A voltammetric enzyme-linked immunoassay based on a new system of o-tilidine (OT)-H2O2-horseradish peroxidase (HRP) has firstly been developed. In this method, the enzyme-catalyzing reaction of H2O2 oxidizing OT couples the electro-reduction reaction of the oxidizing product of OT, which produces a sensitive voltammetric wave at potential of -0.58V (vs. SCE) in Britton-Robinson buffer solution. When it is used in the detection of clasical ELISA method, respectively. The detection limit to HRP is 1.8×10^-^1^2 g/mL and the linear range 5.0×10^-^1^2-1.0×10^-^8 g/mL. The mechanism of the voltammetric enzyme-linked immunoassay system has also been studied in detail.

Key words: VOLTAMMETRY, REACTION MECHANISM, HYDROGEN PEROXIDE, COUPLING REACTION