THE STUDY OF ANTIBACTERIAL ACTIVITY OF NANOSTRUCTURED TiO₂ THIN FILMS
M. ENACHE, C. VĂCĂROIU, G. POPESCU, L. DUMITRU, A. BREZEANU, M. GARTNER, M. ANASTASESCU

Abstract. This paper deals with investigation of antibacterial activity of TiO₂ thin films with various concentration of PEG (0.01–0.1M) and iron (1.23 and 7%) in their composition or doped with nitrogen and followed by thermal treatment at different temperatures (500–1000°C). The results revealed that investigated thin films have antibacterial activity which is influenced by coatings compositions and temperature of thermal treatment. The optimum concentration of iron and PEG enhanced antibacterial activity and induced some change for the surface structure which became congruent with this antibacterial activity. The photocatalytic reaction is higher at low iron content. The investigated nanostructures doped with nitrogen and thermal treated at 600°C have a better antibacterial activity that structures treated at 500°C. On the other hand, this activity has been influenced by illumination time with white artificial light. The electron microscopy investigations revealed that main effect towards microbial cell are at the level of cell membrane and could be associated with cell degradation, minivesicles formation, strong plasmolize and intracellular vacuoles, cellular ghost and membrane fragments.