The Synthesis And Application Of Water-soluble Fluorescent Probes With A Large Stokes Shift

In this thesis,a fluorescent probe CF536 for reversible detection of Cu²⁺,S^2-and probe CF470 for detecting Fe³⁺were designed and synthesized.They displayed a large Stokes shift and excellent water solubility due to the introduction of the extremely hydrophilic trihydroxyl group.The structures of probes were characterized by HRMS,¹³C NMR,¹H NMR and infrared spectroscopy,and its optical properties of the probes was also investigated by fluorescence and UV-vis analysis methods.In addition,CF536 and CF470 were successfully applied for imaging live cells due to their excellent properties.This paper is divided into the following three parts.1)This part mainly introduces the basic structure and different detection mechanism of fluorescent probe,and also described the development of the probes which are used to detect Cu²⁺,S^2-and Fe³⁺.2)The synthesis and the studies of properties of the novel "ON-OFF-ON" fluorescent probe CF536 based on benzothiazole which for reversible detection of Cu²⁺and S^2-were described.3)The third part mainly reports the synthesis and the studies of properties of the novel "ON-OFF" fluorescent probe CF470 for Fe³⁺.The main contents list as follows:Firstly,the 2-?2'-hydroxyphenyl?-benzothiazole?HBT?was select as the platform to construct a reversible fluorescence probe CF536 for Cu²⁺and S^2-,and the crystal structure of probes CF536 was obtained.The probe showed excellent water solubility and large Stokes shift.After the combination of CF536 and Cu²⁺,the fluorescence of CF536 was effectively quenched by the blocking the ESIPT process which was caused by paramagnetic of Cu²⁺.Upon the addition of S^2-,the probe CF536 soon released from the CF536-Cu²⁺complex due to the strong binding affinity of S^2-and Cu²⁺.The fluorescence of CF536 was recovered immediately with the formation of CuS.The probe CF536 was successfully used for imaging of Cu²⁺and S^2-in living cells.The strategy of designing CF536 provided a unique guideline for the construction of a single fluorescent probe for multiple targets.Secondly,the probe CF470,a water-soluble fluorescent probe for iron ion,was designed and synthesized by introducing 2-amino-2-?hydroxymethyl?-1,3-propanediol as recognition group to the fluorophore based on coumarin derivative.Upon the addition of Fe³⁺,the fluorescence was quenched due to the paramagnetic of Fe³⁺.Probe CF470 showed high selectivity and ultra-sensitivity toward Fe³⁺with a rapid response,and the fluorescence response would not be influenced by other common metal ions.Due to its large Stokes shift of 70 nm,the probe can avoid the self-quenching and fluorescence detection errors.And the probe CF470 was successfully used for fluorescent imaging of Fe³⁺in living cells in view of its excellent properties.