Nanocomposite particles composed of gold and iron oxide were synthesized with various ratios of gold and iron oxide in an aqueous phase using γ-rays. Iron oxide nanoparticles of γ-Fe2O3 or Fe3O4 were used as a magnetic phase on which gold nanoparticles with average diameters of 5-10 nm were supported. The efficiency of magnetic separation of biomolecules by the present nanocomposite particles was investigated using glutathione as a model compound. The amount of glutathione magnetically separated was significantly enhanced by the supported gold nanoparticles.
Keywords: γ-Fe2O3, Fe3O4, Au, nanocomposite particle, γ-ray, magnetic separation