The possibility of producing polymer-coated electrodes containing complexing agents capable of collecting metal ions was investigated. The organic ligands 2-mercaptobenzimidazole and 2-mercaptobenzothiazole were used as monomers for electropolymerization on glassy carbon electrodes. The electroanalytical applicability of the modified electrodes was evaluated for Hg2+ ions, by applying a chemical preconcentration step with subsequent measurement by differential pulse voltammetry. The influence of some electropolymerization parameters, such as scan rate, monomer concentration and the number of cyclic scans, on the voltammetric response of mercury(II) was studied. A 5 min preconcentration period allowed the detection of 0.08 mg/L (4.0 x 10(-7) mol L-1) mercury.98614618