(ZnO) thin films using a one-step electrochemical deposition, and investigated the effect of rGO-hybridization on the photoinactivation
efficiency of ZnO thin films towards Staphylococcus aureus (Staph. aureus) and Salmonella enterica serovar Typhi (S. Typhi) as target
bacterial pathogens. Field-emission scanning electron microscopy (FESEM) revealed the formation of geometric, hexagonal flakes of ZnO
on the ITO glass substrate, as well as the incorporation of rGO with ZnO in the rGO/ZnO thin film. Raman spectroscopy indicated the
successful incorporation of rGO with ZnO during the electrodeposition process. Photoluminescence (PL) spectroscopy indicates that rGO
hybridization with ZnO increases the amount of oxygen vacancies, evidenced by the shift of visible PL peak at 650 to 500 nm. The
photoinactivation experiments showed that the thin films were able to reduce the bacterial cell density of Staph. aureus and S. Typhi from
an initial concentration of approximately 108 to 103 CFU/mL within 15 minutes. The rGO/ZnO thin film increased the photoinactivation
rate for Staph. aureus (log[N/No]) from -5.1 (ZnO) to -5.9. In contrast, the application of rGO/ZnO thin film towards the photoinactivation
of S. Typhi did not improve its photoinactivation rate, compared to the ZnO thin film. We may summarise that (1) rGO/ZnO was effective
to accelerate the photoinactivation of Staph. aureus but showed no difference to improve the photoinactivation of S. Typhi, in comparison
to the performance of ZnO thin films, and (2) the photoinactivation in the presence of ZnO and rGO/ZnO was by ROS damage to the
extracellular wall.