Immobilization of serum albumin on the synthesized three layers core–shell structures of super-paramagnetic iron oxide nanoparticles

In this study, the synthesis of four layer structures coated on magnetite nanoparticles such that Fe3O4/SiO2/APTES/PEG/BSA was investigated. Magnetite nanoparticles were synthesized by co-precipitating Fe2+ and Fe3+ in an ammonia solution with the average size of 25 nm. To fabricate Fe3O4/SiO2 core–shells, the magnetite nanoparticles coated by silica with Stöber method. The fabricated nanoparticles were treated by 3-aminopropyl-triethoxysilane to achieve Fe3O4/SiO2/APTES nanostructures. Moreover, the nanoparticles were also attached to reactive polyethylene glycol chains. Eventually, the nanoparticles activated with bovine serum albumin for bio-application. X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, UV–vis spectroscopy and vibrating sample magnetometer were used to support the characterization.