Nanoscale photocatalysts have attracted abundant research attention in the solar-activated disinfection. In this work, we find that solar irradiation significantly improves the antimicrobial activity of graphene quantum dots (GQDs), accompanied by severe oxidative stress and membrane damage. By using electron spin resonance (ESR) technique, we confirm that different reactive oxygen species (ROS), including singlet oxygen (1O2), hydroxyl radical (•OH), and superoxide anion (O2•-) were generated by GQDs upon irradiation with simulated sunlight. Additionally, these generated ROS will further facilitate lipid peroxidation of cell membrane and suppress bacterial antioxidant systems, enhancing the phototoxicity of GQDs. These findings will bring major advancements of GQDs in applications of solar-driven bacterial disinfection.

中文翻译：

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太阳激发的石墨烯量子点可通过产生活性氧来使细菌失活。

纳米级光催化剂在太阳能消毒中引起了广泛的研究关注。在这项工作中，我们发现太阳辐射显着提高了石墨烯量子点（GQDs）的抗菌活性，并伴有严重的氧化应激和膜损伤。通过使用电子自旋共振（ESR）技术，我们确认了GQD照射后会产生不同的活性氧（ROS），包括单线态氧（1O2），羟基自由基（•OH）和超氧阴离子（O2•-）。模拟阳光。另外，这些产生的ROS将进一步促进细胞膜的脂质过氧化并抑制细菌抗氧化剂系统，从而增强GQD的光毒性。这些发现将为太阳能驱动的细菌消毒应用带来GQD的重大进步。