Study and analytical application of bromopyrogallol red as a hydrogen donor substrate for peroxidase Original Research Article

Bromopyrogallol red is used as a hydrogen donor substrate for peroxidase. The steady-state catalytic rate depends upon enzyme and substrate concentrations, and the Michaelis–Menten parameters Km and Vmax are measured at pH 6.2 to be 2.07×10−5 mol l−1 and 1.62×10−7 mol l−1 s−1, respectively. The quantitative assay for horseradish peroxidase is sensitive to 9.2×10−12 mol l−1, and trace hydrogen peroxide (2.1×10−7–1.5×10−5 mol l−1) is determined spectrophotometrically. By coupling with a glucose oxidase-catalyzed reaction, glucose in human serum has been quantified with the same results as by the phenol–4-aminoantipyrine method. The method is simple, rapid and practical with high sensitivity and enzymatic activity.