Nafion® is a porous membrane made from a hydrophobic tetrafluoroethylene polymer lined with hydrophilic sulfonic acid groups. They provide a negative charge when the membrane is exposed to an aqueous electrolyte . Nafions' anti-fouling properties are based on the creation of a physical barrier and electrostatic repulsion of negatively charged pollutants. Both reduction and oxidation peaks of syringaldazine, with pH dependant position were observed in the case of sensors covered with the drop casted layer. However, the signal was not stable and the intensity lowered with each scan. Results for the dip coated sensors were not reproducible, no pH dependant peak shift was observed and we assumed that syringaldazine from the electrode dissolves in the alcoholic polymer solution during coating.