【作者】 蒲文丹；

【导师】 黄承志； 赵华文；

【作者基本信息】 西南大学 ， 分析化学， 2012， 硕士

【摘要】 由于具有独特的光学、电学、磁学特性,纳米材料已被广泛应用在了环境、食品、生物、医药、催化等多个重要领域,并且有望进入其它更多的研究领域。基于此,本文探讨了具有高催化活性和生物相容性的无机纳米材料(碳材料和贵金属纳米材料)的性质,及其在生物分子和重金属离子检测方面的应用。具体研究内容如下：1.金纳米颗粒用于精氨酸的检测。不同于其它氨基酸,精氨酸是唯一含有胍基的氨基酸,并具有最高的等电点。在pH 9.62的酸度下,负电荷的柠檬酸根包被的金纳米颗粒由于静电排斥作用具有较好的分散性,溶液为红色。当向体系中加入精氨酸后,正电荷的精氨酸(pH<pI)通过静电和氢键的作用诱导金纳米颗粒发生聚集,导致溶液颜色由红到蓝的转变。基于此,本文建立了一种可视化检测精氨酸的新方法。在pH 9.62时,其它氨基酸是带负电荷的,对精氨酸的检测不会产生干扰。该方法用于注射液中精氨酸的测定,具有较好的精密度和准确度。2.金纳米颗粒用于Hg2+的检测。没有Hg2+存在时,黄嘌呤(xanthine)的酰亚胺基团通过Au-N键的作用取代金纳米颗粒表面的柠檬酸根,诱导金纳米颗粒发生聚集,溶液变为蓝色。当有Hg2+存在时,Hg2+选择性的和黄嘌呤发生配位作用生成类似于T-Hg2+-T的xanthine-Hg2+-xanthine复合物,阻止黄嘌呤诱导金纳米颗粒发生聚集,溶液颜色逐渐由蓝变红。基于此,本文建立了一种可视化检测Hg2+的新方法。该方法用于合成样中Hg2+的测定,回收率在96.3%-101.7%之间。与其它使用富T的DNA序列来检测Hg2+的方法相比,该方法简便、快捷、价格低廉。3.氧化石墨烯用于三磷酸腺苷(ATP)的检测。由于富含π电子,氧化石墨烯可以通过π-π堆积作用吸附单链DNA (ssDNA),而不与双链DNA (dsDNA)发生作用。基于此,在本文中我们建立了一种检测ATP的新方法。当没有ATP存在时,ATP的核酸适配体(aptamer)与荧光素标记的互补链(FAM-DNA)杂交成为具有荧光的双链DNA(FAM-dsDNA)。加入氧化石墨烯后,由于氧化石墨烯对FAM-dsDNA吸附作用弱,溶液具有较强的荧光。当有ATP时,由于aptamer与ATP的强作用抑制了FAM-DNA与aptamer的杂交,此时FAM-DNA仍以单链的形式存在。加入氧化石墨烯后,氧化石墨烯吸附没有杂交的FAM-DNA,从而猝灭染料的荧光。基于此建立了检测ATP的新的新方法。更多还原

【Abstract】 Owing to the unique optical properties, electrical properties and magnetic properties, nanomaterials have been widely applied in the fields of environment, food, biology, medicine, catalysis, etc, and are expected to enter other more fields of research. For those reasons, in this dissertation, we investigate the properties of inorganic nanomaterials (carbon materials and noble metal nanomaterials), with electrocatalytic activity and high biocompatibility, and explored their applications in the detection of biomolecules and metal ions. The main contents are as follows:1. Gold nanoparticles (AuNPs) used for arginine detection. Different from other amino acids, arginine is the only one that contains guanidine group, and has the highest isoelectronic point (pI). At pH 9.62, negatively charged citrate-capped AuNPs are well dispersed because of strong electrostatic repulsion, and the color of the solution is red. In the presence of arginine, however, positively charged arginine (pH<pI) easily induces negatively charged citrate-capped AuNPs aggregation through electrostatic and hydrogen-interactions, resulting in a red to blue color change of the solution. Therefore, a new method is established for the visual determination of arginine. Furthermore, this method can provide satisfactory results for the determination of arginine in injection samples.2. AuNPs used for Hg2+detection. In the absence of Hg2+, imide group of xanthine easily adsorbs onto the surface of AuNPs through Au-N bond and induces aggregation of AuNPs, resulting in a blue color. In the presence of Hg2+, however, Hg2+can specifically bind with xanthine to form xanthine-Hg2+-xanthine complex, which prevents the AuNPs against xanthine-induced aggregation, resulting in a visible color change from blue to red depend on the concentration of Hg2+. Therefore, a new method can be established for Hg2+visual detection. Hg2+in synthetic samples could be detected with the recovery between 96.3% and 101.7%. Compared with other methods that employ thymine-rich DNA, our method is simple, fast, cost-effective.3. Graphene oxide (GO) used for adenosine triphosphate (ATP) detection. Because of the riched-πelectrons, GO can bind with single-stranded DNA (ssDNA) throughπ-πstacking, but can not with double-stranded DNA (dsDNA). Based on the features, we developed a new method for the detection of ATP. The hybrid of ATP aptamer with its fluorescein (FAM)-labelled complementary DNA (FAM-DNA) demonstrated weak affinity for GO, exhibiting strong fluorescence of FAM-DNA. If ATP was presented, however, the strong fluorescence of FAM-DNA got quenched, for the binding of ATP with its aptamer greatly inhibited the hybridization of the aptamer with FAM-DNA and the unhybridized FAM-DNA was adsorbed on the surface of GO. Therefore, a new method is established for the determination of ATP.更多还原