Label-free electrochemiluminescence immunosensor based on Ce-MOF@g-C3N4/Au nanocomposite for detection of N-terminal pro-B-type natriuretic peptide

Abstract

In this work, a label-free electrochemiluminescence (ECL) immunosensor was constructed for the sensitive detection of a heart failure biomarker, N-terminal pro-B-type natriuretic peptide (NT-proBNP). Graphite-phase carbon nitride nanosheets (g-C3N4 NS) loaded on cerium-metal organic frameworks (Ce-MOF) were exploited as ECL probes. The porous matrix with large specific surface area and excellent adsorption performance not only improves the ECL efficiency of g-C3N4 NS but also obviously enhances the interfacial stability of g-C3N4 NS. In addition, a great many of Au NPs are loaded on the surface of Ce-MOF@g-C3N4, forming a good immunosensor platform, which not only improves the conductivity of Ce-MOF@g-C3N4, but also enables the facile immobilization of anti-NT-proBNP on the platform. Under the optimal experimental conditions, the linear range for the detection of NT-proBNP is 0.005–20ngmL−1, and the detection limit is 3.59pgmL−1. (S/N=3). Compared with the label-based ECL immunoassay, the constructed label-free immunosensor is much simpler and time-saving. Additionally, the ECL immunosensor shows good stability, reproducibility and specificity.