Design,Synthesis And Application Of Multifunctional Fluorescent Probes

In the present work, based on the mechanism of PET, ESIPT and the chelation-inducedring opening of rhodamine, five kinds of multifunctional fluorescent probes for metal ions,anions and small molecules were designed and synthesized. A series of naphthalimide-basedinhibitors of OfHex2 were also designed and synthesized.1.Naphthalimide-based fluorescent probe NPQ that contains a novel receptor wassuccessfully developed. NPQ exhibited "turn"-on fluorescence and excellent selectivitytoward A+g in the presence of various other metal ions especially mercury ions in aqueoussolution. Its fluorescence intensity enhanced in a linear fashion with the concentration of Ag ,thus it can be used potentially for +quantiifcation of Ag. A series of control compounds weredesigned and synthesized in order to explore the photoinduced electron transfer (PET)+quenching mechanism of NPQ and binding mode of NPQ with Ag. Moreover, the NPQ-A+g"complex also behaves as a specific fluorescent sensor for I. The living cells imageexperiments demonstrate that NPQ can be used as a fluorescent probe for monitoirng A+g inliving cells.2.A ratiometric ESIPT-based lfuorescent probe FBNH was designed and synthesized. FBNHexhibited highly selectivity toward N2H4 in the presence of vairous other metal ions, anionsand even some amino compounds in aqueous solution. Addition of N2H4 induced thebathochromic shitf of lfuorescence wavelength up to 150 nm.3. A versatile rhodamine-based trifunctional chemosensor RP was designed and synthesized.It can sensitively and selectively recog2nize C+u in DMSO/H2O (v/v = 10:1-, 2 mM TrisHCl,H72+ ?p .8) by naked eye through the drastic color change from colorless to purple and Zn mCH3CH2OH/H2O through an off-on fluorescence emission along with color change rfomnearly colorless to pink. To the best of our knowledge, this work provides the ifrst example ofone bifunctional chemosensor, which could sensitively and selectively recognize Cu2+ andZn2+ respectively in different aqueous solutions. Interestingly, zinc-containing [RP@Zn2+]complex was also a colorinietirc and fluorimetric dual-responsive probe for His/Cys.F+urthermore, we have demonstrated that the sensor RP is applicable for Zn2 imaging in theliving Hela cells.4. A new bifunctional fluorescent probe RI based on rhodamine with a novel receptor wasdesigned and synthesized. We modulating the selectivity of RI to various metal ions by switching sensing media. RI gives a turn-on fluorimetric and coloirmetric signal toward Cdin CH3OH/H2O (v/v = 4:6, 10 mM HEPES, pH 7.6) and a turn-on colorimetric signal towardPb2+ in CH3OH/H2O (6:4, v/v, 70 mM Tris-HCl, pH 7.6). To the best of our knowledge, thisis the first example of chemosensor based on a small molecule that can selectively recognitionboth Cd2+ and Pb2+ in different sensing systems. Furthermore, we have demonstrated that thesensor RI was applicable for Cd imaging in the living Hela cells.5.We have reported a fluorescent probe RSP, which could sensitively and selectivelyrecogni+ze Hg2 in 99% aqueous solution. Interestingly, Based on the RSP-Hg-C104 ensemble,addition of iodide less than 2.0 equiv. induced the fluorescence further increased and moreiodide induced the fluorescence quenching selectively by removing of Hg2+ rfom theRSP-Hg-C104 ligand, however, addition of bromide induced the fluorescence furtherincreased by exchanging of anion ligand from CIO""4 to Br-. Therefore, RSPHg-C104ensemble can serves as a selective fluorescent probe for iodide and bromide in aqueoussolution. Rational analysis of the sensing mechanism of RSP-Hg2+ ensemble to iodide andbromide based on anion exchanging and metal ion removal was given. This sensingmechanism may be could serve as a novel approach for designing of rhodamine-basedfluorescent probe for anion.6.A seires of naphthalimide derivatives were designed and synthesized. Their inhibitactivities toward OfHex2 were evaluated. The preliminary results showed that six compoundsexhibited exclusive inhibit activities with Ki values low to 1 (iM. These compounds can serveas lead compound for further research.