NIR-dependent photothermal-photodynamic synergistic antibacterial mechanism for titanium carbide nanosheets intercalated and delaminated by tetramethylammonium hydroxide

The infectious disease epidemics caused by pathogens are a serious and growing worldwide public health problem. More seriously, the multiple resistant bacteria extensively spread in hospitals or communities due to antibiotic abuse. In this paper, we fabricate two-dimensional Ti3C2 nanosheets with excellent biocompatibility and photothermal-photodynamic synergistic antibacterial activity against E. coli and S. aureus based on the strategy of tetramethylammonium hydroxide (TMAOH)-driven intercalation and delamination. Compared with the traditional Ti3C2 nanosheets exfoliated by HF or situ HF (HCl + LiF), the photothermal-photodynamic Ti3C2 nanosheets show higher synergistic antibacterial efficiency. In addition, the antibacterial mechanism demonstrates that biofilm disruption and leakage of bacterial contents contribute to reactive oxygen species reaction (ROS) and photothermal antibacterial activity irradiated by NIR after most Ti3C2 nanosheets adhering to target bacteria. In conclusion, the Ti3C2 nanosheets have great potential as an effective antibacterial material without causing drug resistance, relying on intercalating and delaminating by TMAOH.