Hierarchically structured one-dimensional TiO₂ for protein immobilization, direct electrochemistry, and mediator-free glucose sensing

A novel one-dimensional hierarchically structured TiO₂ (1DHS TiO₂) was synthesized by a solvothermal method using multiwalled carbon nanotubes (MWCNTs) as a template and evaluated for the immobilization of protein and biosensing applications. Characterization studies showed that the 1DHS TiO₂ possessed an anatase crystalline structure and a large surface area with narrow pore size distribution. Fast direct electron transfer was observed for glucose oxidase (GOx) immobilized on the 1DHS TiO₂, and excellent electrocatalytic performance for glucose detection can be obtained without a mediator. The glucose sensor based on the GOx/1DHS TiO ₂-modified electrode had a high sensitivity of 9.90 μA mM ^-1 cm^-2 and a low detection limit of 1.29 μM. The fabricated biosensor displayed good selectivity and long-term stability, indicating that the novel structured TiO₂ is a promising material for the immobilization of biomolecules and the fabrication of third-generation biosensors.