A voltammetic enzyme-linked immunoassay based on new system of o- aminophenol (OAP)-H~2O~2-horseradish peroxidase (HRP) has firstly been developed and used for the detection of HRP and ferritin.HRP or labelled HRP catalyzes the oxidation reaction of OAP with H~2O~2, producing a sensitive voltammetric peak at -0.43V(vs.SCE) in Britton- Robinson(B-R) buffer solution.By using this voltammetric peak,HRP can be measured with a detection limit of6.0-10^-^1^3g/mL and a linear range of 1.0*10^-^1^2-4.0*10^-^9g/mL. The detection limit for ferritin is 0.2ng/mL and the linear range 0.2-320ng/mL. The detection limit for ferritin with this method is lower than that with the enzyme-linked immunosorbent spectrophotometric assay(ELISA).

Key words: IMMUNOASSAY, FERRITIN, AMINOPHENOL, HYDROGEN PEROXIDE, VOLTAMMETRY