Electrochemiluminescence of a Novel Iridium(III) Complex with Dual-Potential Emission and Its Sensing for Chloramphenicol

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 in 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 the anodic route) and excellent stability, with a relative ECL efficiency (ΦECL) 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.