▎ 摘　　要

Nobel metal nanoparticles have attracted intense attentions in biological immunoassay due to the inhereted good catalytic activity. In this study, a new kind of nanocomposite of ternary Pt@Pd@Ru nanodendrite-decorated graphene oxide (GO-Pt@Pd@Ru) was prepared as a signal label for ultrasensitive detection of carcinoembryonic antigen (CEA). With a sandwich type immunoassay, the established electrochemical immunosensor showed highly sensitive detection performance towards CEA in a linear range (0.1 pg mL(-1) to 9 ng mL(-1)) with an ultralow detection limit of 0.05 pg mL(-1). The enhancing detection performance could be attributed to: ternary Pt@Pd@Ru nanodendrites have exhibited superior electrochemical reduction activity towards H2O2, then GO-Pt@Pd@Ru can combine all generated electrochemical reduction current towards H2O2 by the decorated Pt@Pd@Ru nanodendrites, which can significantly amplify the detection signal.