【作者】 李中华；

【导师】 王爱军；

【作者基本信息】 河南师范大学 ， 分析化学， 2011， 硕士

【摘要】 近几年来,Fe₃O₄磁性纳米粒子由于其具有较高的超顺磁性、小尺寸效应、高的比表面积、生物安全性、生物兼容性、易于合成和功能化等优点而被广泛研究和应用。Fe₃O₄磁性纳米粒子的研究是当前生物分析化学和电分析化学十分活跃的研究领域,其中包括:酶的固定、电化学传感、废水处理和蛋白质的分离与富集。本论文主要集中研究了Fe₃O₄磁性纳米粒子的合成、表征、构建直接电子传递的电化学传感以及在废水处理方面的应用。一基于血红素功能Fe₃O₄/SiO₂核壳磁性复合材料构建氧气和过氧化氢传感器的研究血红素（hemin）,是血红素类蛋白质的活性中心,通过共价直接将血红素分子嫁接到氨基功能化的Fe₃O₄/SiO₂核壳磁性复合材料表面。通过TEM、IR和UV-vis等技术对所合成的Fe₃O₄/a-SiO₂/hemin复合磁性材料进行了表征。将其滴涂到玻碳电极的表面构建电化学传感器。该电极对氧气和过氧化氢有良好的催化特性,可用于过氧化氢和水中溶解氧的测定。二基于Fe₃O₄/a-SiO₂/Au磁性复合材料构建葡萄糖传感器的研究首先采用溶剂热法合成单分散的Fe₃O₄磁性纳米粒子,通过溶胶凝胶等技术制备核壳结构的Fe₃O₄/ SiO₂,然后在Fe₃O₄/a-SiO₂组装Au纳米粒子得到Fe₃O₄/a-SiO₂/Au复合磁性复合材料,将其用于固定葡萄糖氧化酶（GOD）构建葡萄糖生物传感器。磁性材料的晶型、形貌和结构分别用X射线衍射光谱（XRD）、透射电镜（TEM）、傅里叶变换红外光谱（FT-IR）和紫外可见光谱（UV-vis）进行表征。采用该材料可以提高GOD固载量,其表面平均吸附量高达3.92×10?9 mol·cm-2,同时,所固定的GOD表现出较高的生物活性。该葡萄糖传感器具有线性范围宽、检测限低、灵敏度高的特点。该方法可用于葡萄糖的测定。三单分散Fe₃O₄磁性纳米粒子快速磁吸附除去水中污染物的研究首先采用溶剂热法合成单分散的Fe₃O₄磁性纳米粒子,其晶型、形貌和结构分别用X射线衍射光谱（XRD）、透射电镜（TEM）、傅里叶变换红外光谱（FT-IR）和紫外可见光谱（UV-vis）进行表征。该Fe₃O₄磁性纳米粒子可用作废水处理的吸附剂。实验详细考查了磁性材料从水溶液中利用磁性快速吸附除去有机染料（铍试剂Ⅱ）的条件,如吸附时间、染色剂浓度、磁性材料的浓度、温度和pH等影响因素。吸附数据用Langmuir和Freundlich吸附等温方程进行拟合。实验结果表明能够和Freundlich等温模式很好的拟合。Fe₃O₄磁性纳米粒子可以快速、有效的除去水中的有机污染物。更多还原

【Abstract】 In recent years, Fe₃O₄ magnetic nanoparticles have been extensively studied and applied due to such notable properties as superparamagnetism, small-size effect, the high surface area to volume ratios, biosafety, biocompatibility, the ease of synthesis and subsequent coating and functionalization. The study of Fe₃O₄ magnetic nanoparticles is an active field of analytical chemistry and electroanalytical chemistry presently, involves relevant applications include: enzyme immobilization, electrochemical biosensors, wastewater treatment, protein separation and enrichment. In this thesis, we developed our work focusing on synthesis characterization, constructing electrochemical sensor based on direct electron transfer of Fe₃O₄ magnetic nanoparticles and its application in wastewater treatment field.1. The study of constructing oxygen and hydrogen peroxide sensor based on hemin grafted onto functionalized core-shell Fe₃O₄/SiO₂ magnetic composite materialsHemin that serves as is the active center of heme protein was directly grafted onto amino functionalized core-shell Fe₃O₄/SiO₂ magnetic composite materials by covalent bond. The synthesized Fe₃O₄/a-SiO₂/hemin composite magnetic materials was characterized by transmission electron microscopy （TEM）、infrared （IR） and ultraviolet -visible （UV-vis ）absorption spectroscopy. The resultant particles were deposited onto the glassy carbon electrode for constructing electrochemical sensor. This modified electrode had a good catalytic properties] towards oxygen and hydrogen peroxide and could be used as the determination of hydrogen peroxide and dissolved oxygen in water.2. The study of constructing glucose sensor based on Fe₃O₄/SiO₂/Au magnetic composite materials with core-shell structuresFirst, monodisperse Fe₃O₄ nanoparticles were synthesized by solvothermal method and Fe₃O₄/SiO₂ with core-shell structures were prepared by sol-gel method. Then Au nanoparticles were assembled onto the surface of Fe₃O₄/a-SiO₂ to form Fe₃O₄/a-SiO₂/Au magnetic composite materials. This composite materials employed to immobilize glucose oxidase （GOD） to construct glucose biosensor. The crystallization, morphology, structure, and electrochemistry of the magnetic materials were characterized by X-ray diffraction （XRD）, transmission electron microscope（TEM）, FT-IR （Fourier transform infrared） and （ultraviolet -visible ） UV–vis spectra, respectively. This materials could increase the amount of the immobilized material and its high surface average concentration was up to 3.92×10?9 mol·cm-2. In addition, the immobilized GOD retained its high bioactivity. The glucose biosensor showed wide linear range, low detection limit high sensitivity. The proposed method could be used for determination of glucose.3. The study of quickly magnetic absorption to remove pollutants from water based on monodisperse magnetic Fe₃O₄ NanoparticlesFirst, monodisperse Fe₃O₄ nanoparticles were synthesized by solvothermal method. The crystallization, morphology and structure were characterized by X-ray diffraction spectrum （XRD）, transmission electron microscope （TEM） , Fourier transform infrared spectroscopy （FT-IR） and ultraviolet-visible spectroscopy （UV–vis）, respectively. Fe₃O₄ magnetic NPs were used as adsorbent in wastewater treatment. Experiments examined in detail magnetic material remove to remove organic dye （BeryllonⅡ） by magnetic quickly adsorption under different conditions such as adsorption time, initial dye concentration, magnetic material concentration, temperature and solution pH. Adsorption data was made to fit the isothermal data using Langmuir and Freundlich equations. The experimental results have demonstrated that the equilibrium data are fitted well by a Freundlich equation. The results indicated that Fe₃O₄ magnetic nanoparticles could remove magnetically quickly organic pollutants in water.更多还原