Chromium and cerium co-doped magnetite/reduced graphene oxide nanocomposite as a potent antibacterial agent against S. aureus

Abstract The development of innovative antibacterial samples with high efficacy has received a great deal of interest. Herein, we synthesized magnetite modified by Cr and co-modified by Cr and Ce, along with their reduced graphene oxide (rGO)-based nanocomposites via facile hydrothermal and co-precipitation methods. The rGO-based samples showed proper magnetic behavior, high porosity, and vast specific surface area. The high specific surface area provided more adsorptive active sites with higher potentials for the decomposition of Staphylococcus aureus (S. aureus) cells. The antibacterial performance of the samples against S. aureus was evaluated at 50 and 100 μg mL-1 through the colony-forming unit (CFU) method and the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) values were subsequently determined. As per results, not only chromium cations could effectively damage the DNA of bacteria, but also the antibacterial efficacy was further enhanced by co-doping of cerium and the integration with rGO nanosheets. The antibacterial results were confirmed through the changes observed in the morphology and topology of the bacteria before and after the treatment using SEM and AFM analyses. Ultimately, the plausible S. aureus inactivation mechanism of the samples was disclosed.