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.