Nanocopper-loaded Black Phosphorus Nanocomposites for Efficient Synergistic Antibacterial Application

Abstract Novel nanocopper-loaded black phosphorus (BP/Cu) nanocomposites were synthesized to synergistically exert enhanced antibacterial activities aimed at reducing antibiotics abuse. First, both BP and Cu display low biotoxicity, broadening their application in the microbiological field. Second, the unique electronic properties of BP enable BP/Cu nanocomposites to amplify antibacterial effects via interfacial charge transfer, resulting in a surge of reactive oxygen species (ROS). Third, BP/Cu nanocomposites are relatively stable, which helps to avoid the problem that nanocopper alone is highly oxidized. Finally, BP/Cu was synthesized in an environmentally-friendly manner by a one-step reduction method. The BP/Cu nanocomposites were characterized by transmission electron microscopy and atomic force microscopy. Their antibacterial properties were investigated comprehensively and discussed in detail by inhibition zone assays, dynamic growth curves, membrane potential assays, and live/dead baclight bacterial viability assays, all of which revealed the antimicrobial activities of BP/Cu nanocomposites. Absorption spectra were measured to determine which ROS species were responsible for the bactericidal mechanisms. In summary, our results demonstrated the potential of nanocomposites based on BP in antibacterial therapy due to its excellent electronic properties and outstanding biological performance. This will pave the way for avoiding antibiotic overuse and for providing security to humans and the environment.