Analytical Quality Solid-State Composite Reference Electrode and Electrochemical Platform

The reference electrode is an indispensable part of an electrochemical measurement setup and its role is to establish a precise, stable, and reproducible potential which is independent of the sample composition [1]. Internal filling solution used in conventional reference electrodes causes many drawbacks and inconveniences [2]. There are several papers proposing alternative ways of eliminating the inner filling solutions. The reference electrodes proposed there are indeed interesting from the scientific point of view but they should be further developed to be of practical applicability. The classical reference electrodes have so far been superior in terms of continuous, prolonged, and intensive usage.

A new type of all-solid-state reference electrodes based on a polymer/inorganic salt composite (SSC) was designed and characterized. Both a chemical polymerisation method [3] and an injection moulding method [4] were used for fabricating those novel electrodes.

A rigorous testing procedure was used to reveal possible influence of pH, solution composition, as well as the concentrations and mobility of ions. The tests demonstrated the insensitivity of the electrodes to the matrix effects, excellent stability of the potential readings, and significantly reduced leakage of inorganic salt. It was shown that composite reference electrodes were on par or better in the performed tests than high-quality commercial reference electrodes. The SSC reference electrodes described here are of analytical quality allowing for continuous, prolonged, and intensive usage.

References

1. G. Inzelt, A. Lewenstam, F. Scholz Handbook of reference elctrodes (2013) Springer, Berlin.

2. T. Blaz, J. Migdalski, A. Lewenstam, Analyst 130 (2005) 637-643.

3. Z. Mousavi, K. Granholm, T. Sokalski, A. Lewenstam, Analyst 138 (2013) 5216-5220.

4. K. Granholm, Z. Mousavi, T. Sokalski, Andrzej Lewenstam, J Solid State Electrochem DOI 10.1007/s10008-013-2294-x

Acknowledgements

The study was supported by the SalWe Research Program for IMO (Tekes -the Finnish Funding Agency for Technology and Innovation grant 648/10).