Modular and\nFast Assembly of Self-Immobilizing Fluorogenic\nProbes for β‑Galactosidase Detection

β-Galactosidase\n(β-gal) has emerged as a\npivotal biomarker\nin primary ovarian cancer. Despite the existence of numerous fluorescent\nprobes for β-gal activity detection, quinone methide-based immobilizing\nprobes were shown to avoid rapid diffusion of the activated fluorophore\nand improve the resolution. However, the synthesis of these fluorophores,\nparticularly near-infrared fluorophores, still exhibits lower efficiency.\nIn this study, we introduce modular and rapidly assembled self-immobilizing\nfluorogenic probes, capitalizing on the proximity labeling properties\nof quinone methide (QM). Compared to conventional fluorescent probes,\nthese new probes not only exhibit a fluorogenic response but also\nachieve permanent retention, demonstrating improved detection sensitivity,\nparticularly after cell fixation and in vivo animal model studies.\nThis straightforward synthesis approach holds promise for broader\napplications in detecting other analytes.