Antibacterial Activity of ZnSe, ZnSe-TiO(2) and TiO(2) Particles Tailored by Lysozyme Loading and Visible Light Irradiation

ZnSe, ZnSe-TiO(2) microspheres and nanostructured TiO(2) obtained by hydrothermal and sol–gel methods were tested against Staphylococcus aureus ATCC 25923 and Micrococcus lysodeikticus ATCC 4698 before and after lysozyme (Lys) loading. Morphological characterization of inorganic matrices and hybrid organic–inorganic complexes were performed by microscopy techniques (SEM, AFM and Dark Field Hyperspectral Microscopy). Light absorption properties of ZnSe, ZnSe-TiO(2) and TiO(2) powders were assessed by UV–visible spectroscopy and their ability to generate reactive oxygen species (•OH and O(2)(•−)) under visible light irradiation was investigated. Antibacterial activity of ZnSe, ZnSe-TiO(2), TiO(2), Lys/ZnSe, Lys/ZnSe-TiO(2) and Lys/TiO(2) samples under exposure to visible light irradiation (λ > 420 nm) was tested against Staphylococcus aureus and Micrococcus lysodeikticus and correlated with ROS photogeneration.