Synthesis of water soluble PEG-functionalized iridium complex via click chemistry and application for cellular bioimaging

A water soluble iridium (III) complex was prepared via click chemistry. It shows the bright red phosphorescence centered at 625 nm with a quantum yield of ~ 1.4% in the phosphate buffered saline (PBS) solution. Furthermore, it has low cytotoxicity, good membrane permeability and exclusive staining in cytoplasm, which can be an excellent promising candidate for the design of new generation luminescent bioprobes.