A novel AIE fluorescent probe for β-galactosidase detection and imaging in living cells

An AIE fluorescent probe (TPh-PyBz-β-gal) was designed and synthesized for β-gal detection based on a novel AIE fluorophore and receptor unit D-galactose residue connected by glycosidic bond. The probe exhibited selective and sensitive turn-on fluorescent responses toward β-gal with detection limit reaching to 0.22 U/mL in aqueous environment. After studied from measured data, we proposed that a possible recognition mechanism probably resulted from the cleavage of glycosidic bond along with obviously increasing fluorescent signal at 606 nm. Meanwhile, TPh-PyBz-β-gal showed low cytotoxicity, and could be successfully used for β-gal imaging in cells.