Antifungal potential of SiO₂/TiO₂ composites and their effect on the germination of tomato seed

Nanoparticles (NPs) of silicon dioxide (SiO₂) and titanium dioxide (TiO₂) are two of the most used nanomaterials in agricultural technology. However, the biological activities of these materials in seed germination and phytopathogen control have been poorly studied. In this work, SiO₂-TiO₂ (Si-Ti) nanocomposites were synthesized using the sol-gel method and were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDS), N₂ physisorption, scanning electron microscopy (SEM), Raman, UV-Vis, and Fourier-transform infrared (FT-IR) spectroscopies. In addition, the effect of the nanocomposites on the germination of tomato seeds, the mycelial growth of Botrytis cinerea, the red blood cell lysis and the cell viability of the human fibroblast cell line Detroit 548 was evaluated. The results show that the Si-Ti nanocomposites reduced the percentage of tomato seed germination in a dose-dependent manner. The antifungal activity analysis shows that the nanocomposites reduced the diameter and area of the Botrytis cinerea colony and presented an inhibition percentage of radial growth between 20% and 32% depending on the used quantity and Si and Ti proportions in the composites. The hemolytic activity and cell viability analysis showed that the nanocomposites displayed hemolytic activity depending on the concentration. These materials are biocompatible and could be an alternative to synthetic nano-pesticides.