Electroanalytical parameters of carbon nanotubes are inferior with respect to well defined surfaces of glassy carbon and EPPG

This paper reports on the electroanalytical parameters of single - (SWCNT), double - (DWCNT) and multi-walled carbon nanotubes (MWCNT) compared with the standard, well defined surfaces of glassy carbon (GC) and edge-plane pyrolytic graphite (EPPG) electrodes. Such parameters include repeatability, sensitivity and linearity of the analytical response, and selectivity of the materials using differential pulse voltammetry in two important biological compounds; uric acid and guanine. In terms of repeatability, all CNTs demonstrate extremely poor RSD values; only those for GC and EPPG are deemed analytically acceptable. The final parameter, selectivity, demonstrated that in both uric acid and guanine, some CNTs showed the lowest peak width; however they had an exceptionally high RSD compared with GC. One might wonder whether it is worth using CNTs at all when glassy carbon can give considerably more consistent results. This is an especially pressing issue for the real world, such as in industrial applications of electrochemical sensors, where the reliability is absolutely crucial. (C) 2010 Elsevier B.V. All rights reserved.