Abstract Sodium chloride (NaCl) is commonly found in physiological buffers. This study found out its additional but important role in antibacterial efficiency test by better corroding metallic copper surface. Combined with multiple characterisation methods including scanning electron microscopy, grazing incidence X-ray diffractometry, and inductively coupled plasma mass spectrometry, 0.9% saline was observed to cause localised corrosion attacks on copper surface, enhancing release of copper content. The 1 h killing rate against Escherichia coli was thus promoted from 22% (when re-suspended in pure water) to 98%. By a long-term observation (3-week), residual NaCl crystals on 0.9% saline treated copper surface were found partially disappeared in atmospheric environment, contributing to an additional Cu2O layer forming above the treated surface. Besides, formation of oxygen-containing species was observed on fresh copper surface exposed by focused ion beam after saline treatment, suggesting a chloride-assisted atmospheric corrosion process.

中文翻译：

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氯化钠有助于铜释放，提高抗菌效率，并在铜表面引入大气腐蚀

摘要 氯化钠 (NaCl) 常见于生理缓冲液中。本研究通过更好地腐蚀金属铜表面，发现了其在抗菌效率测试中的额外但重要的作用。结合扫描电子显微镜、掠入射X射线衍射、电感耦合等离子体质谱等多种表征方法，观察到0.9%盐水对铜表面造成局部腐蚀，促进铜含量的释放。因此，对大肠杆菌的 1 小时杀灭率从 22%（重新悬浮在纯水中时）提高到 98%。通过长期观察（3 周），发现在 0.9% 盐水处理过的铜表面上残留的 NaCl 晶体在大气环境中部分消失，有助于在处理过的表面上方形成额外的 Cu2O 层。