A Redox-Nucleophilic Dual-Reactable Probe for Highly Selective and Sensitive Detection of H(2)S: Synthesis, Spectra and Bioimaging

Hydrogen sulfide (H(2)S) is an important signalling molecule with multiple biological functions. The reported H(2)S fluorescent probes are majorly based on redox or nucleophilic reactions. The combination usage of both redox and nucleophilic reactions could improve the probe’s selectivity, sensitivity and stability. Herein we report a new dual-reactable probe with yellow turn-on fluorescence for H(2)S detection. The sensing mechanism of the dual-reactable probe was based on thiolysis of NBD (7-nitro-1,2,3-benzoxadiazole) amine (a nucleophilic reaction) and reduction of azide to amine (a redox reaction). Compared with its corresponding single-reactable probes, the dual-reactable probe has higher selectivity and fluorescence turn-on fold with magnitude of multiplication from that of each single-reactable probe. The highly selective and sensitive properties enabled the dual-reactable probe as a useful tool for efficiently sensing H(2)S in aqueous buffer and in living cells.