Dispersion of multi-wall carbon nanotubes in polyethylenimine: A new alternative for preparing electrochemical sensors.

MARÍA D. RUBIANES ; GUSTAVO A. RIVAS

Elsevier

Lugar: Oxford, England; Año: 2007 vol. 9 p. 480 - 480

p class="MsoBodyText" style="margin: 0cm 0cm 0pt;">In this work we report on the analytical performance of glassy carbon electrodes modified with a dispersion of multi-wall carbon nanotubes in polyethylenimine (GCE/(PEI/CNT)). The resulting electrodes show an excellent electrocatalytic activity toward different bioanalytes like ascorbic acid, dopamine, 3,4-dihydroxyphenylacetic acid (dopac) and hydrogen peroxide. An important decrease in the overvoltages for the oxidation of ascorbic acid (505 mV) and hydrogen peroxide (350 mV) and for the reduction of hydrogen peroxide (450 mV), as well as a dramatic improvement in the reversibility of the electrochemical behavior of dopamine and dopac is obtained. The currents are higher than those obtained with other dispersant agents like Nafion, concentrated acids or chitosan, evidencing the high efficiency of the dispersion in PEI. The GCE/(PEI/CNT) demonstrated to be highly reproducible, with 3.0% RSD for the sensitivity of hydro