Nonenzymatic electrochemical glucose sensor based on MnO2/MWNTs nanocomposite

In this communication, an amperometric glucose biosensor based on MnO2/MWNTs electrode was reported. MnO2 was homogeneously coated on vertically aligned MWNTs by electrodeposition. The MnO2/MWNTs electrode displayed high electrocatalytic activity towards the oxidation of glucose in alkaline solution, showing about 0.30 V negative shift in peak potential with oxidation starting at ca. -0.20 V (vs. 3 M KCl-Ag/AgCl) as compared with bare MWNTs electrode. At an applied potential of +0.30 V, the MnO2/MWNTs electrode gives a linear dependence (R = 0.995) in the glucose concentration up to 28 mM with a sensitivity of 33.19 mu A mM(-1). Meanwhile, the MnO2/MWNTs electrode is also highly resistant toward poisoning by chloride ions. In addition, interference from the oxidation of common interfering species such as ascorbic acid, dopamine, and uric acid is effectively avoided. The MnO2/MWNTs electrode allows highly sensitive, low-potential, stable, and fast amperometric sensing of glucose, which is promising for the development of nonenzymatic glucose sensor. (C) 2008 Elsevier B.V. All rights reserved.