Electrocatalytic oxidation and determination of epinephrine in the presence of uric acid and folic acid at multiwalled carbon nanotubes/molybdenum(vi) complex modified carbon paste electrode

Abstract

A novel modified carbon paste electrode was fabricated by incorporation of carbon nanotubes and a novel molybdenum(VI) complex (MC). The characterization of the modified electrode was carried out by cyclic voltammetry. The apparent charge transfer rate constant, k_s, and transfer coefficient, α, for electron transfer between MC and CNT paste electrode were calculated. Furthermore, the modified electrode showed an excellent electrocatalytic effect on the oxidation of epinephrine (EP). Using differential pulse voltammetry (DPV), the peak currents of EP recorded in pH 7.0 solution were linearly dependent on their concentrations in the range of 0.09–750.0 μM. The limit of detection was 49 nM for EP. Then the modified electrode was used to determine EP in an excess of uric acid (UA) and folic acid (FA) by difference pulse voltammetry. Finally, this method was used for the determination of EP in EP ampoule.