Heterogeneous photoactive antimicrobial coatings based on a fluoroplastic doped with an octahedral molybdenum cluster compound

Abstract

Despite the wide variety of strategies developed to combat pathogenic microorganisms, the infectious diseases they cause remain a worldwide health issue. Hence, the search for new disinfectants, which prevent infection spread, constitutes an extremely urgent task. One of the most promising methods is the use of photoactive compounds – photosensitizers, capable of generating reactive oxygen species, in particular, singlet oxygen (O₂(¹Δ_g)), which causes rapid and effective death of microorganisms of all types. In this work, we propose the utilization of the powdered cluster complex (Bu₄N)₂[{Mo₆I₈}(OTs)₆] as a photoactive additive to commercially available fluoroplastic lacquer F-32L to create heterogeneous self-sterilizing coatings. We show that soaking of the prepared films in water for 60 days did not lead to a decrease in their photosensitization properties indicating their excellent stability. Moreover, the use of the cluster complex in the solid state allowed significant expansion of the operating wavelength range, which covers the UV region and a large part of the visible region (250–650 nm). The films displayed high photoantimicrobial activity against five common pathogens (bacteria and fungi) under white-light irradiation. Overall, the properties demonstrated make these materials promising for practical use in everyday outdoor and indoor disinfection since they are active under both sunlight and artificial lighting.