Development of a novel dual-channel fluorescent probe for discriminative sensing of H2S and GSH/Hcy/Cys in biological systems.

Hydrogen sulfide (H2S), a prototypical inorganic reactive sulfur species, along with organic sulfur compounds such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), constitutes the core components of reactive sulfur species (RSS). These molecules play indispensable roles in diverse physiological and biochemical processes within cells. However, current methodologies still lack the capability to specifically discriminate and detect between inorganic and organic reactive sulfur compounds. In this work, we designed and synthesized a dual-channel fluorescent probe HBR by ingeniously combining coumarin derivatives and naphthalimide fluorophores. This probe exhibits significant spectral separation and high selectivity, enabling the simultaneous monitoring of fluorescent signals in the blue and green channels. This capability allows for the effective differentiation between inorganic reactive sulfur (H2S) and organic reactive sulfur compounds (Cys, Hcy, GSH). Furthermore, HBR has demonstrated exceptional dual-color imaging capabilities in both cellular and zebrafish models, validating its potential for applications in complex biological systems.