Two-Input Fluorescent Probe for Thiols and Hydrogen Sulfide Chemosensing and Live Cell Imaging

Development of multi-input fluorescent probes would facilitate the monitoring of multiple biomolecular events leading to a common disease pathology. Here, we reported a two input fluorescent probe(QME-N-3) based on quinoline scaffold with two distinct reactive sites, the alpha,beta-unsaturated carbonyl at 2 site and 6-azido group, which were specific acceptors of RSH and H2S respectively. The turn-on fluorescent probe could react with the two molecules via the Michael addition at the double bond for RSH and the reduction of the azide by H2S without mutual interference, to generate the intensively fluorescent product, which could act as a two-input AND logic gate. Furthermore, QME-N-3 has very low cytotoxicity and excellent stability, and the resulting sensing product has a high two-photon absorption cross section. Consequently, detection of intracellular thiols and H2S can be achieved by cell fluorescence imaging under both one- and two-photon excitations.