▎ 摘　　要

The present study was conducted to fabricate a sandwich-type electrochemical aptasensor for the simultaneous determination of two important biomarkers in breast cancer, namely carcinoembryonic antigen (CEA) and cancer antigen 15-3 (CA 15-3). Gold nanoparticles three-dimensional graphene hydrogel (AuNPs/3DGH) nanocomposite was used as a biosensing substrate. CEA and CA 15-3 aptamers linked to gold nanoparticles/redox probe/graphene nanocomposite were used as biosensing probes. Herein, hemin and ferrocene had the role of redox probes for CEA and CA 15-3 respectively and provided electrochemical signals for dual biomarker detection. CEA and CA 15-3 aptamers were immobilized on the surface of an AuNPs/3DGH-modified electrode. The peak currents and the potentials in differential pulse voltammograms reflected the concentration and the nature of the biomarkers. The detection limits of CEA and CA 15-3 at the surface of the duplexed aptasensor were found to be 11.2 pg mL(-1) and 11.2 x 10(-2) U mL(-1), respectively. The duplexed aptasensor was also used to analyze clinical serum samples. The results were in good agreement with the ELISA method, indicating the good reliability of the aptasensor.