The device included a 2.77 mm counter electrode and a 1.62 mm2 pseudoreference electrode. Before its use, 5 μL of the Nafion commercial solution was cast on the gold electrodes. After solvent evaporation at room temperature, A Nafion film was generated over the two electrodes that acted a protection barrier and prevented them from adsorption/ desorption and contamination processes of organic species presented in the water samples, while keeping the required electrical contact between the electrodes and the solution.