Visualization of endogenous beta-galactosidase activity in living cells and zebrafish with a turn-on near-infrared fluorescent probe

摘要

beta-Galactosidase (beta-gal) is an important biomarker for primary ovarian cancers. Developing noninvasive bioimaging probes for studying the activity of beta-gal is highly desirable for cancer diagnosis. Herein, a turn-on near-infrared (NIR) fluorescent probe , 2-((6-(((2S, 3R, 4S, 5R, 6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran -2-yl)oxy)-2,3-dihydro-1H-xanthen-4-yl)methylene)malononitrile named DXM-beta-gal, was rationally designed based on enzymatic reaction for the detection of beta-gal activity both in vitro and in vivo. Upon incubating with beta-gal, DXM-beta gal displayed a significant fluorescence enhancement at 640 nm, accompanying by a color change of solution color from red to purple. DXM-beta gal exhibited high selectivity and sensitively to beta-gal with low limit of detection (2.92 x 10(-4) U mL(-1)). Besides, based on its advantages of long-wavelength emission and excellent biocompatibility, DXM-beta gal was successfully applied to imaging beta-gal in living cells and zebrafish. Given these prominent properties, we believe that DXM-beta gal will be a potential tool for investigating beta-gal activity in biomedical research.