Enhancing the Antibacterial Performance of Titanium Dioxide Nanofibers by Coating with Silver Nanoparticles

The potential of titanium dioxide (TiO2) nanofibers in antibacterial applications has received wide attention. This interest is further enhanced by the possible incorporation of silver (Ag) to form a double-antibacterial composite agent. In this study, Ag-doped TiO2 (AgTiO2) nanofibers were synthesized with various Ag concentrations using electrospinning and calcination. The obtained fibers were then assessed for its antibacterial performance against a gamut of common Gram-positive and Gram-negative bacteria cells. The results showed a deterioration in the fiber surface area and pore volume at increasing Ag concentration, which is attributed to pore blocking by the Ag nanoparticles. The fiber diameter is also affected by the addition of Ag, with a minimum fiber diameter of 88.9 ± 22.8 nm achieved at 1% Ag loading. The change in the TiO2 fiber crystallinity is relatively minor, with highly crystalline anatase observed for all samples with small differences in the anatase crystallite sizes. In antibacterial tests, AgTiO2 nanofibers are found to have a performance superior to that of intrinsic TiO2 nanofibers because of the synergistic combination of Ag and photocatalytic TiO2. Maximum log reductions of 5.92 ± 0 and 1.38 ± 0.07 colony-forming units for Salmonella Albany and Staphylococcus aureus bacteria samples, respectively, are reported for AgTiO2 nanofibers with 2% Ag loading.