Application of CuO nano particle/multi-walled carbon nanotube nanocomposite modified electrode for simultaneous determination of dopamine and rutin in real samples

In this work, a new method was developed for simultaneous determination of dopamine and rutin at glassy carbon electrode modified with CuO nanoparticles doped multi-walled carbon nanotubes (CuONPs–MWNT/GCE). This modified electrode has shown excellent electrocatalytic activity toward the oxidation of rutin in acetate buffer solution (pH=5). The modified electrode lowered the overpotential of the reaction by ~500 mV, and this advantage of modified electrode made it aproprate to measure trace values of dopamine in the presence of rutin. First, the electrochemical behavior of CuO nanoparticles, incorporated in the modified electrode, was studied. Then, the behavior of oxidation of rutin and dopamine at the modified electrode was investigated by differntial puls voltammetry. A linear calibration plot was obtained over the range of 0.05-580 µmol L–1 rutin and 0.09-600 μmol L–1 for dopamine. Detection limits of 0.013 µmol L–1 rutin and 0.021 μmol L–1 dopamine were obtained. The relative standard deviation of ten replicate measurements for rutin and dopamine was measured 1.2% and 1.53% respectively. The high sensitivity, low detection limit and reproducibility of the modified electrode, made the proposed electrode suitable for the determination of dopamine in the presence of rutin in pharmaceutical samples