Rapid Synthesis of Aqueous-Phase Magnetite Nanoparticles by Atmospheric Pressure Non-Thermal Microplasma and their Application in Magnetic Resonance Imaging

Here, we present a novel approach for producing Fe3O4 nanoparticles (NPs) in liquid by a non-thermal argon microplasma. The Fe3O4 NPs can be generated in minutes without any surfactant with an average size of 12.5 +/- 2.4nm. They show good aqueous-phase stability and excellent superparamagnetic properties with a saturation magnetization of 60.1emug(-1) and a small coercivity (<10Oe). In vitro magnetic resonance imaging study shows efficient imaging contrast characteristics of these NPs. These Fe3O4 NPs can be further decorated with polyethylene glycol (PEG) by adding 5% PEG into the electrolyte, which resulting in an average diameter of 19.2 +/- 2.7nm. This facile, fast, environmental-friendly and economical preparation strategy of magnetite NPs may be extended to the preparation of other metal oxide compound.