Synchrotron radiation photoelectron spectroscopy study of dextran-coated Fe_3O_4 magnetic nanoparticles

Dextran-coated Fe3O4 nanoparticles were prepared by untrasonification of Fe3O4 nanoparticles with dextran at 85°C in sodium citrate medium. The surface chemical component, structure and bond of uncoated and dextran-coated nanoparticles were measured by synchrotraon radiation XPS (X-ray photoelectron spectroscopy). Qualitative and quantitative analysis of C1s and O1s of Fe3O4 and dextran-Fe3O4 showed that the Fe3O4 nanoparticles were successively coated by sodium citrate via Fe-O-C bond, and dextrans, which can be linked with their carboxylate moiety via hydrogen bond. Sodium citrate could enhance the disperse stability of reaction system and hydrophilicity of dextran-Fe3O4.