▎ 摘　　要

A graphene/gold nanoparticles (Au NPs) composite was one-pot synthesized to design a new gold nanoprobe for electrochemical immunoassay. After sandwich immunoreaction at a carbon nanotubes (CNTs)-based immunosensor, the nanoprobes were quantitatively captured on the immunosensor surface and produced sensitive signal response through the electrochemical stripping analysis of Au NP labels. Both the multi-label signal amplification of nanoprobe and the electrode modification of CNTs greatly improved the signal response resulting in the development of an ultrasensitive immunoassay method for human IgG measurement. Additionally, this method also showed wide linear range, high specificity as well as satisfactory reproducibility, stability and reliability.