新型香豆素类氟离子荧光探针的合成及细胞成像研究

摘要

设计合成了一类基于分子内电荷转移(Intramolecular Charge Transfer,ICT)的香豆素类F-荧光探针CSl,CS2和CS3,经1H NMR,13C NMR,IR和HRMS表征了相应探针的结构,并解析了探针CS3的晶体结构.通过核磁和质谱实验验证了探针与F的作用机理是氟化物脱硅基.光谱分析实验结果显示,CS1,CS2和CS3均具有较好的选择性和灵敏度,且均能成功实现人乳腺癌细胞(MCF-7)中F的检测.%Fluoride,the smallest anion,is one of the most important anions in the human body which is involved in many diseases and many life activities can be displayed by its situation.It is necessary to detect fluoride ions and determine its concentration in organism.Compared to the traditional detection methods,fluorescence probes exhibit high sensitivity,high selectivity and potential for real-time detection.Because coumarin derivatives have strong emission in the visible region,high quantum yield,high photostability and excellent bioactivity,we choose them as fluorophore to prepare new fluorescent probes.Based on the mechanism of intramolecular charge transfer (ICT),the fluorescent probes CS1,CS2 and CS3 that are coumarin-based derivatives were designed,synthesized and utilized in fluoride ions detection.Their structures were confirmed by 1H NMR,13C NMR,IR and HRMS.Meanwhile,the crystals of CS3 were obtained by slow evaporation of an ether solution at room temperature over a period of a few days.The detection limits of CS1,CS2 and CS3 for fluoride ions were respectively determined as 21.77,3.52 and 1.99 μmol/L,indicating that probes have a good sensitivity to the detection of fluoride.The selectivity experiment results demonstrated that the three probes were highly selective for fluoride ions over other competitive.The recognition mechanism of the fluorescent response to fluoride ions was verified by HRMS and NMR experiment in this work.A lot of detailed experiment results indicated that the fluorescent response of probes to fluoride ions attributed to the specific fluoride promoted Si-O cleavage.The study of the effect of probes on viability of cells were carried out using the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay.The experimental results indicated that the three probes had low cytotoxicity.Then the three probes were successfully used to fluorescent detect and image fluoride ions in MCF-7 cells by fluorescence spectrum and confocal fluorescence microscopic imaging,respectively.