ELECTROCHEMICAL SENSOR FOR DOPAMINE BASED ON PRUSSIAN BLUE MODIFIED ELECTRODE

摘要

The electrochemical behaviour of dopamine on Prussian Blue (PB) modified electrodes is presented. Prussian Blue modified electrodes has been prepared in a ferric-ferricyanide solution using potentiostatic and galvanostatic methods onto platinum and indium tin oxide (ITO) electrodes. Preparation and characterisation of PB modified electrodes have been carried out in acidic solutions. The amount of PB deposited onto the electrode surface has been controlled by changing the current density, the electrode potential and the time of the electrolysis. The deposition efficiency and the thickness of the modifier have been determined from chronoamperometric curves and cyclic voltammograms. A spectroelectrochemical study shows the variation of the absorbancies of PB deposited on ITO electrode at different electrode potentials. The electrocatalytic activity of PB has been demonstrated in the electrooxidation of dopamine in acid solutions. A linear response in the range of 0.05 -1.2 mM dopamine has been obtained.