Carbon-nanotube (CNT) modified glassy-carbon electrodes exhibiting strong and stable electrocatalytic response toward NADH are described. A substantial (490 mV) decrease in the overvoltage of the NADH oxidation reaction (compared to ordinary carbon electrodes) is observed using single-wall and multi-wall carbon-nanotube coatings, with oxidation starting at ca. ?0.05V (vs. Ag/AgCl; pH 7.4). Furthermore, the NADH amperometric response of the coated electrodes is extremely stable, with 96 and 90% of the initial activity remaining after 60min stirring of 2x10-4M and 5x10-3M NADH solutions, respectively (compared to 20 and 14% at the bare surface). The CNT-coated electrodes thus allow highly-sensitive, low-potential, stable amperometric sensing. Such ability of carbon-nanotubes to promote the NADH electron-transfer reaction suggests great promise for dehydrogenase-based amperometric biosensors.
Revised: January 14, 2003 |
Published: November 22, 2002
Citation
Musameh M., J. Wang, A. Merkoci, and Y. Lin. 2002.Low-Potential Stable NADH Detection at Carbon-Nanotube-Modified Glassy Carbon Electrodes.Electrochemistry Communications 4.PNNL-SA-37105.