Dual-ligand strategy boosted electrochemiluminescence sensing based on Tb-MOF/Ag₃PO₄@TCPP

A dual-ligand strategy was employed to construct an electrochemiluminescence (ECL) sensing platform based on dual-ligand Tb-MOF and Ag₃PO₄@TCPP for sensitive detection of chloramphenicol (CAP), demonstrating its potential applications in environmental monitoring and food safety. The dual-ligand Tb-MOF can be used as a co-reactant promoter, facilitating the rapid electroreduction of S₂O₈^2- to generate more oxidative mediator SO₄^•-, thereby enhancing the luminescence efficiency of the luminescent material Ag₃PO₄@TCPP. Furthermore, the integration of Ag₃PO₄@TCPP emitter could effectively overcome the aggregation-caused quenching (ACQ) effect of TCPP and then increase the luminescence intensity by seven-fold, which was attributed to the efficient electron transfer and energy transfer between Ag₃PO₄ and TCPP. Additionally, ECL spectra and electron spin resonance (ESR) spectra were utilized to investigate the possible ECL mechanism of the dual-ligand Tb-MOF/Ag₃PO₄@TCPP system. As a proof of concept, we successfully established an ECL biosensor for detecting CAP, which displayed a wide linear range (10^-6 ~ 10^-15 M) and low detection limit (8.29 × 10^-16 M), demonstrating practical feasibility. This study introduces a dual-ligand strategy to enhance ECL signals, expands the application scope of dual-ligand lanthanide MOFs, and provides new insights into designing high-performance sensing platforms.