Discovery of high antibacterial and catalytic activities against multi-drug resistant clinical bacteria and hazardous pollutants by biosynthesized of silver nanoparticles using Stachys inflata extract (AgNPs@SI)

Abstract For the first time in this work, silver nanoparticles were biosynthesized by the facile, rapid and eco-friendly process using Stachys inflata (S. inflate) extract then used as catalytic and antibacterial agents. Different characteristics of biosynthesized AgNPs@SI were determined with UV-Vis, DLS, TEM, FESEM, FT-IR and XRD techniques. The reaction parameters including AgNO3 concentration, temperature, contact time and pH were discussed and optimized. The TEM and FESEM results revealed spherical morphology of AgNPs@SI with size ranging from 35 to 45 nm. The antibacterial activity of AgNPs@SI was checked against gram-positive bacteria like SA-1 (S. aureus), EF-1 (E. faecalis) and gram-negative bacteria like EC-1 (E. coli), PM-1 (P. mirabilis), PA-1 (P. aeruginosa), AB-1 (A. baumannii) and KP-1 (K. pneumonia). The minimum inhibitory concentration (MIC) values of 0.4, 0.4, 0.23, 0.23, 0.9, 0.1 and 0.1 μg/ml were obtained for synthesized AgNPs@SI against PA-1, PM-1, EF-1, AB-1, KP-1, SA-1 and EC-1, respectively. In addition, biosynthesized AgNPs@SI showed antibacterial potency against multi–drug resistant bacteria. It is noteworthy that the biosynthesized AgNPs@SI illustrated significant catalytic performance for degradation of different types of hazardous pollutants like methyl violet and eriochrome black T under UV and visible light irradiations. These findings suggested that the biosynthesized AgNPs is suitable in biomedical and environment fields.