Vertically Aligned TiO₂ Nanotube Arrays Decorated with CuO Mesoclusters for the Nonenzymatic Sensing of Glucose.

Highly ordered titanium dioxide (TiO₂) nanotubes were modified with CuO mesoclusters through electrodeposition followed by electrooxidation. Field Emission Scanning Electron Microscopy (FESEM) revealed the presence of vertically aligned TiO₂ nanotubes with a diameter of 60 nm and CuO mesoclusters of ~500 nm in diameter. Glucose oxidation on the CuO modified TiO₂ electrode occurred at +0.55 V. The electrode exhibited a sensitivity of 1836 and 1416 μA mmol⁻¹ L cm−2 for glucose concentrations ranging from 0.625 to 6.25 mmol L⁻¹ and 6.87 to 12.5 mmol L⁻¹ respectively, a limit of detection of 3.4 μmol L⁻¹ (S/N = 3) and a rapid response time of ≤2 s. Physiological concentrations of ascorbic acid, uric acid and dopamine had no effect on the glucose oxidation. Interference from other sugars (lactose and galactose) was negligible. Result obtained from the estimation of blood glucose was found to be in good agreement with those obtained from commercially available glucose sensor strips.