Electrochemical luminescence immunosensor for α-fetoprotein

A homogeneous immunoassay for α-fetoprotein (AFP) based on electrochemical luminescence is described. Luminol-labeled anti-AFP antibody was synthesized by coupling of diazoluminol with antibody. Homogeneous immunoassay for AFP was performed using the luminol-labeled anti-AFP antibody. A luminol-labeled antibody generated luminescence upon electrochemical oxidation and the luminescence markedly decreased in the presence of antigen, because the bound antigen inhibited the electrode reaction. A standard curve indicated that the lower limit of AFP determination should be 10 −11 g ml −1 in the time required for 5 min. The immunoassay for AFP in human control serum was also studied.