Electrochemical sensor for the detection of dopamine in the presence of ascorbic acid in neutral pH on graphitized nanoporous carbon modified glassy carbon electrode

Selective detection of dopamine (DA) in presence of ascorbic (AA) is an important analytical problem, due to its combined existence in the biological system. In the present study, we are reporting an electrochemical detection of DA in the presence of AA using a graphitized nanoporous carbon (NPC) modified glassy carbon electrode (GCE/NPC) in pH 7 phosphate buffer solution. The GCE/NPC shows excellent electrocatalytic activity towards the oxidation of DA and AA in neutral pH. When compared to unmodified GCE, the GCE/NPC shows well separated and enhanced oxidation peak currents. Differential pulse voltammetric technique was used as qualitative analytical tool for the detection of DA. The oxidation peak potentials for AA and DA were at -80 and 136 mV vs Ag/AgCl respectively. The GCE/NPC shows good stability and reproducibility with the relative standard deviation value of 2.6 %. The analytical application of the GCE/NPC was demonstrated for the individual determination of DA in clinical injection and pharmaceutical tablet by using standard addition method.