Metal-organic framework-enhanced Electrochemiluminescence of pyrene-based ligands for sensitive CEA detection

The early and sensitive detection of cancer, a malignant disease posing significant threats to human health, is of strategic importance for disease prevention and control. This study employed 1,3,6,8-tetra(4-carboxyphenyl)pyrene (H₄TBAPy), a fluorophore exhibiting aggregation-caused quenching (ACQ), to construct a zinc-based metal-organic framework (Zn-TBAPy) serving as an energy donor platform. Polydopamine-coated ZIF-67 (ZIF-67@PDA) was employed as the energy acceptor to construct an electrochemiluminescence (ECL) immunosensor for sensitive carcinoembryonic antigen (CEA) detection. The advantages of ECL immunosensor are primarily manifested in the following three aspects: (1) Zn-TBAPy not only mitigates ACQ caused by polycyclic aromatic hydrocarbon π-π stacking but also enhances chromophore loading capacity and specific surface area. Relative to aggregate systems, the Zn-TBAPy exhibits a 2.5-fold enhancement in ECL signal intensity. (2) ZIF-67@PDA exhibits favorable broad-spectrum absorption characteristics and excellent quenching efficiency; as well as demonstrates superior biocompatibility for immunosensor construction. (3) The immunosensor was constructed through an electrochemiluminescence resonance energy transfer (ECL-RET) mechanism, yielding markedly improved sensitivity; the developed sensor demonstrated a linear detection range from100 fg·mL^-1 to 80 ng·mL^-1with LOD) of 0.275 pg·mL^-1. In conclusion, this study provides a valuable research strategy for the construction of immunosensors based on novel luminophore materials.