Nonenzymatic glucose detection using multi-walled carbon nanotube electrodes

The electrocatalytic oxidation of glucose in alkaline medium directly at well-aligned multi-wall carbon nanotubes (MWNTs) electrodes has been investigated in the present study. Compared to glassy carbon electrode, a substantial (+400 mV) decrease in the overvoltage of the glucose oxidation reaction was observed at MWNTs electrodes with oxidation starting at ca. +0.10 V (vs. 3 M KCl-Ag\AgCl). The electrocatalytic effect is mainly attributed to carbon nanotubes with possible minor contributions from the Co catalysts present on the Ta substrate. At an applied potential of +0.20 V, MWNTs electrodes give a high and reproducible sensitivity of 4.36 muA cm(-2) mM(-1) in the presence of high concentration of chloride ion. The well-aligned MWNTs electrode thus allows highly sensitive, low-potential, stable, and fast amperometric sensing of glucose, promising for the development of nonenzymatic glucose sensors. (C) 2003 Elsevier B.V. All rights reserved.