Synthesis and characterization of hollow magnetic nanospheres modified with Au nanoparticles for bio-encapsulation

摘要

Hollow magnetic nanospheres modified with Au nanoparticles were successfully synthesized. Au/SiO_2 nanospheres fabricated by a radiochemical process were used as templates for ferrite templating. After the ferrite plating process, Au/SiO_2 templates were fully coated with magnetite nanoparticles. Dissolution of the SiO_2 core lead to the formation of hollow magnetic nanospheres with Au nanoparticles inside. The hollow magnetic nanospheres consisted of Fe_3O_4 grains, with an average diameter of 60 nm, connected to form the sphere wall, inside which Au grains with an average diameter of 7.2 nm were encapsulated. The Au nanoparticles immobilized on the SiO_2 templates contributed to the adsorption of the Fe ion precursor and/or Fe_3O_4 seeds. These hollow magnetic nanospheres are proposed as a new type of nanocarrier, as the Au grains could specifically immobilize biomolecules inside the hollow sphere.