Copper Single-Atom Catalysts Boosting Electrochemiluminescence of Iridium Nanoparticles for Perfluorooctanoic Acid Analysis

Iridium complexes have always been the predominant focus in traditional iridium-based electrochemiluminescence (ECL) luminophores. However, their application often involves a laborious preparation process and significant costs. This study innovatively developed a simple and cost-effective method that enabled the direct synthesis of iridium nanoparticles (Ir NPs) from iridium trichloride. This synthesis was achieved through the reduction of iridium ions by 6-aza-2-thiouridine and the inhibition of nonradiative decay of Ir NPs by l-arginine as a second ligand. Moreover, copper single atoms anchored on defect-engineered UiO-66 were developed to significantly enhance ECL emission of Ir NPs at -2.0 V through efficiently catalyzing the generation of sulfate radical species from the coreactant S₂O₈²^-. Ir NPs@Cu_sa/UiO-66 was integrated with an aptamer recognition-driven nucleic acid amplification strategy to enable ultrasensitive ECL detection of perfluorooctanoic acid.