ZnO films grown by pulsed-laser deposition on soda lime glass substrates for the ultraviolet inactivation of Staphylococcus epidermidis biofilms
Open Access
- 1 August 2009
- journal article
- Published by Taylor & Francis Ltd in Science and Technology of Advanced Materials
- Vol. 10 (4), 045003
- https://doi.org/10.1088/1468-6996/10/4/045003
Abstract
We found that a ZnO film of 2 μm thickness which was laser-deposited at room temperature onto a plain soda lime glass substrate, exhibits notable antibacterial activity against a biofilm of Staphylococcus epidermidis when back-illuminated by a UVA light source with a peak emission wavelength of about 365 nm. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-visible absorption spectroscopy, Raman spectroscopy and x-ray photoemission spectroscopy (XPS) were used to characterize the ZnO films before and after the interactions with the biofilm and the ultraviolet light, respectively. The as-deposited film was highly textured with the wurtzite (0002) in-plane orientation (c-axis perpendicular to ZnO surface) and had a surface rms roughness of 49.7 nm. In the as-deposited film, the Zn to O ratio was 1 to 0.95. After the UV and biofilm treatments, the ZnO film surface had become rougher (rms roughness 68.1 nm) and presented uniform micron-sized pitting randomly distributed, while the zinc to oxygen ratio had become 1 to 2.2. In this case, both the UV-visible and Raman spectra pointed to degradation of the structural quality of the material. On the strength of these data, we propose a model for the mediation of the bactericidal activity in which the photogeneration of highly oxidizing species and the presence of active surface defect sites both play an important role. This study is of particular interest for the acute problem of disinfection of pathogenic biofilms which form on medical device/implant surfaces.Keywords
This publication has 56 references indexed in Scilit:
- Effects of Quaternary Ammonium Silane Coatings on Mixed Fungal and Bacterial Biofilms on Tracheoesophageal Shunt ProsthesesApplied and Environmental Microbiology, 2006
- Carcinogenicity of carbon black, titanium dioxide, and talcThe Lancet Oncology, 2006
- A comprehensive review of ZnO materials and devicesJournal of Applied Physics, 2005
- Atomic-scale properties of low-index ZnO surfacesApplied Surface Science, 2004
- Solar photocatalytic disinfection of a group of bacteria and fungi aqueous suspensions with TiO2, ZnO and Sahara desert dustJournal of Photochemistry and Photobiology A: Chemistry, 2004
- Photocatalytic inactivation of Escherichia coli and Lactobacillus helveticus by ZnO and TiO2 activated with ultraviolet lightProcess Biochemistry, 2003
- Measuring the thickness of an outer layer of viable bacteria in an oral biofilm by viability mappingJournal of Microbiological Methods, 2003
- Bactericidal mode of titanium dioxide photocatalysisJournal of Photochemistry and Photobiology A: Chemistry, 2000
- Photocatalytic bactericidal effect of TiO2 thin films: dynamic view of the active oxygen species responsible for the effectJournal of Photochemistry and Photobiology A: Chemistry, 1997
- Photocatalytic production of hydrogen peroxides and organic peroxides in aqueous suspensions of titanium dioxide, zinc oxide, and desert sandEnvironmental Science & Technology, 1988