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Title: Nucleation of Iron Oxide Nanoparticles Mediated by Mms6 Protein in Situ

Biomineralization proteins are widely used as templating agents in biomimetic synthesis of a variety of organic–inorganic nanostructures. However, the role of the protein in controlling the nucleation and growth of biomimetic particles is not well understood, because the mechanism of the bioinspired reaction is often deduced from ex situ analysis of the resultant nanoscale mineral phase. Here we report the direct visualization of biomimetic iron oxide nanoparticle nucleation mediated by an acidic bacterial recombinant protein, Mms6, during an in situ reaction induced by the controlled addition of sodium hydroxide to solution-phase Mms6 protein micelles incubated with ferric chloride. Using in situ liquid cell scanning transmission electron microscopy we observe the liquid iron prenucleation phase and nascent amorphous nanoparticles forming preferentially on the surface of protein micelles. Our results provide insight into the early steps of protein-mediated biomimetic nucleation of iron oxide and point to the importance of an extended protein surface during nanoparticle formation.
 [1] ;  [1] ;  [2] ;  [1] ;  [1]
  1. Ames Laboratory
  2. Iowa State University
Publication Date:
OSTI Identifier:
Report Number(s):
IS-J 8474
Journal ID: ISSN 1936-0851
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Nano; Journal Volume: 8; Journal Issue: 9
American Chemical Society
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
36 MATERIALS SCIENCE; recombinant iron-binding protein, protein-mediated particle nucleation; in situ TEM analysis