A Novel Electrochemical Sensor Based on Multi Walled Carbon Nano Tubes/Poly (Evans Blue) Composite for the Determination of Dopamine in Presence of 5-HT and FA

Abstract

A new sensor was fabricated by electrochemical polymerization of Evans blue (EB) followed by deposition of multi walled carbon nano tubes (MWCNTs) on glassy carbon electrode (GCE). The developed electrode was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode was employed for analyzing neurotransmitter Dopamine (DA) drug and its simultaneous determination in presence of serotonin (5-HT) and folic acid (FA) with the help of differential pulse voltammetry (DPV) technique. The effect of pH of phosphate buffer solution (PBS) was studied and pH - 5.0 was found to be an optimum pH value. In the present investigation the kinetic parameters, such as charge transfer coefficient, number of electrons and rate constant values were evaluated. The voltammetric peak currents showed a linear response for DA concentrations from 0.5 to 100 µM and from the linear relationship the limit of detection (LOD) and limit of quantification (LOQ), values were as evaluated as 0.54 µM and 1.8 µM respectively. The fabricated electrode showed good stability, reproducibility and sensitivity. The practical application of the developed sensor in determining DA levels in pharmaceutical formulation was successfully monitored.