Materials for specifically eliminating antibiotic resistance genes and methods of making and using the same

Abstract

The application belongs to the technical field of antibiotic resistance gene management, and provides a material for specifically removing antibiotic resistance genes, a preparation method and application thereof, the method comprising the following steps: coating ZIF-8 on Fe3O4 particles to obtain a product Fe3O4@ZIF-8; reacting the Fe3O4@ZIF-8 with biomass powder and then adding KOH for carbonization to obtain a product MSC; incubating the MSC with EDC and NHS, then reacting with ethylenediamine, placing the product in a benzaldehyde ethanol aqueous solution and adding water, and then reacting with CTAB and TEOS, and the product is obtained. The product obtained by the application has the characteristics of high void and high specific surface area in the biomass charcoal layer, and through the "island" structure, large-size impurities are screened and further captured small-size antibiotic resistance genes, and efficient and specific adsorption of antibiotic resistance genes is realized.

Description

Technical Field

[0001] This invention belongs to the field of antibiotic resistance gene management technology, specifically relating to a material that specifically eliminates antibiotic resistance genes, its preparation method, and its application. Background Technology

[0002] This invention belongs to the field of antibiotic resistance gene management technology, specifically relating to a material that specifically eliminates antibiotic resistance genes, its preparation method, and its application.

[0003] With the widespread use of antibiotics in human medicine and animal husbandry, the management of antibiotic resistance genes (ARGs) in the environment has become increasingly important. Fecal matter, as a major carrier of antibiotics and their metabolites, has become a significant reservoir and source of ARG transmission. Therefore, developing efficient and economical materials to remove ARGs from fecal matter is of great significance for blocking the environmental transmission pathways of resistance genes and ensuring ecological security and human health.

[0004] In recent years, researchers have focused on constructing various functional materials for the removal of ARGs, mainly including bioligand technology, nano-zero-valent iron, photocatalytic materials, metal-organic frameworks (MOFs), and carbon-based composite materials. Although some promising results have been achieved in these areas, the resulting materials still face several challenges, particularly in terms of raw material costs and preparation processes. Furthermore, the difficulty in recycling these functional materials leads to high costs associated with secondary processing.

[0005] Therefore, how to select green and readily available materials as raw materials and combine simple and mature reaction methods to synthesize materials with highly efficient and specific scavenging effects against antibiotic resistance genes is a topic worthy of research in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a material that is simple to prepare, easy to use, and possesses highly efficient and specific scavenging capabilities against multiple antibiotic resistance genes. The present invention provides the following technical solutions to achieve the aforementioned technical objective.

[0007] A method for preparing a material that specifically eliminates antibiotic resistance genes, the method comprising the following steps: (1) Coating Fe3O4 particles with ZIF-8, and the resulting product is denoted as Fe3O4@ZIF-8; (2) Disperse Fe3O4@ZIF-8 in water, add biomass powder and stir. Adjust the acidity with glacial acetic acid and stir to react. After centrifugation, dry the product and mix it with potassium hydroxide powder. Carbonize the product under nitrogen protection. The product is named MSC. The weight ratio of Fe3O4@ZIF-8 to biomass powder is 1:2.5~3.5. The biomass powder is composed of reed stalk powder and sesame stalk powder in a weight ratio of 1:0.8~1.2. (3) Disperse the MSCs in MES buffer, incubate with EDC and NHS, then add ethylenediamine to react, centrifuge, wash and dry, and record the obtained product as MSC-NH2; (4) The obtained MSC-NH2 was dispersed in benzaldehyde ethanol aqueous solution and reacted and adjusted to alkalinity. After centrifugation, it was washed with ethanol and the product was placed in ethanol. Then water was added and stirred. After solid-liquid separation, water washing and drying were performed. The obtained product was dispersed in ethanol aqueous solution, CTAB was added and adjusted to alkalinity, and then TEOS was added to react. After solid-liquid separation, washing and drying were performed to obtain the material.

[0008] Preferably, the Fe3O4 particles are prepared by dissolving FeCl2·4H2O and FeCl3·6H2O in water at a molar ratio of 1:2, adding excess ammonia under nitrogen protection, and aging at 60°C for 30 minutes; then magnetically separating and washing until neutral to obtain Fe3O4 particles.

[0009] Preferably, the preparation method of Fe3O4@ZIF-8 is as follows: Fe3O4 particles, zinc nitrate hexahydrate, and 2-methylimidazole are prepared in a weight ratio of 10:6:15; the Fe3O4 particles are added to a 50% v / v methanol aqueous solution at a weight-volume ratio of 1:100, and treated with ultrasonic power at 150W for 20 minutes. Then, the ultrasonic power is turned off, and zinc nitrate hexahydrate is added with stirring at 600 rpm. The mixture is stirred for 60 minutes, and then 2-methylimidazole is added and treated with ultrasonic power at 150W for 20 seconds. The ultrasonic power is turned off, and the mixture is stirred at 800 rpm for 3 hours. The reaction product is magnetically separated and washed three times with methanol. The resulting product is then dispersed in a 0.1 M hydrochloric acid-ethanol solution, stirred at room temperature for 30 minutes, magnetically separated again, and washed with ethanol until neutral. Finally, it is freeze-dried to obtain Fe3O4@ZIF-8.

[0010] Preferably, in step (2), when reacting Fe3O4@ZIF-8 with biomass powder, the method is as follows: Fe3O4@ZIF-8 is dispersed in water, and biomass powder is added at room temperature under stirring at 150 rpm and stirring is maintained for 10 minutes; the pH is adjusted to 4.5 with glacial acetic acid, and the mixture is stirred at 60°C and 150 rpm for 2 hours; after centrifugation and collection, it is dried at 60°C, and the resulting product is denoted as Fe3O4@ZIF-8@Biomass.

[0011] Preferably, in step (2), when potassium hydroxide powder is used in the reaction, the method is as follows: Fe3O4@ZIF-8@Biomass is mixed with potassium hydroxide powder at a weight ratio of 1:3, and gently ground until the powder is evenly dispersed; then it is placed in a tube furnace, and under nitrogen protection, the temperature is raised to 800°C at a rate of 5°C / min and held for 1 hour to complete the activation; after cooling, it is washed with 1M hydrochloric acid, then washed with deionized water until no chloride ions are detected, and then dried at 60°C to obtain the MSC.

[0012] Preferably, in step (3), the method for preparing the MSC-NH2 is as follows: prepare the MSC, EDC and NHS in a weight ratio of 100:20:6; disperse the MSC in a MES buffer solution at pH=5.5 in a weight-volume ratio of 2mg:1mL, add EDC and NHS, and incubate at room temperature with stirring speed of 400rpm for 30 minutes; then add 2% of the volume of the solution obtained above with ethylenediamine, adjust the pH to 7.5 with 0.1M NaOH, and stir at room temperature for 12 hours; after magnetic separation of the solid, wash with water until pH=7.0, and then dry at 60℃, and the obtained product is named MSC-NH2.

[0013] Preferably, in step (4), the specific method for dispersing MSC-NH2 in benzaldehyde ethanol aqueous solution is as follows: prepare MSC-NH2 and benzaldehyde at a weight ratio of 200:1, dissolve benzaldehyde in ethanol aqueous solution with a concentration of 50% v / v to obtain benzaldehyde ethanol aqueous solution, and adjust the pH to 5.5 with hydrochloric acid, disperse MSC-NH2 in benzaldehyde ethanol aqueous solution and stir at room temperature for 3 hours; then add 0.1M NaOH dropwise to adjust the pH to 8.5; after magnetic separation of the solid, wash twice with ethanol, and keep the obtained product in ethanol for later use; slowly add water to the product kept in ethanol to make the total water content of the system reach 90% v / v; stir at 300 rpm for 1 hour at room temperature; after magnetic separation of the solid, wash with water until pH=7.0, and then dry at 60℃, and the obtained product is denoted as MSC-island.

[0014] Preferably, in step (4), when CTAB and TEOS are used in the reaction, the specific method is as follows: the MSC-island is dispersed in a 50% v / v ethanol aqueous solution at a weight-volume ratio of 1 mg: 500 mL, and sonicated at 150 W for 10 minutes; then CTAB, which is 20% of the weight of the MSC, is added, and stirred at 300 rpm until completely dissolved, and the pH is adjusted to 10.5 with 0.1 M NaOH; 0.5% of the weight of the MSC is prepared and added dropwise to the resulting solution system at a rate of 0.5 mL / min. After the addition is complete, the container is sealed, and the mixture is stirred at 40°C and 400 rpm for 6 hours. After stirring, it is allowed to stand for 12 hours; after magnetic separation of the solid, the product is added to 0.1 M NaOH at a weight-volume ratio of 1 mg: 500 mL. The solid was stirred in a hydrochloric acid-ethanol solution at 60°C for 3 hours. After magnetic separation of the solid, it was washed twice with ethanol, then washed with deionized water until pH=7.0, and then dried at 60°C to obtain the material.

[0015] A material that specifically eliminates antibiotic resistance genes, said material being prepared by the aforementioned method.

[0016] The aforementioned materials are used to remove antibiotic resistance genes from fecal water.

[0017] The beneficial effects of this invention are: This invention selects common and readily available reed stalks and sesame stalks as raw materials for the biochar layer, using iron oxide (Fe3O4) as the core material. The Fe3O4 is first coated with ZIF-8 and then mixed with biomass powder for carbonization, forming a dense carbonized layer. Silica particles are dispersed on this carbonized layer, forming an "island" structure. The product obtained by this invention, based on the high porosity and high specific surface area of ​​the biochar layer, utilizes the "island" structure to screen out large-sized impurities and further capture small-sized antibiotic resistance genes, achieving highly efficient and specific adsorption of antibiotic resistance genes. Because the raw materials of this invention are readily available, the preparation method is simple, and it is easy to use, this invention has good prospects for practical application. Detailed Implementation

[0018] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above-described invention are still within the scope of protection of the present invention.

[0019] Example 1

[0020] 1. Raw materials FeCl2·4H2O, FeCl3·6H2O: Shanghai Coleman Reagent Co., Ltd.; Zinc nitrate hexahydrate (Zn(NO3)2·6H2O): Shanghai Baishun Biotechnology Co., Ltd. 2-Methylimidazole: Shanghai Hans Chemical Co., Ltd.; Reed stalk powder and sesame stalk powder: The reed stalks and sesame stalks were donated by local farmers. After grinding, the 100-200 mesh fraction (75μm-150μm) was taken. 1-Ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinamide, ethylenediamine: Aladdin (Shanghai, China); MES buffer: Shanghai Kanglang Biotechnology Co., Ltd.; Benzaldehyde: Nanjing Chemical Reagent Co., Ltd.; Hexadecyltrimethylammonium bromide: Zhongshan Dixing Chemical Co., Ltd.; Ethyl orthosilicate: Guangzhou Yuanda New Materials Co., Ltd.; The remaining reagents are all standard reagents and are owned by the inventor's laboratory.

[0021] 2. Preparation process (1) Preparation of ZIF-8 coated Fe3O4 material (abbreviated as Fe3O4@ZIF-8): FeCl2·4H2O and FeCl3·6H2O were dissolved in water at a molar ratio of 1:2. Excess ammonia was added under nitrogen protection, and the mixture was aged at 60°C for 30 minutes. Afterward, the mixture was magnetically separated and washed until neutral to obtain Fe3O4 magnetic cores. Fe3O4 magnetic cores, zinc nitrate hexahydrate (Zn(NO3)2·6H2O), and 2-methylimidazole were prepared in a weight ratio of 10:6:15. The Fe3O4 magnetic cores were added to a methanol-water solution (50% v / v) at a weight-to-volume ratio of 1:100 and treated with an ultrasonic power of 150W for 20 minutes. Then, the ultrasonic power was turned off and zinc nitrate hexahydrate was added with a stirring speed of 600 rpm and stirred for 60 minutes. Then, 2-methylimidazole was added and treated with an ultrasonic power of 150W for 20 seconds. The ultrasonic power was turned off and stirred with 800 rpm for 3 hours. The reaction product was magnetically separated and washed three times with methanol. The resulting product was then dispersed in a 0.1 M hydrochloric acid-ethanol solution and stirred at room temperature for 30 minutes. It was magnetically separated again and washed with ethanol until neutral. Finally, it was freeze-dried to obtain ZIF-8 coated Fe3O4 material (abbreviated as Fe3O4@ZIF-8).

[0022] (2) Magnetic small-pore biomass-based carbonized materials (MSC) Prepare Fe3O4@ZIF-8 and biomass powder (reed stalk powder and sesame stalk powder in a 1:1 weight ratio) at a weight ratio of 1:3. Disperse Fe3O4@ZIF-8 in water, and add biomass powder while stirring at 150 rpm at room temperature for 10 minutes. Adjust the pH to 4.5 with glacial acetic acid, and stir at 60°C and 150 rpm for 2 hours. After centrifugation, collect the mixture and dry it at 60°C to obtain the Fe3O4@ZIF-8 biomass complex (abbreviated as Fe3O4@ZIF-8@Biomass). The obtained Fe3O4@ZIF-8@Biomass was mixed with potassium hydroxide powder at a weight ratio of 1:3 and gently ground until the powder was evenly dispersed. Then, it was placed in a tube furnace and heated to 800°C at a rate of 5°C / min under nitrogen protection and held for 1 hour to complete the activation. After cooling, it was washed with 1M hydrochloric acid and then washed with deionized water until no chloride ions were detected. Finally, it was dried at 60°C to obtain magnetic small-pore biomass-based carbonized material (MSC).

[0023] (3) Sea-island surface-modified magnetic biomass-based carbonized material (MSC-SiO2) Prepare MSCs, EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide), and NHS (N-hydroxysuccinamide) in a weight ratio of 100:20:6. Disperse the obtained MSCs in MES buffer (pH=5.5) at a weight-to-volume ratio of 2 mg:1 mL, add EDC and NHS, and incubate at room temperature with stirring at 400 rpm for 30 minutes. Then add 2% (by volume) of ethylenediamine (EDA) to the obtained solution, adjust the pH to 7.5 with 0.1 M NaOH, and stir at room temperature for 12 hours. After magnetic separation of the solids, wash with water until pH=7.0, and then dry at 60 °C. The obtained product is designated as MSC-NH2. Prepare MSC-NH2 and benzaldehyde at a weight ratio of 200:1. Dissolve benzaldehyde in an aqueous ethanol solution (50% v / v) to obtain a benzaldehyde-ethanol aqueous solution (adjust pH to 5.5 with hydrochloric acid). Disperse the obtained MSC-NH2 in the benzaldehyde-ethanol aqueous solution and stir at room temperature for 3 hours. Then, add 0.1M NaOH dropwise to adjust pH to 8.5. After magnetic separation of the solid, wash twice with ethanol, and retain the product in ethanol for later use. Slowly add water to the product retained in ethanol to make the total water content of the system reach 90% (v / v). Stir at 300 rpm for 1 hour at room temperature. After magnetic separation of the solid, wash with water until pH=7.0, and then dry at 60℃ to obtain a product with "island" binding sites (abbreviated as MSC-island). The obtained MSC-island was dispersed in an ethanol-water solution (50% v / v) at a weight-to-volume ratio of 1 mg:500 mL and sonicated at 150 W for 10 minutes. Then, CTAB (hexadecyltrimethylammonium bromide) at 20% of the weight of MSCs was added, and the solution was stirred at 300 rpm until completely dissolved. The pH was adjusted to 10.5 with 0.1 M NaOH. Tetraethyl orthosilicate (TEOS) at 0.5% of the weight of MSCs was prepared and added dropwise to the aforementioned solution system at a rate of 0.5 mL / min. After the addition was complete, the container was sealed, and the mixture was stirred at 40°C and 400 rpm for 6 hours. After stirring, the mixture was allowed to stand for 12 hours. After magnetic separation of the solids, the product was added to a 0.1 M NaOH solution at a weight-to-volume ratio of 1 mg:500 mL. In a hydrochloric acid-ethanol solution, the mixture is stirred for 3 hours in a water bath at 60°C. After magnetic separation of the solid, it is washed twice with ethanol, then washed with deionized water until pH=7.0, and then dried at 60°C to obtain the final product—island-type surface-modified magnetic biomass-based carbonized material (MSC-SiO2 for short).

[0024] Example 2

[0025] Compared to Example 1, in the preparation of MSC, the weight ratio of Fe3O4@ZIF-8 and biomass powder was adjusted to 1:2.5, and the weight ratio of reed stalk powder and sesame stalk powder was 1:1.2. The rest of the preparation method and raw materials were the same as in Example 1.

[0026] The specific plan is as follows: (1) Preparation of ZIF-8 coated Fe3O4 material (abbreviated as Fe3O4@ZIF-8): FeCl2·4H2O and FeCl3·6H2O were dissolved in water at a molar ratio of 1:2. Excess ammonia was added under nitrogen protection, and the mixture was aged at 60°C for 30 minutes. Afterward, the mixture was magnetically separated and washed until neutral to obtain Fe3O4 magnetic cores. Fe3O4 magnetic cores, zinc nitrate hexahydrate (Zn(NO3)2·6H2O), and 2-methylimidazole were prepared in a weight ratio of 10:6:15. The Fe3O4 magnetic cores were added to a methanol-water solution (50% v / v) at a weight-to-volume ratio of 1:100 and treated with an ultrasonic power of 150W for 20 minutes. Then, the ultrasonic power was turned off and zinc nitrate hexahydrate was added with a stirring speed of 600 rpm and stirred for 60 minutes. Then, 2-methylimidazole was added and treated with an ultrasonic power of 150W for 20 seconds. The ultrasonic power was turned off and stirred with 800 rpm for 3 hours. The reaction product was magnetically separated and washed three times with methanol. The resulting product was then dispersed in a 0.1 M hydrochloric acid-ethanol solution and stirred at room temperature for 30 minutes. It was magnetically separated again and washed with ethanol until neutral. Finally, it was freeze-dried to obtain ZIF-8 coated Fe3O4 material (abbreviated as Fe3O4@ZIF-8).

[0027] (2) Magnetic small-pore biomass-based carbonized materials (MSC) Fe3O4@ZIF-8 and biomass powder (comprising reed stalk powder and sesame stalk powder in a weight ratio of 1:1.2) were prepared at a weight ratio of 1:2.5. Fe3O4@ZIF-8 was dispersed in water, and biomass powder was added at room temperature with stirring at 150 rpm for 10 minutes. The pH was adjusted to 4.5 with glacial acetic acid, and the mixture was stirred at 60°C and 150 rpm for 2 hours. After centrifugation, the mixture was dried at 60°C to obtain the Fe3O4@ZIF-8@Biomass complex. The obtained Fe3O4@ZIF-8@Biomass was mixed with potassium hydroxide powder at a weight ratio of 1:3 and gently ground until the powder was evenly dispersed. Then, it was placed in a tube furnace and heated to 800°C at a rate of 5°C / min under nitrogen protection and held for 1 hour to complete the activation. After cooling, it was washed with 1M hydrochloric acid and then washed with deionized water until no chloride ions were detected. Finally, it was dried at 60°C to obtain magnetic small-pore biomass-based carbonized material (MSC).

[0028] (3) Sea-island surface-modified magnetic biomass-based carbonized material (MSC-SiO2) Prepare MSCs, EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide), and NHS (N-hydroxysuccinamide) in a weight ratio of 100:20:6. Disperse the obtained MSCs in MES buffer (pH=5.5) at a weight-to-volume ratio of 2 mg:1 mL, add EDC and NHS, and incubate at room temperature with stirring at 400 rpm for 30 minutes. Then add 2% (by volume) of ethylenediamine (EDA) to the obtained solution, adjust the pH to 7.5 with 0.1 M NaOH, and stir at room temperature for 12 hours. After magnetic separation of the solids, wash with water until pH=7.0, and then dry at 60 °C. The obtained product is designated as MSC-NH2. Prepare MSC-NH2 and benzaldehyde at a weight ratio of 200:1. Dissolve benzaldehyde in an aqueous ethanol solution (50% v / v) to obtain a benzaldehyde-ethanol aqueous solution (adjust pH to 5.5 with hydrochloric acid). Disperse the obtained MSC-NH2 in the benzaldehyde-ethanol aqueous solution and stir at room temperature for 3 hours. Then, add 0.1M NaOH dropwise to adjust pH to 8.5. After magnetic separation of the solid, wash twice with ethanol, and retain the product in ethanol for later use. Slowly add water to the product retained in ethanol to make the total water content of the system reach 90% (v / v). Stir at 300 rpm for 1 hour at room temperature. After magnetic separation of the solid, wash with water until pH=7.0, and then dry at 60℃ to obtain a product with "island" binding sites (abbreviated as MSC-island). The obtained MSC-island was dispersed in an ethanol-water solution (50% v / v) at a weight-to-volume ratio of 1 mg:500 mL and sonicated at 150 W for 10 minutes. Then, CTAB (hexadecyltrimethylammonium bromide) at 20% of the weight of MSCs was added, and the solution was stirred at 300 rpm until completely dissolved. The pH was adjusted to 10.5 with 0.1 M NaOH. Tetraethyl orthosilicate (TEOS) at 0.5% of the weight of MSCs was prepared and added dropwise to the aforementioned solution system at a rate of 0.5 mL / min. After the addition was complete, the container was sealed, and the mixture was stirred at 40°C and 400 rpm for 6 hours. After stirring, the mixture was allowed to stand for 12 hours. After magnetic separation of the solids, the product was added to a 0.1 M NaOH solution at a weight-to-volume ratio of 1 mg:500 mL. In a hydrochloric acid-ethanol solution, the mixture is stirred for 3 hours in a water bath at 60°C. After magnetic separation of the solid, it is washed twice with ethanol, then washed with deionized water until pH=7.0, and then dried at 60°C to obtain the final product—island-type surface-modified magnetic biomass-based carbonized material (MSC-SiO2 for short).

[0029] Example 3

[0030] Compared to Example 1, in the preparation of MSC, the weight ratio of Fe3O4@ZIF-8 and biomass powder was adjusted to 1:3.5, and the weight ratio of reed stalk powder and sesame stalk powder was 1:0.8. The rest of the preparation method and raw materials were the same as in Example 1.

[0031] The specific plan is as follows: (1) Preparation of ZIF-8 coated Fe3O4 material (abbreviated as Fe3O4@ZIF-8): FeCl2·4H2O and FeCl3·6H2O were dissolved in water at a molar ratio of 1:2. Excess ammonia was added under nitrogen protection, and the mixture was aged at 60°C for 30 minutes. Afterward, the mixture was magnetically separated and washed until neutral to obtain Fe3O4 magnetic cores. Fe3O4 magnetic cores, zinc nitrate hexahydrate (Zn(NO3)2·6H2O), and 2-methylimidazole were prepared in a weight ratio of 10:6:15. The Fe3O4 magnetic cores were added to a methanol-water solution (50% v / v) at a weight-to-volume ratio of 1:100 and treated with an ultrasonic power of 150W for 20 minutes. Then, the ultrasonic power was turned off and zinc nitrate hexahydrate was added with a stirring speed of 600 rpm and stirred for 60 minutes. Then, 2-methylimidazole was added and treated with an ultrasonic power of 150W for 20 seconds. The ultrasonic power was turned off and stirred with 800 rpm for 3 hours. The reaction product was magnetically separated and washed three times with methanol. The resulting product was then dispersed in a 0.1 M hydrochloric acid-ethanol solution and stirred at room temperature for 30 minutes. It was magnetically separated again and washed with ethanol until neutral. Finally, it was freeze-dried to obtain ZIF-8 coated Fe3O4 material (abbreviated as Fe3O4@ZIF-8).

[0032] (2) Magnetic small-pore biomass-based carbonized materials (MSC) Fe3O4@ZIF-8 and biomass powder (composed of reed stalk powder and sesame stalk powder in a weight ratio of 1:3.5) were prepared. Fe3O4@ZIF-8 was dispersed in water, and biomass powder was added at room temperature with stirring at 150 rpm for 10 minutes. The pH was adjusted to 4.5 with glacial acetic acid, and the mixture was stirred at 60°C and 150 rpm for 2 hours. After centrifugation, the mixture was dried at 60°C to obtain the Fe3O4@ZIF-8@Biomass complex. The obtained Fe3O4@ZIF-8@Biomass was mixed with potassium hydroxide powder at a weight ratio of 1:3 and gently ground until the powder was evenly dispersed. Then, it was placed in a tube furnace and heated to 800°C at a rate of 5°C / min under nitrogen protection and held for 1 hour to complete the activation. After cooling, it was washed with 1M hydrochloric acid and then washed with deionized water until no chloride ions were detected. Finally, it was dried at 60°C to obtain magnetic small-pore biomass-based carbonized material (MSC).

[0033] (3) Sea-island surface-modified magnetic biomass-based carbonized material (MSC-SiO2) Prepare MSCs, EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide), and NHS (N-hydroxysuccinamide) in a weight ratio of 100:20:6. Disperse the obtained MSCs in MES buffer (pH=5.5) at a weight-to-volume ratio of 2 mg:1 mL, add EDC and NHS, and incubate at room temperature with stirring at 400 rpm for 30 minutes. Then add 2% (by volume) of ethylenediamine (EDA) to the obtained solution, adjust the pH to 7.5 with 0.1 M NaOH, and stir at room temperature for 12 hours. After magnetic separation of the solids, wash with water until pH=7.0, and then dry at 60 °C. The obtained product is designated as MSC-NH2. Prepare MSC-NH2 and benzaldehyde at a weight ratio of 200:1. Dissolve benzaldehyde in an aqueous ethanol solution (50% v / v) to obtain a benzaldehyde-ethanol aqueous solution (adjust pH to 5.5 with hydrochloric acid). Disperse the obtained MSC-NH2 in the benzaldehyde-ethanol aqueous solution and stir at room temperature for 3 hours. Then, add 0.1M NaOH dropwise to adjust pH to 8.5. After magnetic separation of the solid, wash twice with ethanol, and retain the product in ethanol for later use. Slowly add water to the product retained in ethanol to make the total water content of the system reach 90% (v / v). Stir at 300 rpm for 1 hour at room temperature. After magnetic separation of the solid, wash with water until pH=7.0, and then dry at 60℃ to obtain a product with "island" binding sites (abbreviated as MSC-island). The obtained MSC-island was dispersed in an ethanol-water solution (50% v / v) at a weight-to-volume ratio of 1 mg:500 mL and sonicated at 150 W for 10 minutes. Then, CTAB (hexadecyltrimethylammonium bromide) at 20% of the weight of MSCs was added, and the solution was stirred at 300 rpm until completely dissolved. The pH was adjusted to 10.5 with 0.1 M NaOH. Tetraethyl orthosilicate (TEOS) at 0.5% of the weight of MSCs was prepared and added dropwise to the aforementioned solution system at a rate of 0.5 mL / min. After the addition was complete, the container was sealed, and the mixture was stirred at 40°C and 400 rpm for 6 hours. After stirring, the mixture was allowed to stand for 12 hours. After magnetic separation of the solids, the product was added to a 0.1 M NaOH solution at a weight-to-volume ratio of 1 mg:500 mL. In a hydrochloric acid-ethanol solution, the mixture is stirred for 3 hours in a water bath at 60°C. After magnetic separation of the solid, it is washed twice with ethanol, then washed with deionized water until pH=7.0, and then dried at 60°C to obtain the final product—island-type surface-modified magnetic biomass-based carbonized material (MSC-SiO2 for short).

[0034] Comparative Example 1 Compared to Example 1, the weight ratio of Fe3O4@ZIF-8 and biomass powder was adjusted to 1:5 when preparing MSCs. The rest of the preparation methods and raw materials were the same as in Example 1, and the specific scheme will not be repeated.

[0035] Comparative Example 2 Compared to Example 1, the weight ratio of Fe3O4@ZIF-8 and biomass powder was adjusted to 1:1 when preparing MSCs. The rest of the preparation methods and raw materials were the same as in Example 1, and the specific scheme will not be repeated.

[0036] Comparative Example 3 Compared to Example 1, the weight ratio of reed stalk powder and sesame stalk powder was adjusted to 1:2. The remaining preparation methods and raw materials were the same as in Example 1, and the specific scheme will not be repeated.

[0037] Comparative Example 4 Compared to Example 1, the biomass powder consists only of reed stalk powder, while the rest of the preparation methods and raw materials are the same as in Example 1. The specific scheme will not be repeated.

[0038] Test case Using the treated effluent from a pig farm's wastewater treatment plant in Chengdu as the experimental subject, a 50L sample was taken as the sample solution for later use. Large particles larger than 2mm in diameter were removed from the sample solution. Testing revealed the presence of antibiotic resistance genes in the sample solution, specifically macrolide resistance gene ermB, tetracycline resistance genes tetA, tetE, and tetQ, class 1 integrase gene intl1, and sulfonamide resistance gene sul2. The abundance of each resistance gene is shown in Table 1.

[0039] Table 1

[0040] The materials obtained in Examples 1-3 and Comparative Examples 1-4 were used as experimental groups. The intermediate product MSC obtained in Example 1 was used as control group 1, the intermediate product Fe3O4@ZIF-8 obtained in Example 1 was used as control group 2, and commercial activated carbon (activated carbon powder, product number FZ1454, Foshan Nanhai Jiangshun Chemical Products Factory) was used as control group 3. 0.5 g of the corresponding material from each experimental group and each control group was placed in 1 L of sample solution and stirred at 100 rpm for 1 hour at room temperature. After treatment, the solids from each group were separated, and the separated liquids were sent for testing. The abundance of each resistance gene in the tested liquids of each group is shown in Table 2.

[0041] Table 2

[0042] In preparing the MSC-SiO2 product, this invention first constructs a magnetic core to provide rigid support for the product and impart magnetism, enabling solid-liquid separation through magnetism in practical applications. Then, ZIF-8 is coated onto the surface of the magnetic core to increase its specific surface area and prevent damage to the magnetic core during high-temperature carbonization, providing more anchor points for subsequent loading of biochar. As shown in control group 2, the intermediate product Fe3O4@ZIF-8 exhibits limited ability to scavenge antibiotic resistance genes. This is because ZIF-8's increase in specific surface area is limited, resulting in a lower scavenging ability against antibiotic resistance genes compared to conventional activated carbon.

[0043] Initially, the inventors considered loading a layer of biochar onto Fe3O4@ZIF-8, leveraging the high specific surface area, rigidity of the magnetic core, and ease of recyclability of biochar to prepare materials with practical applications. However, as shown in control group 1, the resulting product's ability to clear antibiotic resistance genes was unsatisfactory. The inventors speculated that this might be due to the excessively dense pores of the biochar (achieved through etching numerous dense micropores with potassium hydroxide). While this effectively accommodates antibiotic resistance gene fragments at physical sizes, it is also easily occupied by impurities. To address this issue, the inventors considered dispersing silica particles on the biochar layer, constructing a structure where the biochar layer acts as a "sea" and silica as "islands." This structure reduces the surface density of the material and allows for the sieving of large-sized substances using protruding silica particles. Simultaneously, the silica particles can act as "tentacles," better "capturing" antibiotic resistance gene fragments to achieve specific clearance of antibiotic resistance genes.

[0044] However, the selection of biomass raw materials is also crucial in the aforementioned preparation system. Through experimentation, the inventors discovered that when reed stalk powder and sesame stalk powder were used as raw materials for preparing the biochar layer in a 1:1 weight ratio, the final product showed better scavenging effects on antibiotic resistance genes. However, adjusting the weight ratio or using only reed stalk powder resulted in poorer scavenging effects on antibiotic resistance genes. This may be because sesame stalks contain more oil, hemicellulose, and pectin, which, compared to reed stalks with their high cellulose and lignin content, result in a relatively softer material during pore formation, making the char layer material more sponge-like and reducing the overall rigidity of the final product. Simultaneously, the high volatile content of sesame stalks easily leads to the formation of irregular large pores, causing the specific surface area to decrease rather than increase, ultimately reducing the number and height of the "islands." Using only reed stalk powder as a raw material results in dense and excessive micropores on the char layer, leading to excessive steric hindrance during subsequent amination treatment, ultimately causing disordered aggregation of silica and affecting the scavenging effect on antibiotic resistance genes. In addition, the inventors also noted that the weight ratio of Fe3O4@ZIF-8 to biomass powder also affects the function of the final product. This is because both excessively high or low ratios affect the amination treatment effect, thereby affecting the formation of "islands" and ultimately the scavenging effect of the resulting product on antibiotic resistance genes.

[0045] As shown in Table 2, Examples 1-3 of the present invention have excellent clearance effects on the resistance genes of six antibiotics in the sample solution. In addition, they can be recovered by magnetic means, which shows good prospects for practical application.

Claims

1. A method for preparing a material that specifically eliminates antibiotic resistance genes, characterized in that, The preparation method includes the following steps: (1) Coating Fe3O4 particles with ZIF-8, and the resulting product is denoted as Fe3O4@ZIF-8; (2) Disperse Fe3O4@ZIF-8 in water, add biomass powder and stir. Adjust the acidity with glacial acetic acid and stir to react. After centrifugation, dry the product and mix it with potassium hydroxide powder. Carbonize the product under nitrogen protection. The product is named MSC. The weight ratio of Fe3O4@ZIF-8 to biomass powder is 1:2.5~3.

5. The biomass powder is composed of reed stalk powder and sesame stalk powder in a weight ratio of 1:0.8~1.

2. (3) Disperse the MSCs in MES buffer, incubate with EDC and NHS, then add ethylenediamine to react, centrifuge, wash and dry, and record the obtained product as MSC-NH2; (4) The obtained MSC-NH2 was dispersed in benzaldehyde ethanol aqueous solution and reacted and adjusted to alkalinity. After centrifugation, it was washed with ethanol and the product was placed in ethanol. Then water was added and stirred. After solid-liquid separation, water washing and drying were performed. The obtained product was dispersed in ethanol aqueous solution, CTAB was added and adjusted to alkalinity, and then TEOS was added to react. After solid-liquid separation, washing and drying were performed to obtain the material.

2. The method for preparing a material that specifically eliminates antibiotic resistance genes according to claim 1, characterized in that, The Fe3O4 particles are prepared as follows: FeCl2·4H2O and FeCl3·6H2O are dissolved in water at a molar ratio of 1:2, excess ammonia is added under nitrogen protection, and the mixture is aged at 60°C for 30 minutes; then, it is magnetically separated and washed until neutral to obtain Fe3O4 particles.

3. The method for preparing a material that specifically eliminates antibiotic resistance genes according to claim 2, characterized in that, The preparation method of Fe3O4@ZIF-8 is as follows: Fe3O4 particles, zinc nitrate hexahydrate, and 2-methylimidazole are prepared in a weight ratio of 10:6:15; the Fe3O4 particles are added to a 50% v / v methanol aqueous solution at a weight-volume ratio of 1:100, and treated with ultrasonic power at 150W for 20 minutes. Then, the ultrasonic power is turned off, and zinc nitrate hexahydrate is added with stirring at 600 rpm. The mixture is stirred for 60 minutes, then 2-methylimidazole is added and treated with ultrasonic power at 150W for 20 seconds. The ultrasonic power is turned off, and the mixture is stirred at 800 rpm for 3 hours. The reaction product is magnetically separated and washed three times with methanol. The resulting product is then dispersed in a 0.1 M hydrochloric acid-ethanol solution, stirred at room temperature for 30 minutes, magnetically separated again, and washed with ethanol until neutral. Finally, it is freeze-dried to obtain Fe3O4@ZIF-8.

4. A method for preparing a material that specifically eliminates antibiotic resistance genes according to any one of claims 1 to 3, characterized in that, In step (2), when Fe3O4@ZIF-8 reacts with biomass powder, the method is as follows: Fe3O4@ZIF-8 is dispersed in water, and biomass powder is added at room temperature with stirring at 150 rpm and stirring is maintained for 10 minutes; the pH is adjusted to 4.5 with glacial acetic acid, and the mixture is stirred at 60℃ and 150 rpm for 2 hours; after centrifugation, the product is dried at 60℃ and the obtained product is named Fe3O4@ZIF-8@Biomass.

5. A method for preparing a material that specifically eliminates antibiotic resistance genes according to any one of claims 4, characterized in that, In step (2), when potassium hydroxide powder is used in carbonization, the method is as follows: Fe3O4@ZIF-8@Biomass and potassium hydroxide powder are mixed at a weight ratio of 1:3, and gently ground until the powder is evenly dispersed; then placed in a tube furnace, and heated to 800°C at a rate of 5°C / min and held for 1 hour under nitrogen protection to complete carbonization; After cooling, the MSCs were washed with 1M hydrochloric acid, then washed with deionized water until no chloride ions were detected, and then dried at 60°C to obtain the MSCs.

6. A method for preparing a material that specifically eliminates antibiotic resistance genes according to claim 1 or 5, characterized in that, In step (3), the method for preparing the MSC-NH2 is as follows: prepare the MSC, EDC and NHS in a weight ratio of 100:20:6; disperse the MSC in MES buffer at pH=5.5 in a weight-volume ratio of 2mg:1mL, add EDC and NHS, and incubate at room temperature with stirring speed of 400rpm for 30 minutes; then add 2% of the volume of the obtained solution of ethylenediamine, adjust the pH to 7.5 with 0.1M NaOH, and stir at room temperature for 12 hours; after magnetic separation of the solid, wash with water until pH=7.0, and then dry at 60℃, and the obtained product is named MSC-NH2.

7. The method for preparing a material that specifically eliminates antibiotic resistance genes according to claim 6, characterized in that, In step (4), the specific method for dispersing MSC-NH2 in benzaldehyde ethanol aqueous solution is as follows: prepare MSC-NH2 and benzaldehyde at a weight ratio of 200:1, dissolve benzaldehyde in ethanol aqueous solution with a concentration of 50% v / v to obtain benzaldehyde ethanol aqueous solution and adjust pH=5.5 with hydrochloric acid, disperse MSC-NH2 in benzaldehyde ethanol aqueous solution and stir at room temperature for 3 hours; Then add 0.1M NaOH to adjust the pH to 8.5; After magnetic separation of the solid, the product was washed twice with ethanol and kept in ethanol for later use. Water was slowly added to the product kept in ethanol to make the total water content of the system reach 90% v / v. The mixture was stirred at 300 rpm for 1 hour at room temperature. After magnetic separation of the solid, the product was washed with water until pH=7.0 and then dried at 60℃. The product was named MSC-island.

8. The method for preparing a material that specifically eliminates antibiotic resistance genes according to claim 7, characterized in that, In step (4), when CTAB and TEOS are used in the reaction, the specific method is as follows: the MSC-island is dispersed in an ethanol aqueous solution with a concentration of 50% v / v at a weight-volume ratio of 1 mg: 500 mL, and sonicated at 150 W for 10 minutes; then CTAB with a weight of 20% of the MSC weight is added, and stirred at 300 rpm until completely dissolved, and the pH is adjusted to 10.5 with 0.1 M NaOH; TEOS with a weight of 0.5% of the MSC weight is prepared and added dropwise to the obtained solution system at a rate of 0.5 mL / min. After the addition is complete, the container is sealed, and stirred at 40℃ and 400 rpm for 6 hours. After stirring, it is allowed to stand for 12 hours; after magnetic separation of the solid, the product is added to a 0.1 M hydrochloric acid ethanol solution at a weight-volume ratio of 1 mg: 500 mL, and stirred in a water bath at 60℃ for 3 hours; after magnetic separation of the solid, it is washed twice with ethanol, then washed with deionized water until pH=7.0, and then dried at 60℃ to obtain the material.

9. A material that specifically eliminates antibiotic resistance genes, characterized in that, The material is prepared by the method described in any one of claims 1 to 8.

10. The use of the material as described in claim 9 in removing antibiotic resistance genes from fecal water.

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