Voltammetric determination of dopamine in the presence of ascorbic acid and uric acid at sodium dodecyl sulphate/reduced graphene oxide modified carbon paste electrode

Abstract

In this work, the electrochemical behaviour of dopamine in the presence of various surfactants via sodium dodecyl sulphate (SDS), cetyltrimethylammonium bromide (CTAB) and Tween-20 was examined. It is found that in anionic surfactant, SDS enhanced electrochemical response at reduced graphene oxide modified carbon paste electrode (R-GO/MCPE). The electrochemical parameters, such as heterogeneous rate constant and number of electron transfer were calculated and the overall sweep rate effect shows that the electrode process was diffusion and adsorption controlled. The detection limits were 0.26 and 0.35μM for DA and UA respectively. Differential pulse voltammetric technique was used for the simultaneous determination of dopamine (DA), ascorbic acid (AA) and uric acid (UA). The separation of the oxidation peak potentials for DA-AA and DA-UA by SDS/R-GO/MCPE was 178 and 114mV, respectively. The experimental results suggest that the modified electrode showed good sensitivity and selectivity for dopamine.