【作者】 郭薇；

【导师】 张昕彤； 白玉白；

【作者基本信息】 吉林大学 ， 物理化学， 2004， 硕士

【摘要】 纳米粒子的合成及其二维组装的特性研究是纳米科技研究中十分活跃的前沿领域。我们在这方面通过各种方法做了一系列研究工作： 首先，以粒径为 50 nm 的金溶胶作为晶种，在羟胺－四氯金酸体系中，通过表面自催化反应，成功地合成了粒径范围在150 nm以下的一系列球形、单分散的金纳米粒子水溶胶，将球形单分散金纳米粒子的合成极限从 70 nm扩大到 150 nm 左右。 然后，成功地对云母表面进行了修饰，并在其上制备了分散均匀的金纳米颗粒单层膜，对组装过程、机理进行了研究，以 AFM 为表征手段，对组装条件的影响进行了探讨，得到了一些规律性的结果。发现云母浸泡在Mn2+溶液中，其表面的 K+与溶液中的 Mn2+进行了交换，因而使云母表面带有正电，金纳米粒子通过静电作用吸附在云母表面。同时，探讨了金纳米粒子组装的动力学。结果证明，这是一种很好的、简便的、行之有效的金纳米粒子的组装方法，该组装体系将在 SERS 光谱学、纳米刻蚀等领域中具有广泛的应用前景。 通过合理的超分子相互作用的设计，利用 DPN 技术将针尖上的蛋白质分子、抗体分子直接书写到镀金的云母基底上，得到了尺寸、形状和位置均精确可控的生物材料纳米图形，为纳米生物器件的制造提供了一个简单的、低成本的、崭新的办法。这种方法迥异于 Mirkin 小组提出的关于构建蛋白阵列的方法。利用 DPN 技术成功书写分子的关键在于设计好针尖与样品分子、样品分子与基底相互之间的协同作用力，这样才能将针尖上的分子书写到基底上，因而实现纳米刻蚀和纳米制造的目的。这里所说的分子不仅仅局限于蛋白，将其推而广之乃至有机分子、无机纳米晶等具有特殊的光学、电学、磁学的纳米材料。这也就恰恰显示了利用 DPN 直接书写技术的广阔前景。 基于免疫检测的目的，选用葡聚糖包覆超顺磁性的 Fe3O4纳米粒子，通过葡聚糖表面的醛基化实现与单克隆抗体的偶联，制得了 Fe3O4/葡聚糖/抗体磁性纳米生物探针，并利用 XRD、电子衍射、热重、紫外－可见光谱、红外光谱和 SQUID 对复合物进行了研究，证实了醛基化的磁性葡聚糖的生成。并用免疫酶联分析法对偶联后抗体的活性进行了研究，结果表明，偶联反应后，抗体仍然具有较高的反应活性。 利用抗体与对应的抗抗体间的特异性识别相互作用，将磁标鼠源单克隆乙肝病毒表面抗原抗体(IgGH)组装到抗抗体(anti-IgGH)修饰的镀金的硅基底上。利用 AFM、红外光谱和 X－光电子能谱(XPS)跟踪监测了整个组装过程，尤其是抗体的特异性识别事件。此外，还利用横向力显微镜(LFM)和磁力显微镜(MFM)帮助进一步分辨和确认免疫识别复合物。 91<WP=98>吉林大学硕士论文 最后，通过 LBL 技术，利用聚电解质成功的制备了不同间隔层的Fe3O4/CdTe 纳米晶异质结构，并研究了此结构的荧光强度与 CdTe 和 Fe3O4之间的距离的关系，对不同间隔的 Fe3O4/CdTe 和 WO3/CdTe 复合膜进行了荧光跟踪测试。在聚电解质的精确间隔下，发现 Fe3O4/CdTe 纳米晶异质结构的荧光强度与距离相关，而且这种荧光强度的变化规律不同于 WO3/CdTe 异质结构。研究认为，Fe3O4对 CdTe 的猝灭一部分是由共振能量转移造成的，属于长程的猝灭作用；而 WO3对 CdTe 的猝灭属于电子隧穿相互作用。还对Fe3O4/CdTe 和 WO3/CdTe 单层间隔复合膜做了时间分辨荧光光谱的测试，更加确认了这一假设。 92更多还原

【Abstract】 The preparation and study of nano-scaled assembled structuresare immensely attractive and rapidly expanding area in nano research.In this field, some new results were obtained by different assemblymethods. The main results are outlined as following: Firstly, gold nanoparticles, prepared by the Frens method andcrystal-seed method, have been electrostatically assembled ontomica substrates which were treated with different concentration ofMnCl2 solution. The assemblies have been investigated by means ofatomic force microscopy (AFM). Both the immersing time of bare micain Mn2+ solution and the concentration of Mn2+ solution havesignificant effects on the assembled process of gold nanoparticulatemonolayer. The coverage of gold particles shows periodical evolutionwith the increase of immersing time of mica in MnCl2 solution. Thehigher is the concentration of MnCl2, the shorter is the time toattain maximum coverage. An ion-exchanged and layer dissociatedmechanism is put forth to explain the experimental results above.And such nano-assembly structure was studied as SERS substrate. Secondly, by utilizing Dip-Pen Nanolithography (DPN), proteinand antibody have been first directly written onto Au substratethrough reasonable design. The patterns with submicrometerdimensions were obtained with accurately controlling the size, shapeand site. When using Bovine Serum Albumin (BSA) and PSA as the inkin the DPN procedure, we were able to differentiate between Ausubstrate and patterned area deposited with monolayers throughlateral force microscopy (LFM). The interaction between ink andsubstrate was disccussed according to the data of XPS, FT-IR, etc.Directly writing provides a new, easy and cheap method for preparingbio-nano devices. Thirdly, dextran-coated magnetite nanocomposite was coupledwith anti-HBsAg for biology assay. Magnetite-labled anti-HBsAg wasimmobilized onto Au substrate which was modified with anti-IgGpreviously. In order to distinguish the true recognized sites ofanti-IgG, LFM and MFM measurements were performed as well as AFM.The morphological varation was easily identified. However, LFM andMFM are more accurate than AFM in our experiment, and can further 93<WP=100>吉林大学硕士论文comfirm the specific binding event. This study enhanced ourunderstanding of anti-antibody/antibody binding process. At last, we designed a heterostructure of Fe3O4 and CdTenanocrystals with different space distance controlled bypolyelectrolyte using layer-by-layer (LBL) self-assembly technique.We have investigated the interaction between Fe3O4 and CdTenanocrystals through fluorescence spectra, as well theheterostructure of WO3 and CdTe nanocrystals. The photoluminescence(PL) intensity of the heterostructure of Fe3O4 and CdTe was quenchedwithin a wide range of space distance between two kinds ofnanocrystals, about 30 nm. Unlike the heterostructure of CdTe andFe3O4, PL intensity of the heterostructure of WO3 and CdTe was onlyquenched in the range of about 10 nm. The different mechanism of theenergy transfer of two heterostructures was discussed and thetime-resolved luminescence measurements were executed to makefuther confirmation. 94更多还原