Electrochemiluminescence of a novel iridium(iii) complex with dual-potential emission and its application in chloramphenicol sensing

Abstract

Three Ir(C^N)₂(N^N)⁺ complexes with the same C^N ligand and different N^N ligands were synthesized, and their electrochemiluminescence (ECL) properties were systematically investigated using TPA and K₂S₂O₈ as coreactants, respectively. It was found that the introduction of carboxyl groups into the N^N ligand gave Ir-COOH the strongest ECL signal. Additionally, the cathodic ECL pathway (with K₂S₂O₈) exhibited significantly higher intensity (10-fold greater than that of the anodic route) and excellent stability, with a relative ECL efficiency (Φ_ECL) of 188% (vs. 100% for the Ru(bpy)₃²⁺/K₂S₂O₈ reference). Then, a sensitive ECL sensor based on Ir-COOH-SWCNTs–Au/GCE for chloramphenicol (CAP) detection was constructed.