Green synthesis of silver nanoparticles using Artemisia annua and Sida acuta leaves extract and their antimicrobial, antioxidant and corrosion inhibition potentials

Silver nanoparticles were synthesized by a rapid, cost effective and environmentally benign technique using ground leaves extract of Artemisia annua and Sida acuta as reducing as well as capping agent. Silver nanoparticles (AgNps) were formed within 10-15 minutes by sunlight irradiation of aqueous solution (0.1M) of silver nitrate (AgNO₃) with leaves extract of Artemisia annua and Sida acuta. The synthesized AgNp's of both extracts were characterized using UV-visible spectrophotometer. The reaction mixtures showed absorbance at 450nm which is characteristic of silver nanoparticles due to the surface plasmon resonance absorption band. The antibacterial activity of these nanoparticles was studied against (Staphylococcus aureus, Escherichia coli and Streptococcus faecalis). Antifungal activity was studied against Candida albicans. The results of the antimicrobial studies showed good inhibitory effect against Staphylococcus aureus, Escherichia coli and Candida albican. Also, anti-corrosion activity of these silver nanoparticles on the corrosion of mild steel in 0.5M HCl solution was studied by potentiodynamic polarization curves and the results show that they are good inhibitors. The antioxidant activity of both the extracts and synthesized AgNP's was analyzed by 1,1-diphenyl-2-picryl-hydrazzyl (DPPH) radical scavenging assay using ascorbic acid as control and they were all found to exhibit good antioxidant activity especially at lower concentrations.