The Design, Synthesis And Application Of Reaction-based Fluorescent Probes

Recently, fluorescence method has been wildly used in the field of biological,clinical, and environmental for its simplicity, high selectivity and sensitivity, lowdetection limit, good biocompatibility, and especially in temporal and spatialresolution. In comparison with the traditional metal-ligand-based fluorescent probes,reaction-based fluorescence probes, which were based on the highly specific chemicalreactions, have got much attention.Inspired for all of these works, we present here the design, synthesis andapplication of four reaction-based fluorescent probes for RSS.(1) A novel aggregation induced emission (AIE)-based fluorescent probeS1(AIE-S) for the detection of H2S has been developed. S1was aggregated in waterand thus shows strong blue fluorescent emission due to its poor solubility, after bindto Cu2+, the fluorescence of S1was decreased for the formation of good solubility ofAIE-S-Cu complex, which was restored when S2-added to the mixture solution ofAIE-S-Cu. S1exhibits ‘ON–OFF–ON’ mode fluorescence changes with alternateaddition of Cu2+and S2-, and displays high sensitivity and selectivity for H2S and Cu2+,respectively, in the presence of other possible competitive anions and catins.Moreover, probe S1could be successfully utilized in living cells for real-timedetection of H2S.(2) A novel ratiometric fluorescence probe S2based on Intramolecular ChargeTransfer (ICT) for the detection of H2S has been developed.4-hydroxy-1,8-naphthalimide has been chosed for the fluorophore, and4-azidophen-yl group wasresponsible for the H2S. In the presence of H2S, the azido group was reduced to anamino group, which followed by classic1,6-elimination reaction to release the free4-hydroxy-1,8-naphthalimide. S2showed a good colormetric and ratiometricresponse with a bathochromic shift from369to569nm and a red-shift emission from443to537nm, The detection limit of probe S2was71.0nM.(3) A novel ICT-based fluorescent probe S3for the detection of GSH has been designed and synthesized. It should be mentioned that4-methylbenzenesulfonyl group,an electron-withdrawing group which block the ICT effect of4-amino-1,8-naphthalimide, has never been reported to response to GSH. S3is almostnon-fluorescence (Φ=0.08%). However, in the presence of GSH, a classicnucleophilic substitution reaction has ocuured and triggered the green fluorescenceemission (Φ=9.01%). By the way, S3shows about110-fold fluorescence increaseand exhibited high sensitivity for the response to GSH.(4) A novel BODIPY-based fluorescence probe S5for the ratiometric detectionof Cys has been developed. S5exhibited the fast and sensitive response to Cys even inthe presence of the homologous RSS such as Hcy and GSH in aqueous solution.