Glasses of the pseudo-binary system Ag₂S-As₂S₃ are well known to be good ionic conductors and the addition of HgI₂ allows considering the glasses of the pseudo-ternary system HgI₂-Ag₂S-As₂S₃ as ion-membrane dedicated to mercury sensing in aqueous solution. The limits of its vitreous domain were verified by X-ray diffraction. Changes in macroscopic properties of glasses, including density and characteristic temperatures (Tg, Tc et Tm) were systematically investigated. Conduction properties of HgI₂-Ag₂S-As₂S₃ glasses were evaluated using the complex impedance spectroscopy and 108mAg tracer diffusion measurements. One of the most interesting results concerns the conductivity increase if Ag₂S is substituted by HgI₂. To understand the conduction mechanisms involved, structural studies were carried out by Raman spectroscopy, neutron scattering and high-energy X-ray diffraction. To understand the structure of these complex glasses, preliminary studies on the two pseudo-binary systems Ag₂S-As₂S₃ and HgI₂-As₂S₃ were also undertaken. These techniques have underlined exchange reactions that occur during the synthesis. The last part of this research work is entirely devoted to the characterization of new chemical sensors for the detection of Hg²+ ions in solution. Different compositions were tested to determine the sensitivity, detection limit and selectivity coefficients in the presence of interfering ions.
