title: Size and crystallinity in protein-templated inorganic nanoparticles.
abstract: Protein cages such as ferritins and virus capsids have been used as containers to synthesize a wide variety of protein-templated inorganic nanoparticles. While identification of the inorganic crystal phase has been successful in some cases, very little is known about the detailed nanoscale structure of the inorganic component. We have used pair distribution function analysis of total X-ray scattering to measure the crystalline domain size in nanoparticles of ferrihydrite, γ-Fe2O3, Mn3O4, CoPt, and FePt grown inside 24-meric ferritin cages fromH. sapiensandP. furiosus. The material properties of these protein-templated nanoparticles are influenced by processes at a variety of length scales: the chemistry of the material determines the precise arrangement of atoms at very short distances, while the interior volume of the protein cage constrains the maximum nanoparticle size attainable. At intermediate length scales, the size of coherent crystalline domains appears to be constrained by the arrangement of crystal nucleation sites on the interior of the cage. Based on these observations, some potential synthetic strategies for the control of crystalline domain size in protein-templated nanoparticles are suggested.
authors.affiliation: Department of Chemistry & Biochemistry, Montana State University ; Astrobiology Biogeocatalysis Research Center, Montana State University.
authors.forename: Craig C
authors.initials: CC
authors.lastname: Jolley
authors.forename: Masaki
authors.initials: M
authors.lastname: Uchida
authors.forename: Courtney
authors.initials: C
authors.lastname: Reichhardt
authors.forename: Richard
authors.initials: R
authors.lastname: Harrington
authors.forename: Sebyung
authors.initials: S
authors.lastname: Kang
authors.forename: Michael T
authors.initials: MT
authors.lastname: Klem
authors.forename: John B
authors.initials: JB
authors.lastname: Parise
authors.forename: Trevor
authors.initials: T
authors.lastname: Douglas
keywords: Biomineralization; Ferritin; Nanoparticles; Pair Distribution Function