Novel electrochemical aptamer biosensor based on gold nanoparticles signal amplification for the detection of carcinoembryonic antigen

A novel electrochemical aptamer biosensor was designed based on the signal amplification of gold nanoparticles (AuNPs) for the detection of a tumor biomarker, carcinoembryonic antigen (CEA). The electrochemical biosensor was constructed by sandwiching the CEA between an Au electrode modified with thiol-terminated CEA aptamer-1 (Apt1) and the AuNPs with thiol-terminated CEA aptamer-2 (Apt2) and 6-ferrocenyl hexanethiol (Fc). Amperometric detection of Fc by differential pulse voltammetry (DPV) on the electrochemical biosensor was used to quantify the concentration of CEA. The biosensor provided a linear range from 1 to 200 ng/mL for CEA with a detection limit of 0.5 ng/mL. Its performance was successfully evaluated with human serum spiked with CEA, indicating that the aptasensor has great potential for practical application. In addition, the electrochemical biosensor exhibited excellent selectivity responses and good stability toward the target analyte.