Design,Synthesis And Characterization Of Novel Fluorescent Probe Based On Iso-quinolinyl Hydrazide Schiff Base

Schiff base ligands which contain C=N groups are electron-rich.After the introduction of fluorescent groups,they can be used as good fluorescence sensors for metal ions.As fluorescent groups,iso-quinoline and its derivatives posess excellent optical properties and good biocompatibility.We synthesized isoquinoline hydrazide,and reacted it with different aromatic aldehydes,further generated the corresponding schiff base compounds as fluorescent probes.The fluorescent probes can combined with specific target metal ions and formed stable complexes.The fluorescence properties of probe molecules could be adjusted by introducing different substitute groups and modificating the conjugated structure.The probe molecules have good sensitivity and selectivity,and are suitable for detecting metal ions or biological small molecules in vivo and in vitro.Objective:Series of fluorescent probes based on iso-quinolinyl hydrazine were synthesized and screened for detecting metal ions or biological small molecules.The structures of different fluorescent probes were determined and their fluorescence properties were studied.The relationship between the structure and fluorescence performance was discussed,and we selected fluorescence probes with good fluorescence performance.Intracellular ions or biomolecular were detected by cell fluorescence imaging.The objective is obtaining the probe molecules with low detection limit that could be used for the qualitative and quantitative detection of metal ions or small biological molecules.Content and method:New schiff base ligands were synthesized based on iso-quinolinyl hydrazine,for which a large number of literatures were studied.The structures of ligands and complexes were confrimed by IR(Infrared Spectroscopy),NMR(Nuclear Magnetic Resonance)and MS(Mass spectrometry).The fluorescence performance was tested by fluorescence spectrum,UV-vis spectrum and other methods to explore the relationship between the structure and fluorescence performance.The fluorescent probes can be used for the detection of metal ions or small biological molecules in vivo,which were verified by fluorescence imaging of cells and zebrafish.Results:(1)The aluminum ion fluorescent probes HL1,HL2 and HL3 were synthesized base on iso-quinolinyl hydrazide schiff base,and the aluminum ion fluorescent probes HL1 with the strongest fluorescence performance were selected through screening,which could be used for the detection of aluminium-containing drugs.(2)Dual functional fluorescence probe HL4 for zinc and magnesium ion was synthesized base on iso-quinolinyl hydrazide schiff base.Zinc ion and magnesium ion could be clearly distinguished by changing the solvent system.The fluorescent probes can be used for the detection of metal ions in vivo,which were verified by fluorescence imaging of cells and zebrafish.(3)Hydrogen sulfide fluorescent probe L5 was synthesized base on iso-quinolinyl hydrazide schiff base.L5 itself has a strong fluorescence signal,which is quenched by copper ion.The fluorescence signal can be restored because of the extremely low solubility of CuS(Ksp=6.36 ×10-36),thus hydrogen sulfide can detected.Conclusion:A series of schiff base ligands were synthesized based on iso-quinolinyl hydrazine,and we selected three fluorescence probes which have strong selectivity,high sensitivity and good anti-interference.We obtain Aluminum ion fluorescence probes with detection limit of 8.08 × 10-8 mol/L,dual function fluorescent probes for zinc and magnesium ion detection and biological small molecule hydrogen sulfide fluorescence probes.