【作者】 徐常龙；

【导师】 张爱东； 涂海洋；

【作者基本信息】 华中师范大学 ， 有机化学， 2006， 硕士

【摘要】 近年来,通过界面自组装在固体表面形成超薄层有机材料的研究受到人们的广泛的关注,这种通过有机分子反应活性头基与固体界面之间自发反应形成的稳定、有序、紧密堆积的超薄膜结构叫做自组装膜(self-assembled monolayers,SAMs)。SAMs在非线形化学、分子生物学、材料科学、分子器件,特别是生物传感器等领域具有广泛的应用前景。 生物素(biotin)与链霉亲合素蛋白(streptavidin)有非常强的亲和力。利用具有自组装功能的生物素在金表面形成自组装膜,在其自组装膜上组装链霉亲合素。利用链霉亲合素含有四个与生物素结合位点的特性,可以进一步与各种含有生物素的分子材料的组装,获得具有各种应用目的的分子组装材料。 作为以Biotin-Streptavidin分子组装材料的前期研究工作,本论文合成了含Q.硫辛酸、11-巯基十一烷基和长醚链的生物素衍生物,在金电极表面构建了含生物素的自组装膜体系,用电化学方法对这些自组装膜的结构和性质进行了研究。主要内容如下: 1.设计合成了α-硫辛酸-(8-生物素酰胺基-3,6-二氧辛基)酰胺(TBDA);α-硫辛酸-(13-生物素酰胺基-4,7,10-三氧十三烷基)酰胺(TBTA)。采用~1HNMR、GC-MS、IR等对中间体及目标产物的分子结构进行了表征。 2.设计合成了11-巯基十一酸-(8-生物素酰胺基-3,6-二氧辛基)酰胺(MBDA);11-巯基十一酸-(13-生物素酰胺基-4,7,10-三氧十三烷基)酰胺(MBTA)。用~1HNMR、GC-MS、IR等对中间体和目标产物的分子结构进行了表征。 3.利用自组装膜技术,在金电极上制备了TBDA、TBTA、MBDA、MBTA的自组装膜,以及TBTA和MBDA与膜介质分子11,11’-二硫二(十一醇)(DT)的混合自组装膜。 4.用循环伏安法和电化学交流阻抗谱技术,对上述自组装膜进行了表征,初步研究了这些自组装膜的结构。结果表明这些自组装膜的覆盖度都比较高,覆盖度达到99%以上;对于TBDA和TBTA或MBDA和MBTA自组装膜修饰的金电极,随着醚链的增长,其循环伏安图上表现为氧化还原峰电流逐渐变小,说明膜的结构变得越来越致密;对于混合自组装膜而言,其在金电极上的覆盖度高于单组分自组装膜的覆盖度,并且随着膜介质分子DT比例的增加而增加。另外,在电化学交流阻更多还原

【Abstract】 Recently, the ultrathin films materials formed by interfacial self-assembly on solid surfaces have attracted great attention. This stable, ordered and closely packed ultrathin films are fabricated by spontaneously chemical reactions between reactive headgroups of organic molecules and solid surface functional groups, which are known as self assembled monolayers (SAMs). Materials based on SAMs have many applications in the fields such as non-linear optics, molecular biology, science of materials, molecular devices, and biosensors, etc.Biotin has great affinity to streptavidin. Taking use of the formation of self-assembled monolayers with the terminal Biotin, streptavidin can be constructed on the top of various biotin terminated SAMs. Streptavidin is a special protein which posseses four binding sites for biotin molecule. Thus various bitinylated molecules can be further assembled on SAMs with various properties for special applications. Hence, synthesis of biotinylated thiols or disulfides and applications of SAMs of these biotinylaed thiols or disulfides on gold will have great significance.As for the premise work for the further applications of biotin-streptavidin assembled systems, this thesis presents the synthesis of thioctic acid-containing and 11-mercaptoundecanoic acid-containg biotin derivatives with ether linkage, and construction of these biotin derivatives onto gold electrodes to form self-assembled monnolayers. The structures and the properties of these modified elctrodes were studied by electrochemical methods. The main contents are listed as the following:1. Thioctic-(8-biotinoylamido-3,6-dioxaoctyl)amide(TBDA),Thioctic-(13-biotinoy lamido-4,7,10-trioaxatridecaneamine) amide (TBTA) were synthesized. The molecular structures of the intermediates and the target compounds were confirmed by ~1H NMR, GC-MS and FT-IR.2. 11-Mercaptoundecanoic-(8-biotinoylamido-3,6-dioxaoctyl) amide (MBDA), 11-Mercaptoundecanoic-(13-biotinoylamido-4,7,10-trioaxatridecaneamine)amide(MBTA) were synthesized. The molecular structures of the intermediates and the target compounds were confirmed by ~1H NMR, GC-MS and FT-IR.3. The pure SAMs of MBDA/Au, MBTA/Au, TBDA/Au and TBTA/Au were prepared by the self-assembly monolayer technology. Meanwhile, using 11,11’-diundecanolthiol (DT) as the medium molecule, the mixed SAMs of MBDA/DT and TBTA/DT on gold were also fabricated.4. The electrochemical cyclic voltammetry and electrochemical impendence spectra were employed to characterize the structures and the properties of the above mentioned SAMs on gold. The results shows that closely packed and well ordered SAMs have been fabricated and their surface coverages are over 99%. Mixed SAMs have higher coverages than the corresponding pure SAMs, and the coverage increases with the increase of the molar ratio of the medium molecule DT. At the same time, with the lengthening of the ether linkage between thioctic acid or 11-mercaptoundecanoic acid and biotin, the SAMs will have a greater surface coverage.更多还原