Electrochemical immunosensor based on hyperbranched structure for carcinoembryonic antigen detection

Sensitive determination of carcinoembryonic antigen (CEA) is very important in clinical research and diagnosis. Herein we report the design and synthesis of a new kind of immunosensor based on the benefits of hyperbranched structure. The hyperbranched polyester was grafted to the surface of indium tin oxides glass (ITO) electrode, and the grafting processes were characterized by attentuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). After CEA and horse radish peroxidase (HRP)-labeled antibody-conjugated AuNPs (HRP-Ab(2)-AuNPs) bioconjugates were immobilized on the surface of the hyperbranched structure-modified electrode, the optimized conditions of the above electrode were investigated. Moreover, the analytical performance of the proposed immunosensor showed a high sensitivity, a linear range from 0.01 to 80 ng/mL with a low detection limit of 2.36 pg/mL, and good selectivity for CEA. The designed immunoassay system holds great potential for ultrasensitive electrochemical biosensing of other analytes. (C) 2014 Elsevier B.V. All rights reserved.