EPFL-SB-ISIC-GPAO, Ecole Polytechnique Fédérale de Lausanne Station 6, CH-1015, Lausanne, Switzerland.
ACS Appl Mater Interfaces. 2012 Oct 24;4(10):5234-40. doi: 10.1021/am301153j. Epub 2012 Sep 28.
The bacterial inactivation of E. coli by cotton TiO(2)/Cu DC-magnetron sputtered thin films was investigated in the dark and under low-intensity actinic light. The TiO(2)/Cu sputtered layers revealed to be sensitive to actinic light showing the spectral characteristics of Cu/CuO. This indicates that Cu does not substitute Ti(4+) in the crystal lattice. Under diffuse actinic light (4 mW/cm(2)), the hybrid composite TiO(2)/Cu sample lead to fast bacterial inactivation times <5 min. This study presents evidence for a direct relation between the film optical absorption obtained by diffuse reflectance spectroscopy (DRS) and the bacterial inactivation kinetics by the TiO(2)/Cu samples. The Cu-ions inactivating the bacteria were followed in solution by inductively plasma coupled spectroscopy (ICPS). The amounts of Cu-ions detected by ICPS provide the evidence for an oligodynamic antibacterial effect. The changes in the oxidation state of Cu during bacterial inactivation were followed by XPS. The E. coli cell viability was detected by standard coliform counting CFU methods. The TiO(2)/Cu thickness layer was determined by profilometry and the film microstructure by XPS, TEM, AFM, XRD, XRF and contact angle (CA). A mechanism of bacterial inactivation by TiO(2)/Cu samples is suggested in terms of interfacial charge transfer (IFCT) involving charge transfer between TiO(2) and Cu.
黑暗中和低强度感光光线下，棉 TiO(2)/Cu 直流磁控溅射薄膜对大肠杆菌的细菌失活作用进行了研究。溅射层 TiO(2)/Cu 对感光光敏感，显示出 Cu/CuO 的光谱特征。这表明 Cu 没有替代晶格中的 Ti(4+)。在漫射感光光（4 mW/cm(2)）下，混合复合 TiO(2)/Cu 样品导致快速细菌失活时间<5 分钟。本研究提供了证据，证明薄膜光吸收与 TiO(2)/Cu 样品的细菌失活动力学之间存在直接关系。通过电感耦合等离子体光谱法（ICPS）在溶液中跟踪 Cu-离子失活细菌。ICPS 检测到的 Cu-离子数量提供了具有杀生性的抗菌效果的证据。通过 XPS 跟踪细菌失活过程中 Cu 的氧化态变化。通过标准大肠菌群计数 CFU 方法检测大肠杆菌细胞活力。通过轮廓仪确定 TiO(2)/Cu 厚度层，并通过 XPS、TEM、AFM、XRD、XRF 和接触角（CA）确定薄膜微观结构。提出了一种基于界面电荷转移（IFCT）的 TiO(2)/Cu 样品细菌失活机制，涉及 TiO(2)和 Cu 之间的电荷转移。
