Electrochemically selective determination of dopamine in the presence of ascorbic and uric acids on the surface of the modified Nafion/single wall carbon nanotube/poly(3-methylthiophene) glassy carbon electrodes

Selective determination of dopamine in the presence of uric acid and ascorbic acid by N,N′-bis(indole-3-carboxaldimine)-1,2-diaminocyclohexane thin film modified glassy carbon electrode by differential pulse voltammetry

“…The latter was Ipa (lA) = 0.0742C (lM) + 2.0768, r = 0.9904. The reason for two linear region may be as follows: After 11.8 lM, a saturation took place and this defined the decrease in the current in the interval from 11.8 to 90.0 lM or DA transport mechanism altered toward the electrode surface [50]. At higher DA concentration than 90.0 lM, the peak current diverges from the straight line.…”

“…The decrease in sensitivity (slope) at higher linear range of DA is attributed to the kinetic limitation of the ICDACH. In addition, DA transport mechanism altered toward the electrode surface from adsorptive to diffusional mode, accordingly characterized for the lower and higher regions of DA concentration [50]. One possible reason may be the transition from monolayer adsorption state into more complicated multilayer adsorption state [46].…”

Pre-concentration and in situ electrochemical sensing of 1-hydroxypyrene on an electrodeposited poly(3-methylthiophene) film modified electrode

“…Poly(3-methylthiophene) (P3MT) is a widely used electronically polythiophene derivative, which can be easily electrodeposited onto electrode by electrooxidation of its monomer at lower potential compared to polythiophene and other derivatives [32,33]. Numerous studied have shown that P3MT modified electrodes can minimize the surface fouling and effectively electrocatalyze oxidation of some conjugated compounds, such as dopamine [34,35], 8-hydroxy-2 0 -deoxyguanosine [36,37] and phenolic compounds [38,39]. In this paper, electropolymerized P3MT was chosen as a typical representative polythiophene to electrodeposit on glassy carbon electrode.…”

The Electrochemical Behavior of Zinc Oxide/Reduced Graphene Oxide Composite Electrode in Dopamine

“…To investigate the reaction kinetics, the influence of scan rates on the electrocatalytic response of ZnO/rGO/GCE in K 4 [Fe(CN) 6 ] was examined and the results are shown in Figure 4b. The scan cycles and potential range were standardized at value of 0.10 mM, 6 scan cycles, and -0.2 V to 0.8 V respectively.…”

“…Among these methods, electrochemical method are favorable owing to their advantages such fast speed, low cost, low detection limits and also high in accuracy [3]. However, uric acid (UA) and ascorbic acid (AA) are usually coexisted with DA in the extracellular fluids of the central nervous system in mammals or the biological fluid such as urine, blood and human breast milk [4]. Thus, AA and UA will become the interfering species that will result in poor selectivity and sensitivity towards DA detection.…”