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Staff and Students > Vicky Coker

Vicky Coker

Functional Bionanomaterials

   The use of bacteria in nano-manufacturing is an unexploited area of enormous potential which I am, as part of a larger research group, actively exploring. The behaviour of Fe(III)-reducing bacteria, a relatively newly discovered group of anaerobic microorganisms, offers a specific untapped resource for bio-nanotechnologies. These organisms can precipitate regular shaped nano-sized (20nm) crystals of the ferromagnetic ferrite spinel, magnetite (Fe3O4 ).  This process works by coupling the oxidation of organic matter to the reduction of Fe(III)-oxyhydroxides and is accomplished by direct contact between the terminal Fe(III) reductase in the bacteria and the mineral surface.  By controlling and manipulating this process of biomineral production, a low cost, low energy, environmentally friendly method of manufacture of nanoparticles can be developed to replace existing practices. Ferrite spinel nanoparticles (especially magnetite, Fe3O4, and related structures) are of great technological interest (e.g. in recording device materials) and we have succeeded in producing biogenic magnetites doped with Co, Ni, Mn and Zn that tune their electrical and magnetic properties; and we are currently developing up-scaling methodologies. Our focus is now on producing biogenic nanomagnetite-supported precious metal catalysts using  Pd, Pt, Au and Ag which are all catalytically active and highly conductive elements both individually and as alloys. Our aim is to produce a versatile group of novel magnetite nanomaterials with unique characteristics that can be customised to enhance their properties as catalysts, magnets, and electronic devices.