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Updated: Jun 13, 2026

Iridium(III) Luminescent Probe for Detection of the Malarial Protein Biomarker Histidine Rich Protein-II
Published on: July 7, 2015
Cationic iridium(III) complex containing both triarylboron and carbazole moieties as a ratiometric fluoride probe
Wen-Juan Xu1, Shu-Juan Liu, Xin-Yan Zhao
1Jiangsu Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210046, China.
Abstract:
A novel cationic Ir(III) complex [Ir(Bpq)(2)(CzbpyCz)]PF(6) (Bpq=2-[4-(dimesitylboryl)phenyl]quinoline, CzbpyCz = 5,5'-bis(9-hexyl-9H-carbazol-3-yl)-2,2'-bipyridine) containing both triarylboron and carbazole moieties was synthesized. The excited-state properties of [Ir(Bpq)(2)(CzbpyCz)]PF(6) were investigated through UV/Vis absorption and photoluminescence spectroscopy and molecular-orbital calculations. This complex displayed highly efficient orange-red phosphorescent emission with an emission peak of 583 nm and quantum efficiency of Phi=0.30 in dichloromethane at room temperature. The binding of fluoride ions to [Ir(Bpq)(2)(CzbpyCz)]PF(6) can quench the phosphorescent emission from the Ir(III) complex and enhance the fluorescent emission from the N--N ligand, which corresponds to a visual change in the emission from orange-red to blue. Thus, both colorimetric and ratiometric fluoride sensing can be realized. Interestingly, an unusual intense absorption band in the visible region was observed. And the detection of F(-) ions can also be carried out with visible light as the excitation wavelength. More importantly, the linear response of the probe absorbance change at lambda=351 nm versus the concentration of F(-) ions allows efficient and accurate quantification of F(-) ions in the range 0-50 microM.
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