Green synthesis, and characterization of zinc oxide nanoparticles using <i>Piper longum</i> catkin extract and its <i>in vitro</i> antimicrobial activity against multi-drug-resistant non-typhoidal <i>Salmonella</i> spp.

Abstract

This study attempted synthesis and characterization of zinc oxide nanoparticles (ZnO NPs) using the aqueous extract of Piper longum catkin and its in vitro antibacterial efficacy against multi-drug-resistant strains (MDR) of non- typhoidal Salmonella (NTS) spp. (S. enterica Typhimurium and S. Enteritidis). The green synthesized ZnO NPs exhibited an absorbance peak at 340 nm by UV-Vis spectroscopy, which was confirmed by FTIR analysis. The TGA/DTA revealed a progressive thermal degradation of the ZnO NPs between 250 °C and 400 °C; however, good thermal stability was exhibited for annealing temperatures between 900 °C and 1300 °C. The ZnO NPs exhibited hexagonal wurtzite crystalline structure by PXRD analysis, which was further confirmed by electron microscopy. Microbroth dilution technique exhibited an MIC and MBC values of 125 and 250 µg/mL, respectively. Overall, the study demonstrated a facile, eco-friendly method for the synthesis of ZnO NPs, which could be employed as a potential antimicrobial alternative candidate.