Photocatalytic Inactivation of Co-Culture of E. coli and S. epidermidis Using APTES-Modified TiO₂

The presented work shows the antibacterial activity of TiO₂ photocatalysts modified by 3-aminopropyltriethoxysilane (APTES). The APTES-functionalized TiO₂ samples were obtained by the solvothermal process followed by calcination. The antibacterial activity of APTES/TiO₂ samples was evaluated with two species of bacteria, Escherichia coli and Staphylococcus epidermidis, under artificial solar light (ASL) irradiation. The used bacteria are model organisms characterized by negative zeta potential (approx. -44.2 mV for E. coli and -42.3 mV for S. epidermidis). For the first time, the antibacterial properties of APTES-functionalized TiO₂ were evaluated against mono- and co-cultured bacteria. The high antibacterial properties characterized the obtained APTES-modified nanomaterials. The best antibacterial properties were presented in the TiO₂-4 h-120 °C-300 mM-Ar-300 °C sample (modified with 300 mM of APTES and calcined at 300 °C). The improvement of the antibacterial properties was attributed to a positive value of zeta potential, high surface area, and porous volume.