A novel self-cleaning, non-enzymatic glucose sensor working under a very low applied potential based on a Pt nanoparticle-decorated TiO sub(2) nanotube array electrode

In this paper, a non-enzymatic amperometnc glucose sensor working under a very low applied potential of -0.5 V (vs. saturated calomel electrode or SCE) was developed based on a Pt nanoparticle-decorated TiO sub(2) nanotube array (Pt/TiO sub(2) NTA) electrode. A highly ordered TiO sub(2) NTA with a diameter of 200 nm was fabricated by anodization of Ti in ethylene glycol containing 0.5 wt% NH sub(4)F, 10 vol% H sub(2)O, and 0.9 vol% H sub(2)SO sub(4). Pt nanoparticles ~5 nm in diameter were uniformly decorated inside the TiO sub(2) nanotubes through ion-exchange reaction with Pt (NH sub(3)) sub(4)Cl sub(2), followed by reduction with NaBH sub(4). The morphology of the electrode was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The performance of the as-prepared electrode was characterized by cyclic voltammetry and chronoamperometry. The sensor can accurately detect glucose in 0.1 M NaOH solution at an applied potential of -0 5 V (vs. SCE) in the presence of interferences, such as ascorbic acid and uric acid, with a linear range of 1-15 mM and a detection limit of 0.2 mM at a signal-to-noise ratio of 3. The Pt/TiO sub(2) synergistic effect shows a good self-cleaning ability. The electrocatalytic ability of the present Pt/TiO sub(2) NTA electrode toward glucose oxidation under a very low applied potential has promising applications in blood glucose measurement and mediator-free anodes for glucose biofuel cells