Green synthesis of gold nanostructures using pear extract as effective reducing and coordinating agent

Abstract

Biosynthesis of gold nanoparticles and nanoplates (GNPs) was accomplished using aqueous fractions of pear extract as a safe, reducing, particle-stabilizing, and shape-directing agent. The maximum yields of spherical gold nanoparticles having the average sizes of 40, 20, and 10 nm were achieved at 30, 60, and 90 °C, respectively, at a pear extract concentration of 45% (v/v). The maximum yield of gold nanoplates was obtained with sizes ranging from 20 to 400 nm, particularly at reaction temperatures of 30, 60, and 90 °C, at a pear extract concentration of 5% (v/v). The surface chemistry analysis of the GNPs suggests that the sugars and peptides or proteins as key biomolecules of the pear extract play a crucial role in the reduction of Au(III), subsequently resulting in healthy capping. Therefore, this environmentally friendly synthesis method of GNPs for the particular type of morphologies is expected to be a competitive alternative to existing physical and chemical methods.