An anthracenecarboximide fluorescent probe for: In vitro and in vivo ratiometric imaging of endogenous alpha-l-fucosidase for hepatocellular carcinoma diagnosis

Alpha-l-fucosidase (AFU) plays vital roles in some physiological processes that closely relate to several diseases. Herein, a ratiometric fluorescent probe for the alpha-l-fucosidase (AFU) assay based on a single fluorophore has been developed by functionalizing a new fluorophore platform (6-bromo-anthracenecarboximide) with an α-l-fucose group. AFU cleaves the α-l-fucose group from the probe molecule and remarkably alters its photophysical properties, thus realizing ratiometric detection of AFU. Due to the specificity and high efficiency of the enzymatic reaction, this probe can sensitively and selectively detect AFU in aqueous media and biological milieus with a detection limit of 0.0033 U mL^-1. Moreover, the probe can be employed to monitor and spatially map endogenous AFU levels in a hepatocellular carcinoma (HCC) model of zebrafish. Hence, the probe holds significant promise for conducting pathological research on AFU-involved diseases.