Based on multi-omics technology study the antibacterial mechanisms of pH-dependent N-GQDs beyond ROS.

ABSTRACT

Currently, graphene quantum dots (GQDs) are widely used as antibacterial agents, and their effects are dependent on the reactive oxygen species (ROS) generated by photodynamic and peroxidase activities. Nevertheless, the supply of substrates or light greatly limits GQDs application. Besides, due to compensatory mechanisms in bacteria, comprehensive analysis of the molecular mechanism underlying the effects of GQDs based on cellular-level experiments is insufficient. Therefore, N-GQDs with inherent excellent, broad-spectrum antibacterial efficacy under acidic conditions were successfully synthesized. Then, via multi-omics analyses, the antibacterial mechanisms of the N-GQDs were found to not only involve generation ROS but also be associated with changes in osmotic pressure, interference with nucleic acid synthesis and inhibition of energy metabolism. More surprisingly, the N-GQDs could destroy intracellular acid-base homeostasis, causing bacterial cell death. In conclusion, this study provides important insights into the antibacterial mechanism of GQDs, offering a basis for the engineering design of antibacterial nanomaterials.