Synthesis of Silver Nanoparticles Using Extracts from Yerba Mate (Ilex paraguariensis) Wastes

Abstract

Synthesis of metallic nanoparticles by an eco-friendly and sustainable process is an important target to be developed in nanotechnology area. In the present work, two different commercial brands of yerba mate from Argentina and their wastes (PYM and TYM samples) were used for the preparation of aqueous extracts, in order to synthesize silver nanoparticles at room temperature (25 °C). The silver nanoparticles obtained were spherical, hexagonal and, triangular in shape with the average particle size of 50 nm and, shows a surface plasmon peak around 460 nm. The antimicrobial activity of the silver nanoparticles obtained with the extracts from yerba mate wastes was evaluated against E. coli and S. aureus. The minimum inhibitory concentrations required for E. coli were 7.66 and 17.66 µg ml−1 using the treatment T2YE and P2YE, respectively and, for S. aureus were 23.25 and 50.60 µg ml−1 for the treatment T2YE and P2YE, respectively. The study suggests that polyphenols present in I. paraguariensis leaf extract act as reducing agent and stabilizer of the nanoparticles.