Study On Using Benzoxazole Derived Fluorescence Probe To Detect Zinc Ion In Plant

Zinc ion is an important trace element and closely related to plant growth process.It plays a crucial influence on protein metabolism,carbohydrate metabolism and hormone regulation in plant.Abnormal zinc concerntration can always be the cause of unnecessary plant diseases,such as albinism,lobular disease and mosaic disease,which seriously affects the plant's health and the quality of food crops.The zinc absorption resource of human body is mainly from food,as for developing countries are more easily to appear zinc deficiency phenomenon because people's diet structure is prone to few zinc content of food crops in a long time.Therefore,this research designed and synthesized a benzoxazole derived zinc fluorescence probe to quickly study the content and distribution of zinc ion,which can provide an efficient and effective technical support for functional exploration,qualitative and quantitative research,tracing and enrichment technique of zinc ion in plant.2-(2-hydroxyphenyl)benzoxazole is an excellent fluorophore that has the characteristics of good performance,small molecular weight,simple structure and wavelength doesn't overlap with chloroplasts in plant,emerging as the hotspot of photochemical sensors research in recent years.Considering these,it has obvious advantages to take it as the parent structure of fluorescent probe molecule.The main content of this thesis has been summarized as follows:(1)We chose 2-(2-hydroxyphenyl)benzoxazole as the parent molecule and introduced hydrophilic hydroxyl methyl group at the 3',5' position to improve the probe's water solubility.The pure compound 2-(3',5'-dihydroxymethyl-2-hydroxyphenyl)benzoxazole(DHHBO)was obtained in 89% yield after the optimization of synthetic route The structure of DHHBO was characterized by NMR,MS and X-ray single crystal diffraction technology.The results of its spectrum performance study indicated that the probe had good selectivity and sensitivity to zinc ion.After interacting with zine ion,the fluorescence color changed from light blue to brilliant blue,and the emission wavelength had a hypochromatic shift from 471 nm to 451 nm and the intensity was greatly enhanced.Simultaneously,the fluorescence intensity increased linearly with the zinc concentration in the range 1-6 ?mol/L and the detection limit was 78 nmol/L which were suitable to use in biological systems.The study of its application performance showed that the probe can be used in animal cells to across the cell membrane to detect intracellular zinc ion and to realize the conduction and test of zinc ion in plant's xylem and phloem.(2)For further,in order to improve the water solubility and stability of probe,sulfo group and benzene ring were introduced to increase water solubility and stability respectively,finally sulfonyl fluorescence probe(SHBO)was obtained in 77.1% yield.Studied the effects of different solvents,pH values and temperatures on the probe performance,dual emission peaks(for the keto and enol forms,respectively)were founded.Meanwhile,UV-Vis spectrums had relatively small impact by different solvents,fluorescence emission spectrums were more in-deepth influenced by different solvents and pH values,and smaller impact by different temperatures.Considering the basic spectrum performance researches,we found that its performance was superior but still need further development to establish a foundation for its applications in future.