title: Cobalt ferrite nanocrystals: out-performing magnetotactic bacteria.
abstract: Magnetotactic bacteria produce exquisitely ordered chains of uniform magnetite (Fe(3)O(4)) nanocrystals, and the use of the bacterial mms6 protein allows for the shape-selective synthesis of Fe(3)O(4) nanocrystals. Cobalt ferrite (CoFe(2)O(4)) nanoparticles, on the other hand, are not known to occur in living organisms. Here we report on the use of the recombinant mms6 protein in a templated synthesis of CoFe(2)O(4) nanocrystals in vitro. We have covalently attached the full-length mms6 protein and a synthetic C-terminal domain of mms6 protein to self-assembling polymers in order to template hierarchical CoFe(2)O(4) nanostructures. This new synthesis pathway enables facile room-temperature shape-specific synthesis of complex magnetic crystalline nanomaterials with particle sizes in the range of 40-100 nm that are difficult to produce using conventional techniques.
authors.affiliation: Ames Laboratory, U.S. Department of Energy, Ames, IA 50011, USA.
authors.forename: Tanya
authors.initials: T
authors.lastname: Prozorov
authors.forename: Pierre
authors.initials: P
authors.lastname: Palo
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.forename: Marit
authors.initials: M
authors.lastname: Nilsen-Hamilton
authors.forename: DeAnna
authors.initials: D
authors.lastname: Jones
authors.forename: Daniel
authors.initials: D
authors.lastname: Orr
authors.forename: Surya K
authors.initials: SK
authors.lastname: Mallapragada
authors.forename: Balaji
authors.initials: B
authors.lastname: Narasimhan
authors.forename: Paul C
authors.initials: PC
authors.lastname: Canfield
authors.forename: Ruslan
authors.initials: R
authors.lastname: Prozorov
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D003035:Cobalt / Q000737:chemistry*; D004058:Diffusion; D005290:Ferric Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008280:Magnetics; D042201:Magnetospirillum / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001426:Bacterial Proteins; D005290:Ferric Compounds; D011108:Polymers; D014867:Water; C001215:ferrite; D003035:Cobalt