Intracellular pH undertakes critical functions in various biological and pathological processes. It is important 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 hydrogen 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 permeability. 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.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |