Silane Bridged Surface Tailoring on Magnetite Nanoparticles

Magnetic Fe₃O₄ nanoparticles (NPs) with average diameter 25plusmn5 nm are prepared by modified chemical coprecipitation, and silane bridged surface tailoring are exploited to obtain amino-coated and thiolated magnetite NPs via corresponding 3-aminopropyltriethyloxysilane (APTES) and mercaptopropyltriethoxysilane (MPTES) modification, respectively. The particles properties and structure are characterized by X-ray powder diffraction (XRD), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and magnetic property measurement system (MPMS) with superconducting quantum interference device (SQUID) magnetometry. The result reveals that the surface functionalized magnetic particles have a slight dimensional increase in average diameter while retain almost original saturation magnetization; APTES is prone to maintain the morphology of the magnetite NPs, but MPTES has an outstanding hypochromic effect though it caused a slight decrease in the saturation magnetization. The finding is of practical significance for magnetic nanoparticle applications associated with bioconjugation, target carriers and biosensing.