Low potential detection of nicotine at multiwalled carbon nanotube-alumina-coated silica nanocomposite

Electrocatalytic oxidation of nicotine at multiwalled carbon nanotube (MWCNT)-alumina-coated silica (ACS) nanocomposite modified glassy carbon electrode are described. The sensing performance of the MWCNT-ACS nanocomposite modified glassy carbon electrode for the electrooxidation of nicotine was investigated using cyclic voltammetry and amperometry in 0.1 M phosphate buffer solution (pH 8). The MWCNT-ACS nanocomposite modified glassy carbon electrode exhibited the abilities to decrease the electrooxidation potential, to prevent the electrode surface fouling, and to raise the current responses. The MWCNT-ACS nanocomposite responded rapidly to nicotine with a sensitivity of 1.786 A M-1 cm(-2) and a detection limit of 1.42 mu M (according to 3 sigma criterion). A signal almost 180 times more sensitive was obtained at MWCNT-ACS nanocomposite modified glassy carbon electrodes as compared to bare glassy carbon electrode. The nicotine oxidation potential obtained in this study is much lower than that at boron-doped diamond electrodes. (C) 2009 Elsevier B.V. All rights reserved.