Direct electrochemistry of glucose oxidase immobilized on TiO2–graphene/nickel oxide nanocomposite film and its application

A novel electrochemical platform based on nickel oxide (NiO) nanoparticles and TiO2–graphene (TiO2–Gr) was developed for the direct electrochemistry of glucose oxidase (GOD). The electrochemical behavior of the sensor was studied using cyclic voltammetry and chronoamperometry. The experimental results demonstrated that the nanocomposite well retained the activity of GOD and the modified electrode GOD/NiO/TiO2–Gr/GCE exhibited excellent electrocatalytic activity toward the redox of GOD as evidenced by the significant enhancement of redox peak currents in comparison with bare GCE. The biosensor responded linearly to glucose in the range of 1.0–12.0 mM, with a sensitivity of 4.129 μA mM−1 and a detection limit of 1.2 × 10−6 M under optimized conditions. The response time of the biosensor was 3 s. In addition, the developed biosensor possessed good reproducibility and stability, and there was negligible interference from other electroactive components.