First aggregation-induced emission-active probe for species-specific detection of β-galactosidase

Sensitive detection of β-galactosidase (β-gal) is of great significance for early diagnosis of ovarian cancer. Fluorescent probes for detecting β-gal have received great interest due to the non-invasiveness, excellent sensitivity, high temporal, and superior spatial resolution. However, most reported fluorescent sensors for β-gal suffer from aggregation caused quenching effect when accumulated, and cannot discriminate β-gal from other species, especially, Escherichia coliβ-gal. Herein, we report the first aggregation-induced emission (AIE)-active fluorescent probe HBTTPAG, which achieves species-selective detection of β-gal. Probe HBTTPAG can discriminate Aspergillus oryzae β-gal from Escherichia coliβ-gal, with high sensitivity (detection limit of 3.7 × 10-3 UmL-1), superior selectivity and low cytotoxicity. Furthermore, HBTTPAG is utilized to visualize endogenous β-gal in lysosomes of SKOV-3 cells, as well as to detect β-gal activity in ovarian cancer tissues. Notably, owing to the AIE-active, HBTTPAG realizes long-term (12 h) tracking β-gal in ovarian cancer cells. This work provides a promising method for species-selective detection of β-gal in preclinical.