A near-infrared fluorescent probe with large stokes shift for accurate detection of β‑glucuronidase in living cells and mouse models

β-Glucuronidase (GLU) plays a vital role in the growth, migration, angiogenesis, and metastasis of tumors. The reliable detection of GLU is an effective approach for early diagnosis of numerous disease such as cholelithiasis and colorectal cancer. In this work, a near-infrared fluorescent probe (DP-GLU) with a large Stokes shift was rationally designed for accurate detection of GLU in living cells and mouse models. DP-GLU was composed of two moieties: dicyanoisophorone as NIR fluorophore and enzyme substrate as GLU recognizable group. Upon reaction with GLU, DP-GLU rapidly displayed a strong emission at 676 nm and the Stokes shift could reach 131 nm. DP-GLU also exhibited high sensitivity toward GLU, and the linearity was fitted in the concentration range of 0−100 μg/L with the detection limit as low as 1.45 × 10−2 μg/L. Furthermore, DP-GLU was used for distinguishing GLU-overexpression tumor cells from normal cells and revealed functions of noninvasive tracking GLU levels in mouse tumor models. Remarkably, DP-GLU was great potential application for cancer imaging in the early diagnoses and therapies of pathologies, which could obtain a comprehensive of the physiological functions of GLU.