Micelle-Enhanced Fluorescein Chemiluminescence Catalyzed by Horseradish Peroxidase for the Determination of Hydrogen Peroxide

Abstract

Cationic micelles of hexadecyltrimethylammonium chloride (CTAC) markedly enhanced the intensity of fluorescein chemiluminescence (CL) catalyzed by horseradish peroxidase (HRP). No enhancement was observed with anionic micelles of sodium dodecyl sulfate or noionic micelles of polyoxyethylene(23)dodecanol. The CL enhancement was attributed to the electrostatic interaction of anionic fluorescein with the CTAC micelle. The local concentration of fluorescein onto the micellar surface increased the efficiency of the energy transfer from singlet oxygen (which was produced in peroxidation catalyzed by HRP) to fluorescein. This enhanced CL was applied to the determination of trace hydrogen peroxide. The calibration curve was linear over the range from the detection limit of 5.0nM to 1.0μM. The detection limit was more than three-times lower than that of the aqueous fluorescein CL.