Microcavity based solid-contact ion-selective microelectrodes

F Sundfors, R Bereczki, Johan Bobacka, K Toth, Ari Ivaska, RE Gyurcsanyi

Research output: Contribution to journalArticleScientificpeer-review

51 Citations (Scopus)


A novel design and fabrication procedure is proposed for the preparation of robust ionophore based ion-selective microelectrodes. The essential component of the new design is a microcavity that is formed after recessing a voltarnmetric inlaid disk type gold microelectrode by chemical etching of the gold microwire. The microcavity of ca. 50 pL volume and 25 mu m diameter accommodates the inherently conducting polymeric inner contact and the ionselective liquid membrane, which are thereby mechanically protected from the sample environment. As inner contacts poly(3,4-ethylenedioxythiophene) (PEDOT) films doped with poly (4-styrenesulfonate) (PSS) and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB) electropolymerized from aqueous and organic solvents, respectively, were used. Potassium- and calcium-selective microelectrodes fabricated according to the new procedure exhibited potentiometric characteristics similar to the conventional electrodes. The formation of an aqueous layer below the ion-selective membrane could be avoided by using the proposed electrode construction.
Original languageUndefined/Unknown
Pages (from-to)1372–1378
Number of pages7
Issue number13-14
Publication statusPublished - 2006
MoE publication typeA1 Journal article-refereed


  • ion-selective microelectrode
  • microcavity
  • inherently conducting polymers
  • Solid contact

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