Electrochemical determination of dopamine using a poly(2-picolinic acid) modified glassy carbon electrode

Abstract

A poly(2-picolinic acid) chemically modified electrode (CME) for the determination of dopamine (DA) by cyclic voltammetry is described. Compared with a bare glassy carbon electrode, the CME exhibits a 200 mV shift of the oxidation potential of DA in the cathodic direction and a marked enhancement of the current response. In pH 7.0 buffer solution, a linear calibration graph is obtained over the range from 2.5 ×10⁻⁷ to 1.0 × 10⁻⁵ mol dm⁻³ with a correlation coefficient of 0.998. The detection limit is 3.0 × 10⁻⁸ mol dm⁻³. The modified electrode eliminated efficiently the interference from ascorbic acid (AA) when present in a 150-fold concentration ratio. It also showed excellent stability and reproducibility.