A liquid-junction-free reference electrode based on a PEDOT solid-contact and ionogel capping membrane.
Liquid-junction-free reference electrodes have been prepared on screen printed substrates using poly-3,4-ethylenedioxythiophene (PEDOT) as solid-contact and novel ionogels as capping membrane. The chemico-physical properties of the PEDOT layer were tuned by changing the electropolymerization media and the electrodeposition technique. Electrodepositing PEDOT films potentiostatically or potentiodynamically were found to have a significant impact on the stability of the electrodes during the conditioning step. Optimization of the capping membrane formulation, e.g., acrylate monomers, ionic liquid, cross-linkers and photo-initiators, produced electrodes with properties almost equivalent with a commercial reference electrode. Thus, calibration plots of Na(+) ion-selective electrodes against the optimized solid-contact ionogel reference electrodes (SCI-REs) or against a double-liquid junction Ag/AgCl electrode did not present any significant difference. Such SCI-REs may provide an effective route to the generation of future low-cost components for potentiometric sensing strips.
Clarity Centre for Sensor Web Technologies, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland. Electronic address: c.zuliani@imperial.ac.uk.
Claudio
C
Zuliani
Clarity Centre for Sensor Web Technologies, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland.
Giusy
G
Matzeu
Clarity Centre for Sensor Web Technologies, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland. Electronic address: dermot.diamond@dcu.ie.
Dermot
D
Diamond
Ion-Selective Electrode (ISEs); Ionic liquid; Ionogel; Poly-3,4-ethylenedioxythiophene (PEDOT); Reference electrode; Screen printing; Solid-contact