▎ 摘　　要

In this work, we designed a gold nanoparticles (Au NPs) as a sensing platform, rGO/Co3O4@PDA-Ag NPs-Ab(2) as a tag electrochemical immunosensor for the detection of carcinoembryonic antigen (CEA). Graphene (rGO) rich in oxygen-containing groups can be more loaded with cobalt trioxide (Co3O4) and mild dopamine (DA) reduced silver nanoparticles (Ag NPs). The sensitive detection of CEA was obtained by differential pulse voltammetry (DPV) through the double-amplified electrochemical signal of hydrogen peroxide (H2O2) reduction catalyzed by Ag NPs and Co3O4. The linear range of the immunosensor is 0.0005 ng/mL-80 ng/mL, the minimum detection limit is 0.17 pg/mL. Immunosensor exhibit excellent repeatability, sensitivity and selectivity. This strategy has potential application value for initial clinical diagnosis.