Title of the paper: ‘Synthesis, Characterization and Catalytic Application of Bioinspired Gold Nanoparticles.
aSchool of Biotechnology, National Centre for Sensor Research, Dublin
City University, Ireland. E-mail: enrico.marsili@dcu.ie
bMaterials and Surface Science Institute, University of Limerick, Ireland
cNational Institute for Cellular Biotechnology, School of Chemical
Science, Dublin City University, Ireland
Abstracts: A simple one-pot green chemical method for the biosynthesis of gold nanoparticles (AuNPs) by reducing chloroauric acid (HAuCl4) with protein extract of Rhizopus oryzae to produce novel gold nano-bioconjugates (AuNBC) is described. AuNBCs, having sizes ranging from 5 to 65 nm, were synthesized by altering the HAuCl4–protein extract ratio. The conjugates were characterized by spectroscopic, electron microscopic, light scattering and electrophoretic mobility measurements. It was found that the aqueous AuNBC suspensions exhibited excellent stability over a wide range of ionic strength, pH and temperature.
The effect of pH and ionic strength indicated that stabilization is due to electrostatic repulsion arising from the negative charge of the conjugate proteins. The AuNBCs were stable at temperatures lower than the denaturation temperature of the fungal proteins. The catalytic activity of the as-synthesized AuNBCs was quantified by analysing the reduction of p-nitrophenol by borohydride. The conjugates exhibited interesting size and shape dependent catalytic activity, which was stronger than that observed for AuNPs prepared by conventional chemical methods. The catalytic activity was found to be sensitive to both the surface-area-to-volume ratio and the thickness of the protein coating on the NP.
Green Chem., 2012,14, 1322-1334
Authors: Sujoy K. Das,a Calum Dickinson,b Fathima Lafir,b Dermot F. Broughamc and Enrico Marsili*a
University/Institute:aSchool of Biotechnology, National Centre for Sensor Research, Dublin
City University, Ireland. E-mail: enrico.marsili@dcu.ie
bMaterials and Surface Science Institute, University of Limerick, Ireland
cNational Institute for Cellular Biotechnology, School of Chemical
Science, Dublin City University, Ireland
Abstracts: A simple one-pot green chemical method for the biosynthesis of gold nanoparticles (AuNPs) by reducing chloroauric acid (HAuCl4) with protein extract of Rhizopus oryzae to produce novel gold nano-bioconjugates (AuNBC) is described. AuNBCs, having sizes ranging from 5 to 65 nm, were synthesized by altering the HAuCl4–protein extract ratio. The conjugates were characterized by spectroscopic, electron microscopic, light scattering and electrophoretic mobility measurements. It was found that the aqueous AuNBC suspensions exhibited excellent stability over a wide range of ionic strength, pH and temperature.
The effect of pH and ionic strength indicated that stabilization is due to electrostatic repulsion arising from the negative charge of the conjugate proteins. The AuNBCs were stable at temperatures lower than the denaturation temperature of the fungal proteins. The catalytic activity of the as-synthesized AuNBCs was quantified by analysing the reduction of p-nitrophenol by borohydride. The conjugates exhibited interesting size and shape dependent catalytic activity, which was stronger than that observed for AuNPs prepared by conventional chemical methods. The catalytic activity was found to be sensitive to both the surface-area-to-volume ratio and the thickness of the protein coating on the NP.
Links to the pape: http://pubs.rsc.org/en/Content/ArticleLanding/2012/GC/C2GC16676C
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