Aqueous and ethanol extracts of Aneilema aquinoctiale were used as solvents in the biosynthesis of silver nanoparticles (AgNPs). This facile, cost-efficient, benign and green method has shown effectiveness in a photo-inducive procedure for the biomolecule-aided synthesis of silver nanoparticles. The colour changes from black to dark brown and brownish green to black for silver nanoparticles (AgNPs) for aqueous and ethanol extract respectively, Suggestive of oxidation and eduction of metal ion. UV-visible (UV-Vis) spectroscopic technique was used to monitor the formation by measuring surface plasma resonance. The absorption bands shifted from 400 nm to 675 nm indicating the absorption of biomolecules and the formation of silver nanoparticles (AgNPs). Fourier transform infrared (FT-IR) spectroscopy showed absorbance synonymous to active biomolecules present in A.aquinoctaile extract. Scanning electron microscopy/energy dispersive X-ray (SEM/EDX) revealed polymorphous particles. The high energy dispersive X-ray peaks for silver, confirm the presence of Ag in the particles. The transmission electron microscopy (TEM) results revealed particles of 10 nm and 20 nm. Antimicrobial activity of the silver nanoparticles (AgNPs) on both gram-positive and gram-negative bacteria showed that the synthesized particles at concentrations 50 mg/mL and 25 mg/mL have prominent activity against microbes with maximum inhibition on Pseudomonas aeruginosan at 24 mm/50 mg/mL and 18 mm/25 mg/mL for silver nanoparticles (AgNPs) of aqueous extract and 38 mm/50 mg/mL and 28 mm/25 mg/mL for silver nanoparticles (AgNPs) in ethanol extract.

Keywords: biosynthesis, biomolecules, photo-induced, nanoparticles, silver nanoparticles