Inhibition of Fungal Growth Using Modified TiO₂ with Core@Shell Structure of Ag@CuO Clusters

The photocatalytic disinfection (PCD) properties of TiO₂ have attracted attention in the research communities because the produced reactive oxygen species (ROS) allow destruction of different types of microbes, such as fungi, bacteria, viruses, algae, unicellular organisms, etc. on surfaces, in water, and in air. However, TiO₂ requires UV irradiation to produce the ROS, which limits its photoactivity in indoor environments. Surface-modified TiO₂ with small Ag and CuO nanoclusters in a core-shell structure exhibits antifungal properties under dark and visible conditions, possibly because of the interaction between Ag-CuO nanoclusters in the fungi membrane and their penetration, and the co-presence of Cu²⁺ and Ag⁺ ions. Therefore, a synergetic effect is obtained with co-modification of TiO₂ with silver and copper, and the sample Ag@CuO/TiO₂ (core-shell structure of Ag-Cu in a ratio of 1:3) exhibits the highest antifungal activity; that is, fungi growth inhibition is observed for Aspergillus melleus and Penicillium chrysogenum. Moreover, significant inhibitions of the sporulation and generation of droplets, possibly containing mycotoxins and sclerotia under dark and visible exposure, are also obtained.