Vacancy-Induced Antibacterial Activity of XS2-yQuantum Dots against Drug-Resistant Bacteria for Treatment of Bacterial Keratitis

Due to the widespread antibiotic-resistant microbes and the slow development in antibiotics, innovative new antibacterial agents are eagerly desired to control infection in the resistance era. Here, it is demonstrated that the antibacterial ability against drug-resistant bacteria can be endowed to transition metal dichalcogenides (XS2, X = Mo/W) quantum dots by sulfur vacancies, and their application in bacterial keratitis. The sulfur vacancies are generated by the ion irradiation with the controlled influences, which ensures the one-way electron transport from the external environment to XS(2)leading to a strong reactive oxygen speciesindependent oxidative stress. With the concentration of 140 mu g mL(-1)of XS(2-0.1)quantum dots, the sterilization efficiency of Gram-positiveStaphylococcus aureusand methicillin-resistantStaphylococcus aureusmore than 99.9% within 20 min at room temperature in the dark is realized. For biomedical application against bacterial keratitis, it is observed that the occurrence of severe clinical manifestation like ocular perforation can be prevented. This work demonstrates the vacancy as a novel, simple, and effective strategy to tune XS(2)as the antibacterial agent with a fast response and no reliance on light that has significant potential therapeutic effects on clinical drug resistant bacterial keratitis.