【作者】 唐苹苹；

【导师】 苏庆德；

【作者基本信息】 中国科学技术大学 ， 分析化学， 2010， 博士

【摘要】 实际生物和环境样品组成复杂、检测时基质干扰严重,故对实际样品的研究需采用高选择性的分离分析方法。使用特异性强的方法,将样品的分离与预富集-体化,是解决这一问题的关键。近年来发展起来的样品前处理技术,如固相萃取和固相微萃取,有很多优越性,针对不同分析物质发展高选择性的萃取吸附材料成为当前研究的热点。本研究选取生物和环境体系中存在的抗生素磺胺甲恶唑(SMX)、牛血清白蛋白(BSA)、葡萄糖苷和牛血纤维蛋白原(BFg)4种重要物质,针对每种物质的特性,结合分子印迹、免疫分析和酶与专一性抑制剂相互作用等多种分析新技术,发展高选择性的固相萃取固定相或固相微萃取纤维涂层材料,建立了一系列高选择性的分离分析新方法。论文共分为五章。各章内容概括如下：第一章：综述固相萃取和固相微萃取技术,以及萃取吸附材料的研究进展,概述了与本论文研究相关的一些高选择性分离技术,包括分子印迹、抗原抗体免疫分析和酶与专一性抑制剂的相互作用。介绍了本论文课题的提出和主要研究内容。第二章：分子印迹聚合物在线固相萃取和表面等离子体共振技术联用的SMX间接抑制免疫分析法。制备了SMX分子印迹聚合物涂层的毛细管,对制备条件如功能单体和印迹分子的比例、功能单体和交联剂的比例以及聚合时间等进行了优化。扫描电子显微镜观察到最优化涂层厚度为198nm。将毛细管连接到BIAcore3000生物传感器上,用于表面等离子体共振免疫检测前的在线固相萃取和预富集。根据抑制免疫分析,制备了SMX芯片,作为anti-SMX单克隆抗体(MAbs)的检测芯片,检测未被抑制的anti-SMX MAbs的浓度。anti-SMX MAbs被毛细管富集的SMX抑制后,流经传感器芯片的浓度减小。减小的量与样品中SMX的浓度成正比。方法线性范围为0.04-10 ng/mL,灵敏度为0.01 ng/mL,可直接用于低浓度实际样品的检测。具有操作简单,自动化程度高,灵敏度高的优点。第三章：BSA在CdS量子点表面印迹的新型蛋白质印迹方法。蛋白质印迹技术是近几年发展起来的用于蛋白质特异性分离的新方法。对于BSA,表面印迹是使用较多的方法,但到目前为止,其吸附容量较小。半导体量子点是一种新型纳米材料,其比表面积大和表面缺陷多的特点,有利于物质的吸附。本研究合成了L-半胱氨酸修饰的水溶性CdS量子点,将其掺杂在BSA的分子印迹预聚合溶液中,合成在量子点表面印迹的BSA分子印迹聚合物。对聚合条件和吸附条件进行了优化。合成的量子点和分子印迹聚合物颗粒大小均为纳米级别。当聚合物重新结合模板分子后,量子点的荧光发射强度大大减小。荧光淬灭的原因是量子点和模板分子BSA之间的荧光共振能量转移。考察了该新型聚合物对模板分子BSA的吸附行为,符合Langmuir单层吸附,化学吸附为控速步骤。该掺杂了量子点的分子印迹聚合物的吸附容量比未掺杂的提高了142.4mg/g,证明了将量子点用于蛋白质表面印迹以提高吸附容量的可行性。第四章：β-D-葡萄糖苷特异性固相萃取固定相的合成、表征及应用。β-D-葡萄糖脒是β-D-葡萄糖苷酶的特异性抑制剂,而β-D-葡萄糖苷是β-D-葡萄糖苷酶催化作用的底物,因此可推测p-D-葡萄糖脒和β-D-葡萄糖苷之间也有特异性的相互作用。该研究模拟β-D-葡萄糖脒的结构,通过β-D-葡萄糖胺和2-亚胺基硫代烷盐酸盐反应,使糖基通过N-糖苷键与脒苷元链接,吡喃糖环一侧胺基保持带正电的活化状态。然后再连接到由马来酰亚胺基活化的凝胶树脂上,作为SPE的固定相。用红外、核磁、紫外可见吸收光谱等方法验证了产物的结构。在这种状态下,合成的β-D-葡萄糖脒固定相不仅能与β-D-葡萄糖苷化合物进行选择性地可逆结合,而且自身也非常稳定。结合的β-D-葡萄糖苷能被β-D-葡萄糖溶液洗脱下来。结果表明,该固定相是通过糖苷中糖环的特异性进行识别的。第五章：碳纳米管(CNTs)作为萃取纤维涂层分离牛血浆中BFg的固相微萃取方法。.CNTs是近年来发展起来的新型碳材料,其疏水性强,比表面积大。研究将多壁碳纳米管(MWCNTs)和单壁碳纳米管(SWCNTs)用有机键合剂粘于固相微萃取装置的萃取纤维上,直接对蛋白质进行吸附富集,研究其对牛血纤维蛋白原和牛血清白蛋白的吸附性质,并对吸附条件进行了优化。改变溶液pH值或离子强度,可将吸附的蛋白质洗脱下来,并对洗脱条件进行了优化。结果表明：无论是MWCNTs,还是SWCNTs,其对大分子蛋白质牛血纤维蛋白原的吸附能力远大于其对小分子蛋白质牛血清白蛋白的吸附。在一定条件下,CNTs可选择性地吸附BFg。涂层了CNTs的纤维比传统的聚二甲基硅氧烷纤维选择性好。该方法可直接用于从牛血浆中粗略除去牛血纤维原并定量。方法操作简单,可有望直接用于活体检测。更多还原

【Abstract】 The composition in real words samples, such as biological and environmental samples, is relatively complicated. The interference of matrix to target compound is serious when directly analyzed, so analytical methods with strong selectivity are recommended in real word sample analysis. Using methods with high specificity to integrate sample separation and preconcentration is the key step to solve this problem. Solid phase extraction (SPE) and solid phase microextraction (SPME) are sample pre-treatment technologies developing rapidly these years. They have many advantages over traditional methods. Development of different high specific adsorption materials for different target compounds is the hot spot nowadays. In this research, four important compounds in biological and environmental samples, including antibiotic sulfamethoxazole (SMX), glucoside, bovine serum albumin (BSA) and bovine serum fibrinogen (BFg), are chosen as the target compounds. In consideration of special characteristics of each compound, specific SPE stationary or SPME fiber coating is developed. Combining with such new analytical methods as molecular imprinting, immunoassay and interaction between enzyme and its specific inhibitor, a series of new analytical methods with high selectivity is established. There are five chapters in this dissertation and the content of each is as follows:Chapter 1:The basic concepts of SPE and SPME are briefly described. Develo-pment of research in extraction and adsorption materials is reviewed. Then, some new analytical methods with high selectivity, including molecularly imprinting, immunoassay and specific interaction between enzyme and its inhibitor, are introduced. At last, how to bring forward the research idea and main contents of the research are introduced.Chapter 2:A new indirect inhibitive immunoassay using surface plasmon resonance (SPR) coupled with molecularly imprinting technology for SMX.A SMX-MIP coating capillary was produced. The preparation conditions, such as ratio of monomer to imprinting molecule, ratio of monomer to cross-linker, polymerization time and so on, were optimized. The scanning electron microscope (SEM) image illustrated that the thickness of the coating was 198nm. The capillary was connected to a biosensor BIAcore3000 and used as an in-tube SPE and on-line preconcentration device before immunoassay. A SMX sensor chip was produced and used to detect the concentration of uninhibited anti-SMX monoclonal antibodies (MAbs). The anti-SMX MAbs was inhibited by SMX extracted by the MIP coating and the detected concentration by the sensor chip decreased accordingly. The reduced MAbs concentration was linear with extracted SMX amount. The calibration curve was generated by linear fit over the range of 0.04-10 ng/mL. The limit of detection was 0.01 ng/mL. This method was applied to the detection of low concentration samples successfully. It is easy to be operated, and has high sensitivity and automatization.Chapter 3:A new protein imprinting method of imprinting BSA on the surface of CdS quantum dots.Protein imprinting is a new method for specific recognition of target proteins. For BSA, surface imprinting is most favorable. But the adsorption capacity is not good enough. Semiconductor nanocrystals, also called quantum dots (QDs), are new nanoscale materials. They have large specific surface area and many surface deficiencies, which is in favor of adsorption. In this study, a BSA surface imprinting method was developed by the incorporation of water soluble L-cysteine-QDs into molecularly imprinted polymers, which can offer shape selectivity. Preparation and adsorption conditions were optimized. Size of the QDs and QDs-MIP particles was nanoscale illustrated by SEM images. Photoluminescence emission of CdS was quenched when rebinding of the template. The quenching of photoluminescence emissions is presumably due to the fluorescence resonance energy transfer between quantum dots and template molecule BSA. The adsorption is compiled with Langmuir isotherm and chemical adsorption is the rate-controlling step. The maximum adsorption capacity was 142.4 mg/g larger than that of undoped BSA MIP method. This study demonstrates the validity of QDs coupled with MIP technology to analyze BSA.Chapter 4:Preparation, characterization and evaluation of new stationary phase for SPE ofβ-D-glucosides.Glucosylamidine is highly potent and selective inhibitor of glucosidase and glucosides are substrate of glucosidase catalytic reaction. So, it is presumed that there might be specific interaction between glucosylamidine and glucosides. In this study, a positively charged P-D-glucosylamidine was immobilized through a one-pot synthesis procedure involving the addition ofβ-glucosylamine and 2-iminothiolane.HCl simultaneously to a matrix modified with maleimido groups via an appropriate spacer to give a SPE stationary phase for P-D-glucosides. During synthesis, infrared spectroscopy, nuclear magnetic resonance spectroscopy and ultraviolet-visible spectroscopy was used to characterize products. The synthesizedβ-D-glucosylamidine stationary phase is stable and can interact withβ-D-glucosides selectively and reversibly. The retainedβ-D-glucopyranoside could only be eluted byβ-D-glucose solution. It indicates that the binding of theβ-D-glucoside was of specific nature that corresponds to the glycon substrate specificity of theβ-D-glucoside.Chapter 5:A new SPME method of extracting BFg from bovine plasma using carbon nanotubes (CNTs) coating fiber.CNTs are a kind of novel and interesting carbon material with high hydrophobicity and large specific surface area. In this investigation, commercial polydimethylsiloxane (PDMS) fiber was coated with single-wall nanotubes (SWCNTs) and multi-wall nanotubes (MWCNTs) by organic bonding agent, to study their adsorption and extraction ability of proteins, and bovine fibrinogen (BFg) and BSA were selected as the target proteins. The adsorption conditions were optimized. The adsorbed proteins could be desorbed when changing the pH and ionic strength of the adsorption buffer. The desorption conditions were also optimized. Either SWCNTs or MWCNTs adsorbed bigger protein BFg more strongly than. BSA. They can selectively adsorb BFg in certain conditions. The fibers coated with CNTs had advantages over PDMS fiber in selectivity. It could be used to separate and purify BFg in bovine blood plasma and quantify its concentration. This method is easy to be operated and hopeful to be directly applied to in-vivo detection.更多还原