Elucidating the Bioinspired Synthesis Process of Magnetosomes‐Like Fe3O4 Nanoparticles

Abstract Iron oxide nanoparticles are a kind of important biomedical nanomaterials. Although their industrial‐scale production can be realized by the conventional coprecipitation method, the controllability of their size and morphology remains a huge challenge. In this study, a kind of synthetic polypeptide Mms6‐28 which mimics the magnetosome protein Mms6 is used for the bioinspired synthesis of Fe 3 O 4 nanoparticles (NPs). Magnetosomes‐like Fe 3 O 4 NPs with uniform size, cubooctahedral shape, and smooth crystal surfaces are synthesized via a partial oxidation process. The Mms6‐28 polypeptides play an important role by binding with iron ions and forming nucleation templates and are also preferably attached to the [100] and [111] crystal planes to induce the formation of uniform cubooctahedral Fe 3 O 4 NPs. The continuous release and oxidation of Fe 2+ from pre‐formed Fe 2+ ‐rich precursors within the Mms6‐28‐based template make the reaction much controllable. The study affords new insights into the bioinspired‐ and bio‐synthesis mechanism of magnetosomes.