A fluorescent probe for specific detection of β-galactosidase in living cells and tissues based on ESIPT mechanism

beta-galactosidase is of great significance to living organisms, which is an important marker of primary ovarian cancer and cellular senescence. To detect the activity of beta-galactosidase, a novel fluorescent probe ESIPT-GAL which based on excited state intramolecular proton transfer (ESIPT) mechanism for detecting beta-galactosidase is developed in this work with low background fluorescence and high sensitivity (Phi(F) = 0. 0045-0.2409). The fluorescence intensity at 552 nm of this probe increased by similar to 55 times with beta-galactosidase addition (0-4 U/mL), and its detection limit is very low (3.9 x 10(-5) U/mL). In addition, the spectral data (pseudo-first-order rate: 1.303 min(-1)) and enzyme kinetic parameter (V-max = 69.5 gM.S-1) both show that the probe can achieve rapid response to beta-galactosidase. Moreover, the probe has good water solubility, which ensures that it has good biocompatibility and can be easily applied to detect beta-galactosidase in living cells and tissues. Importantly, the probe ESIPT-GAL can monitor Bgalactosidase in deep mouse tissue sections (90 mu m). (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel fluorescent probe ESIPT-GAL based on excited state intramolecular proton transfer mechanism is developed for detecting beta-galactosidase with low background fluorescence and high sensitivity. The probe shows rapid response to beta-galactosidase activity and concentration in living cells and tissues, with good water solubility and the ability to monitor enzyme in deep tissue sections.