A facile synthesis of monodisperse CoFe2O4/SiO2 nanoparticles

Aminated-CoFe2O4/SiO2 magnetic nanoparticles (NPs) were prepared from primary silica particles using modified StÖber method. By optimizing the preparation conditions, monodisperse CoFe2O4/SiO2 NPs with high amino groups’ density were obtained, which is necessary for enzyme immobilization. TEM confirm that the sample is a core/shell structure. These aminated-CoFe2O4/SiO2 NPs have narrow size distributions with a mean size of about 60 nm. Moreover, the aminated-CoFe2O4/SiO2 NPs can be easily dispersed in aqueous medium. The experimental results also show that the NPs have superparamagnetism, indicating that the aminated-CoFe2O4/SiO2 NPs can be used as an effective carrier for the enzyme immobilization.