Abstract In an attempt to advance GO-based environmental applications, herein we probed the anti-biofouling properties and mechanisms of graphene oxide (GO) surface coating. A flexible and mechanically stable GO membrane was fabricated using vacuum filtration technique and its ability to inactivate bacterial growth and subsequent biofilm formation was investigated. Our preliminary results authenticate that the GO membrane, owing to its unique physicochemical surface properties, exhibits superior antibacterial activity against planktonic cell proliferation. An optical coherence tomography (OCT)-based nondestructive in situ monitoring of bacterial biofilm evolution and behavior revealed that the GO surface initially inhibited biofilm growth for 24 h under continuous flow conditions but was incapable of completely averting biofilm development under long-term operation (48 h). We further confirmed that the observed biofilm on the GO membrane was highly unstable and reversibly attached and could be conveniently removed from the surface under a gentle rinsing. Finally, we confirmed that upon direct bacterium-GO contact, GO simultaneously induces cellular membrane disruption and oxidative stress followed by degradation/release of intracellular organelles, thereby causing bacterial inactivation or cell death. We believe our findings will offer new understandings into the anti-biofouling properties of GO-coated membranes and highlight their potential for practical application in membrane-based water and wastewater treatment technologies.

中文翻译：

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使用光学相干断层扫描技术对氧化石墨烯膜上的细菌灭活和生物膜发育进行原位监测

摘要 为了推进基于 GO 的环境应用，我们探索了氧化石墨烯 (GO) 表面涂层的抗生物污垢特性和机制。使用真空过滤技术制造了柔性且机械稳定的 GO 膜，并研究了其灭活细菌生长和随后的生物膜形成的能力。我们的初步结果证实，GO 膜由于其独特的物理化学表面特性，对浮游细胞增殖表现出优异的抗菌活性。基于光学相干断层扫描 (OCT) 的细菌生物膜演化和行为的非破坏性原位监测表明，GO 表面最初在连续流动条件下抑制生物膜生长 24 小时，但在长期操作下无法完全避免生物膜的发展（48 H）。我们进一步证实，GO 膜上观察到的生物膜高度不稳定且可逆地附着，并且可以在温和冲洗下方便地从表面去除。最后，我们证实，在细菌-GO 直接接触时，GO 同时诱导细胞膜破裂和氧化应激，随后细胞内细胞器降解/释放，从而导致细菌失活或细胞死亡。