pH-responsive aldehyde-bearing cyclometalated iridium(Ⅲ)complex for tracking intracellular pH fluctuations under external stimulation

• Published in: 中国化学快报（英文版） 2023, Vol.34 (2), p.244-248
• Main Authors: Manping Qian, Danyang Zhang, Hetong Qi, Xuebing Yang, Guanjun Yin, Chengxiao Zhang, Jianzhong Guo, Honglan Qi
• Format: Article
• Language: English
• ISSN: 1001-8417

Intracellular pH undertakes critical functions in various biological and pathological processes.It is impor-tant to monitor intracellular pH fluctuations for understanding physiological and pathological processes.Here,one aldehyde-bearing cyclometalated iridium(Ⅲ)complex([(4-pba)2Ir(dcphen)]PF6,4-pba=4-(2-pyridyl)benzaldehyde,dcphen=4,7-dichloro-1,10-phenanthroline,probe 1)was synthesized and used to track intracellular pH fluctuations.Probe 1 displayed pH-dependent luminescence property in pH range of 1.81-6.81 with an evaluated pKa value of 4.30 in BR buffer-DMSO(v∶v=99∶1).An intramolecular hy-drogen bonds assisted pH-responsive mechanism was proposed for the pH-responsive behavior of probe 1.Probe 1 was successfully applied for imaging and tracking pH fluctuations in HeLa cells under external stimulation with fast response time,good photostability as well as low cytotoxicity and high cell perme-ability.This work demonstrates that aldehyde-bearing cyclometalated iridium(Ⅲ)complex can be used as alternative pH-responsive probe for real-time tracking intracellular pH fluctuations,which provides a strategy for the design of pH-responsive probe in versatile applications.