Silk fibroin-assisted exfoliation and functionalization of transition metal dichalcogenide nanosheets for antibacterial wound dressings.

Two-dimensional transition metal dichalcogenides (TMDs) have attracted rapidly increasing attention due to their fascinating properties and potential applications. However, scalable and cost-effective methods to produce thin-layer TMD nanosheets and their functional composites with environmental benignity are still limited. Herein, we develop a facile and environmentally friendly method for the scalable production of thin-layer TMD nanosheets in an aqueous medium by using silk fibroin, a natural and abundant biopolymer, as the exfoliating agent. Specifically, carboxyl-modified silk fibroin significantly improves the exfoliation efficiency, achieving the high-yield production of thin-layer MoSe2 nanosheets with good solution stabilization and excellent biocompatibility. Strong binding interactions endow the resultant MoSe2 nanosheets with unprecedentedly high concentrations. By virtue of the solution-processability of silk fibroin, MoSe2 hybrid nanosheets are readily fabricated into macroscopic freestanding films. Furthermore, due to the superior peroxidase-like activity of MoSe2 nanosheets, MoSe2-based films show rapid and effective wound disinfection and healing efficacy with the use of low-dose H2O2in vivo, avoiding the side effects of high-dose H2O2 in traditional medical therapy. This work may offer new opportunities to apply two-dimensional TMD nanosheets for clinical applications.