A water-soluble cyclometalated iridium(III) complex with fluorescent sensing capability for hypochlorite.

Herein, a novel cyclometalated iridium (III) complex (Ir-1) with good water-solubility was designed and synthesized to sensitively detect hypochlorite (ClO−) in aqueous buffer solution. The sensor Ir-1 was prepared by incorporating a methacrylate group into cyclometalated ligands, which was a specific response site toward ClO− through an oxidation process. Ir-1 displayed strong emission at 615 nm, while significant fluorescence quenching was observed upon addition of ClO− with a low detection limit of 0.41 μM. Moreover, probe Ir-1 exhibited a rapid response (<30 s) for ClO− with high selectivity over potentially competing species. The sensing process was evidenced by NMR and MS characterization. Further application in bioimaging of ClO− was successfully performed in living HepG2 cells. Image 1 • A water-soluble fluorescent probe based on cyclometalated iridium (III) complex was designed and synthesized. • The probe displayed a fast response toward ClO− (<30 s) with a low detection limit of 0.41 μM. • The probe showed high selectivity toward ClO− over other reactive oxygen species. • The probe was successfully applied for bioimaging of ClO− in living cells. [ABSTRACT FROM AUTHOR]