Bio-mediated electrochemically synthesis of silver nanoparticles using green tea (Camellia sinensis) leaves extract and their antibacterial activity

Since the antibacterial properties of silver nanoparticles are well established, the synthesis method for AgNPs, which provides excellent antibacterial activity, is highly promising. The study investigated the inexpensive, fast, and environmentally friendly synthesis of silver nanoparticles (AgNPs) using green tea leaf extract as a bio-mediated electrochemical synthesis. The green tea extract solution acts as an electrolyte in the system, ensuring that the electrolyte occurs and facilitating the formation of AgNP. The AgNP formation was indicated by a single peak at 421 nm. FTIR spectra revealed that green tea extract plays a dual role as a reducing and stabilizing agent. The method produces polycrystalline nanoparticles with sizes ranging from 8 to 26 nm, a mostly spherical shape, and a high purity (96.25 % in mass). Antibacterial assay of AgNP against E. coli and S. aureus showed the highest activity compared to Ag⁺ ions, green tea extract, and synthesized AgNP using NaBH₄. The results provide a new method for producing AgNPs with excellent antibacterial activity.