Pb2+ potentiometric chemical sensors based on lead and silver doped thioaresenate glasses

Lead doped chalcogenide glass compositions, in the pseudo-ternary AgI-PbS-As2S3, were examined as activemembrane materials for the construction of Pb(II) ion-selective sensors, Pb(II) ISE. The basic glass properties ofthe synthesised bulk samples such as vitreous state, macroscopic, thermal and electric properties were studied.To this end, several techniques were used, including X-ray powder diffraction, density measurements, differentialscanning calorimetry, scanning electron microscopy and impedance complex spectroscopy. It is found that thedensity increases with increased AgI and PbS contents. The glass transition temperatures for the studied com-positions were also reported. The electrical measurement show the conductivity increases with increasing AgIcontent. Meanwhile, for the glasses with same AgI content and increasing PbS content, the conductivity de-creases. For the fabricated sensors, several key analytical parameters were investigated to evaluate the differentglass compositions as active membranes in Pb(II) ISE, including detection limit, sensitivity, linearity, ionicselectivity (in the presence of K+, Na+, Ni2+, Ca2+, Cd2+, Cu2+ and Hg2+ interfering cations), reproducibility andoptimal pH-range