Synthesis And Application Of Fluorescent Probes Based On Purine Ring Modification

At present,the fluorescent probe detection method has become an emerging detection method,which can be used for detecting heavy metal ions and small organic molecules in living organisms,and has the advantages of high sensitivity,visualization,simple operation,low cost,good selectivity,and the like.Used in the fields of chemical engineering,environmental testing,biomedicine,analytical chemistry,etc.In recent years,the design and development of fluorescent probes have attracted widespread attention.Fluorescent probes modified by purine ring can be used to detect metal ions in the environment and organisms.Because purine compounds have a planar rigid structure,the nitrogen atoms on the purine ring have the ability to bind metal ions and have low biotoxicity.However,it has rarely been reported that purine ring is introduced into fluorescent probes and used to detect metal ions in the environment and in living organisms.In this thesis,fluorescent probes based on purine ring modification were synthesized and their performance applications were studied.This paper is divided into the following three parts:Firstly,overview of definition and design principles of fluorescent probes and introduced the development of purine,rhodamine,dicyanoisophorone in recent years.Secondly,a rhodamine B fluorescent probe RBTP based on purine ring modification was designed and synthesized.The structure of RBTP was characterized by nuclear magnetic resonance,mass spectrometry and single crystal diffraction.Then a series of analysis experiments on RBTP were carried out,and finally the probe RBTP was applied.It was found that the probe RBTP can specifically recognize palladium ions under the condition of pH>6.In the EtOH/H₂O?3/2,v/v,pH 7.4,HEPES buffer,0.5mM?system,the probe RBTP and palladium ion by 1:1 binding,the detection limit is49.5 nM,the binding constant is 1.15×10⁴ M^-1,and the detection time of palladium ions is 40 min;the probe RBTP can be made into a portable test strip for detecting the concentration of palladium ions in the aqueous solution.Thirdly,a dicyanoisophorone fluorescent probe YPT based on purine ringmodification was designed and synthesized.The structure of YPT was first characterized by nuclear magnetic resonance and high resolution mass spectrometry;then a series of analytical experiments were performed on YPT,and finally the probe YPT was applied.The study found that probe YPT can efficiently and specifically identify zinc ions in DMSO/H₂O?3/2,v/v,pH 7.4,HEPES buffer,0.5 mM?system.The probe YPT and zinc ions by 1:1 binding,the detection limit is 12 nM,the binding constant is 8.33×10⁴ M^-1,and the detection time for zinc ions is 30 s,and the probe YPT can be used not only to make portable test strips for detecting the concentration of zinc ions in the solution,but also to detect zinc ions in living cells.