Manganese dioxide (MnO2) nanosheets have shown exciting potential in nanomedicine because of their ultrathin thickness, large surface area, high near-infrared (NIR) absorbance and good biocompatibility. However, the effect of MnO2 nanosheets on bacteria is still unclear. In this study, MnO2 nanosheets were shown for the first time to possess highly efficient antibacterial activity by using Salmonella as a model pathogen. The growth curve and surface plate assay uncovered that 125 μg/mL MnO2 nanosheets could kill 99.2% of Salmonella, which was further verified by fluorescence-based live/dead staining measurement. Mechanism analysis indicated that MnO2 nanosheet treatment could dramatically induce reactive oxygen species production, increase ATPase activity and cause the leakage of electrolytes and protein contents, leading to bacterial death. These results uncover the previously undefined role of MnO2 nanosheets and provide novel strategies for developing antimicrobial agents.

中文翻译：

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ROS介导的途径和破坏膜完整性对二氧化锰纳米片的抗菌活性

二氧化锰（MnO2）纳米片具有超薄的厚度，较大的表面积，高的近红外（NIR）吸收率和良好的生物相容性，在纳米医学中显示出令人兴奋的潜力。但是，MnO2纳米片对细菌的作用仍不清楚。在这项研究中，通过使用沙门氏菌作为模型病原体，首次证明MnO2纳米片具有高效的抗菌活性。生长曲线和表面平板检测发现125μg/ mL MnO2纳米片可杀死99.2％的沙门氏菌，这已通过基于荧光的活/死染色测量进一步证实。机理分析表明，MnO2纳米片处理可显着诱导活性氧的产生，增加ATPase活性并引起电解质和蛋白质含量的泄漏，从而导致细菌死亡。