An electrochemical immunosensor modified with titanium IV oxide/polyacrylonitrile nanofibers for the determination of a carcinoembryonic antigen

Abstract

Carcinoembryonic antigen (CEA) is considerably addressed for the clinical diagnosis of miscellaneous tumor types. In this study, an electrochemical immunosensor for the determination of the CEA biomarker was presented. Titanium(IV) oxide nanoparticle (TiO₂np)-loaded polyacrylonitrile nanofibers (PANnf) were prepared by electrospinning at the surface of the discharged battery coal electrode (DBC), and loaded with CEA antibodies (Anti-CEA) as the CEA biomarker receptor. Finally, DBC/PANnf + TiO₂np/Anti-CEA was utilized for the CEA detection. Fabrication steps were characterized by cyclic voltammetry and electrochemical impedance spectroscopy in the presence of a [Fe(CN)₆]^3−/4− probe. Results demonstrated that PANnf and TiO₂nps exhibited a very fine network for immunosensing. The usage of this composite system is a novel immunosensor development approach for the label-free detection of CEA. Under optimal conditions, the DBC/PANnf + TiO₂np/Anti-CEA immunosensor exhibited high sensitivity toward the CEA biomarker in the low concentration range of 0.01–10 ng mL⁻¹, with the detection limit of 0.01 ng mL⁻¹ and relative standard deviation of 1.17 (n = 5). Results indicated that even very small changes in the CEA concentration can be sensed with the presented system. Also, the recovery of the immunosensor was found to be 99.42% ± 1.41 in real sera samples containing dopamine and ascorbic acid. It has great potential in the clinical screening of divergent cancer biomarkers.