Biological composite material loaded with magnetic nanoparticles with core-shell structure, the preparation therefore and the application

A preparation method of a Bacillus subtilis biological composite material loaded with Fe3O4 magnetic nanoparticles with core-shell structure, which comprises the following steps:

• 1) preparation of Fe3O4 nanoparticles:
• add ferrous sulfate heptahydrate and anhydrous sodium acetate to ethylene glycol according to the mole ratio of ferrous sulfate heptahydrate:anhydrous sodium acetate=1:5 to 8 to obtain an ethylene glycol solution, stir until the ethylene glycol solution is transparent and transfer the ethylene glycol solution to a high pressure reaction vessel and the ethylene glycol solution is sealed in the high pressure reaction vessel for 5 to 8 hours at 150 to 200 DEG C., after centrifugation, washing and drying of the ethylene glycol solution, obtain the Fe3O4 nanoparticles;
• 2) preparation of Fe3O4@mSiO2 nanoparticles:
• add the Fe3O4 nanoparticles obtained in step 1) to a mixture of ethanol and water, and disperse ultrasonically, add hexadecyltrimethylammonium bromide and tetraethoxysilane in accordance with the Fe3O4 nanoparticles:cetyltrimethylammonium bromide:tetraethoxysilane=1:3 to 5:2 to 3 to obtain a Fe3O4@mSiO2 solution and keep at room temperature for 6 to 10 hours, after magnetic separation, washing and drying of the Fe3O4@mSiO2 solution, obtain the Fe3O4@mSiO2 nanoparticles;
• 3) preparation of Fe3O4@mSiO2@MANHE (MANHE:
• Monomer 4,4-Azobis(4-cyanovaleric acid) 4-vinyl pyridine N-hydroxysuccinimide) nanoparticles:
• add the Fe3O4@mSiO2 nanoparticles obtained in step 2) to N, N-dimethylformamide, disperse by ultrasonic, add γ-aminopropyltriethoxysilane in accordance with the Fe3O4@mSiO2 nanoparticles:γ-aminopropyltriethoxysilane=50-100 mg:1 mL to obtain an amino-modified Fe3O4@mSiO2 solution, stir for 24 hours at room temperature, then centrifuge, wash and dry the amino-modified Fe3O4@mSiO2 solution to obtain amino-modified Fe3O4@mSiO2 nanoparticles;
• add the amino-modified Fe3O4@mSiO2 nanoparticles into cyclohexanone and disperse by ultrasonic, add 4,4′-azobis (4-cyanovaleryl chloride) in accordance with the amino-modified Fe3O4@mSiO2 nanoparticles:4,4′-azobis (4-cyanovaleryl chloride)=1:20-30 in mass ratio to obtain an ABCPA (4,4-azobis (4-cyanopentanoicchloride)) modified Fe3O4@mSiO2 solution, stir for 24 hours at room temperature, and centrifuge, wash and dry the ABCPA modified Fe3O4@mSiO2 solution to obtain ABCPA modified Fe3O4@mSiO2 nanoparticles;
• add the ABCPA-modified Fe3O4@mSiO2 nanoparticles to cyclohexanone and disperse by ultrasonic, add N-acryloyloxysuccinimide and 4-vinylpyridine in accordance with the ABCPA modified Fe3O4@mSiO2 nano-particles:N-acryloyloxysuccinimide=1:20 to 30 in mass ratio and N-acryloyloxysuccinimide:4-vinylpyridine=1 g:10 to 15 mL to obtain a Fe3O4@mSiO2@MANHE solution, react at 70-80 DEG C. for 0.5-1 hour, and centrifuge, wash and dry the Fe3O4@mSiO2@MANHE solution to obtain the Fe3O4@mSiO2@MANHE nano-particles;
• 4) preparation of Bacillus subtilis@Fe3O4@mSiO2@ MANHE composite:
• add Bacillus subtilis to a PBS solution and disperse evenly, add the Fe3O4@mSiO2@MANHE nano-particles obtained in step 3) in accordance with the wet weight of Bacillus subtilis:Fe3O4@mSiO2@MANHE nano-particles=50-100:1 in mass ratio to obtain a Bacillus subtilis@Fe3O mSiO2@ MANHE solution, and place on a constant temperature shaker at 30° C./120 rpm for 24 hours, magnetic centrifuge, wash and dry the Bacillus subtilis@Fe3O4@mSiO2@ MANHE solution to obtain the Bacillus subtilis biological composite material loaded with Fe3O4 magnetic nanoparticles with core-shell structure.