PEDOT/Palladium composite material: synthesis, characterization and application to simultaneous determination of dopamine and uric acid

Palladium (Pd) incorporated poly (3,4-ethylenedioxythiophene) (PEDOT) films were synthesized through an electrochemical route and characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrochemical study showed catalytic oxidation of dopamine (DA) with optimum loading of Pd. DA and uric acid (UA) were detected using differential pulse voltammetry (DPV). In the presence of ascorbic acid (AA), DA-AA showed peak potential separation of 0.19 V while 0.32 V between UA-AA on Pd-incorporated PEDOT. These peak separations are large enough for sensing DA and UA in the presence of AA. DA and UA exhibited linear calibration plots and the minimum detection limits are 0.5 and 7 mu M respectively. On Pd-PEDOT, the reversibility of DA oxidation was found to increase compared to bare glassy carbon electrode (GCE) and PEDOT modified GCE. Fouling effects were also found to be minimal making Pd-PEDOT composite suitable for electroanalysis.