Identification of Aptamer Specific for Carcinoembryonic Antigen and its Analytical Applications

Carcinoembryonic Antigen (CEA) is an approved cancer biomarker by the Food and Drug Administration (FDA) for the early detection, diagnosis, and for the use in the regular screening of patients at high risk for the development of cancer. Traditional methods to determine the concentrations of CEA are based on utilizing antibodies. In this project, a graphene oxide (GO)?assisted systematic evolution of ligands through exponential enrichment (SELEX) was used to identify DNA aptamers specific for CEA. The dissociation constants of the identified aptamers were determined with surface plasmon resonance (SPR). Comparison of the dissociation constants of aptamers isolated from the GO-based SELEX and affinity SELEX found the dissociation constant of the aptamers isolated from GO-assisted SELEX was three times lower than aptamers isolated from the affinity SELEX. The analytical applications of the identified aptamers were studied by developing a colorimetric test for the determination of CEA with un-modified gold nanoparticles.