Green synthesis of tea Ag nanocomposite hydrogels via mint leaf extraction for effective antibacterial activity

Abstract

In this report, we investigated the swelling behavior and antibacterial property of nanosilver composite hydrogels made from tea with polyacrylamide via a free-radical polymerization and green process technique. This is probably for the first time; tea-based nano silver composite hydrogels were developed. The composite hydrogels comprise embedded nano silver particles in the tea hydrogel matrix via a green process with mint leaf extract. The size of the nano silver particles in the hydrogel matrix was found to be < 10 nm. The nano silver composite hydrogels formed and their blank hydrogels from the mint leaf were characterized by using ultraviolet-visible spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis and X-ray diffraction studies. The nano silver composite hydrogels developed exhibit eminent antibacterial activity against Escherichia coli and Staphylococcus aureus. This clearly indicates that the nano silver composite hydrogels are potential candidates for antimicrobial applications.

Keywords:

• Tea
• mint leaves extract
• AgNPs
• composite hydrogels

Acknowledgements

The author, Kokkarachedu Varaprasad wishes to acknowledge the Fondecyt N^o 11160073 and Centre de Investigación de Polimeros Avanzados (CIPA), CONICYT Regional, GORE BIO-BIO PRFC0002. The author, Tippabattini Jayaramudu wishes to acknowledge the Fondecyt Postdoctoral Project N^o 3170272.