Hydrogen peroxide-induced cathodic terbium(III) electroluminescence at a terbium-doped oxide-covered zirconium electrode

• Published in: Analytica chimica acta 1992-08, Vol.266 (1), p.51-66
• Main Authors: Lipiäinen, K., Kulmala, S., Haapakka, K.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemiluminescence; Chemistry; Electrochemical methods; Electroluminescence; Exact sciences and technology; Glucose; Terbium; Zirconium electrode
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/0003-2670(92)85279-F

It has been found that the conventional low-voltage d.c. anodization of a zirconium electrode in an aqueous terbium(III)-containing sodium acetate solution furnishes an electrode surface with a thin oxide layer which may contain terbium at levels up to around 35 at.% at the surface. The cathodic polarization of the interface between the terbium-doped oxide layer and the aqueous hydrogen peroxide-containing electrolyte excites the oxide-bound terbium(III) to its lowest singlet state and thus is able to generate a terbium(III)-characteristic electroluminescence. This paper treats in details the preparation and characterization of highly electroluminescent terbium-doped oxide layers at a zirconium electrode surface and demonstrates that the cathodic terbium(III) electroluminescence can be used to detect hydrogen peroxide with different kinds of electroluminescence cells, e.g., rotating working electrode cell, flow cell and static microcell. On the basis of the results from the experiments with the well known β- d-glucose-glucose oxidase-oxygen system as a model system for enzymatically liberated hydrogen peroxide, the use of this terbium-doped oxide-covered zirconium electrode is proposed as a versatile sensor for clinical analysis through its response to hydrogen peroxide.