Effects of thin-layer diffusion in the electrochemical detection of nicotine on basal plane pyrolytic graphite (BPPG) electrodes modified with layers of multi-walled carbon nanotubes (MWCNT-BPPG)

The oxidative electrochemistry of nicotine is measured in aqueous Solution at a multi-walled carbon nanotube modified basal plane pyrolytic graphite (MWCNT-BPPG) electrode. Quantitative detection of nicotine is obtained with a limit of detection of 1.5 mu M (based on 3 sigma) and a linear range of at least up to I mM. Evidence is found for a mass transport regime that includes thin-layer (within the MWCNT layers) as well as semi-infinite (from bulk solution) diffusional signatures, adding to the growing picture that the fundamental Source of the 'electrocatalytic' properties claimed of many porous and multi-walled carbon nanotube-based modified electrodes may, at least in some cases, be clue to mass transport effects rather than electronic or structural peculiarities of the modifying layers. (C) 2009 Elsevier B.V. All rights reserved.