Laser-Mediated antibacterial effects of Few- and Multi-Layer Ti3C2Tx MXenes

Ti3C2TX nano-sheets (MXenes) with excellent light-conversion capacity have gained importance in treating in-fectious diseases due to their limited bacterial resistance. In this study, we exploit this property to design pho-tothermal antibacterial therapy using few- (FX) and multi-layer (MX) Ti3C2Tx nano-sheets. We demonstrate that FX have a higher cytocompatibility and conversion of light to heat, but MX show a better efficacy in inhibiting growth of S. aureus and E. coli due to MXenes' reversible bacteria trapping. For MX (25 ?g/mL), ?37% of E. coli and ?23% of S. aureus cells survived, while the effect was less pronounced for FX with ?72% of E. coli and ?46% of S. aureus viable cells after treatment. After using 100 ?g/mL of MX, ?11% of E. coli and ?4% of S. aureus survived, while FX had only a mild effect on both species. The NIR laser treatment increased the efficacy of both materials: 100 ?g/mL of MX combined with 5 min laser treatment at 5.7 W cm