A NIR, special recognition on HS−/CN− colorimetric and fluorescent imaging material for endogenous H2S based on nucleophilic addition

•A novel NIR fluorescent material was prepared firstly and characterized fully.•The material can specially recognize HS−/CN− as a colorimetric and fluorescent probe.•The NIR fluorescent material was successfully used to detect endogenous H2S in A549 cells under SNP induced.

A novel NIR fluorescent material, which is constructed with interweaved quinline and benzimidazole as the fluorophore system, indolium as a dye and reactive site under connected double bond conjugation. The sensor mechanism relied on strong nucleophilic attack of only HS−/CN− which shortened the conjugated system resulting in the fluorescent spectral changes as well as a change in color. Other nucleophilic reagents such as thiols and bisulfate did not undergo the reaction and therefore did not induce color and fluorescence changes. The pretty 1H NMR titration results strongly proved the nucleophilic mechanism. The fluorescent material was successfully used to detect endogenous H2S in A549 cells using S-Nitroso-N-acetyl-DL- penicillamine (SNP), a commercial NO donor to stimulate production of H2S and exogenous H2S.

Graphical abstractA novel NIR fluorescent material was constructed. Only strong nucleophiles such as HS−/CN− could attack and shorten the conjugated system resulting in the color and fluorescence change, thiols and bisulfate did not undergo the reaction. The material was showed a success application by A549 cell imaging under SNP stimulation.Download high-res image (73KB)Download full-size image