Synthesis and stabilization of monodisperse Fe nanoparticles.

Monodisperse Fe nanoparticles are synthesized via a simple one-pot thermal decomposition of Fe(CO)5 in the presence of oleylamine. Controlled oxidation of the iron surface leads to crystalline Fe3O4 shell and results in dramatic increase of chemical and dispersion stability of the nanoparticles. Surface ligand exchange is readily applied to transfer the core/shell nanoparticles from hydrophobic to hydrophilic, and a stable aqueous nanoparticle dispersion in PBS is formed. The functionalized nanoparticles are suitable for biomolecule attachment and biomedical applications.