Gold decorated shape-tailored zinc oxide-rGO nanohybrids: Candidate for pathogenic microbe destruction and hazardous dye degradation

This work explores noble metal coupled carbon-based nanohybrid materials specifically for their antibacterial and photo-disinfection capabilities from a broader perspective of health to clean. Using gold (Au) nanoparticles (NPs) on the surface of two different shaped zinc oxide-graphene (ZnO-rGO) nanohybrids such as flake and spherical, this experiment aims to manage a pathogen-free environment while filtering and recycling carcinogenic dye-containing wastewater. The shape-tailored ZnO-rGO-Au hybrid generate a substantial amount of reactive oxygen species ; ROSs: hydroxyl radical (•OH), superoxide (•O 2 - ), singlet oxygen, and ( 1 O 2 ) and focal electrostatic interactions on (gram-negative Escherichia coli and gram-positive Staphylococcus aureus ) bacterial cell membranes . Redox cycling and strong potential binding tendency rapture the structural organization of cells that is clearly reflected in growth kinetics, (3(4, 5-dimethylthiazol-2-yl)−2), 5-diphenyl tetrazolium bromide (MTT), inner permeable/ protein/ malondialdehyde assay, and microscopical images after the morphology dependent physical as well as the chemical effects of nanocomposites . The minimum bactericidal concentration (MBC) or minimum inhibitory concentration (MIC) studies show the Au/rGO-ZnO system to be the very potent antibacterial agent , and that only 0.18 mg/ml represents significant bactericidal activity while their toxicity towards mammalian cells is very low (>2 mg/ml). Furthermore, Au NPs alter the bandgap energy of Au/rGO-ZnO hybrids, causing the formation of ROSs at different pH levels or dosages of the catalyst, which results in excellent photocatalytic activity (96% degradation of Rhodamine B when using 0.75 mg catalyst). Based on a Pseudo-first-order kinetic model , a likely mechanistic pathway towards exceptional dye decomposition has also been identified.