Characterisation and application of electrodes with hydrogenated titania nanotubes modified with M13 bacteriophages

The sponge-like hydrogenated titania nanotubes (S-TiO₂-NTs) modified with M13 bacteriophages were investigated for bacterial detection. The electrodes used in this study were fabricated via anodisation and calcination in a hydrogen atmosphere. Electrochemical methods were used to study the capacitive and Faradaic currents of the S-TiO₂-NTs electrodes in varying concentrations of M13 phage lysate immobilised through physisorption. Moreover, measurements over time, at 37 °C and in human serum, were performed to evaluate the stability of the phage-modified electrodes. The obtained results demonstrated that the phages were successfully adsorbed on the electrode surface, which was also confirmed by scanning electron microscopy. Furthermore, the S-TiO₂-NTs with wild-type M13 phage were used to detect E. coli bacteria. The limit of detection (LOD) for the electrode was LOD = 3 cells/mL, and the linear range was 10–10⁴ cells/mL. The results demonstrate that S-TiO₂-NTs electrodes are promising immobilisation platforms for M13 phage.