synthesis and study of structural and magnetic properties of superparamagnetic fe3o4@sio2 core/shell nanocomposite for biomedical applications

objective(s): this paper describes coating of magnetite nanoparticles (mnps) with amorphous silica shells.   materials and methods: first, magnetite (fe3o4) nps were synthesized by co-precipitation method and then treated with stabilizer molecule of trisodium citrate to enhance their dispersibility. afterwards, coating with silica was carried out via a sol-gel approach in which the electrostatically stabilized mnps were used as seeds. the samples were characterized by means of x-ray diffraction (xrd), transmission electron microscopy (tem), fourier transform infrared (ft-ir) spectroscopy and vibrating sample magnetometer (vsm). results: the results of xrd analysis implied that the prepared nanocomposite consists of two compounds of crystalline magnetite and amorphous silica that formation of their core/shell structure with the shell thickness of about 5 nm was confirmed by tem images. the magnetic studies also indicated that produced fe3o4@sio2 core/shell nanocomposite exhibits superparamagnetic properties at room temperature. conclusion: these core/shell structure due to having superparamagnetic property of fe3o4 and unique properties of sio2, offers a high potential for many biomedical applications.