Solution-cast films of poly(3,4-ethylenedioxythiophene) as ion-to-electron transducers in all-solid-state ion-selective electrodes

Electrochemical Sensors

“…The group of Ivaska also characterized the sensing properties of undoped poly(3-octylthiophene) itself, without covering ion-selective membrane, and found a preference for silver ions with Nernstian response slopes, even for undoped polymer films, and no evidence for polymer oxidation by silver ions. 26 This again suggests that POT is resistant to oxidation, which, together with its lipophilic character makes it an attractive candidate for solid contact ISEs as supported also by other works discussed in this review. Brzozka and Malinowska and co-workers studied various ferrocene terminated disulfide self-assembled monolayers on gold as solid inner contact systems, and long term stabilities with phenyl-spaced derivatives compared favorable to hydrogel inner contact systems.27 For this purpose, oxygen, carbon dioxide and water layer tests were critically performed and a drastic improvement was observed compared to bare gold underlayers.…”

Development of miniature all-solid-state potentiometric sensing system

“…The use of conductive polymers as intermediate layers in solid-state ISEs is relatively common practice these days and in this work we used PEDOT due to its stability and low sensitivity to O 2 and CO 2 [28,29]. Furthermore, it is one of the most studied conductive polymers and it has been used in both reference electrodes [14,15] and other sensor applications [9].…”

“…Various conductive polymers have been examined as possible internal contact materials that could simultaneously stabilize the overall electrode potential and remove the need for an inner filling solution [9][10][11]. This application of CPs was supported by fundamental theoretical interpretation of signal formation by Lewenstam at al [28] and, in particular, a deeper understanding of the instabilities of solid-contact sensors as provided by Fibbioli and co-authors [29]. In order to avoid the formation of a water layer and to better define the redox potential at the membrane/solid support phase boundary, it was suggested that a lipophilic redox-active layer such as a self-assembled monolayer (SAM) could be introduced between the membrane and the solid support [12].…”

Properties and Customization of Sensor Materials for Biomedical Applications

“…SC-ISEs are more convenient for remote monitoring than liquid-filled ISEs as they are more compatible with microfabrication technologies (114,(174)(175)(176)(177)(178). While CPs have been extensively used as a solid contact material, it is important to note that the choice of the conducting polymer is imperative in the ISE's longevity as it will affect the stability over time and the LOD (114,129,(174)(175)(176)(177)(178)(179)(180)(181)(182)(183)(184)(185). In addition, the type of CP to be used as a solid contact can also depend on the ion analyte (186).…”