Low-potential stable NADH detection at carbon-nanotube-modified glassy carbon electrodes

• Published in: Electrochemistry communications 2002-10, Vol.4 (10), p.743-746
• Main Authors: Musameh, Mustafa, Wang, Joseph, Merkoci, Arben, Lin, Yuehe
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biosensors; Biotechnology; Carbon nanotubes; Chemistry; Electrocatalysis; Electrochemistry; Electrodes: preparations and properties; Exact sciences and technology; Fouling; Fundamental and applied biological sciences. Psychology; General and physical chemistry; Ion selective electrodes; Methods. Procedures. Technologies; NADH; Various methods and equipments
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/S1388-2481(02)00451-4

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. −0.05 V (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 60 min stirring of 2×10 −4 and 5×10 −3 M 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.