Synthesis and Characterization of Silver Colloidal Particles of Ageratum conyzoides L. Plant Extracts

Abstract

Colloidal particles with controlled size and composition are of fundamental and technological interest as they provide solution to many technological and environmental challenges. In this study, an environmentally friendly approach was adopted to synthesize silver colloidal particles using aqueous extract of A. conyzoides L. plant. The reaction of this plant's extract with a solution of 1mM AgNO 3 changed its colour into reddish brown colour due to reduction of silver ions to silver atoms. UV-Visible and FTIR spectroscopy techniques were employed to characterize the colloidal particles. The UV-Visible spectroscopy revealed the formation of silver colloidal particles by exhibiting the typical surface plasmon absorption maximum at 420nm of UV-Visible spectra. The results showed that the size of the silver nanoparticles in the colloidal solution, range from 2-100nm. The FTIR measurements were carried out to identify the possible bio-molecules or functional groups responsible for capping and efficient stabilization of the metal colloidal particles synthesized by the plant extract and the results showed that the synthesized colloidal particles may be surrounded by proteins and metabolites having the functional groups of alcohols, ketones, aldehydes and carboxylic acids. The results signify that Ageratum conyzoides is a potential medicinal plant for the synthesis of silver colloidal particles.