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

Ovarian cancer was a common malignant tumor of female genital organs and accounted for 3.5% of new cases of female malignancy. Compared with normal ovarian cancer, β-gal activity in primary ovarian cancer was much higher. Moreover, β-gal played hypostatic roles in maintaining human biological systems. Therefore, it's of great significance to develop efficient detection methods for quantitative determination of β-gal activity. A new-type colorimetric and turn-on fluorescent probe called MC-βGal was designed for the specific detection of β-gal. MC-βGal was constructed based on merocyanine as a chromophore with ICT effect and D-galactose residues as a fluorescence-quenching and enzyme-responsive moiety. MC-βGal had the advantages of high sensitivity, superior selectivity, low limit of detection and a visible color change. In addition, low cytotoxicity and bioimaging experiments had demonstrated that MC-βGal successfully visual detects endogenous and exogenous β-gal in OVCAR-3 cells.