New Class of Ag/AgCl Electrodes Based on Hydrophobic Ionic Liquid Saturated with AgCl

Abstract

A new type of Ag/AgCl electrodes based on a hydrophobic ionic liquid has been proposed. The electrode consists of a Ag/AgCl electrode immersed in or coated with a AgCl-saturated ionic liquid, 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide ([C(8)mim+][C(1)C(1)N-]), instead of the internal aqueous solution. The [C(8)mim+][C(1)C(1)N-] phase plays dual roles, that is, as a medium dissolving AgCl and an ionic-liquid-type salt bridge upon contact with an aqueous solution. The gelation of the [C(8)mim+][C(1)C(1)N-] phase allows us to prepare coated-wire-type solid-state reference electrodes with a well-defined thermodynamic basis for the electrode potential. Both gelled and nongelled types show stable electrode potentials against the change in the concentration of KCl between 0.05 mmol dm(-3) and 2 mol dm(-3). This new class of reference electrodes opens the way for a variety of miniaturized and solid-state reference electrodes.

Application of Room Temperature Ionic Liquids in Electrochemical Sensors and Biosensors

“…In this way, the electrode showed good potential stability and reproducibility. In 2007, Kakiuchi et al have also introduced a new solid-state reference electrode (Kakiuchi et al, 2007). A new type of Ag/AgCl reference electrode is consists of a Ag/AgCl electrode coated with a AgCl-saturated with a hydrophobic ionic liquid ionic liquid, 1-methyl-3-octylimidazolium bis ( There is another report in 2009 (Chernyshov et al 2009) in which ILs that melt slightly above room temperature (and may be called low-melting ionic solids, LMISs) were used as sensing materials for the detection of ions in aqueous solutions.…”

Mutual Solubility of Hydrophobic Ionic Liquids and Water in Liquid-Liquid Two-phase Systems for Analytical Chemistry

“…From an electroanalytical chemistry viewpoint, hydrophobic ILs are promising for modifying the electrode surface, [98][99][100][101][102][103][104][105][106] preparing membranes for ion-selective electrodes, [107][108][109][110][111] salt bridges, [112][113][114] and other potentiometric as well as voltammetric sensors. 115 A remarkable growth in the number of papers dealing with carbon paste and other carbon electrodes impregnated with ILs attests the strong interest to apply ILs for electroanalytical chemistry.…”

Properties and Customization of Sensor Materials for Biomedical Applications

“…The authors successfully employed these reference electrodes for the potentiometric measurement of Pb 2þ solutions, cyclic voltammetry of a solution-phase redox probe, and impedance spectroscopy of a polymer membrane. Results comparable to standard reference electrodes have been obtained with hydrophobic ionic liquids, such as 1-methy-3-octylimidazolium bis-(trifluoromethylsulfonyl)imide, which was jellified and saturated with AgCl (117,118). The electrodes suffered from component leaching and signal deviations (in the mV range) due, for example, to phthalate ions or chloride interference at concentrations greater than 0.1 M (117,118).…”