WSP-1

WSP-1 (CAS No.: 1352750-34-5) is a reactive disulfide-containing fluorescent probe widely used for the selective detection of hydrogen sulfide (H2S) in biological systems, representing an important tool in the study of gasotransmitter signaling in physiology and disease. As a small-molecule chemical probe, WSP-1 operates via a reaction-based fluorescence turn-on mechanism in which it rapidly and specifically reacts with H2S to release a fluorescent signal with excitation and emission maxima at approximately 465 and 515 nm, enabling sensitive visualization of H2S generation in complex biological environments. H2S is a key endogenous signaling molecule implicated in the regulation of cardiovascular, neurological, immune, and pulmonary functions, and WSP-1 facilitates mechanistic investigations into these pathways by allowing real-time monitoring of intracellular and extracellular H2S dynamics. The probe demonstrates high selectivity over other reactive sulfur and oxygen species and exhibits fast response kinetics suitable for live-cell imaging applications, including studies in vascular smooth muscle cells following treatment with H2S donors. While quantitative activity parameters such as binding constants are not typically defined for this class of probes, WSP-1 is generally applied in the low micromolar range in vitro, with concentrations adjusted according to experimental design and detection sensitivity requirements. Its utility extends to cell-based assays, fluorescence microscopy, and high-content screening platforms, making it valuable for investigating H2S-related signaling pathways, evaluating donor compounds, and supporting drug discovery efforts targeting gasotransmitter biology.