Development of microelectrode arrays modified with inorganic–organic composite materials for dopamine electroanalysis

Abstract

New electrode materials based on composite inorganic redox material–organic conducting polymer for electroanalysis of dopamine were developed. The composite inorganic–organic coatings based on Prussian blue (PB) and poly(3,4-ethylenedioxythiophene) (PEDOT) have been prepared by electrochemical methods onto gold disk microelectrode arrays. Both insoluble and soluble forms of PB were prepared in situ inside the organic matrix and their electrochemical behaviour was investigated in electrolyte solution. The composite inorganic–organic coating containing the soluble PB form exhibited good electrocatalytic activity towards dopamine (DA) oxidation in aqueous buffered solutions. The DA concentration was determined by cyclic voltammetry in the presence of a high excess of ascorbic acid (AA). A linear response for DA concentrations ranging from 10 uM to 50 uM, in the presence of 1 mM AA, with a sensitivity of 460 uA/uM and a detection limit of 4.3 uM, have been obtained.