Sol–gel horseradish peroxidase biosensor for the chemiluminescent flow determination of hydrogen peroxide

Abstract

A chemiluminescent (CL) H₂O₂ sensor based on horseradish peroxidase (HRP) immobilized by the sol–gel method has been proposed in this paper. A new process of fabricating a non-cracking HRP encapsulated sol–gel membrane has been suggested. Flow injection analysis (FIA) was used to give reproducible results. Under optimum conditions, the sensor showed a linear response toward hydrogen peroxide in the range 0.01–2 mM with a detection limit of 8 µM. The linear relative coefficient r = 0.998. The sensor showed rapid response, good reproducibility (relative standard deviation = 2.4%) and a long lifetime of at least two months. The proposed sensor was used to determine a 30% H₂O₂ solution that has been stored for a long time. The results were in good agreement with the standard volumetric method.