INVESTIGATION OF VOLTAMMETRIC ENZYME-LINK ED IMMUNOASSAY BASED ON NEWSYSTEM OF OT-H2O2-HRP

A voltammetric enzyme-linked immunoassay based on a new system of o-ti lidine (OT)-H2O2-horseradish peroxidase (HRP) has firstly been develop ed. In this method, the enzyme-catalyzing reaction of H2O2 oxidizing O T couples the electro-reduction reaction of the oxidizing product of O T, 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 free HRP and labelled HRP, the sensitivity is nearly two and four-order higher than that of classical ELISA method, respective ly. The detection limit to HRP is 1.8X10(-12) g/mL and the linear rang e 5.0X10(-12)similar to 1.0X10(-8) g/mL. The mechanism of the voltamme tric enzyme-linked immunoassay system has also been studied in detail.