Self-redox reaction driven in situ formation of Cu2O/Ti3C2Tx nanosheets boost the photocatalytic eradication of multi-drug resistant bacteria from infected wound

MXenes with interesting optical and electrical properties have been attractive in biomedical applications such as antibacterial and anticancer agents, but their low photogeneration efficiency of reactive oxygen species (ROS) and poor stability are major concerns against microbial resistance. Water-dispersible single layer Ti.sub.3C.sub.2T.sub.x-based MXene through etching tightly stacked MAX phase precursor using a minimally intensive layer delamination method. After addition of Cu(II) ions, the adsorbed Cu(II) ions underwent self-redox reactions with the surface oxygenated moieties of MXene, leading to in situ formation of Cu.sub.2O species to yield Cu.sub.2O/Ti.sub.3C.sub.2T.sub.x nanosheets (heterostructures). Under NIR irradiation, the Cu.sub.2O enhanced generation of electron-hole pairs, which boosted the photocatalytic production of superoxide and subsequent transformation into hydrogen peroxide. Broad-spectrum antimicrobial performance of Cu.sub.2O/Ti.sub.3C.sub.2T.sub.x nanosheets with sharp edges is attributed to the direct contact-induced membrane disruption, localized photothermal therapy, and in situ generated cytotoxic free radicals. The minimum inhibitory concentration of Cu.sub.2O/Ti.sub.3C.sub.2T.sub.x nanosheets reduced at least tenfold upon NIR laser irradiation compared to pristine Cu.sub.2O/Ti.sub.3C.sub.2T.sub.x nanosheets. The Cu.sub.2O/Ti.sub.3C.sub.2T.sub.x nanosheets were topically administrated on the methicillin-resistant Staphylococcus aureus (MRSA) infected wounds on diabetic mice. Upon NIR illumination, Cu.sub.2O/Ti.sub.3C.sub.2T.sub.x nanosheets eradicated MRSA and their associated biofilm to promote wound healing. The Cu.sub.2O/Ti.sub.3C.sub.2T.sub.x nanosheets with superior catalytic and photothermal properties have a great scope as an effective antimicrobial modality for the treatment of infected wounds.