Development of electrochemical immunosensor for CEAdetection

In this study, an electrochemical immunosensor was developed for the detection of carcinoembryonic antigen (CEA). For this purpose, a monolayer consisting of a mixture of 3-mercaptopropionic acid (MPA) and 11-mercaptoundecanoic acid (MUA) was initially formed on the gold electrode surface. Subsequently, the electrode surface was sequentially modified with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS), anti-CEA, and bovine serum albumin (BSA) for the preparation of the immunosensor. For the prepared immunosensor, the MPA/MUA ratio and the times of MPA/MUA, EDC/NHS, BSA, anti-CEA, and CEA were optimized. Differential pulse voltammetry was used for electrochemical measurements. The linear range of the immunosensor was determined to be 0.05-50 ng/mL, and the limit of detection was 0.03 ng/mL.