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PubMed · 1801607

Amperometric enzyme electrode for theophylline.

J Wang·E Dempsey·M Ozsoz·M R Smyth
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Abstract

An amperometric biosensor for theophylline, based on the recently isolated enzyme theophylline oxidase, is described. The enzyme is entrapped, together with a ferricytochrome C cofactor, within a polymeric (Nafion) coating. The anodic detection (at +0.4 V versus Ag-AgCl) is facilitated by the addition of a redox-mediating hexacyanoferrate(III) ion. The influence of various experimental variables is described. The limit of detection is 2 x 10(-6) mol dm-3 theophylline, with linearity prevailing up to 3 x 10(-4) mol dm-3. The fast response and wash times permit rapid flow-injection measurements, with a frequency of 180 samples h-1 and a relative standard deviation of 3.0-4.0%. Prospects of using this electrode for clinical diagnostics are discussed.

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Biosensing TechniquesElectrochemistryElectrodesOxidoreductasesTheophyllineJournal ArticleResearch Support, Non-U.S. Gov't

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J Wang, E Dempsey, M Ozsoz, M R Smyth. 1991. Amperometric enzyme electrode for theophylline.. https://doi.org/10.1039/an9911600997

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