Synthesis And Properties Research Of Near-infrared Fluorescent Probes Based On Dicyanoisophorone For H₂S

The identification of important biological molecules is of great significance to life science research.The development of fluorescent probe technology has brought great convenience to life science exploration and played an irreplaceable role.Fluorescent probes are simple,capable of high sensitivity,non-invasive as well as bio-real-time analysis,fluorescent probes with large Stokes shift in the near-infrared region are more beneficial for biological applications.Hydrogen sulfide(H2S)has received much attentions because it was considered as an important gas signal molecule,and its level of abnormality is closely related to many serious diseases.Therefore,two fluorescent probes for H2S with large Stokes shift in near-infrared are designed and synthesized,and their optical properties and potential applications are studied.The main research are as follows:1.We designed and synthesized a dicyanoisophorone fluorescent probe DCI-CHO-DNP with an ortho-aldehyde group for the recognition of H2S.Upon addition of H2S,a fast nucleophilie addition of H2S to the aldehyde group and a following efficient intramolecular thiolysis of dinitrophenyl ether occurred,which leads to release the fluorophore and give a rapid NIR fluorescence turn-on response for H2S with a super large Stokes shift(244 nm).The fluorescence enhancement was found up to 105-fold.Importantly,this probe shows high selectivity and sensitivity(LOD=42 nm)for H2S without interference from biothiols.Furthermore,NIR fluorescent imaging of exogenous and endogenous H2S in living cells with this probe was also successfully applied.2.A novel dicyanoisophorone-based NIR fluorescent turn-on probe DCIP-NIR-HS for H2S was developed.This probe uses a sulfonamide group for the first time as a selective reaction site for H2S and more importantly,it displays a rapid(<1 min),highly selective and sensitive(LOD=6 nM)response for H2S,giving bright NIR fluorescence output(fluorescence enhancement>130-fold)with a remarkable large Stokes shift(221 nm).Moreover,it has low cytotoxicity and can be used for tracking and imaging of H2S in living cells and animals.