磁性纳米材料的制备及其在酚类化合物和三磷酸腺苷检测中的应用研究

论文摘要

磁性纳米材料是20世纪70年代后逐渐产生、发展起来的新型纳米材料,广泛应用于生物医学、磁性共振成像、催化、环境治理、生物分离以及生物传感等诸多科学领域,被称为面向21世纪的新型材料。磁性纳米材料具有粒径小、比表面积大、磁性性能优良等不同于常规磁性材料的特性,因此得到众多研究者的青睐。但是,相比其他的纳米材料而言,磁性纳米材料也有其自身的弱点,更易被氧化或团聚,因而磁性纳米材料的表面修饰改性成为研究的热点。表面修饰改性是指用化学、物理方法对粒子表面进行处理,有目的地改变粒子表面的物理化学性质。比如表面电荷性质、表面亲水性、表面化学结构、化学吸附及反应特性等等。Fe304是一种被广泛研究的磁性材料,其化学及物理性能都极其稳定,而且表面可以根据需要进一步修饰改性。通常在磁性粒子表面包覆有机或无机物,主要是为了弥补其在抗氧化能力、抗腐蚀能力、生物相容性及在使用溶剂中的分散性、稳定性等缺陷。此外,为了拥有特殊的使用功能,还可以通过表面改性赋予磁性纳米粒子表面不同的反应性功能基团（如-COOH、-NH2）。本论文的主要内容如下：首先,通过化学沉淀法合成了分散性好的Fe304纳米颗粒,通过振动样品磁强计（VSM）测定磁化强度为76.64emu g-1,通过外加磁场可以实现快速分离。电子透射电镜（TEM）结果显示其粒径分布均匀,平均粒径为9.1nm。实验测得Fe304纳米颗粒的等电点为6.3,通过调节溶剂的pH值可以控制纳米颗粒表面电荷密度。加入适量带相反电荷的离子液体1-十六烷基-3-甲基咪唑溴盐（C16mimBr）可在磁性纳米粒子表面形成混合半胶束,通过疏水和静电作用实现对环境水样中氯酚（2,4-二氯苯酚,2,4,6-三氯苯酚）的富集。实验考察了磁性纳米粒子与C16mimBr的用量、吸附平衡时间、最大萃取体积、解析条件等实验条件。洗脱液用高效液相色谱在285nm检测,结果表明仅用40mg Fe304NPs和24mg C16mimBr就能获得满意的回收率（74-90%）。其次,制备了以Si02包覆的Fe304纳米颗粒为核,4-硝基酚（4-NP）为模板,甲基丙烯酸（MAA）为功能单体,二乙烯基苯作为聚合基质的分子印迹聚合物（MIP）。制备的结构如下：Fe304@Si02@MIP。利用X射线衍射分析仪（XRD）,红外光谱仪（FTIR）,电子透射电镜（TEM）,热重分析仪（TAG）,振动样品磁强计（VSM）和比表面积分析（BET）研究了聚合产物的物理化学性质。实验考察了吸附平衡时间、最大吸附量、解析溶剂等实验条件。聚合产物粒径分布在90-110nm,饱和磁化强度为47.08emu g-1,最大吸附容量为263mgg-1。聚合物被用于快速选择性富集环境水样中的酚类,该方法被成功运用于分析环境样品并获得了满意的结果。第三,建立基于磁性纳米微球表面的DNA双链检测三磷酸腺苷（ATP）的方法。通过先将与ATP适配体互补的寡核苷酸链固定到磁性微球表面,ATP的适配体链通过DNA链互补杂交到功能化的磁性微球上,由此建立了一个基于磁性分离分析的适配体检测ATP的荧光传感器。通过在607nm处荧光强度的变化,调查嵌插到双链DNA分子中的溴乙锭染料的最大浓度。样品中不存在ATP时,荧光强度恒定；当样品中含有ATP时,ATP与适配体链特异性结合引起竞争反应导致DNA双链解离,嵌插的EB减少,导致荧光信号强度产生变化。实验考察了适配体对ATP、CTP（三磷酸胞苷）、GTP（三磷酸鸟苷）、UTP（三磷酸尿苷）的选择性,结果表明ATP适配体链与ATP特异识别。ATP检测的线性范围为5-50μM,检测极限为0.49μM。该方法用于尿样的分析,获得了满意的结果。

论文目录

• 摘要
• Abstract
• Part Ⅰ Introduction
• 1. Introduction of nanomaterials
• 2. Introduction of magnetic nanomaterials
• 3. Progress in the synthesis method of magnetic nanoparticles
• 3.1. Chemical coprecipitation
• 3.2. Thermal decomposition
• 3.3. Microemulsion
• 3.4. Hydrothermal synthesis
• 3.5. Sonochemical synthesis
• 4. Surface functionalization of magnetic nanoparticles
• 4.1. Small molecules and surfactants coating
• 4.2. Polymers coating
• 4.3. Biological molecules coating
• 4.4. Silica coating
• 5. Application of magnetic nanoparticles
• 5.1. Applications in catalysis
• 5.2. Applications in drug
• 5.3. Applications in bio-separation
• 5.4. Applications in environmental detection
• References
• Part Ⅱ Main research work
• 3O₄ magneticnanoparticles with high-performance liquid chromato graphic analysis'>Section 1. Mixed hemimicelles solid-phase extraction of chlorophenols in environmentalwater samples with 1-hexadecyl-3-methylimidazolium bromide-coated Fe₃O₄ magneticnanoparticles with high-performance liquid chromato graphic analysis
• 1.1 Introduction
• 1.2 Experimental
• 1.2.1 Chemicals and materials
• 3O₄ nanoparticles'>1.2.2 Preparation of magnetic Fe₃O₄nanoparticles
• 1.2.3 Characterization
• 1.2.4 SPE procedures
• 1.2.5 HPLC-UV analysis of environmental water samples
• 1.3 Results and discussion
• 3O₄ nanoparticles'>1.3.1 Physical characteristics of Fe₃O₄nanoparticles
• 1.3.2 Isoelectric point
• 1.3.3 Optimization of the analysis conditions
• 16mimBr on the adsorption of CPs'>1.3.3.1 Effect of the amount of C₁₆mimBr on the adsorption of CPs
• 3O₄ NPs'>1.3.3.2 Effect of the amount of Fe₃O₄NPs
• 1.3.3.3 Effect of solution pH
• 1.3.3.4 Effect of ionic strength
• 1.3.3.5 Standing and magnetic separating time
• 1.3.3.6 Effect of solution volume and desorption conditions
• 1.3.3.7 Analytical performance and application
• 1.4 Conclusions
• References
• Section 2. Synthesis of a magnetic molecularly imprinted polymer for the selectiveextraction of phenolic compounds from environmental water samples withhigh-performance liquid chromatographic analysis
• 2.1 Introduction
• 2.2 Experimental
• 2.2.1 Chemicals and materials
• 2.2.2 Procedures for the preparation of magnetic 4-NP-imprinted polymeric microspheres
• 2.2.3 Characterization
• 2.2.4 Adsorption experiments
• 2.2.5 Application of magnetic molecularly imprinted polymer for extraction of phenolic compounds from environmental water samples
• 2.2.6 Chromatographic system and conditions
• 2.3 Results and discussion
• 2.3.1. Characterizations of the magenitc molecularly imprinted polymers
• 2.3.2 Adsorption study
• 2.3.3 Effect of extraction and desorption conditions
• 2.3.4 Analytical performance and the application of the magenitc molecularly imprinted polymers to real samples
• 2.4 Conclusions
• References
• Section 3. Adenosine Triphosphate assay employing a label-free aptamer andfunctional magnetic nanoparticles
• 3.1 Introduction
• 3.2 Experimental
• 3.2.1 Chemicals and apparatus
• 3.2.2 Preparation of the oligonucleotide functioned magnetic nanoparticles
• 3.2.3 Fabrication of complementary aptamer duplexes-modified magnetic nanoparticles
• 3.2.4 Incubation of ATP with the aptamer duplexes-modified magnetic nanoparticles
• 3.2.5 ATP assay and the selectivity study
• 3.3 Results and discussion
• 3.3.1 ATP assay strategy
• 3.3.2 Optimization of conditions for target detection
• 3.3.2.1 Optimization of the correlation parameters for the complementary aptamer duplexes-modified magnetic nanoparticles
• 3.3.2.2 Effect of the EB concentration
• 3.3.2.3 Optimization of the target ATP incubation temperature and time
• 3.3.3 Analytical performance and application
• 3.4 Conclusion
• References
• Conclusions
• 致谢
• Appendix: Paper published during the graduate