Electrochemical Immunosensor for a-Fetoprotein Based on Gold Nanoparticles/Graphene-Prussian Blue

The electrochemical immunosensor for a-fetoprotein (AFP) was fabricated based on the platform of gold nanoparticles (GNP)/graphene (Gr)-prussian blue (PB). By electrodeposition, GNP were modified on the surface of the prepared Gr-PB. The anti-AFP-1,1'-ferrocenedicarboxylic acid (FcDA) as label was directly immobilized on the platform of GNP/Gr-PB. And after the immunoreactions, the formed complex inhibited the electron transfer and decreased the catalytic current of FcDA toward the reduction of H2O2. And in the range of 10-3200 pg center dot mL-1, the decreased current is linear with the concentration of AFP, with a detection limit of 3 pg center dot mL-1. The developed immunoassay method showed good precision, high sensitivity, acceptable stability and reproducibility, and could be used for the detection of real samples with consistent results in comparison with those obtained by the enzyme linked immunosorbent assay (ELISA) method.