A Sm-MOF@Ag electrochemiluminescence immunosensor mediated by CuBi2O4@PDA dual-mode quenching for sensitive detection of anti-Müllerian hormone.

By exploiting the dual-quenching effect of CuBi2O4@PDA on Sm-MOF@Ag, we developed a signal-on/signal-off electrochemiluminescence (ECL) immunosensor for the sensitive detection of anti-Müllerian hormone (AMH). A novel samarium-based metal-organic framework (Sm-MOF) was employed as the luminophore, with K2S2O8 used as the co-reactant to generate a stable ECL signal. Silver nanoparticles were in situ decorated on the Sm-MOF surface to act as co-reactant accelerators, promoting SO4•- generation and significantly enhancing the ECL intensity. For signal quenching, energy transfer from the Sm-MOF@Ag donor to the CuBi2O4 acceptor was rationally designed based on their matched energy levels, resulting in pronounced attenuation of the ECL emission. Meanwhile, the polydopamine shell further improved the quenching efficiency by scavenging SO4•- radicals. Under optimized conditions, the proposed ECL immunosensor exhibited a wide linear range from 10 fg·mL- 1 to 100 ng·mL- 1 and a detection limit of 2.6 fg·mL- 1. This dual-quenching strategy represents a novel method for the detection of AMH, with substantial potential for implementation in clinical diagnostics.