One step electrochemically deposited nanocomposite film of chitosan–carbon nanotubes–gold nanoparticles for carcinoembryonic antigen immunosensor application

A simple and controllable one-step electrodeposition method for the preparation of a chitosan–carbon nanotubes–gold nanoparticles (CS–CNTs–GNPs) nanocomposite film was used to fabricate an immunosensor for detection of carcinoembryonic antigen (CEA). The porous three-dimensional CS–CNTs–GNPs nanocomposite film, which offered a large specific surface area for immobilization of antibodies, exhibited improved conductivity, high stability and good biocompatibility. The morphology of the formed nanocomposite film was investigated by scanning electron microscopy (SEM), and the electrochemical behaviors of the immunosensor were characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Under the optimal conditions, the proposed immunosensor could detect CEA in two linear ranges from 0.1 to 2.0 ng mL−1 and from 2.0 to 200.0 ng mL−1, with a detection limit of 0.04 ng mL−1. The immunosensor based on CS–CNTs–GNPs nanocomposite film as the antibody immobilization matrix could exhibit good sensitivity, stability, and reproducibility for the determination of CEA.