Exploring the Antibacteria Performance of Multicolor Ag, Au, and Cu Nanoclusters

Integrating kinds of bactericides as one entirety shows prospect for improving antibacterial efficiency, thus a new type of nanoclusters based on bactericide-directed herein emerged as a combination for achieving a higher antibacterial effect. Specifically, an easily operated approach for preparing bacitracin-directed silver, gold, and copper nanoclusters (AgNCs, AuNCs, and CuNCs, respectively) was proposed. Meanwhile, AgNCs@Bacitracin, AuNCs@Bacitracin, and CuNCs@Bacitracin emitted cyan, yellow, and red colors of fluorescence, respectively, and different sizes and nitrogen contents of these nanoclusters played a critical role for their fluorescence alterations. Significantly, AgNCs@Bacitracin exhibited robust bacteria-killing efficiency than other nanoclusters, owing to its marked damage on the bacterial membrane. Additionally, propidium iodide (PI) staining indicated the bacterial membrane damage of 72.3% to the bacteria population followed by the treatment with AgNCs@Bacitracin, and the introduction of AgNCs@Bacitracin lead to the higher reactive oxygen species (ROS) production, facilitating their attractive antibacterial activity. Moreover, this strategy of developing new nanoclusters broadened the avenues for designing the improved antibacterial materials.