TY - JOUR

T1 - Voltammetric Ion Sensing with Ionophore-Based Ion-Selective Electrodes Containing Internal Aqueous Solution, Improving Lifetime of Sensors

AU - Керестень, Валентина Максимовна

AU - Михельсон, Константин Николаевич

PY - 2022/11

Y1 - 2022/11

N2 - The possibility of voltammetric ion sensing is demonstrated, for the first time, for ion-selective electrodes (ISEs) containing an internal aqueous solution. ISEs selective to calcium, lithium and potassium ions are used as model systems. The internal solution of the ISEs contains a chloride salt of the respective cation and a ferrocenemethanol or ferrocyanide/ferricyanide redox couple. A platinum wire is used as the internal reference electrode. It is shown, theoretically and experimentally, that the dependence of oxidation and reduction peak potentials on the sample composition obeys the Nernst law, while the peak currents virtually do not depend on the sample composition. Thus, the electrode behavior is similar to that reported by Bakker’s group for solid contact ISEs with ultra-thin membranes (200–300 nm). It is shown that the use of classical ISEs with relatively thick membranes (100–300 µm) and internal aqueous solution allows for the sensor lifetime of about one month. It is also shown that use of a suitable background electrolyte allows for improvement of the detection limits in voltammetric measurements with ISEs.

AB - The possibility of voltammetric ion sensing is demonstrated, for the first time, for ion-selective electrodes (ISEs) containing an internal aqueous solution. ISEs selective to calcium, lithium and potassium ions are used as model systems. The internal solution of the ISEs contains a chloride salt of the respective cation and a ferrocenemethanol or ferrocyanide/ferricyanide redox couple. A platinum wire is used as the internal reference electrode. It is shown, theoretically and experimentally, that the dependence of oxidation and reduction peak potentials on the sample composition obeys the Nernst law, while the peak currents virtually do not depend on the sample composition. Thus, the electrode behavior is similar to that reported by Bakker’s group for solid contact ISEs with ultra-thin membranes (200–300 nm). It is shown that the use of classical ISEs with relatively thick membranes (100–300 µm) and internal aqueous solution allows for the sensor lifetime of about one month. It is also shown that use of a suitable background electrolyte allows for improvement of the detection limits in voltammetric measurements with ISEs.

KW - electrochemical impedance

KW - ion-selective electrodes

KW - ionophores

KW - lifetime

KW - potentiometry

KW - voltammetry

KW - water uptake

UR - http://www.scopus.com/inward/record.url?scp=85141730569&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/69859dea-9456-3999-aac6-6c6ce24a7e40/

U2 - 10.3390/membranes12111048

DO - 10.3390/membranes12111048

M3 - Article

C2 - 36363603

VL - 12

JO - Membranes

JF - Membranes

SN - 2077-0375

IS - 11

M1 - 1048

ER -