A dual-enzyme activated fluorescent probe for precise identification of tumor senescence

Precise recognition of senescent cells is essential owing to their key role in various diseases, including aging and tumor suppression. Although senescence-associated β-galactosidase (SA-β-Gal) is widely used as a senescence biomarker, it is not remarkably accurate due to its overexpression in some non-senescent cells. Herein, we developed a dual-channel fluorescent probe to improve the identification accuracy of senescent cells through simultaneous detection of β-gal and α-l-fucosidase (AFU) because the two markers are upregulated in senescent cells. The dual-channel fluorescent probe named HDQ-NA-AFU-Gal was employed to detect β-gal and AFU and identify senescence in living cells and tumor-bearing mice. When the two are present, the dual-enzyme activated probe emits strong red and green fluorescence at 740 nm and 550 nm, respectively, enabling independent detection of β-gal and AFU. This dual-enzyme detection approach allows for the precise differentiation between normal and senescent cells, particularly in ovarian cancer cells overexpressing β-gal. Furthermore, the probe can be applied as an effective tool for tracing β-gal and AFU during tumor senescence in mice. Thus, the dual-enzyme-responsive fluorescent probe has promising applications in biological research and clinical medicine.