Voltammetric Determination of Horseradish Peroxidase with 1-Naphthylamine as Substrate

A new system of immunoassay,composing of horseradish peroxidase (HRP),hydrogen peroxide and 1-naphthyl amine,was proposed for the voltammetric determination of HRP.In a phosphate buffer of pH 7.0,the oxidation of 1-naphthylamin by H2O2 was catalyzed by the presence of HRP,producing an electroactive compound which gave a well-defined sensitive reduction peak at the potential -0.43 V (vs.SCE).Under optimum enzyme-catalytic conditions,linear relationship between values of ΔI″p and concentration of HRP was obtained in the range of 3.0×10-7-5.0×10-5g·L-1 of HRP with a detection limit of 2.5×10-7g·L-1.