Solid state potentiometric sensors with gold internal contact
Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, Warszawa 00-664, Poland
Ion selective electrodes with ion-selective polymeric membrane coated directly on a metallic conductor belong to the group of solid-state sensors. The elimination of the internal electrolyte solution from a sensor architecture was found to affect the electrochemical stability of this type sensors. This was explained by not well thermodynamically defined interface between the polymeric membrane and solid conductor. To overcome this problem, several approaches have been proposed, including an addition of lipophilic silver-ligand complexes or conducting polymers into polymeric films as well as an incorporation of intermediate layer between metal contact and ion-selective membrane. For the later approach, redox-active polymer layers, conducting polymers and redox-active self-assembled monolayers (SAMs) have been investigated as the intermediate phase.
This talk will cover the general principles of solid-state ion-selective sensors, with special emphasis on their appropriate architecture and the role of intermediate layers. It will be shown that the improvement of the stability of sensors can be achieved by the application of hydrophobic interface that exhibits reversible electron/ion transfer at the membrane/solid contact. The steps of chemical modification of transducers with gold internal electrode, leading to ion-selective sensors of improved stability, will be discussed.
Presentation: Tutorial lecture at SMCBS'2005 Workshop, by Elzbieta Malinowska
See On-line Journal of SMCBS'2005 Workshop
Submitted: 2005-08-01 10:52 Revised: 2009-06-07 00:44