Milionis Athanasios, Tripathy Abinash, Donati Matteo, Sharma Chander Shekhar, Pan Fei, Maniura-Weber Katharina, Ren Qun, Poulikakos Dimos
Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zürich, 8092 Zürich, Switzerland.
Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014 St. Gallen, Switzerland.
Ind Eng Chem Res. 2020 Aug 12;59(32):14323-14333. doi: 10.1021/acs.iecr.0c01998. Epub 2020 Jul 7.
Bacterial colonization poses significant health risks, such as infestation of surfaces in biomedical applications and clean water unavailability. If maintaining the surrounding water clean is a target, developing surfaces with strong bactericidal action, which is facilitated by bacterial access to the surface and mixing, can be a solution. On the other hand, if sustenance of a surface free of bacteria is the goal, developing surfaces with ultralow bacterial adhesion often suffices. Here we report a facile, scalable, and environmentally benign strategy that delivers customized surfaces for these challenges. For bactericidal action, nanostructures of inherently antibacterial ZnO, through simple immersion of zinc in hot water, are fabricated. The resulting nanostructured surface exhibits extreme bactericidal effectiveness (9250 cells cm h) that eliminates bacteria in direct contact and also remotely through the action of reactive oxygen species. Remarkably, the remote bactericidal action is achieved without the need for any illumination, otherwise required in conventional approaches. As a result, ZnO nanostructures yield outstanding water disinfection of >99.98%, in the dark, by inactivating the bacteria within 3 h. Moreover, Zn released to the aqueous medium from the nanostructured ZnO surface have a concentration of 0.73 ± 0.15 ppm, markedly below the legal limit for safe drinking water (5-6 ppm). The same nanostructures, when hydrophobized (through a water-based or fluorine-free spray process), exhibit strong bacterial repulsion, thus substantially reducing bacterial adhesion. Such environmentally benign and scalable methods showcase pathways toward inhibiting surface bacterial colonization.
细菌定植带来了重大的健康风险，例如生物医学应用中表面的污染以及清洁水的短缺。如果将保持周围水体清洁作为目标，开发具有强大杀菌作用的表面可能是一种解决方案，这种表面杀菌作用可通过细菌与表面的接触和混合来实现。另一方面，如果目标是维持表面无细菌，那么开发具有超低细菌附着力的表面通常就足够了。在此，我们报告了一种简便、可扩展且对环境无害的策略，可为这些挑战提供定制化表面。对于杀菌作用，通过将锌简单浸入热水中，制备出具有固有抗菌性能的氧化锌纳米结构。所得的纳米结构表面展现出极高的杀菌效率（9250个细胞/平方厘米·小时），能直接消除接触表面的细菌，还能通过活性氧的作用远程杀菌。值得注意的是，这种远程杀菌作用无需传统方法中所需的任何光照即可实现。因此，氧化锌纳米结构在黑暗环境下3小时内就能使细菌失活，实现超过99.98%的出色水消毒效果。此外，从纳米结构的氧化锌表面释放到水介质中的锌浓度为0.73±0.15 ppm，明显低于安全饮用水的法定限值（5 - 6 ppm）。同样的纳米结构，经疏水化处理（通过水基或无氟喷涂工艺）后，表现出强烈的细菌排斥性，从而大幅降低细菌附着力。这种对环境无害且可扩展的方法展示了抑制表面细菌定植的途径。
