Aggregation-Induced Near-Infrared Emission and Electrochemiluminescence of an Iridium(III) Complex for Ampicillin Sodium Sensing

Abstract

A new iridium(III) complex was synthesized and characterized. Its photophysical properties and aggregation-induced emission and electrochemiluminescence in the near-infrared range were studied. The large conjugated cyclometallic ligand 1,2-phenylbenzoquinoline (pbq) was selected to form the Ir−C bond with the metal iridium(III) center and provide near-infrared emission of the complex. The auxiliary ligand 4,4′-diamino-2,2′-bipyridine (dabpy) can form hydrogen bonds, which was beneficial for the generation of aggregation-induced emission. The complex was aggregated into small spherical nanoparticles in 80% water and fascinating nanorings in 90% water. The sensing of ampicillin sodium (AMP) antibiotic by the iridium(III) complex were also investigated by photoluminescent and electrochemiluminescent methods. The complex showed a good selectivity toward AMP antibiotic compared to sodium phenylacetate and other eight antibiotics. The detection limits for AMP antibiotic was 0.76 μg/mL. This work provided a new strategy for the design of iridium(III) complex-based aggregation-induced emission and electrochemiluminescence probes for the sensing application.

Towards efficient Ir(iii) anticancer photodynamic therapy agents by extending π-conjugation on N^N ligands

“…This effect is ascribed to the shielding caused by π,π-stacking interactions between the N^N ligands of different Ir molecules. 22,49–51 In contrast, the resonances of the aromatic protons of the C^N ligands are either, not shifted, or only slightly shifted downfield. Therefore, these results confirm the tendency of IrL4 and IrL5 to form self-aggregates mediated by π,π-stacking interactions when the concentration is increased.…”