PEDOT copolymers as a new ion selective electrode back-contact and reference electrode

Description:
Solid-contact ion-selective electrodes (ISEs) have the inherent advantage of being miniaturized in addition to maintaining the high selectivity and sensitivity of the ionophore-based ISE. However, the main drawback of these ISEs is the requirement to produce a calibration curve before conducting experiments (variating the intercept in the linear calibration curve equation each time), which restricts their utility as single-use sensors. We created a novel back contact using 3,4-ethylenedioxythiophene (EDOT) and 4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid, sodium salt, to address these issues (EDOT-S). While preserving their respective selectivity against major interfering ions, the calibration-free ISEs displayed near Nernstian responses of 57.2 mV/log [K+] and 28.5 mV/log [Ca2+]. Recent developments in using these sensors in creek water samples will be presented. In addition, the new applications in using these back contacts as a solid-state reference electrode in a non-aqueous solution will also be presented at the conference.

Speaker: Dipankar Koley - Oregon State University