Mössbauer spectroscopy of protein-passivated iron oxide nanoparticles

Within this work we report a Mössbauer spectroscopic study of uncoated and bovine serum albumin (BSA-) passivated magnetic iron oxide particles. Electron microscopy confirms the successful preparation of the particles with sizes in the 10 to 30 nm range. The analysis of the Mössbauer spectra at high fields shows that only 20% of the iron is present in form of Fe3O4–nanoparticles. The majority (80%) of the iron is present as maghemite (γ–Fe2O3). Coating with BSA does not influence the particle morphology and does also not affect the magnetite to maghemite ratio.