Electrochemiluminescence immunosensor for sensitive determination of tumor biomarker CEA based on multifunctionalized Flower-like Au@BSA nanoparticles

A novel electrochemiluminescence (ECL) immunosensor has been designed for determination of tumor marker carcinoembryonic antigen (CEA) by utilizing multifunctionalized Flower-like Au@BSA nanoparticles as biosensing interface. In this work, Au@BSA nanoparticles with large surface area, good electroconductivity and excellent biocompatibility were not only employed as an electrochemiluminescence interface but also as ideal carriers to immobilize numerous luminol molecules and CEA capture antibodies (Anti-CEA) acted as signal probe and molecule recognition probe, respectively. In addition, AuNPs were electrodeposited onto the glassy carbon electrode (GCE) surface to construct an outstanding base for this immunosensor. The fast constructed sensing platform could specifically capture antigen CEA, hindering the electron transfer of the ECL reaction between luminol and H2O2 owing to the barrier of the attached immunoprotein layer and thereby resulted in the decrease of ECL intensity. Under the optimal conditions, ECL intensity of the immunosensor decreased linearly with the logarithm of CEA concentration ranging from 0.001 to 200 ng/mL with a low detection limit of 0.0003 ng/mL (S/N = 3). The as-prepared sensing technique exhibited favorable performance and could be applied to detect CEA in real serum samples with satisfactory results, indicating that the proposed strategy provides an alternative scheme for other clinically important biomarkers assay.