Electrogenerated Chemiluminescence Immunoassay for Human IgG with Electrochemical Polymerization-based Immobilization Method

Rabbit-antihuman Immunoglobulin G (IgG) was immobilized on a gold electrode by electrochemical polymerization with pyrrole. An efficient immunoassay strategy for human IgG determined in human serum was developed based on the specific immunological reaction between the rabbit-antihuman IgG, human IgG, and Ru(bpy)32+-labled goat-anti-human IgG, which forms sandwich-typed immunocomplex. Then, the target IgG in the sandwich-typed structure was determined using electrogenerated chemiluminescence. The parameters of polymerization time, the incubation time, and the pH of detection solution were optimized. The protocol has been characterized with impendence, cyclic voltammogram, and electrogenerated chemiluminescent (ECL). A good linear relationship between ECL intensity and human IgG in the range of 0.05–2 mg l−1 was obtained, and the detection limit was 20 μg l−1.