Kill two birds with one stone: A near-infrared ratiometric fluorescent probe for simultaneous detection of β-galactosidase in senescent and cancer cells

beta-galactosidase, as a typical lysosomal glycosidase, is one of the irreplaceable markers in ovarian cancer and senile cells. Therefore, a new method to detect endogenous beta-gal is urgently needed to better understand its role in related biological processes. Here, a novel near-infrared proportional fluorescent probe was designed and screened to detect the activity of beta-gal in cancer and senescent cells. The probe achieved a rapid response (within 15 min) to beta-gal, a large stoke-shift (170 nm), and an 80-fold fluorescence enhancement with a maximum emission wavelength of 670 nm after interaction with beta-gal. The probe has good biocompatibility and can effectively avoid the interference of biological background. Subsequently, the developed probe was used to detect and image endogenous beta-gal in cells and zebrafish. In addition, TZ-Br has been successfully used to evaluate the therapeutic effects of dasatinib and quercetin combination on senile cells, which provides a powerful tool for further understanding the physiological and pathological functions of beta-gal in living systems.