Near-infrared triggered antibacterial nanocomposite membrane containing upconversion nanoparticles.

Many conventional bactericidal materials exhibit antibacterial activities by releasing biocides, which potentially trigger antibiotic resistance and cause environmental concerns. In the present work, we reported the development of antibacterial nanocomposite membrane containing upconversion nanoparticles (UCNPs) by electrospinning. The nanocomposite membrane itself was not bactericidal but exhibits strongly antimicrobial performance on demand as activated by near-infrared (NIR) light. Upon just 5 min of NIR irradiation, the UCNPs in the nanocomposite membrane could trigger the release of reactive oxygen species (ROS) from photosensitizers, which could kill both Gram-positive Staphylococcus aureus (94.5%) and Gram-negative Escherichia coli (93.2%) rapidly. Moreover, the bactericidal activity could be effectively maintained for at least four cycles. In addition, the nanocomposite membrane showed no adverse effects on the mammalian cells, as verified by a cytotoxicity assay. This work provided a new strategy in designing novel antibacterial materials that might be potentially applied in infection-resistant and wound healing.