Ginkgo leaf derived amphiphilic and biocompatible carbon dots for sterilization and MRSA biofilm destruction

Abstract

Multidrug-resistant (MDR) bacterial infections, typified by methicillin-resistant Staphylococcus aureus (MRSA), have become a severe global challenge to healthcare systems. In response, antibacterial carbon dots (CDs) have attracted growing interest in the fight against MRSA. In this study, nitrogen self-doped ginkgo leaf (GL) carbon dots (GLCDs) were synthesized through a facile one-step solvothermal method combined with extraction technology. The prepared GLCDs are spherical nanoparticles with a crystalline structure and carry a positive charge of + 7.62 mV. The minimum inhibitory concentration (MIC) of GLCDs against MRSA was found to be 250 μg/mL. Notably, at a concentration of 750 μg/mL, GLCDs could completely eliminate 1 × 10⁶ MRSA within 240 minutes and effectively suppress MRSA biofilm formation in a dose-dependent manner. The antimicrobial mechanisms involve electrostatic interaction enabling penetration into MRSA, disruption of the cell structure leading to intracellular component leakage, induction of oxidative stress, and inhibition of antioxidant enzymes and respiratory function. Moreover, GLCDs demonstrated excellent biocompatibility in hemolysis and in vitro cytotoxicity tests. This research presents a novel natural-plant-based antimicrobial nanomaterial, providing valuable insights into the rational utilization of natural biomass to combat MRSA infections.