Fluorometric determination of microamounts of hydrogen peroxide with an immobilized enzyme prepared by coupling horseradish peroxidase to chitosan beads

It has been established that an immobilized enzyme which consists of chitosan beads as a carrier and horseradish peroxidase as an enzyme can be utilized for the determination of microamounts of hydrogen peroxide in environmental samples. The enzyme is immobilized on the carrier by a bridging method with glutaraldehyde; the immobilized reaction is simpler and involves milder condition compared with other immobilizing methods such as glass-amino beads. The immobilized enzyme was used for the fluorometric determination of hydrogen peroxide using 3-(p-hydroxyphenyl)propionic acid as fluorescent substrate by a batch method. The determination limit of the proposed method is about 50 ng cm(-3). The immobilized enzyme can be repeatedly employed for the determination of hydrogen peroxide. It can be used for seven days at least as long as it is stored at 4 degrees C in a preserving solution which is prepared using bovine serum albumin, sodium chloride and trishydroxymethylaminomethane. (C) 1998 Elsevier Science B.V. All rights reserved.