Redox probe-based amperometric sensing for solid-contact ion-selective electrodes

Xiaotong Sun; Tanji Yin; Ziping Zhang; Wei Qin

doi:10.1016/j.talanta.2021.123114

Redox probe-based amperometric sensing for solid-contact ion-selective electrodes

Talanta. 2022 Mar 1:239:123114. doi: 10.1016/j.talanta.2021.123114. Epub 2021 Nov 29.

Authors

Xiaotong Sun¹, Tanji Yin², Ziping Zhang³, Wei Qin⁴

Affiliations

¹ College of Life Sciences, Yantai University, Yantai, 264005, China; CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China.
² CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 26620, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong, 266071, PR China. Electronic address: tjyin@yic.ac.cn.
³ College of Life Sciences, Yantai University, Yantai, 264005, China. Electronic address: zipingzhang@ytu.edu.cn.
⁴ CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 26620, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong, 266071, PR China.

PMID: 34864532
DOI: 10.1016/j.talanta.2021.123114

Abstract

The transformation from the traditional potentiometric response of an ion-selective electrode (ISE) to other signal readout is promising to realize the potential signal amplification. In this work, the redox probes, including ferrocyanide/ferricyanide (Fe(CN)₆^3-/4-), hexaammineruthenium (Ru(NH₃)₆³⁺) and ferrocene derivatives, were introduced to read out the potentiometric response for the solid-contact Ca²⁺-ISE. The mechanism is that the oxidation current of the redox probe on a glassy carbon electrode is modulated by the potential of the ISE through changing the concentrations/activities of Ca²⁺ under the control of the constant applied potential. Results show that the linear range and the slope sensitivity for detection Ca²⁺ by using the amperometric signal based on Fe(CN)₆^4-/3- redox probe are adjustable through changing the applied potentials. Moreover, the redox probe-based amperometric signal for the solid-contact Ca²⁺-ISE is found to be related to both of the types of the redox probes and the electrode areas. This work provides a convenient and general method for translating the potential response at mV grade to the amperometric signal at the μA level, and is promising for detection of ions with high sensitivity by using the ISEs.

Keywords: Amperometric signal; Ca(2+); Fe(CN)(6)(4−/3-); Ion-selective electrode; Redox probe.

MeSH terms

Carbon*
Electrodes
Ion-Selective Electrodes*
Ions
Oxidation-Reduction
Potentiometry

Substances

Ions
Carbon