Nano Archive

Microbial manufacture of chalcogenide-based nanoparticles via the reduction of selenite using Veillonella atypica: an in situ EXAFS study

Pearce, Carolyn I. and Coker, Victoria S. and Charnock, John M. and Pattrick, Richard A. D. and Mosselmans, J. Frederick W. and Law, Nicholas and Beveridge, Terry J. and Lloyd, Jonathan R. (2008) Microbial manufacture of chalcogenide-based nanoparticles via the reduction of selenite using Veillonella atypica: an in situ EXAFS study. NANOTECHNOLOGY, 19 (15).

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Official URL: http://www.iop.org/EJ/abstract/0957-4484/19/15/155...

Abstract

The ability of metal-reducing bacteria to produce nanoparticles, and their precursors, can be harnessed for the biological manufacture of fluorescent, semiconducting nanomaterials. The anaerobic bacterium Veillonella atypica can reduce selenium oxyanions to form nanospheres of elemental selenium. These selenium nanospheres are then further reduced by the bacterium to form reactive selenide which could be precipitated with a suitable metal cation to produce nanoscale chalcogenide precipitates, such as zinc selenide, with optical and semiconducting properties. The whole cells used hydrogen as the electron donor for selenite reduction and an enhancement of the reduction rate was observed with the addition of a redox mediator (anthraquinone disulfonic acid). A novel synchrotron-based in situ time-resolved x-ray absorption spectroscopy technique was used, in conjunction with ion chromatography and inductively coupled plasma-atomic emission spectroscopy, to study the mechanisms and kinetics of the microbial reduction of selenite to selenide. The products of this biotransformation were also assessed using electron microscopy, energy-dispersive spectroscopy, x-ray diffraction and fluorescence spectroscopy. This process offers the potential to prepare chalcogenide-based nanocrystals, for application in optoelectronic devices and biological labelling, from more environmentally benign precursors than those used in conventional organometallic synthesis.

Item Type:Article
Subjects:Material Science > Nanofabrication processes and tools
Physical Science > Nano objects
Biomedical Science > Nanobiotechnology
Analytical Science > Beam methods
ID Code:2407
Deposited By:Anuj Seth
Deposited On:17 Dec 2008 11:10
Last Modified:20 Jan 2009 10:30

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