Individual and successive detection of H2S and HClO in living cells and zebrafish by a dual-channel fluorescent probe with longer emission wavelength

Highlights: • A novel dual-channel fluorescent probe (MB-NAP-N₃) is designed and prepared. • The probe can response to H₂S and HClO in an individual or successive mode. • The probe can detect endogenous and exogenous HClO/H₂S in living cells and zebrafish. Reactive oxygen species (ROS) and reactive sulfur species (RSS) participate in many physiological activities and help maintaining the redox homeostasis in biological system. The complicated intrinsic connection between specific ROS/RSS needs to be further explored. Herein, a novel fluorescent probe (MB-NAP-N₃) with longer emission wavelength has been rationally designed and synthesized based on the conjugation of the methylene blue moiety and the naphthalimide moiety for the detection of hypochlorous acid (HClO) and hydrogen sulfide (H₂S). The dual-signal probe exhibits rapid turn-on fluorescence responses for individual and successive detection of H₂S and HClO in green and red channels, respectively. Owning to its advantages such as fast response, good selectivity and high sensitivity, the probe was successfully applied to detect endogenous and exogenous HClO/H₂S in living cells. Furthermore, the outstanding luminescence performance makes it suitable for the visualization of the in vivo interaction between the two analytes in zebrafish.