An electrochemiluminescence immunosensor based on functionalized metal organic layers as emitters for sensitive detection of carcinoembryonic antigen

The concentration of carcinoembryonic antigen (CEA) is an important indicator for clinical monitoring and diagnosis of tumor. Early sensitive detection of CEA is significant for cancer diagnosis and therapy. In this study, a sensitive electrochemiluminescence (ECL) immunosensor was fabricated based on functionalized metal organic layers (MOLs) for the determination of CEA. In this immunosensor, Au nanoparticles (AuNPs) were grown on ultrathin two-dimensional MOLs via in situ reduction. AuNPs not only can accelerate the electron transfer but also can be used as the labels to conjugate with antibody. The as-prepared AuNPs@Ir-Zr-MOL nanocomposite showed high ECL efficiency and can be used as an ECL emitter owing to the great ECL property of Ir-Zr-MOL. The ECL intensity of AuNPs@Ir-Zr-MOL decreased linearly with the logarithm of CEA concentration in the range from 1.00 pg mL−1 to 100 ng mL−1. And the detection limit was 0.200 pg mL−1 (S/N = 3). What’s more, the as-prepared immunosensor worked well in human blood samples, showing its potential for real analysis.