Green Synthesis of Biogenic Zinc Oxide Nanoflower as Dual Agent for Photodegradation of an Organic Dye and Tyrosinase Inhibitor

In the study, metabolites of Euphorbia sanguinea were used as benign reducing and stabilizing agents to obtain zinc oxide nanoparticles (ZnO-NPs). The nanoparticles were evaluated as dual agent for photodegradation of Malachite green dye and tyrosinase inhibitior of mushroom tyrosine enzyme. Surface plasmon bands and energy band gaps of the ZnO-NPs were within the range 356–378 nm and 2.72–4.37 eV respectively as obtained from the UV–Vis spectra. SEM/EDS elemental mapping of the nanoparticles gave flower-like shape and even distribution of zinc and oxygen. XRD result revealed crystallographic peaks assigned to hexagonal phase of zinc oxide. The metal oxide nanoparticles were used to achieve 53% percentage degradation of Malachite green dye solution in less than a minute of solar radiation, which increased to 92% in 60 min. A first order kinetics with correlation coefficient R 2 of 0.937, rate constant of 0.0084 min −1 and half-life of 82.52 min was established for the photodegradation process. The ZnONPs exhibited good tyrosinase inhibition with IC50 of 49.016 µg/ml. The mode of enzymatic inhibition was competitive with an inhibition constant (Ki) of 0.525 mM using Lineweaver–Burk kinetic model.