synthesis and characterization of fe3o4@sio2 core/shell nanoparticles for biological applications

Magnetic nanoparticles have received extensive attention in biological applications such as enrichment, bioseparation, detection, and purification# in this report, nanoparticles of magnetite (fe3o4) are prepared from the solution of ferrous/ferric mixed salt solution in an alkaline solution using the modified chemical coprecipitation process# next, the synthesized magnetic nanoparticles were coated with silica shells by the stober method# then, the surface of fe3o4@sio2 nanoparticles modified with organosilane for the investigation of biological applications# the core/shell nanoparticles were characterized by x-ray powder diffraction (xrd), fourier transforms infrared spectrometer (ftir) ,and scanning electron microscopy (sem)# the results of xrd indicated that the nanoparticles were composed of crystalline fe3o4 core and sio2 shell# the sem image of fe3o4 nanoparticles showed the diameter could be tuned from 15 to 25 nm# the average diameter of the uniform spherical core/shell nanoparticles was approximately 170 ± 50 nm, and the average thickness of the silica shell was 30 nm# finally, the protein adsorption studies on the nanoparticles revealed the ability of these nanoparticles for use in biological applications#