Amplified detection of β-glucuronidase activity based on cascade catalysis

β-Glucuronidase (β-GLU) plays a pivotal role in disease progression and serves both as a biomarker and a therapeutic target. Novel strategies for β-GLU detection are highly desirable. Here, we present a cascade catalytic strategy for amplified detection of β-GLU activity. Using 8-hydroxyquinoline-β-D-glucuronide (8-HQG) as the substrate, β-GLU enzymatically releases 8-hydroxyquinoline (8-HQ), which effectively activates the catalytic activity of Co²⁺, thereby facilitating the H₂O₂-dependent oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). This strategy enables sensitive colorimetric detection of β-GLU activity with a limit of detection (LOD) of 0.022 U/mL. The results demonstrate the potential of our cascade catalytic system not only for β-GLU detection but also for inhibitor selection and enhancing treatment for related diseases.