Photocatalytic degradation of environmental perilous gentian violet dye using leucaena-mediated zinc oxide nanoparticle and its anticancer activity

Phytomediated synthesis of metal oxide nanoparticles has become a key research area in nanotechnology due to its wide applicability in various biomedical fields. The present work explores the biosynthesis of zinc oxide nanoparticles (ZnO-NPs) using Leucaena leucocephala leaf extract. The synthesised ZnO-NPs were characterised by ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) studies. Biosynthesised ZnO-NPs are found to have wurtzite hexagonal structure with particles distributed in the range of 50-200 nm as confirmed by TEM studies. The anticancer activity of ZnO-NPs against MCF-7 (breast cancer) and PC-3 (human prostate cancer) cell lines was evaluated using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. From the assay, biosynthesised ZnO-NPs have better cytotoxic activity on PC-3 cell lines than MCF-7 cell lines. The in vitro cytotoxicity studies of biosynthesised ZnO-NPs against Dalton lymphoma ascites (DLA) cells reveal better antitumor activity of 92% inhibition with concentration of 200 mu gml(-1) of ZnO-NPs, and as the concentration increases, the anticancer efficiency as well increases, and also, it has excellent photocatalytic activity to degrade crystal violet dye in aqueous solution after irradiation of 90 min. The result suggests that the green synthesis of ZnO-NPs could be easily recovered and reused several times without any significant loss of the catalytic activity. The advantage of this technique lies in its low cost, easily climbable and non-use of toxic agents.