SiO2 nanocarrier in a preferred embodiment of the present invention;

[0026] Figure 3 This is a transmission electron microscope image of the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0027] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] Example 1

[0029] The preparation method of the Fe3O4@mesoporous SiO2 drug-carrying system based on photothermal-pesticide synergistic insecticide comprises the following steps:

[0030] S1. Preparation of magnetic spherical nano-Fe3O4

[0031] By using the solvothermal method, 1.2g of ferric chloride, 0.5g of sodium citrate and 2.5g of sodium acetate were dissolved in 50mL of ethylene glycol solution, reacted in a reactor at 220℃ for 12h, washed with water and dried to obtain spherical nano-Fe3O4. Figure 1 As shown;

[0032] Preparation of S2, Fe3O4@mesoporous SiO2 nanocarriers

[0033] Dissolve 0.1 g of spherical nano-Fe3O4 obtained in step S1 in ethanol solution, add 2 mL of 28% ammonia water, 160 μL of ethyl tetrasilicate, 1 mL of water, and 50 mL of ethanol in sequence, react at 45 ° C for 6 h, and collect the precipitate by centrifugation;

[0034] Then, 1 mL of ethyl tetrasilicate, 1 mL of 28% ammonia water, 50 mL of water, 30 mL of ethanol and 0.15 g of undecyltrimethylammonium bromide were added in sequence and reacted at 40°C for 24 h.

[0035] Finally, water was used as an etchant and incubated in water at 60 °C for 12 h to remove undecyltrimethylammonium bromide and obtain Fe3O4@mesoporous SiO2 nanocarriers;

[0036] Preparation of S3, Fe3O4@mesoporous SiO2 nano-drug delivery system

[0037] A hydrophobic pesticide molecule such as emamectin benzoate dissolved in ethanol solution at 10 mg / mL was used as the active ingredient of the insecticide and reacted with 100 mg of Fe3O4@mesoporous SiO2 nanocarrier for 12 hours. The solvent was removed by centrifugation and the Fe3O4@mesoporous SiO2 nanodrug delivery system was obtained after vacuum drying.

[0038] Example 2

[0039] The difference between this embodiment and the first embodiment is that the 28% ammonia water in step S2 is changed to 25% ammonia water, and other conditions are the same.

[0040] Example 3

[0041] The difference between this embodiment and the first embodiment is that the 100 mg of Fe3O4@mesoporous SiO2 nanocarrier in step S3 is replaced with 150 mg of Fe3O4@mesoporous SiO2 nanocarrier, and other conditions are the same.

[0042] Morphology and Particle Size Analysis of Fe3O4@mesoporous SiO2 Nano-drug Delivery System

[0043] like Figure 2 As shown in the figure, the pore size distribution of the Fe3O4@mesoporous SiO2 nanocarrier measured by a fully automatic physical adsorption instrument (BET) is narrow, concentrated in the range of 2-3 nm, which belongs to the mesoporous range. Its pore size distribution is sufficient to allow pesticides to pass through the pores of the mesoporous material, meeting the requirements of the pesticide slow-release carrier structure. Figure 3 As shown, further characterization of the morphology and particle size of the nano-drug delivery system by transmission electron microscopy showed that the nano-drug delivery system was spherical, with uniform particle size of about 200 nm.

[0044] Under the premise that no conflict occurs, those skilled in the art may freely combine and superimpose the above-mentioned additional technical features.

[0045] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A method for preparing a Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide, characterized in that: The following steps are involved: S1. Preparation of magnetic spherical nano-Fe3O4 Ferric chloride, sodium citrate and sodium acetate were added into a reaction kettle containing ethylene glycol solution and reacted at 220-225°C for 12 hours, and then washed and dried to obtain magnetic spherical nano-Fe3O4. Preparation of S2, Fe3O4@mesoporous SiO2 nanocarriers Using the sol-gel method, ethyl tetrasilicate, ammonia, water, ethanol, and the magnetic spherical nano-Fe3O4 obtained in step S1 were sequentially added to the reactor and reacted at 45°C for 6 hours. Then, using the self-template method, the template agent and ethyl tetrasilicate were stirred and reacted at 30-40°C for 24 hours. Finally, water was used as an etchant and the mixture was incubated in water at 60°C for 12 hours to obtain Fe3O4@mesoporous SiO2 nanocarriers. The template agent is undecyltrimethylammonium bromide; The mass ratio of the tetraethyl silicate, ammonia water, water, ethanol and nano-Fe3O4 is 1:2-3:7-8:300-305:0.6-0.8; Preparation of S3, Fe3O4@mesoporous SiO2 nano-drug delivery system The active component of the insecticide was added to a reactor containing an ethanol solution, and then the Fe3O4@mesoporous SiO2 nanocarrier prepared in step S2 was added. The reaction was continued for 12 hours, the solvent was removed by centrifugation, and the mixture was dried under vacuum to obtain the Fe3O4@mesoporous SiO2 nanocarrier system. The active component of the insecticide is a hydrophobic insecticide molecule, and the hydrophobic insecticide molecule is emamectin benzoate.

2. The method for preparing the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide according to claim 1 is characterized in that: The mass ratio of the ferric chloride, sodium citrate and sodium acetate is 1:0.3-0.4:2-2.

5.

3. The method for preparing the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide according to claim 1, characterized in that: The concentration of the ammonia water is 25-30%.

4. The method for preparing the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide according to claim 1, characterized in that: The template agent is hexadecyltrimethylammonium bromide.

5. The method for preparing the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide according to claim 1, characterized in that: The reaction temperature of the self-template method in step S2 is 25° C., and the stirring speed is 300 rpm / min.

6. The method for preparing the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide according to claim 1, characterized in that: The mass concentration of the insecticide active component is 10 mg / mL.

7. The method for preparing the Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide according to claim 1, characterized in that: The mass of the Fe3O4@mesoporous SiO2 nanocarrier is 100-150 mg.

8. Fe3O4@mesoporous SiO2 drug delivery system based on photothermal-pesticide synergistic insecticide, characterized by: The preparation method is based on the Fe3O4@mesoporous SiO2 drug delivery system for photothermal-pesticide synergistic insecticide according to any one of claims 1 to 7.

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