Green Synthesis, Characterization and Screening for Antibacterial Activity of Gold Nanoparticles Produced by Salacia fruticosa Leaf Extract

In the present investigation, a detailed study on the synthesis, characterization and application of Gold Nanoparticles (GNPs) using medicinally important plant Salacia fruticosa is reported for the first time. The aqueous leaf extract of S. fructicosa was used as reducing agent for more rapid, facile, cost-effective and eco-friendly synthesis of metallic GNPs. The synthesis of gold nanoparticles was done by treating the different concentrations of aqueous Gold (III) chloride trihydrate(HAuCl4)solution with the plant leaf extract at physiological condition (pH 7.4). The formation of GNPs was studied by varying the metal salt concentrations in the reaction medium and was initially confirmed by UV-visible spectroscopy by measuring the peak between 400-700 nm. The GNPs synthesised at optimised gold salt concentration showed a peak at 545 nm. X-ray diffraction (XRD) analysis displayed Bragg's peak conferring the 310, 310, 330, 420 and 422 facets of the face centered cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. Possible interaction of phytochemicals in mediating and stabilization of nanoparticles was confirmed with Fourier transform infrared spectroscopy (FTIR). Size and shape of the nanoparticles was determined using Transmission electron microscopy (TEM) with size ranging from 20-50 nm. The plant S. fructicosa may found to be quite competent for the purpose of commercial gold nanoparticles production, since it is synthesized extracellular as well as rapidly. This work also presents a scientific support for the antibacterial activity of the gold nanoparticles against bacterial pathogens Staphylococcus aureus and Pseudomonas aeruginosa and consequently it may be used to discover the potential applications in the treatment of the infection caused by other microbial pathogens.