High consumption of antibiotics has led to resistance of pathogenic microorganisms, which prompted the testing of antimicrobial activity of various plant extracts or other substances in order to find new antimicrobial agents. Alternatively, silver and silver-based topical dressings have been used to treat bacterial infections. To overcome the problems associated with the excessive usage of antibiotics and chemicals, there is a need of eco-friendly synthesis and inexpensive antimicrobial agent(s) to treat infectious. Metallic nanoparticles (MNPs) have been receiving considerable attention in recent years because of their unique properties and a wide range of applications in various fields, including medicine. Among the various MNPs, silver nanoparticles have been widely studied because of their exceptional characteristic features. Recent research indicates a great potential for the application of biological molecules in an eco-friendly process for obtaining AgNPs, thus avoiding the use of hazardous chemicals. Extracts of various plants and groups of microorganisms are most exploited in such processes.
On the other hand, this paper examines the possibility of using pulverized waste biomass obtained from the processing of medicinal herbs which, only in Serbia, reaches about 100 tons annually. From economical point of view, utilization of such waste material with low cost price (if any) is profitable because it can be transformed in other valuable products. In this study, we developed eco-friendly method to synthesize silver nanoparticles (AgNPs) using aqueous extract of Equisetum arvense (EQ), (dust remained after production of tea) and evaluated their effect on both Gram+ and Gram– bacteria, associated with different infections.