Dual‐emissive Iridium(III) Complexes as Phosphorescent Probes with Orthogonal Responses to Analyte Binding and Oxygen Quenching

• Published in: Angewandte Chemie International Edition Vol. 62; no. 37; pp. e202309178 - n/a
• Main Authors: Zhu, Rongji, Dai, Peiling, Yang, Jun, Zhou, Jie, Zhang, Jin, Zhang, Kenneth Yin, Li, Yonghua, Liu, Shujuan, Lo, Kenneth Kam‐Wing, Zhao, Qiang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 11-09-2023
• Edition: International ed. in English
• Subjects: Aqueous solutions; Bioimaging; Colorimetry; Copper; Dual-Emission; Ions; Iridium; Iridium compounds; Oxygen; Phosphorescence; Probes; Quenching; Wavelength; Dual-Emission; Bioimaging; Phosphorescence; Iridium; Probes
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202309178

Phosphorescent probes often show sensitive response toward analytes at a specific wavelength. However, oxygen quenching usually occurs at the same wavelength and thus hinders the accurate detection of analytes. In this study, we have developed dual‐emissive iridium(III) complexes that exhibit phosphorescence responses to copper(II) ions at a wavelength distinct from that where oxygen quenching occurs. The complexes displayed colorimetric phosphorescence response in aqueous solutions under different copper(II) and oxygen conditions. In cellular imaging, variation in oxygen concentration over a large range from 5 % to 80 % can modulate the intensity and lifetime of green phosphorescence without affecting the response of red phosphorescence toward intracellular copper(II) ions.
We reported dual‐emissive iridium(III) complexes bearing a di(2‐picolyl)‐amine (DPA) unit, which exhibited green and red dual phosphorescence in aqueous solutions. The complexes exhibited static and dynamic phosphorescence quenching in response to copper(II) ions and oxygen, respectively, at different wavelengths, achieving colorimetric emission response in solutions and multichannel response in live cell imaging.