A ratiometric fluorescent probe for the detection of β-galactosidase and its application

Herein, a coumarin fluorescent probe (Probe 1) was developed for the ratiometric detection of beta-galactosidase (beta-gal) activity. The detection range was 0-0.1 U mL(-1) and 0.2-0.8 U mL(-1), and the limit of detection (LOD) was 0.0054 U mL(-1). Moreover, the luminous intensity of Probe 1 increased gradually with increase in beta-gal activity. It could be observed under 254 nm UV irradiation by the naked eye. Furthermore, this method only required a small amount of sample (20 mu L) and a short analytical time (30 min) for the detection of beta-gal activity with a low LOD. Probe 1 was successfully used to detect beta-gal activity in real fruit samples, and can be applied to the quantitative and qualitative detection of beta-gal activity.