A sandwich-type electrochemical immunosensor for detection of carcino embryonie antigen (CEA) was fabricated based on supermolecular labeling strategy. In this work, beta-cyclodextrin (beta-CD)-based host-guest recognition was used to immobilize capture antibody and label detection antibody. beta-CDs functionalized multiwalled carbon nanotube (CDs-MWCNT) was used to immobilize adamantanecarboxylic acid (ADA) functionalized capture antibody onto electrode surface based on host-guest interaction between ADA and beta-CD. The detection antibody was first labeled with ferrocenecarboxylic acid (Fc) and then attached to magnetic Fe3O4@SiO2 core-shell nano particles based on the inclusion interaction between Fc and beta-CD. Fc acts as not only a linker molecule but also electroactive specie. The multiplex labeling of Fc on Fe3O4@SiO2 nanoparticles enabled the signals amplification for CEA after the specific immunoreaction, which was Monitored by square wave voltammetry. Under the optimal conditions, the immunosensor displayed a relatively wide linear range from 0.001 ng mL(-1) to 15 ng with a detection limit of 0.33 pg mL(-1) for the detection of CEA. The newly designed immunosensor showed a promising potential application in clinical diagnosis. (C) 2016 Elsevier B.V. All rights reserved.