Hydnocarpus alpina Wt extract mediated green synthesis of ZnO nanoparticle and screening of its anti-microbial, free radical scavenging, and photocatalytic activity

Abstract

Abstract This paper reports green synthesis of ZnO nanoparticle (ZnO Np) using Hydnocarpus alpina aqueous alcoholic extract as capping agent. These green synthesized ZnO Nps were characterized using Fourier transform Infrared (FT-IR), powder X-ray diffraction (PXRD), Field Emission Scanning electron microscopy (FE-SEM), and UV–visible diffuse reflectance spectroscopy (DRS-UV). FE-SEM and PXRD results revealed that these synthesized ZnO NPs had spherical morphology with diameter of 38.84 nm and high phase purity. Gas chromatography–mass spectrophotometric (GC-MS) phytochemical fingerprinting analysis of the plant extract showed the presence of 19 phytoconstituents that might potentially act as stabilizing and capping templates in the formation of nano particles. These synthesized ZnO NPs were tested against various Gram (+) ve and Gram (−) ve microorganism. They were more active against Proteus vulgaris and Salmonella enterica typhimurium compared to other organisms studied. Furthermore, these ZnO NPs showed potential in scavenging 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals. They also possessed potential photocatalytic activity against methylene blue degradation of about 96% in basic pH. These results suggest that these green synthesized ZnO NPs using HA extract can be used as effective anti-microbial and photo catalysts for controlling pathogenic microbes and degradation of dyes in industrial effluents.