Analytical Sciences

Abstract − Analytical Sciences, 20(7), 1055 (2004).

A Chitosan-Multiwall Carbon Nanotube Modified Electrode for Simultaneous Detection of Dopamine and Ascorbic Acid
Lingyan JIANG,* Chuanyin LIU,* Liping JIANG,* Zhen PENG,** and Guanghan LU*
*College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
**Department of Chemistry, Caohu College, Anhui 238000, People’s Republic of China
A chemically modified electrode based on a chitosan-multiwall carbon nanotube (MWNT) coated glassy carbon electrode (GCE) is described, which exhibits an attractive ability to determine dopamine (DA) and ascorbic acid (AA) simultaneously. The modified electrode exhibited a high differential pulse voltammetry (DPV) current response to DA at 0.144 V and AA at -0.029 V (vs. SCE) in a 0.1 mol l-1 phosphate buffer solution (pH = 7.2). The properties and behaviors of the chitosanmultiwall carbon nanotube modified electrode (MC/GCE) were characterized using cyclic voltammetry (CV) and DPV methods. The mechanism for the discrimination of dopamine from ascorbic acid at MC/GCE is discussed. The linear calibration range for DA and AA were 5 × 10-7 mol l-1 to 1 × 10-4 mol l-1 (r = 0.997), and 5 × 10-6 mol l-1 to 1 × 10-3 mol l-1 (r = 0.996), respectively. The MC/GCE showed good sensitivity, selectivity and stability.