Photodynamic chitosan functionalized MoS2 nanocomposite with enhanced and broad-spectrum antibacterial activity.

Bacterial infection accompanied by antibiotic resistance leads to the lack of effective antibacterial agents, which has become an imminent problem afflicting people. Therefore, development of highly effective and broad-spectrum disinfecting alternatives to tackle this challenge is of great necessity. In view of the different cell wall structures of bacteria, we designed photodynamic antibacterial system based on chlorin e6 (Ce6) loaded chitosan functionalized molybdenum sulfide (MoS2) nanocomposites (M-CS-Ce6). The nanocomposite can not only allow Ce6 to enter the cells of Gram-positive bacteria, but also destroy the cell wall permeability of Gram-negative bacteria and enhance the photo-antibacterial effect. 10 μg/mL of M-CS-Ce6 irradiated by 660 nm laser for 5 min, completely killed the target pathogens, exhibiting significantly enhanced photo-antibacterial performance against both Gram-positive and Gram-negative bacteria. Compared with other cationic photodynamic composites, M-CS-Ce6 had stronger and broad-spectrum photo-antibacterial effect. Taken together, M-CS-Ce6 could be a promising and safe broad-spectrum antibacterial agent.