Elaboration of an impedancemetric sensor for cobalt detection by polymeric membrane incorporating a heteropolyanion of Dawson type

The elaboration of an electrochemical sensor by impedance technique; in order to detect metallic cations found in aqueous solution is studied. A siloprene-based membrane was chosen, the used ionophore is the acidic form of a heteropolyanion of Dawson type (HPA) in order to detect cobalt. This membrane is deposited on a gold electrode previously thiolated. The cobalt concentrations that can be detected are in the range of 10− 6 to 10− 3 M.