A highly selective fluorescent nanoprobe based on AIE and ESIPT for imaging hydrogen sulfide in live cells and zebrafish

The rational design of effective tools capable of monitoring hydrogen sulfide (H₂S) is of great importance to fully understand its physiological and pathological functions. Herein, a self-assembled fluorescent nanoprobe with both aggregation-induced emission (AIE) and excited-state intramolecular proton transfer (ESIPT) characteristics for H₂S detection has been successfully developed via a modified nanoprecipitation method. The nanoprobe features high water dispersibility, a large Stokes shift (ca. 100 nm), good biocompatibility as well as high selectivity towards H₂S over other putative interferents. Live cell imaging experiments demonstrate that the nanoprobe, with good cell-membrane permeability, can facilitate the visualization of exogenous and endogenous H₂S levels. Moreover, the nanoprobe has also been found capable of detecting H₂S in zebrafish. This nanoprobe with AIE and ESIPT characteristics can provide a novel method for the development of fluorescent probes for monitoring biological processes.