Synthesis of TiO 2 -Cu 2+ /CuI Nanocomposites and Evaluation of Antifungal and Cytotoxic Activity.

Fungal infections have become a significant public health concern due to their increasing recurrence and harmful effects on plants, animals, and humans. Opportunistic pathogens ( among others from the genera Candida and Aspergillus ) can be present in indoor air, becoming a risk for people with suppressed immune systems. Engineered nanomaterials are novel alternatives to traditional antifungal therapy. In this work, copper(I) iodide (CuI) and a copper-doped titanium dioxide-copper(I) iodide (TiO 2 -Cu 2+ /CuI) composite nanomaterials (NMs)-were synthesized and tested as antifungal agents. The materials were synthesized using sol-gel (TiO 2 -Cu 2+ ) and co-precipitation (CuI) techniques. The resulting colloids were evaluated as antifungal agents against Candida parapsilosis and Aspergillus niger strains. The NMs were characterized by XRD, HRTEM, AFM, and DLS to evaluate their physicochemical properties. The NMs present a high size dispersion and different geometrical shapes of agglomerates. The antifungal capacity of the NMs by the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) was below 15 µg/mL against Candida parapsilosis and below 600 µg/mL against Aspergillus niger for both NMs. Holotomography microscopy showed that the NMs could penetrate cell membranes causing cell death through its rupture and reactive oxygen species (ROS) production. Cytotoxicity tests showed that NMs could be safe to use at low concentrations. The synthesized nanomaterials could be potential antifungal agents for biomedical or environmental applications.