Photogenerated reactive oxygen species and hyperthermia by Cu3SnS4 nanoflakes for advanced photocatalytic and photothermal antibacterial therapy

Abstract Background The rapid spread of infectious bacteria has brought great challenges to public health. It is imperative to explore effective and environment-friendly antibacterial modality to defeat antibiotic-resistant bacteria with high biosafety and broad-spectrum antibacterial property. Results Herein, biocompatible Cu 3 SnS 4 nanoflakes (NFs) were prepared by a facile and low-cost fabrication procedure. These Cu 3 SnS 4 NFs could be activated by visible light, leading to visible light-mediated photocatalytic generation of a myriad of reactive oxygen species (ROS). Besides, the plasmonic Cu 3 SnS 4 NFs exhibit strong near infrared (NIR) absorption and a high photothermal conversion efficiency of 55.7%. The ROS mediated cellular oxidative damage and the NIR mediated photothermal disruption of bacterial membranes collaboratively contributed to the advanced antibacterial therapy, which has been validated by the efficient eradication of both Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus strains in vitro and in vivo. Meanwhile, the exogenous copper ions metabolism from the Cu 3 SnS 4 NFs facilitated the endothelial cell angiogenesis and collagen deposition, thus expediting the wound healing. Importantly, the inherent localized surface plasmon resonance effect of Cu 3 SnS 4 NFs empowered them as an active substrate for surface-enhanced Raman scattering (SERS) imaging and SERS-labeled bacteria detection. Conclusions The low cost and biocompatibility together with the solar-driven broad-spectrum photocatalytic/photothermal antibacterial property of Cu 3 SnS 4 NFs make them a candidate for sensitive bacteria detection and effective antibacterial treatment. Graphical Abstract