Highly Sensitive Detection of Dopamine, Ascorbic and Uric Acids using Dianix Yellow/Multi-walled Carbon Nanotubes Modified Electrode

Abstract

A glassy carbon electrode has been modified by electrochemical polymerization of dianix yellow along with multi-walled carbon nanotubes (MWCNTs) and utilized for the selective determination of dopamine (DA), ascorbic acid (AA) and uric acid (UA). Atomic force microscopy and scanning electron microscopy images were obtained to compare the surface morphology and topography of the bare and modified electrodes. Also, the electrochemical activities of DA, AA, and UA on the bare and modified electrodes were evaluated with the use of cyclic, linear sweep and differential pulse voltammetry (DPV). Large peak separation, good sensitivity, and stability allow to apply the poly-dianix yellow/MWCNTs modified electrode for the determination of DA individually and in the presence of AA and UA. The DPV data showed the linearity of DA, AA, and UA peak currents in the concentrations ranges of 7–2500 nM, 5–110 µM, and 0.100–7.500 µM with the detection limits of 6.1, 99 and 8.9 nM, respectively. The proposed electrode was applied for the quantification of dopamine in human blood serum samples.