Elimination of Electrooxidizable Interferant-Produced Currents in Amperometric Biosensors.
Abstract
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 glucose/interferant 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1992
- Accession Number
- ADA256923
Entities
People
- Adam Heller
- Ruben Maidan
Organizations
- University of Texas at Austin