Pentafluorobenzenesulfonyl fluorescein

Pentafluorobenzenesulfonyl fluorescein (CAS No.: 728912-45-6) is a synthetic small-molecule fluorescent probe widely employed in biomedical research for the selective detection of intracellular hydrogen peroxide, a key reactive oxygen species involved in oxidative stress and redox signaling. Functioning through a nonoxidative mechanism, this probe is initially non-fluorescent but undergoes perhydrolysis of its sulfonyl linkage in the presence of hydrogen peroxide, resulting in a marked fluorescence increase that enables sensitive and real-time monitoring of peroxide levels in living cells. It exhibits high selectivity for hydrogen peroxide over other reactive oxygen and nitrogen species, including hydroxyl radicals, superoxide anions, singlet oxygen, and organic peroxides, making it particularly valuable for dissecting specific redox pathways. As a tool compound rather than a therapeutic agent, it does not act on classical protein targets but instead serves as a chemical sensor to interrogate oxidative stress-related processes, including signaling cascades associated with cellular damage, inflammation, and metabolic regulation. In vitro applications typically involve low micromolar concentrations, although optimal dosing depends on cell type, probe loading conditions, and experimental design. Pentafluorobenzenesulfonyl fluorescein is broadly utilized in cell-based assays, high-content imaging, and mechanistic studies of disease models where hydrogen peroxide plays a critical role, supporting drug discovery efforts aimed at modulating oxidative stress and antioxidant defense systems.