Catalytic Oxidation of Dopamine at a Copper Hexacyanoferrate Surface Modified GNP Graphite Wax Composite Electrode

A chemically modified electrode was successfully fabricated by means of depositing a thin layer of Copper hexacyanoferrate (CuHCF) on an amine adsorbed gold nanoparticle graphite paraffin wax composite electrode using a new approach. The electrochemical characteristics of the modified electrode were studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The modified electrode was able to catalyze dopamine (DA) and moreover was able to eliminate the electrode fouling caused by the electrochemical oxidation of dopamine at the bare electrode.. However when the modified electrode was further covered with a Nafion membrane, the interference could be diminished. The catalytic current for oxidation of dopamine at the modified electrode increased linearly with a concentration range of 3.5 x 10 -6 to 1.4 x 10 -3 M. of dopamine with a correlation coefficient of 0.999. The limit of detection was found to be 1.2x10 -7 M. Based on S/N=3. Flow injection analysis technique was used for the determination of dopamine and it was found that the electrode produced excellent reproducible results. KeywordsGNP; Copper hexacyanoferrate; Dopamine