A novel micron europium cluster coordination polymer as a strong electrochemiluminescent emitter for accurate and sensitive detection of tetracycline

•A self-luminescent lanthanide cluster coordination polymer (Eu-CCP) was synthesized.•Eu-CCP has a high-nucleation luminescence center (Eu in Eu-CCP is 50.1%).•The ECL intensity of Eu-CCP/S2O82− is 6.5-fold higher than that of Ru(bpy)32+/S2O82−.•An efficiency ECL sensor for TC detection was built using Eu-CCP as a luminophore.•This ECL sensor achieves accurate and sensitive detection of TC in actual samples. In this work, a self-luminescent micron europium cluster coordination polymer (Eu-CCP) cathode electrochemiluminescence (ECL) emitter is first reported. The mass percentage of Eu in Eu-CCP is 50.1%, indicating that Eu-CCP has a high-nucleation luminescence center. In addition, our Eu-CCP possesses a stable and efficient ECL red emission performance, and the intensity is approximately 6.5-fold higher than that of the traditional tris(2,2′-bipyridyl)ruthenium(II) dichloride. The enhancement of Eu-CCP luminescence in our system is due to the following reasons: (1) the mixed ligand and high nuclear europium luminescent center can cooperate to improve the quenching effect induced by water or hydroxyl groups; and (2) external coreaction accelerator and coreactant enhancement. We also investigate the application of Eu-CCP in ECL sensors by sensitive detection of tetracycline (TC). The low detection limit (73.5 fmol·L−1), high selectivity, good stability and satisfactory recoveries indicate that our ECL strategy can be used to detect TC accurately and sensitively.