Complexation of poly(pyrrole-EDTA like) film modified electrodes: Application to metal cations electroanalysis

Complexing polymer-coated electrodes have been synthesized by oxidative electropolymerization of N,N′-ethylenebis[N-[(3-(pyrrole-1-yl)propyl) carbamoyl) methyl]-glycine] (L). There were used for the electrochemical detection of Cu(II), Pb(II) and Cd(II) ions by means of the chemical preconcentration-anodic stripping technique. For thick polymeric binding materials and long accumulation times, competitive experiments showed that the polyL film modified electrodes are selective towards Cu(II) ions and particularly insensitive to the presence of Cd(II). In contrast, imprinted polymer-coated electrodes prepared by electropolymerization of the Cd(II) complex of L allowed an efficient complexation and sensing of Cd(II) cations. The selectivity of the molecular electrode materials can thus be subtly modulated upon playing on the accumulation time and on the pre-structuration of the complexing polymers.