Nano Archive

On the enzymatic formation of platinum nanoparticles

Govender, Y. and Riddin, T. L. and Gericke, M. and Whiteley, C. G. (2009) On the enzymatic formation of platinum nanoparticles. Journal of Nanoparticle Research, 12 (1). pp. 261-271. ISSN 1388-0764 (Print) 1572-896X (Online)

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Official URL: http://www.springerlink.com/content/x18w7p564341h3...

Abstract

A dimeric hydrogenase enzyme (44.5 and 39.4 kDa sub units) was isolated in a 39.5% yield from the fungus Fusarium oxysporum and purified 4.64-fold by ion exchange chromatography on Sephacryl S-200. Characterisation of the enzyme afforded pH and temperature optima of 7.5 and 38 °C, respectively, a half-life stability of 36 min and a V max and K m of 3.57 nmol min−1 mL−1 and 2.25 mM, respectively. This enzyme was inhibited (non-competitively) by hydrogen hexachloroplatinic acid (H2PtCl6) at 1 or 2 mM with a K i value of 118 μM. Incubation of the platinum salt with the pure enzyme under an atmosphere of hydrogen and optimum enzyme conditions (pH 7.5, 38 °C) afforded <10% bioreduction after 8 h while at conditions suitable for platinum nanoparticle formation (pH 9, 65 °C) over 90% reduction took place after the same length of time. Cell-free extract from the fungal isolates produced nearly 90% bioreduction of the platinum salt under both pH and temperature conditions. The bioreduction of the platinum salt by a hydrogenase enzyme takes place by a passive process and not an active one as previously understood.

Item Type:Article
Uncontrolled Keywords:Platinum - Nanoparticles - Hydrogenase - Fusarium - Synthesis
Subjects:Biomedical Science > Nanobiotechnology
Material Science > Nanostructured materials
Material Science > Nanochemistry
ID Code:8124
Deposited By:IoN
Deposited On:01 Mar 2010 10:17
Last Modified:01 Mar 2010 10:17

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