Sequentially Reduced Biogenic Silver-gold Nanoparticles With Enhanced Antimicrobial Potential Over Silver And Gold Monometallic Nanoparticles

Bimetallic nanoparticles have emerged up as advanced nanomaterials due to the synergism between two metallic nanoparticles in core-shell or alloy arrangement. Moreover, bioinspired synthesis of nanoparticles is an evergreen approach of nanobiosciences. In this experiment, we have fabricated silver, gold and silver (core) - gold (shell) bimetallic nanoparticles using leaf extract of Catharanthus roseus Linn. by sequential reduction technique. The sequentially reduced silver-gold nanoparticles in core-shell arrangement were detected by shift in the surface plasmon resonance of nanoparticles from 423 nm to 526 nm with the aid of UV-Visible spectrophotometer. Nanoparticle tracking analysis confirmed the mean particle size for all the nanoparticles within the range 11 to 65 nm. X-Ray diffraction analysis revealed Bragg’s reflections denoting face cubic centered crystalline nature of all the synthesized nanoparticles. Transmission electron microscopy showed that silver and silver-gold nanopa