Novel fluorescent probe for rapid and ratiometric detection of β-galactosidase and live cell imaging

Abstract β -Galactosidase ( β -gal) is an important biomarker for primary ovarian cancers and cell senescence; however, a fast response fluorescent probe for ratiometric monitoring is still rare. A novel, ratiometric water-soluble fluorescent probe ( FLM ) for β -gal was developed. The emission ratio F 550 / F 450 reached the maxima at about 5 min and can be used for real-time detection of β -gal; the ratio gained an ultimate enhancement of about 260-fold. The ratio ( F 550 / F 450 ) displayed brilliant β -gal-dependent performance and responded linearly with β -gal activity. The probe showed wonderful biocompatibility and was successfully used for the bioimaging of endogenous β -gal in the human ovarian cancer cell line OVCAR-3.