Changyu Zhang

Dual-Reactable Fluorescent Probes for Highly Selective and Sensitive Detection of Biological H2 S.

Hydrogen sulfide (H2 S) is an important endogenous signaling molecule with a variety of biological functions. Development of fluorescent probes for highly selective and sensitive detection of H2 S is necessary. We show here that dual-reactable fluorescent H2 S probes could react with higher selectivity than single-reactable probes. One of the dual-reactable probes gives more than 4000-fold turn-on response when reacting with H2 S, the largest response among fluorescent H2 S probes reported thus far. In addition, the probe could be used for high-throughput enzymatic assays and for the detection of Cys-induced H2 S in cells and in zebrafish. These dual-reactable probes hold potential for highly selective and sensitive detection of H2 S in biological systems.

Fast‐Response Turn‐on Fluorescent Probes Based on Thiolysis of NBD Amine for H2S Bioimaging

Hydrogen sulfide (H2S) is an important endogenous signaling molecule with multiple biological functions. New selective fluorescent turn‐on probes based on fast thiolyling of NBD (7‐nitro‐1,2,3‐benzoxadiazole) amine were explored for sensing H2S in aqueous buffer and in living cells. The syntheses of both probes are simple and quite straightforward. The probes are highly sensitive and selective toward H2S over other biologically relevant species. The fluorescein‐NBD‐based probe showed 65‐fold green fluorescent increase upon H2S activation. The rhodamine‐NBD‐based probe reacted rapidly with H2S (t1/2≈1 min) to give a 4.5‐fold increase in red fluorescence. Moreover, both probes were successfully used for monitoring H2S in living cells and in mice. Based on such probe‐based tools, we could observe H2O2‐induced H2S biogenesis in a concentration‐dependent and time‐dependent fashion in living cells.

A Redox-Nucleophilic Dual-Reactable Probe for Highly Selective and Sensitive Detection of H2S: Synthesis, Spectra and Bioimaging

Hydrogen sulfide (H2S) is an important signalling molecule with multiple biological functions. The reported H2S 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 H2S 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 H2S in aqueous buffer and in living cells.

A NBD-S-rhodamine dyad for dual-color discriminative imaging of biothiols and Cys/Hcy

Biothiols are essential biomolecules in sustaining intracellular redox homeostasis. Abnormal levels of Cys, Hcy, GSH and H2S are linked to different diseases, respectively. Although many fluorescent probes are successfully applied in the detection of these biothiols in living biological samples, probes with high selectivity to discriminatively detect biothiols are underdeveloped. Herein, we designed and synthesized a new dual-color NBD-S-rhodamine fluorescent probe based on fast thiolysis of NBD thioether, a non-thiol-consuming receptor. This probe could react with GSH/H2S to give red fluorescence, and with Cys/Hcy to give both green and red fluorescence for discriminative detection of biothiols and Cys/Hcy. The results revealed that this probe exhibited good selectivity and high sensitivity toward biothiols, and could be used in bioimaging. Based on the probe tool, we could selectively detect Cys/Hcy in the presence of GSH in living mammalian cells.