Fabrication of N-hollow carbon nanospheres@Fe7S8 and their ion-release-based antibacterial properties

Bacterial infection is a growing threat to public health worldwide. Ferrous ions have been proved to have good antibacterial properties. However, ferrous ions are easy to be oxidized, which limited its further application. Therefore, the design of nanosystems that can stably release ferrous ions is highly desirable. Here, N-doped hollow carbon nanospheres anchored with Fe 7 S 8 nanosheets (N-HCNs@Fe 7 S 8 ) were synthesized by a hydrothermal method. The particle size, crystal form, and specific surface area of the synthesized composites were characterized. N-HCNs@Fe 7 S 8 can release Fe 2+ ions, which could kill Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) without using light or H 2 O 2 . Fe 2+ concentration increases with the prolonged soak time of N-HCNs@Fe 7 S 8 , and the antibacterial ability is closely related to Fe 2+ concentration. The Fe 2+ released by N-HCNs@Fe 7 S 8 has a promoting effect on the healing of skin wounds infected with S. aureus . The proinflammatory cytokines (TNF-α and IL-6) were effectively reduced in N-HCNs@Fe 7 S 8 -treated wounds, and N-HCNs@Fe 7 S 8 could effectively inhibit inflammation. Therefore, the Fe 2+ release effect of N-HCNs@Fe 7 S 8 and its good biocompatibility make it a candidate material for antibacterial therapy and promoting wound healing. Graphical abstract