A nopinone-based ratiometric fluorescent probe for rapid detection of GSH and its applications in the environment and biological imaging.

Herein, we have developed a novel ratiometric fluorescent probe through rational design and synthesis, named 2-((5-(4-(3,3-dimethyl-1,2,3,4-tetrahydro-2,4-methoxyacridin-9-yl) phenyl) thiophen-2-yl) methylene)-1H-indene-1,3 (2H)-dione, abbreviated as TA-PT-ID. TA-PT-ID is based on the nopinone skeleton and utilizes a Michael addition reaction as the GSH recognition mechanism. TA-PT-ID exhibits excellent photophysical properties, including a rapid response to GSH (within 1 min), a good linear correlation (R2 = 0.9919), and a low detection limit of 50 nM. TA-PT-ID was successfully applied to the detection of GSH in soil and water samples. Furthermore, ratiometric imaging of endogenous GSH was achieved using TA-PT-ID in HeLa cells, RAW264.7 cells, and zebrafish. In summary, TA-PT-ID provides a powerful new tool for the real-time detection of GSH in complex environments, and its rapid response and broad pH adaptability make it highly promising for applications in biological imaging and environmental monitoring.