title: Investigations on bactericidal properties of molybdenum-tungsten oxides combinatorial thin film material libraries.
abstract: A combinatorial thin film material library from the molybdenum-tungsten refractory metals oxides system was prepared by thermal coevaporation, and its structural and morphological properties were investigated after a multiple step heat treatment. A mixture of crystalline and amorphous oxides and suboxides was obtained, as well as surface structuring caused by the enrichment of molybdenum oxides in large grains. It was found that the oxide phases and the surface morphology change as a function of the compositional gradient. Tests of the library antimicrobial activity against E. coli were performed and the antimicrobial activity was proven in some defined compositional ranges. A mechanism for explaining the observed activity is proposed, involving a collective contribution from (i) increased local acidity due to the enrichment in large grains of molybdenum oxides with different stoichiometry and (ii) the release of free radicals from the W18O49 phase under visible light.
authors.affiliation: Christian Doppler Laboratory for Combinatorial Oxide Chemistry at the ‡Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz , Altenberger Strasse 69, 4040 Linz, Austria.
authors.forename: Cezarina Cela
authors.initials: CC
authors.lastname: Mardare
authors.forename: Achim Walter
authors.initials: AW
authors.lastname: Hassel
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D020650:Combinatorial Chemistry Techniques; D004926:Escherichia coli / Q000187:drug effects*; D004927:Escherichia coli Infections / Q000517:prevention & control; D006801:Humans; D008982:Molybdenum / Q000737:chemistry* / Q000494:pharmacology*; D010087:Oxides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D013499:Surface Properties; D014414:Tungsten / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D010087:Oxides; D008982:Molybdenum; C511604:tungsten oxide; D014414:Tungsten
keywords: antibacterial properties; combinatorial thin film material library; molybdenum−tungsten oxides; surface structuring