Redox labeling of two antiepileptic drugs with metallocenes and their simultaneous detection by a Nafion-modified electrode
✍ Scribed by Anne-Line Bordes; Bernd Schöllhorn; Benoît Limoges; Chantal Degrand
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 104 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0268-2605
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✦ Synopsis
Two different cationic redox labels, i.e. a ferroceneammonium ion and a cobaltocenium ion, were covalently attached to two antiepileptics, phenytoin and phenobarbital, respectively. The two labeled drugs possess distinct standard redox potentials of 0.39 V for the phenytoin derivative and Ϫ 0.92 V for phenobarbital derivative (vs Ag/AgCl, Cl ؊ 0.05 M) at a carbon paste electrode. After preconcentration in a polyanionic Nafionloaded carbon paste electrode the positively charged labeled phenytoin and phenobarbital derivatives could be simultaneously detected in concentration ranges which were relevant to the therapeutic ranges of the antiepileptics, with a view to a future dual-analyte immunoassay. Square-wave voltammetry permitted detection limits of 5ϫ 10 Ϫ8 M (for the phenytoin derivative) and 2.5ϫ 10 Ϫ8 M (for the phenobarbital derivative) for non-simultaneous detection.