Hydrogen sulfide detection and zebrafish imaging by a designed sensitive and selective fluorescent probe based on resorufin.

A new long-wavelength fluorescent probe 1 that could specifically identify HS has been successfully synthesized and applied for imaging HS in zebrafish. Probe 1 was readily prepared by featuring nitrobenzene as the recognition unit coupled to resorufin. The fluorescence off-on response is based on the fact that HS can reduce the nitro group to an amino group, followed by the 1,6-rearrangement-elimination and the release of resorufin. By evaluating the application abilities of probe 1 in vivo and vitro, it is shown that probe 1 has high sensitivity and selectivity to HS, low background fluorescence interference, with a low detection limit of 17.30 μM. Notably, the occurrence of the reaction can be observed by the naked eye, and the color of the solution changes from yellow to pink. More importantly, it is the first time that using paper chips as carrier to detect HS, which lays a foundation for the practical application of detecting HS. The excellent analysis and application capabilities of probe 1 make it an effective tool for further application in practice.