Synthesis of Fe70Pd30 nanoparticles and their surface modification by zwitterionic linker

Ferromagnetic shape memory alloy Fe70Pd30 nanoparticles (NPs) are processed by using polyol method, which is then annealed at 770 degrees C to convert to the correct nanocrystalline. The nanostructure properties of Fe70Pd30 NPs are also measured by X-ray diffraction, vibrating-sample magnetometer and X-ray photoelectron spectroscopy (XPS) studies. XPS spectra revealed Fe70Pd30 NPs have Fe2O3 shell layer on their surface. As-annealed Fe70Pd30 NPs are then coated with zwitterionic sulfobetaine silane (SBSi) linker. The surface characteristics with SBS-icoated FePd NPs are studied by Fourier transform infrared spectroscopy, thermogravimetric analysis and quartz crystal microbalance. These results indicated that successful coating of SBSi is formed on the surface of as-annealed Fe70Pd30 NPs. The SBSi coating provides hydrophilic surface with good chemical stability and exceptional fouling resistance. In addition, the surface modification with SBSi showed anti-protein adsorption property and increases a longer-term dispeisibility of Fe70Pd30 NPs in solution.