Elimination of Electrooxidizable Interferant-Produced Currents in Amperometric Biosensors.
Technical rept. Oct 91-Sep 92,
TEXAS UNIV AT AUSTIN DEPT OF CHEMICAL ENGINEERING
Pagination or Media Count:
Electrooxidizable ascorbate, urate and acetaminophen, that interfere with amperometric glucose assays are completely and rapidly oxidized by hydrogen peroxide in a multilayer electrode. The multilayer electrode is composed of an immobilized, but not electrically wired , horseradish peroxidase HRP film coated onto a film of electrically wired glucose oxidase GOX. The wired enzyme is connected by a redox epoxy network to a vitreous carbon electrode. The current from the electrooxidizable interferants is decreased by their peroxidase-catalyzed Biosensors Amperometric Interferants. preoxidation by a factor of 2500 and the glucoseinterferant current ratio is increased 103 fold. Undesired electroreduction of hydrogen peroxide can result when HRP is also wired to the electrode. Such unwanted wiring is prevented by incorporating an electrically insulating barrier layer between the wired GO film and the HRP film. The hydrogen peroxide necessary for elimination of interferants can be added externally, or, when this is not possible, it can be generated in situ by means of a coupled enzyme reaction.
- Organic Chemistry
- Physical Chemistry