【作者】 张丽珠；

【导师】 彭孝军；

【作者基本信息】 大连理工大学 ， 应用化学， 2008， 博士

【摘要】 罗丹明类荧光染料是以氧杂葸为母体的碱性咕吨染料,由于其特殊的结构及相应的荧光特性,使之广泛应用于化学和生物分析领域。目前,通过修饰后的罗丹明荧光染料对小分子及离子的荧光分析正朝着高选择性、高灵敏度、生物活体内检测的方向不断的发展。本论文总结现有的研究成果,设计合成了一系列含有活性取代基团的、方便应用于生物标记的罗丹明类荧光染料和高选择性识别金属离子的罗丹明类荧光分子探针。利用对位含有不同取代基的苯甲醛为原料,设计合成了六个苯环对位取代基不同的罗丹明荧光染料。通过改变合成方法,避免了异构体的产生,获得了单一产物。光谱性能的测定结果发现醛代替酸酐合成的染料在质子和非质子性溶剂中的摩尔消光系数变化不大,避免了传统罗丹明B染料在非质子溶剂中形成内酯结构所导致的光谱性能变化。光稳定性实验显示:合成得到的染料与传统染料一样有好的稳定性。利用“关-开”荧光分子开关原理,设计合成了三个Cr³⁺荧光分子探针。吸收和荧光光谱的测试结果表明,探针RhoCr1在Tris-HCI中性缓冲溶液中能高选择性的识别Cr³⁺并产生了荧光增强,通过对探针光谱性能的测试和TEPN滴定实验表明,探针RhoCr1与Cr³⁺的络合是一个可逆的过程。此外,用化学模拟的方法将K₂Cr₂O₇中的Cr⁶⁺还原成Cr³⁺,与探针结合后荧光增强,进一步说明了RhoCr1对Cr³⁺的识别。活体细胞PC12细胞中RhoCr1对铬离子识别的荧光成像结果表明,RhoCr1能够进入细胞并能络合Cr³⁺后出现荧光增强。通过乙二胺柔性链将不同的醛与罗丹明B共价相连,设计合成了五个金属阳离子荧光探针,在水相和有机相中对金属离子选择性的紫外吸收、荧光光谱表明,含不同取代基的醛不同,对Fe³⁺和Cr³⁺识别的选择性也有很大差别,其中,吡啶环和氨基对Cr³⁺离子可能有较高的选择性,而噻酚环和羟基决定了配体对Fe³⁺的络合。设计合成了以罗丹明6G为荧光母体的Fe³⁺荧光探针Rh6GFe1、Rh6GFe2、Rh6GFe3和Rh6GFe4。其中Rh6GFe1在Tris-HCI中性缓冲溶液中能够高选择性地络合Fe³⁺并促进了荧光增强。加入Fe³⁺后,Rh6GFe1的荧光强度增大70倍。活细胞Hele细胞和PC12细胞的荧光显微成像结果表明该探针能够穿透细胞并能识别细胞内的Fe³⁺。以噻酚醛、吡啶醛和水扬醛为识别基团的荧光分子探针Rh6GFe2、3、4,在pH 5-9的范围内对氢质子不敏感,pK_a分别为3.76,3.82,3.77。通过对探针对Fe³⁺的线性滴定和络合常数计算,表明这三个荧光分子探能够检测微摩尔浓度范围内的Fe³⁺。更多还原

【Abstract】 As one kind of the xanthenes,rhodarnine dyes are widely used in the fields of chemical and biological analysis because of their unique character& Today,the fluorescent analysis of ions and molecular based on revised rhodamine dyes is developing to high selectivity,high sensitivity and fluorescence imaging in cells Based on these published results,a series of rhodamine dyes with active groups using in biology and fluorescent sensors with high sel ectivity for metal ions were designed and synthesized.Six rhodamine dyes with different substituents in phenyl contraposition were designed and synthesized based on different substituent benzaldehyde as raw materials.Through altering synthesis method,the products were sole,avoiding the production of isomers mixture. The spectral results showed that the changes of molar extinction coeffidents were i ndepended upon proton and aprotic solvents,which avoided fluorescent quenching in aprotic solvent made by lactonic form of traditional rhodarnine B dyes.Finally,the photostabilities of these dyes were investigated.Compared with traditional rhodamine dyes,these dyes were found to have the same good photostabiliti es as that of traditional rhodami ne dyes.Based on "Off-On" fluorescent switch principle,three fluorescent probes have been designed and synthesized.RhoCr1 showed can selectively recognize Cr³⁺in Tris-HCI neutral buffers through the absorption and emission spectrum.The coordi nation of RhoCrl with Cr³⁺ was a reversible process through RhoCrl with Cr³⁺and TPEN titration experirnent.Moreover, the recognition of RhoCr1 for Cr³⁺was further proved by simulative way which reduced Cr⁶⁺ in K₂Cr₂O₇ to Cr³⁺and coordinated with RhoCr1.The fluorescence images that RhoCr1 coordinated with Cr³⁺in PC12 cells showed RhoCr1 to be capable of penetrating into living cells and imaging intracellular Cr³⁺changesFive probes have been designed and synthesized,where different aldehydes were covalently linked to rhodamine B dyes with diethylamine flexible chains.The selectivity in aqueous and organic solution was studied through their UV-Vis absorption and emission spectra.The results indicated that selectivity for Cr³⁺or Fe³⁺were different with substituents in aldehyde& The pyridine and amido would like to improve coordination affinity for Cr³⁺. The thi ophene and hydroxyl would refer to coordi nati on wi th Fe³⁺.Four fluorescent probes Rh6GFe1,Rh6GFe2,Rh6GFe3 and Rh6GFe4 based on rhodamine 6G were designed and synthesized.In tris-HCI neutral buffers,Rh6GFel displayed an excellent selectivity for Fe3 over the other metal ions and a strong fluorescence appeared.Upon addition of saturating Fe³⁺,the fluorescence intensity enhanced nearly 70-fold. By using fluorescence microscopy of Hele cells and PC12 cells,probe Rh6GFe1 was shown to be capable of penetrating into living cells and imaging intracellular Fe³⁺distribution. Fluorescent probes Rh6GFe2,Rh6GFe3 and Rh6GFe4 by using thiophene-2-carboxaldehyde, pydine-2-carboxaldehyde and 2-hydroxybenzaldehyde as chelaters for metal ions were pH-independent in the range of pH5-9.Their pK_a value were 3.76,3.82,3.77 respectively. Through linear titration and Ka calculation,these probes could detect for Fe³⁺at the level of micromole.更多还原