A method for immobilizing and mediating the spatial distribution of functional oxide (such as SiO2 and Fe3O4) nanoparticles (NPs) on (100)-oriented single crystal silicon surface, via Si-C bonded poly(3-(trimethoxysilyl)propyl methacrylate) (P(TMSPM)) brushes from surface-initiated atom transfer radical polymerization (ATRP) of (3-(trimethoxysilyl)propyl methacrylate) (TMSPM), was described. The ATRP initiator was covalently immobilized via UV-induced hydrosilylation of 4-vinylbenzyl chloride (VBC) with the hydrogen-terminated Si(100) surface (Si-H surface). The surface-immobilized Fe3O4 NPs retained their superparamagnetic characteristics and their magnetization intensity could be mediated by adjusting the thickness of the P(TMSPM) brushes.