Green Synthesis of Liquid Metal-Doped Carbon Dots for Treating Multidrug-Resistant Gram-Negative Bacteria

Abstract

Global emergence of multidrug-resistant (MDR) gram-negative bacteria triggers severe infections that result in an epidemic. It is urgent to discover novel classes of antibacterial agents. Here, a green route for synthesizing polyethylene glycol-based carbon dots (PEG-CDs) doped with liquid metal (LM-Cdots) via a solvent-free system is presented. LM-Cdots synthesized via ultrasound exhibit great antibacterial activity against gram-negative bacteria (E. coli, P. aeruginosa, K. pneumoniae, and A. baumannii) and their multidrug-resistant (MDR) clinical isolates. In the in vitro antibacterial test with MDR K. pneumoniae, LM-Cdots show an extremely low minimum inhibition concentration (MIC) of 0.63 µg mL−1. Compared to naked PEG-CDs, the MIC is improved by 1000 times. In vivo results reveal that LM-Cdots can accelerate wound healing with low biotoxicity and inflammation.