A convenient signal amplification strategy for the carcinoembryonic antigen determination based on the self-polymerization of dopamine

In this study, due to the oxidative and strong adhesion characteristics of mussel-inspired polydopamine, the aimed antibody-anti-CEA could be directly attached to the polydopamine-coated glassy carbon electrode surface. The immobilization method and sandwich immunoreactions strategy were applied to form a facile and effective electrochemical immunosensor. Anti-CEA was verified by attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Under optimum conditions, a linear response range of CEA from 0.01 to 80 ng/mL with a low detection limit of 1.58 pg/mL was obtained by the differential pulse voltammetry determination. Assay results of clinical serum samples using the standard ELISA and reference methods gave an excellent correlation and dependence. Moreover, the preparation of immunosensor with low cost, convenient operation, and all steps processing at room temperature which possesses great potentials for practical applications.