An electrochemical immunosensor for simultaneous point-of-care cancer markers based on the host–guest inclusion of β-cyclodextrin–graphene oxide

Abstract

A novel electrochemical immunosensor was developed for the simultaneous detection of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) using Cu₂O-graphene oxide-β-cyclodextrin (Cu₂O-GO-CD) and β-cyclodextrin-graphene oxide-ferrocenecarboxylic acid (GO-CD-Fc-COOH) as the distinguishable signal probe, and graphene oxide-gold nanoparticles (GO-AuNPs) as the sensor platform. GO-CD displayed excellent solubility in water and rich capture capability to Fc-COOH and the secondary antibody. The proposed immunosensor exhibited an excellent electrochemical performance. The linear ranges were from 0.001 ng mL^-1 to 80 ng mL^-1 for AFP and CEA with a detection limit of 0.0002 ng mL^-1 for AFP and 0.0001 ng mL^-1 for CEA. With the merits of acceptable stability, high sensitivity, a wide linear range and a low detection limit, the proposed immunosensor showed great potential for the simultaneous detection of multi-analytes in clinical diagnosis.