This paper presents an original method to obtain, in one step, core/shell nanoparticles grafted covalently with polymer and functionalized with amino groups. By combining polyvinyl alcohol (PVA) and silica precursors, we were able to obtain silica-coated and amino-functionalized iron oxide nanoparticles (SPIONs) cross-linked with PVA. We also showed that using silica and amino-silica precursors together significantly increased the amount of PVA covalently bonded to the SPION surface compared to using only silica precursors. This original and interesting method has high potential for the industrial development of biocompatible functionalized nanoparticles for targeting nanomedicine.