Highly ordered platinum-nanotubule arrays for amperometric glucose sensing

Direct glucose sensing on highly ordered platinum-nanotubule array electrodes (NTAEs) is systematically investigated. The NTAEs are fabricated by electrochemical deposition of platinum in a 3-aminopropyltrimetlioxysilane-modified anodic alumina membrane. Their structures and morphologies are then characterized using X-ray diffraction and scanning electron microscopy, respectively. Electrochemical results show that NTAEs with different real surface areas could be achieved by controlling the deposition time or by using anodic alumina membranes with different pore size. Electrochemical responses of the as-synthesized NTAEs to glucose in a solutions of either 0.5 M H2SO4, or phosphate-buffered saline (PBS, pH 7.4) containing 0.1 M KCl are discussed. Based on the different electrochemical reaction mechanisms of glucose and interferents such asp-acetamedophenol and ascorbic acid, their high roughness factor makes NTAEs sensitive, selective, and stable enough to be a kind of biosensor for the non-enzymatic detection of glucose. Such a glucose sensor allows the determination of glucose in the linear range 2-14 mM, with a sensitivity of 0.1 mu A cm(-2) mM(-1) (correlation coefficient 0.999), and a detection limit of 1.0 mu M glucose, with neglectable interference from physiological levels of 0.1 mM p-acetamedophenol, 0.1 mM ascorbic acid, and 0.02 mM uric acid.