Ciprofloxacin-based zinc-doped carbon dots with peroxidase-like activity against Escherichia coli and biofilm eradication

Herein, we rationally designed a novel and forceful ciprofloxacin (CIP) grafted zinc-doped-carbon dots (CIP@Zn/CDs) as an efficient artificial nanozyme against Escherichia coli (E. coli), multi-drug-resistant E. coli (AREC), and E. coli biofilms through the peroxidase (POD)-like catalytic activity and the synergistic antibacterial activity of CIP and Zn²⁺. On the one hand, extracellular DNA (eDNA) cleave by high levels of hydroxyl radicals (•OH) catalyzed by the POD-like catalytic activity of CIP@Zn/CDs. On the other hand, CIP@Zn/CDs with positive surface potential, elimination abilities against E. coli via electrostatic interaction, changing the cell membrane permeability and eventually leading to E. coli death within E. coli biofilms. Furthermore, the ultrasmall size of CIP@Zn/CDs possesses good biocompatibility favoring clinical translation. This work provides potential to develop CD-based techniques for applications in the field of selective antibacterial agents towards Gram-negative bacteria.