Multi-ion sensitivity of AgGeSe ion selective electrodes

SILVEYRA, J. M.; CONDE GARRIDO, J. M.; MARIA ANDREA UREÑA

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2016 vol. 89 p. 115 - 119

0022-3697

Chalcogenide glasses have successfully been applied as sensitive membranes of ion selective electrodes (ISEs) for many decades. In particular, they present cross-sensitivity (i.e. various degrees of sensitivities to the presence of different ions), which is a key property for the development of multi-electrode systems like electronic tongues. In previous works, we have shown that ISEs with AgGeSe membranes have good sensitivity to Ag+ and Cu2+ ions. In the present work, we prepared two types of ISEs with either bulk (by melt-quenching) or thin film (by pulsed laser deposition) membranes of composition AgX(Ge0.25Se0.75)100-X (10 ≤ X ≤ 30). We studied how the pH of the solution affects the response of the ISEs and measured their sensitivities to several ions: Hg2+, Pb2+, Fe3+, Cr3+, Cd2+, Ni2+, Mg2+, and K+. There was no noticeable trend with type or composition of the membrane. The ISEs showed an important response to the presence of Hg2+, Pb2+, and Fe3+, a low response to the presence of Cr3+ and a total lack of response to the presence of Cd2+, Ni2+, Mg2+, or K+. The potentials of the ISEs were practically constant in neutral or acidic solutions and changed drastically in basic solutions when the primary ion was not present. We conclude that ISEs with membranes of the system AgGeSe are good candidates to integrate multi-electrode systems.