Hydroxyphenylquinazolinone-based turn-on fluorescent probe for β-galactosidase activity detection and application in living cells

A new-type fluorescent probe HPQ-βGal based on aggregation induced emission (AIE) and excited state intramolecular proton transfer (ESIPT) is designed, showing a superior detection performance to β-galactosidase activity. HPQ-βGal regulates the β-galactopyranoside to react with β-gal and release the chromophore. The probe proves favorable advantages, such as high sensitivity and selectivity, convenient handling procedures, a large Stokes shift and self-exciting at an aggregated condition. Moreover, HPQ-βGal was also applied in detecting of endogenous and exogenous β-galactosidase activity in OVCAR-3 cells, and the imaging was achieved with high contrast benefitted from its good retention in living cells.