Pre-clinical validation study of a miniaturized electrochemical immunoassay based on square wave voltammetry for early detection of carcinoembryonic antigen in human serum

Background: The ELISA format for measuring carcinoembryonic antigen (CEA) serves as a reference standard against which other assays are compared. Because the World Health Organization (WHO) increasingly recommends the use of serum CEA as a diagnostic tool for cancer, it is relevant to explore the reliability of the new decentralized CEA point-of-care-testing (POCT) technologies that are available to physicians and patients, in compliance with mandates of the clinical laboratories' regulatory agencies. Methods: Electrochemical immunoassay (ECIA) based on trace lead (Pb) analysis by anodic stripping techniques using sandwich-type immunocomplex conjugates: (MB)Ab/Ag-CEA/Ab(PbS), and a commercial ELISA test system with optical transmission. Results: The ECIA provides better analytical performance than does the ELISA. The within assay precision coefficient of variance (%CVw) of the ECIA is lower than the value recommended by the Hong Kong Association of Medical Laboratories (HKAML), and the recoveries of CEA at 1.0, 5.0, 10.0, 25.0 and 50.0 ng/ml are in the range of 99-110% for control serum samples. The ECIA showed a minimal positive bias of 0.0267 +/- 03270 ng/ml (P = 0.9389). Conclusions: The proposed CEA screening technology can be practically employed for decentralized clinical analysis of CEA in human serum. Therefore, it can be viewed as a control method for personalized therapy. (C) 2015 Elsevier B.V. All rights reserved.