Eco-friendly synthesis of gold nanoparticles by gold mine bacteria Brevibacillus formosus and their antibacterial and biocompatible studies

Nanotechnology is recently emerging in various fields especially in biomedical applications as many pathogenic organisms are gaining resistant against available antibiotics. In the present study, we have synthesized biocompatible therapeutic gold nanoparticles using Brevibacillus formosus isolated from the Hutti gold mine, India. Gold nanoparticles (AuNPs) synthesised by the reduction of gold chloride (HAuCl4) using bacterial metabolites as reducing and stabilizing agents. The synthesized AuNPs are characterized by using UV-vis spectroscopy, Fourier transfer infrared spectroscopy (FTIR), Dynamic light scattering (DLS) and Transmission electron microscopy (TEM). The UV-vis spectrum of the AuNPs showed peak around 535 nm and presence of functional groups on AuNPs were confirmed by FTIR analysis. The size and shape of synthesized AuNPs were found to be spherical with an average particles size of 5-12 nm. A DLS result confirms the formation of monodispersed AuNPs. AuNPs were showed good antibacterial activity against gram positive Staphylococcus aureus and less activity against gram negative E. coli. Further, biocompatibility of biogenic AuNPs was verified by incubating with chiken RBCs and showed no hemolysis. The outcome of the study clearly indicates that as synthesized AuNPs are biocompatible and show good antibacterial activity could be effectively utilized in biomedical applications.