Photo-responsive chitosan/Ag/MoS2 for rapid bacteria-killing

Bacterial infection is a serious problem threatening human health. The chitosan (CS)-modified MoS2 coating loaded with silver nanoparticles (Ag NPs) was designed on the surface of titanium (Ti) to kill bacteria rapidly and efficiently under 660 nm visible light. Ag/MoS2 exhibited high photocatalytic activity due to the rapid transfer of photo-inspired electrons from MoS2 to Ag NPs, resulting in higher yields of radical oxygen species (ROS) to kill bacteria. The covering of CS made the composite coating positively charged to further enhance the antibacterial property of the coating. In addition, CS/Ag/MoS2-Ti also showed a certain photothermal effect. in vitro results showed that the antibacterial efficiency of the coating on Staphylococcus aureus and Escherichia coli was 98.66% and 99.77% respectively, when the coating was irradiated by 660 nm visible light for 20 min. Cell culture tests showed that CS/Ag/MoS2-Ti had no adverse effects on cell growth. Hence, this surface system will be a very promising strategy for eliminating bacterial infection on biomedical device and implants safely and effectively within a short time.