Mechanism of inhibition of graphene oxide/zinc oxide nanocomposite against wound infection causing pathogens

Infection and colony formation by microbes has been a negative consequence in wound care. Graphene oxide (GO) has a large surface area and it is biocompatible. Zinc oxide (ZnO) exhibits antimicrobial activity against various infectious microbes. In GO/ZnO nanocomposite, ZnO nanoparticle is homogeneously supported on the GO sheet. It controls the infection in wound area and promotes angiogenesis. The synthesized nanocomposite was characterized using XRD, FTIR, Raman Spectroscopy, UV-DRS, FESEM with EDS, TEM and ICP-OES. Antibacterial activity was studied using the well diffusion method, growth curve, death kinetics, sensitivity coefficient, biofilm inhibition and colony counting method. Reactive oxygen species assay (ROS), lactate dehydrogenase leakage assay (LDH) and DNA fragmentation studies were done to analyze the mechanism of inhibition of nanocomposite against bacteria. A hemolytic study was done to confirm the blood biocompatibility of the nanocomposites. The mechanism of bacterial inhibition is by the production of ROS, loss of membrane integrity, not by DNA fragmentation. The nanocomposites enhanced its antibacterial activity in the presence of visible light compared to dark conditions.