Biogenic synthesis of AuNPs using Solanum virginianum L. and their antibacterial, antioxidant and catalytic applications

Biogenic synthesis of nanoparticles is gaining popularity worldwide because of being ecofriendly as well as economical, with minimal production of hazardous by-products. The present study was targeted to determine the antibacterial, free radical scavenging and catalytic activity of gold nanoparticles synthesized from Solanum virginianum L. (Sv-AuNPs). After addition of auric chloride, the color of aqueous plant extract changed from light yellow to purple-red, indicating the formation of nanoparticles. A strong peak at 536 nm affirmed synthesis of Sv-AuNPs, and negative zeta potential (- 30.7) indicated their being wrapped in anions. They exhibited face-centered cubic and crystalline nature as revealed by X-ray diffraction. Elemental composition of Sv-AuNPs was ascertained by energy-dispersive X-ray spectroscopy, and a sharp peak at 2.2 keV confirmed the presence of gold. The shape of Sv-AuNPs synthesized was spherical with size ranging from 29.1 +/- 1 nm to 51.2 +/- 0.7 nm. Antibacterial potential was evaluated against E. coli, C. violaceum, K. pneumoniae, P. aeruginosa, B. subtilis, M. smegmatis, and S. aureus and was found to be greater than aqueous plant extract. Sv-AuNPs exhibited antioxidant potential comparable to ascorbic acid, demonstrating their vital role in the prevention of reactive oxygen species related diseases. Apart from their pharmaceutical potential, these nanoparticles also exhibited promising catalytic efficacy. They degraded harmful dyes i.e. 4-nitro phenol (4-NP) and congo red (CR) at a very low concentration of 50 mu g/ml. This is the first report on the antibacterial, antioxidant, and catalytic properties of Sv-AuNPs and we hope it will lead the way for nanoparticles multifunctionality. [GRAPHICS] .