A graphene‐PEDOT:PSS modified paper‐based aptasensor for electrochemical impedance spectroscopy detection of tumor marker

Abstract

A graphene and poly (3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) modified conductive paper‐based electrochemical impedance spectroscopy (EIS) aptasensor has been successfully fabricated by a simple and continuous coating process. A graphene/PEDOT:PSS modified paper electrode forms the nanocomposite providing a conductive and sensitive substrate for further aptamer functionalization of the biosensor. This low‐cost paper‐based aptasensor exhibits its sensitivity to carcinoembryonic antigens (CEA) in standard buffer solutions and human serum samples in a linear range of 0.77–14 ng∙mL−1. The limit of detection (LOD) is found to be 0.45 ng∙mL−1 and 1.06 ng∙mL−1 for CEA in both samples, separately. This aptamer‐based sensing device was also evaluated and received a good correlation with the immunoassay detection method. The proposed paper‐based aptasensor has demonstrated its potential as a rapid simple point‐of‐care analytical platform for early cancer diagnosis in less developed areas where manufacturing facilities, analytical instruments, and trained specialists are limited.