Cobalt Ferrite Nanocrystals: Out-Performing Magnetotactic

Magnetotactic bacteria produce exquisitely ordered chains of uniform magnetite (Fe3O4) nanocrystals, and the use of the bacterial mms6 protein allows for the shape-selective synthesis of Fe3O4 nanocrystals.Cobaltferrite(CoFe2O4)nanoparticles,ontheotherhand,arenotknowntooccurinlivingorganisms. Here we report on the use of the recombinant mms6 protein in a templated synthesis of CoFe2O4nanocrystalsin 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 CoFe2O4nanostructures. This new synthesis pathwayenablesfacileroom-temperatureshape-specificsynthesisofcomplexmagneticcrystallinenanomaterials with particle sizes in the range of 40-100 nm that are difficult to produce using conventional techniques.