Thin films of chalcogenide glass as sensitive membranes for the detection of mercuric ions in solution

Abstract Thin vitreous films elaborated by microelectronic techniques can be used to build up sensitive microsystems in order to detect ionic species (Hg 2+ ) in aqueous solution. Characteristics of sensing systems based on thin films of chalcogenide glasses are presented. The microsensors exhibit quasi-Nernstian potentiometric response over five orders of magnitude with a limit of detection below 10 −6 mol 1 −1 . In the presence of interfering heavy-metal ions (PB 2+ , CD 2+ ) the sensing systems are very selective, since low selectivity coefficients are obtained versus those ionic species.