Fabrication of thiol/amine-bifunctional Fe3O4 magnetic nanoparticles via plasma-enhanced atomic layer deposition of TiO2 coating and sequential silanization

Abstract

Developing multifunctional nanomaterials with independently reactive surface groups is promising for advanced catalytic, environmental, and sensing technologies. Here, we present a versatile strategy to engineer bifunctional magnetic nanoparticles integrating both thiol and amine surface chemistries on a single particle. A TiO2 shell was deposited on Fe3O4 nanoparticles, pre-deposited on a Si wafer, via atomic layer deposition (ALD) to create titania-modified magnetic nanoparticles. Sequential silanization was performed with (3-mercaptopropyl)trimethoxysilane (MPTMS) and (3-aminopropyl)triethoxysilane (APTES) which introduced thiol (–SH) and amino (–NH2) groups, respectively. Surface charact..