<p>The residue of chloramphenicol (CAP) in animal-derived foods and the environment poses a serious threat to human health, highlighting the urgent need for sensitive, selective, and rapid detection methods. In this study, a novel electrochemiluminescence resonance energy transfer (ECL-RET)-based sensing platform was developed for the ultrasensitive detection of CAP, employing a Tb-PTC/Ag MOF composite as the energy donor and hollow ZIF-8@polydopamine (ZIF-8@PDA) as the energy acceptor. Coordination of Tb³⁺ with PTCA ligands within the MOF framework effectively suppressed aggregation-induced quenching, while the incorporation of Ag MOF further enhanced and stabilized the ECL intensity through synergistic effects. Efficient ECL-RET was achieved owing to the spectral overlap between the UV-vis absorption of the acceptor and the ECL emission of the donor, with a high energy transfer efficiency of 75.1%, significantly improving the sensitivity of the sensor. The proposed platform exhibited a wide linear range from 10⁻⁵ to 10⁻¹⁵&#xa0;mol L⁻¹ for CAP detection, with an exceptionally low detection limit of 1.57 × 10⁻¹⁵&#xa0;mol L⁻¹. By integrating the structural advantages of MOFs with the high sensitivity of the ECL-RET strategy, this work establishes a robust and promising platform for trace-level CAP monitoring in environmental and food samples.</p> Graphical abstract <p></p>