Characterization of an azo-calix[4]arene-based optical sensor for Europium (III) ions

Abstract: Selective and sensitive optical sensor membranes (optodes) were elaborated to detect cations in aqueous solutions. The sensing films are based on chromogenic calix[4]arene derivatives. The optode membranes were studied using UV/Vis absorption spectroscopy measurements. The sensitivity of the optode has been tested for Pb2+, Cd2+, Mg2+ and Eu3+ ions at pH 6.8. The results showed a good selectivity response towards Eu3+. Low selectivity coefficients were observed for Cd2+ and Mg2+ where Pb2+ can be considered as interfering ions. The characteristics of this optode such as response time, regeneration, reproducibility and lifetime are discussed. [Copyright &y& Elsevier]