Design, Synthesis And Properties On Several "OFF-ON" Colorimetric Metal Ion Fluorescence Sensors

In this thesis,four fluorescent sensor molecules ST,HS,YG and FC had been designed and synthesized by modifying quinaldine,2-hydroxy-1-naphthaldehyde and rhodamine B,respectively.Their structures and the spectral properties were characterized and investigated by a series of analytical methods.The main work for the thesis is presented as below:Firstly,the development of fluorescence spectroscopy and the research background of fluorescence sensors had been reviewed;at the same time,the research development of fluorescence sensors for Zn²⁺,Hg²⁺and Cu²⁺were introduced and foused.Then,two kinds of colorimetric fluorescence sensors?ST and HS?for Zn²⁺based on PET mechanism were designed and synthesized,which exhibited extremely high selectivity to Zn²⁺in the CH₃CH₂OH-H₂O?4:1,v/v?solution.The imaging experiments in 293T cells demonstrated that both sensor molecules have good biocompatibility.Therefore they could be applied in aspect of biosensing.Finally,two colorimetric fluorescence sensors for Hg²⁺and Cu²⁺based on rhodamine B were designed and synthesized.Experiments showed that sensor YG had unique property to recognize Hg²⁺in the CH₃OH-H₂O?4:1,v/v,Tris-HCl buffer solution pH=8.0?solution.The binding constant of YG to Hg²⁺was 5.5×10⁵M^-1;the detection limit was 1.5×10^-8 M.It is found that the sensor FC had unique selectivity and sensitivity toward Cu²⁺.The binding constant and the detection limit for the ligand FC to Cu²⁺had been carried out.The cell imaging experiments indicated that both of above sensors can penetrate the cell membrane so that Hg²⁺,Cu²⁺could be detected in living cells,respectively.