Highly selective determination of dopamine in the presence of ascorbic acid and serotonin at glassy carbon electrodes modified with carbon nanotubes dispersed in polyethylenimine

MARCELA C. RODRÍGUEZ, MARÍA D. RUBIANES, GUSTAVO A. RIVAS*; M. D. RUBIANES; G. A. RIVAS

AMER SCIENTIFIC PUBLISHERS

Año: 2008 vol. 8 p. 6003 - 6003

p style="LINE-HEIGHT: 200%; TEXT-INDENT: 35.4pt; MARGIN: 0cm 0cm 0pt" class="TAMainText">We report the highly selective and sensitive voltammetric dopamine quantification in the presence of ascorbic acid and serotonin by using glassy carbon electrodes modified with a dispersion of multi-wall carbon nanotubes (MWCNT) in polyethylenimine, PEI (GCE/MWCNT-PEI) The electrocatalytic activity of the MWCNT deposited on the glassy carbon electrode has allowed an important decrease in the overvoltages for the oxidation of ascorbic acid and dopamine, making possible a clear definition of dopamine, serotonin and ascorbic acid oxidation processes. The sensitivities for dopamine in the presence and absence of 1.0 mM ascorbic acid and serotonin were (2.18 ± 0.03) x 105 µAM-1 (r = 0.9998); and (2.10