Development of high magnetization [Fe.sub.3][O.sub.4]/polystyrene/silica nanospheres via combined miniemulsion/emulsion polymerization

A new process combining double-miniemulsion/emulsion polymerization with Sol-gel technology to synthesize monodispersed hydrophilic magnetic nanospheres that exhibit a much higher saturation magnetization due to a large fraction of magnetite is developed. The superparamagnetic properties of nanospheres would allow them to serve as ideal candidates for biomedical applications such as nucleic acid extraction, cancer diagnosis and treatment, biosensors, and drug delivery.