Content area
Full Text
J Nanopart Res (2010) 12:16671675 DOI 10.1007/s11051-009-9835-3
RESEARCH PAPER
Biosynthesis of gold and silver nanoparticles by natural precursor clove and their functionalization with amine group
Ashwani Kumar Singh Mahe Talat
D. P. Singh O. N. Srivastava
Received: 2 July 2009 / Accepted: 17 December 2009 / Published online: 6 January 2010 Springer Science+Business Media B.V. 2010
Abstract We report a simple and cost effective way for synthesis of metallic nanoparticles (Au and Ag) using natural precursor clove. Au and Ag nanoparticles have been synthesized by reducing the aqueous solution of AuCl4 and AgNO3 with clove extract. One interesting aspect here is that reduction time is quite small (few minutes instead of hours as compared to other natural precursors). We synthesized gold and silver nanoparticles of different shape and size by varying the ratio of AuCl4 and AgNO3 with respect to clove extract, where the dominant component is eugenol. The evolution of Au and Ag nanoparticles from the reduction of different ratios of AuCl4 and
AgNO3 with optimised concentration of the clove extract has been evaluated through monitoring of surface plasmon behaviour as a function of time. The reduction of AuCl4 and AgNO3 by eugenol is because of the inductive effect of methoxy and allyl groups which are present at ortho and para positions of
proton releasing OH group as two electrons are released from one molecule of eugenol. This is followed by the formation of resonating structure of the anionic form of eugenol. The presence of methoxy and allyl groups has been conrmed by FTIR. To the best of our knowledge, use of clove as reducing agent, the consequent very short time (minutes instead of hours and without any scavenger) and the elucidation of mechanism of reduction based on FTIR analysis has not been attempted earlier.
Keywords Au nanoparticles Ag nanoparticles
Clove extract Eugenol Functionalization
Nanobiotechnology
Introduction
Metal nanoparticles exhibit unique optical, electronic and catalytic properties which are primarily based on their small size and their high surface to volume ratio. The properties of these materials are often different from corresponding bulk materials of the same kind and are usually inuenced by the particle size. Metal nanoparticles also show potential for bio sensing (Willets and Van Duyne 2007; Zhao et al. 2006) and cancer therapy...