High Efficiency and Long-Term Antibacterial Carbon Dots for Combating Antibiotic Resistance

Combating antibiotic resistance is critically significant for global public health. The development of new antibacterial nanomaterial is a promising way to do this. In this study, a bottom-up approach was employed to fabricate antibacterial carbon dots (ACDs). During the synthesis, quaternary ammonium function groups with long alkyl chains were successfully grafted on ACDs' surfaces. The obtained ACDs exhibited potent inhibitory against methicillin-resistant Staphylococcus aureus (MRSA) bacteria with minimum inhibitory concentrations of 2.5 µg/mL. Crucially, 2.5 µg/mL of ACDs could inhibit the growth of MRSA for as long as 72 h, which highlighted their long-term activity. Mechanistic investigations revealed that ACDs exerted bactericidal effects for MRSA bacteria primarily through disrupting the cell wall/membrane, destroying cell membrane potential, inducing the generation of excessive ROS, and triggering the leakage of nucleic acids and intracellular components. In sum, this work provided a kind of ACD with high efficiency and long-term antibacterial activity, offering promising potential for combating drug-resistant bacterial infections.