Electrochemical Determination of Dopamine at Pre-Anodized Helical Multi-Walled Carbon Nanotubes Modified Glassy Carbon Electrode

In this article we electrochemically investigated the determination of dopamine (DA) at pre-anodized helical multi-walled carbon nanotubes (H-MWCNTs) modified glassy carbon electrode (GCE) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The pre-anodized H-MWCNTs/GCE could catalyze DA redox reaction greatly, and the oxidation current of DA from DPV measurement on pre-anodized H-MWCNTs/GCE was about 25 time bigger than on GCE. Furthermore, the pre-anodized HMWCNTs/GCE could separate the oxidation peak potentials of DA, ascorbic acid (AA) and uric acid (UA) with well-defined peak separation as 164 mV for DA and UA, and 208 mV for DA and AA. The calibration curves of DA were obtained linearly in the range of 1 x 10(-7) similar to 2 x 10(-6) M and 6 x 10(-5) similar to 2 x 10(-4) M with the limit of detection (LOD, S/N = 3) and the limit of quantification (LOQ, S/N = 10) as 2.1 x 10(-8) M and 7.0 x 10(-8) M respectively. The sensor had been applied for DA measurement in dopamine injection samples with satisfactory results. (c) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.