Journal of Nanoparticle Research

, Volume 12, Issue 1, pp 261–271

On the enzymatic formation of platinum nanoparticles

  • Y. Govender
  • T. L. Riddin
  • M. Gericke
  • C. G. Whiteley
Research Paper

DOI: 10.1007/s11051-009-9604-3

Cite this article as:
Govender, Y., Riddin, T.L., Gericke, M. et al. J Nanopart Res (2010) 12: 261. doi:10.1007/s11051-009-9604-3

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 Vmax and Km 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 Ki 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.

Keywords

PlatinumNanoparticlesHydrogenaseFusariumSynthesis

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Y. Govender
    • 1
  • T. L. Riddin
    • 1
  • M. Gericke
    • 2
  • C. G. Whiteley
    • 1
  1. 1.Department of Biochemistry, Microbiology & BiotechnologyRhodes UniversityGrahamstownSouth Africa
  2. 2.MINTEKRandburgSouth Africa