Polysiloxane-gel matrices for ion sensitive membrane

Polysiloxane membranes containing specific receptor molecules (i.e., 2,9-(o-methoxy)-phenoxydecane dicarboxylic acid, alpha- and beta-cyclodextrin) are used in the preparation of electrolyte insulator semiconductor (EIS) devices. Polysiloxane-gel matrices were characterized by spectroscopic methods. Ion sensitivity and selectivity of EIS devices to different ionic species have been tested for Fe3+ Pb2+ and Cd2+ ions in aqueous solution. The results show a super-Nernstian response for dispersed AE/polysiloxane (DS-AE/PS) film to Fe3+ ions. A Nernstian response was observed for linked CD/polysiloxane (LK-CD/PS) film to heavy metal ions (i.e., Pb2+ and Cd2+). LK-(alpha)CD/PS shows a good affinity to Cd2+ ions (28 mV/pCd(2+)), whereas LK-(beta)CD/PS was shown to be sensitive to Pb2+. (C) 2000 Elsevier Science Ltd. All rights reserved.