▎ 摘　　要

In the present study, catechin was successfully grafted in reduced graphene oxide Zinc oxide (rGO/ZnO) nanocomposite by solvent free hydrothermal method. Absorption spectra at 207 and 280 nm confirms the formation of Catechin overlaid rGO/ZnO nanocomposite (Ca@rGO/ZnO NCs). Characterization of Ca@rGO/ZnO NCs revealed the presence of hexagonal wurtzite structure with aggregated morphology and size of 111.7 nm which is suitable for cellular entry. Enhanced release of drug catechin was observed (74.60 +/- 0.55%) at acidic pH within 24 h. 3-(4,5-Dimethylthiazol-2-yl)-2,5-DiphenyltetrazoliumBromide and Lactate dehydrogenase assays revealed dose-dependent antiproliferative effect of Ca@rGO/ZnO NCs (IC50 value 17.02 +/- 0.002 mu g/ml) and cell membrane damage. Fluorescent microscopic studies revealed that nanocomposite enhanced the release of ROS level leading to transmembrane potential loss, enhancing cytochrome C release eventually mediating apoptosis. Antibiofilm studies revealed Ca@rGO/ZnO NCs exhibited drastic reduction in biofilm formation with IC50 value of 5 +/- 0.25 mu g/ml. Acridine orange/Ethidium bromide dual staining showed disruption in biofilm architecture with reduced microcolonies mostly dead cells in treated groups. In vitro toxicity studies depicted the biocompatible nature of Ca@rGO/ZnO NCs. Taken together the present study represents rGO/ZnO as suitable nanocarrier for catechin and Ca@rGO/ZnO NCs as an emerging paradigm for treatment of infectious disease and lung cancer.