Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 5, 2012
Previous Article Next Article

Synthesis, characterization and catalytic activity of gold nanoparticles biosynthesized with Rhizopus oryzae protein extract

Author affiliations

Abstract

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-bio-conjugates (AuNBC) is described. AuNBCs, having sizes ranging from 5 to 65 nm, were synthesized by altering the HAuCl4protein 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.

Graphical abstract: Synthesis, characterization and catalytic activity of gold nanoparticles biosynthesized with Rhizopus oryzae protein extract

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 28 Dec 2011, accepted on 03 Feb 2012 and first published on 14 Mar 2012


Article type: Paper
DOI: 10.1039/C2GC16676C
Citation: Green Chem., 2012,14, 1322-1334
  •   Request permissions

    Synthesis, characterization and catalytic activity of gold nanoparticles biosynthesized with Rhizopus oryzae protein extract

    S. K. Das, C. Dickinson, F. Lafir, D. F. Brougham and E. Marsili, Green Chem., 2012, 14, 1322
    DOI: 10.1039/C2GC16676C

Search articles by author