Potentiometric properties of polypyrrole films doped with calmagite

Electrochemically deposited polypyrrole films doped with calmagite, a multivaient complexing ligand, has been studied. The films were deposited on a platinum substrate by using cyclic voltammetry. Calmagite was incorporated in the polymer matrix during polymerisation. Calmagite belongs to the group of metallochromic indicators and forms complexes with calcium, magnesium and copper. By using calmagite as doping ion the sensitivity of the film towards these specific cations is enhanced. This was checked by measuring the potentiometric response of the films. As the complexation between calmagite and the metal ions is pH dependent the proper pH range had to be used to obtain good potentiometric response of the films. EDAX spectroscopy was used to get further information about the complexation.