Green synthesis of ZnO nanoparticles using Tecoma castanifolia leaf extract: Characterization and evaluation of its antioxidant, bactericidal and anticancer activities

An efficient, facile and green synthesis of zinc oxide nanoparticles (ZnO NPs) using Tecoma castanifolia leaf extract was reported. ZnO NPs was characterized by UV-Vis spectroscopy, TEM, EDX, XRD and FTIR. Phytochemical constituents of T. castanifolia leaf extract were analyzed by GC-MS. UV-Vis absorption showed SPR band at 370-400 nm which confirms the formation of ZnO NPs. TEM analysis exhibits spherical shape with size 70-75 nm and XRD results revealed the hexagonal phase of wurtzite structure. FTIR spectra confirmed the presence of O-H, C-H, amide-I, II groups, C-O bond and metal-oxygen groups. The presence of bioactive phytochemical constituents in the methanolic extracts of T. castanifolia was identified by GC-MS. An excellent antibacterial activity was observed for both Gram positive and Gram negative bacteria. Results of antioxidant activity showed that increase in concentration of ZnO nanoparticles increases the radical scavenging activity. Anticancer activity with IC50 value as 65 mu g/mL which conferred better cytotoxic effects of ZnO NPs on proliferation of A549 cell line. The present study revealed that the pharmacologically active compounds present in the green synthesized ZnO nanoparticles pave the way to lead its effective application in biomedical and nano drug delivery systems.