Sub-Micromolar Detection of Hydrogen Peroxide at a Peroxidase/Tetramethylbenzidine Solid Carbon Paste Electrode

Abstract

Horseradish peroxidase and the substrate 3,3′,5,5′-tetramethylbenzidine have been incorporated into a solid carbon paste electrode for the development of a H₂O₂ probe. The electrode exhibited a detection limit of 10⁻⁸ mol/L H₂O₂ and a linearity extended over three orders of magnitude. Glucose oxidase was then used in the paste or covalently immobilized onto a preactivated membrane for the detection of glucose. Using both immobilization procedures the measurement of glucose in the micromolar range and an extended linearity was achieved.

Key Words:

• Carbon paste
• peroxidase
• hydrogen peroxide
• glucose
• biosensor