Abstract
The plasmonic metal doping on the UV-active metal oxide nanoparticle turns the resultant plasmonic metal-metal oxide (PMMO) into visible light active and upon exogenous illumination the photogenerated energetic charge carriers and the in situ generated reactive oxygen species (ROS, e.g. ·OH and O2 -·) authoritatively enhances its biological and catalytic activity. Herein, a hexagonal rod-shaped ZnO nanoparticles (NP) precursor was prepared using the sol-gel method, which in the presence of varying concentrations of gold (0.005M, 0.01M, and 0.015M) via a greener citrate reduction method afforded a nanocrystalline Au-ZnO nanocomposite. Using which, the visible-light driven photo-degradation kinetics investigation of rhodamine-6G (R6G) dye under blue LED irradiation were carried out. The use of 20mg 0.015-Au-ZnO completes the degradation of R6G (97.0%, k=6.5 X 10-3s-1at pH 7) within 55min while 50mg of 0.015-Au-ZnO catalyst improves the rate of R6G degradation (15min 97.8%, k=14.8×10-3 s-1) and it is reusable up to three cycles. The LC-MS spectra of the remains of R6G (after 15min) identified various low molecular ions (up m/z=65). Further, the blue-LED assisted anti-cancer studies (MTT assay) using 0.015-Au-ZnO towards human lung cancer cells (A549), breast cancer cells (SKBr3) show high anti-proliferation rate and low cytotoxicity against healthy human embryonic kidney cells (HEK-293) with an IC50 value of 65, 53 and 124μg/mL respectively. Also, the AO-EB dual staining and DCFH-DA analysis of SKBr3 and A549cells revealed ROS-mediated cell death via apoptosis. Moreover, plasmid cleavage studies against supercoiled pBR322 DNA result in single-stranded linear DNA without traversing the nicked circular form, suggesting the possible DNA targeting activity of Au-ZnO nanozyme. Thus, the synthesized Au-ZnO nanocomposite shows excellent photocatalytic and biological activity.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call