Design,Synthesis And Applied Research Of Base-modified Diethylenetriamine Pentaacetic Acid(DTPA)-Tb(?) Complex Fluorescent Probe

Fluorescent probe,which is defined by the international union of pure and applied chemistry?IUPAC?,is considered as"a device for converting chemical information into useful analytical signals."Fluorescent probe usually consists of receptor?recognition group?,fluorophore?signal moiety?and a linker that connects them together.The receptor determines the selectivity and specificity of the fluorescent probe,the fluorophore determines the sensitivity of the recognition,and the linker can serve as a hinge to connect the two parts.Due to the high selectivity,sensitivity,anti-interference and designability,fluorescent probe has become an important part of science and technology and has been widely adopted for many fields,including medicine,biology and environment.In this dissertation,the aminopolycarboxylic acid fluorescent probe based on diethylenetriamine pentaacetic acid?dtpa?are designed and synthesized,that is the ligand dtpa-bis?cytosine?detects Eu³⁺in rare earth metal ions,and the complex Tb^?-dtpa-?2,6-diaminopurine?detects and analyzes uric acid in urine.The chemical composition and structure of fluorescent probes are characterized by FT-IR spectroscopy,UV-Vis spectroscopy and NMR spectroscopy.The selectivity,anti-interference,pH responsivity and response to the analyte concentration of two fluorescent probes are studied and the detection mechanism also is deduced.The specific process is as follows:1.In the first part,a novel ligand dtpa-bis?cytosine?is synthesized by the nucleophilic substitution reaction between dtpa anhydride and cytosine amino group.The ligand has medium intensity fluorescence emission under the excitation of certain wavelength light.The complexation is occurred between Eu³⁺and ligand form Eu^?-dtpa-bis?cytosine?complex when the Eu³⁺was added to the ligand solution.The fluorescence intensity of the ligand dtpa-bis?cytosine?is significantly enhanced by observe the fluorescence spectroscopy.We also studied the effect of other rare earth metal ions on the detection of Eu³⁺by use dtpa-bis?cytosine?as a fluorescent probe.It is found that other rare earth metal ions can not enhance the fluorescence of the ligand except for Eu³⁺.At the same time,the pH of solution and concentration of Eu³⁺are also studied,and a good linear relationship and detection limit?LOD?are obtained.From the above experimental results,the reaction mechanism of the dtpa-bis?cytosine?as a fluorescent probe for detect Eu³⁺is analyzed and inferred.2.The second part designs and synthesizes a novel fluorescent probe Tb^?-dtpa-?2,6-diaminopurine?based on the stacking effect in single-stranded DNA molecules.This part mainly examines the process and mechanism of detecting and analyzing uric acid in urine using Tb^?-dtpa-?2,6-diaminopurine?as a fluorescent probe.At the same time,the interference of tyrosine,creatinine,ascorbic acid,hippuric acid,tryptophan and histidine,which are other base compounds coexisting with uric acid in urine,are investigated and found that they do not affect the detection of uric acid.The pH of solution varied from 4.40 to 10.40,as a result,the fluorescent probe is able to detect uric acid in a wide pH range.Under optimal conditions,the response of fluorescent probe Tb^?-dtpa-?2,6-diaminopurine?to uric acid concentration is investigated,and a good linear relationship and detection limit?LOD?are obtained.From the above test results,the mechanism of interaction between uric acid and fluorescent probe Tb^?-dtpa-?2,6-diaminopurine?is infered.Finally,the fluorescent probe is applied to the real urine sample to detect uric acid by fluorescence spectroscopy.The experient result shows that the fluorescent probe can be used for the analysis of uric acid in real urine samples.