Spectroscopic and Photoelectrochemical Study of Nanoparticles-Cytochrome c Hybrid Systems

近年来，纳米粒子与生物大分子，尤其是与蛋白质的相互结合作用及应用成为化学，生物学和医学领域的研究热点。DNA、蛋白质（抗原/抗体、酶）等生物大分子由于和纳米粒子尺寸相近，两者可以很好地构筑纳米粒子-生物大分子复合体系。生物分子具有生物独特的催化性能和独特的分子识别能力，而纳米粒子具有特殊的光学、电学、催化性质，复合体系结合两者的独特优势，而被广泛应用在生物传感器、微型电路、纳米设备等等各个方面，同时对生物学研究和医学诊断也有一定的指导意义。 本文的工作围绕着纳米粒子-细胞色素c复合体系的光谱性质，两者内部的相互作用及应用展开，主要进行了以下两方面的工作： 1. 构筑半导体纳米粒子-细胞色素...In recent years, the integration between nanoparticles and biomacromolecules, especially proteins has attracted a great many concerns in chemistry, biology and medicine field. Many biomaterials such as DNA and proteins (antigens/antibodies, enzyme) possess nanometric dimensions comparable to those of nanoparticles, and the size comparability paves a way to integrate nanoparticles and biomacromolec...学位：理学硕士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：2052007115096

Au Nanoparticles Based Colorimetric Detection of Conformational Changes in Cytochrome c

Corresponding author. Email: [email protected]; Tel: +86-592-2189663.[中文文摘]金纳米粒子(AuNPs)的颜色会随着细胞色素c(Cytc)构象变化而发生较大的变化,作者在改变原测定流程的基础上利用这种有规律的变化研究和测定了H+和L-半胱氨酸(L-Cys)对Cytc的构象变化.实验中分别加入pH=1-13的Cytc,可以使AuNPs显示青、蓝、紫、红等明显不同的颜色,从而可以利用AuNPs比色快速测定不同pH值的Cytc构象变化.在pH=7时,当附加L-Cys浓度从低浓度变化到高浓度时,AuNPs颜色逐渐从紫色变化到蓝色、青色,从而实现利用AuNPs比色测定由L-Cys所引起Cytc构象变化.圆二色(CD)光谱证实了pH=1-13和不同浓度L-Cys下的Cytc构象变化.借助紫外-可见吸收光谱和扫描电子显微镜(SEM)进一步明确了加入Cytc后AuNPs的不同聚集状态与其颜色变化的关系.[英文文摘]The colors of Au nanoparticles(Au NPs) change along with conformational changes in cytochrome c(Cyt c).We exploited this property for the colorimetric detection of Cyt c conformational changes induced by H + and L-cysteine(L-Cys).We improved the conventional procedure for this detection.After the addition of Cyt c within different pH values,the Au NPs are either cyan,blue,purple or red.This indicates that the Au NPs can be applied to the rapid colorimetric detection of pH-induced conformational changes in Cyt c conformational changes caused by interaction with L-Cys. The conformational changes of Cyt c were verified by circular dichroism (CD) spectroscopy. The relationship between the aggregation states and colors of the Au NPs after the addition of Cyt c was characterized by UV-Vis absorption spectroscopy and scanning electron microscopy (SEM).国家自然科学基金(20603027,20423002)资助项

Electrochemical Behavior of Redox Proteins on ZnO Nanorod-Modified Electrodes Prepared by Electrodeposition

Corresponding authors. ZHOU Jian-Zhang, Email: [email protected]; Tel: +86-592-2189663.[中文文摘]采用恒电位阴极还原法在金电极表面一步修饰ZnO纳米棒,制备成ZnO纳米棒修饰电极.扫描电子显微镜(SEM)和X射线衍射(XRD)结果显示制得的ZnO为直径约100nm的六棱柱状纤锌矿晶体纳米棒.使用ZnO纳米棒修饰的金电极研究细胞色素c的直接电化学行为,结果表明:ZnO纳米棒修饰的金电极能有效探测到细胞色素c的铁卟啉辅基在不同价态下的电化学行为;细胞色素c吸附后,ZnO纳米棒修饰的金电极对过氧化氢的电流响应呈现良好的线性关系.[英文文摘]We successfully prepared ZnO nanorod-modified Au (ZnO nanorod/Au) electrodes using one-step cathodic electrodeposition. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the morphology and crystal phase of the ZnO nanorods. The data showed that the ZnO nanorods were wurtzite type crystals with a hexagonal rod shape and a diameter of about 100 nm and that the ZnO nanorods were arranged well on the surface of electrodes. These ZnO nanorod-modified electrodes were able to detect direct electron transfer from cytochrome c (cyt c). Cyclic voltammograms showed that the direct electron transfer of cyt c with heme iron in different valence states was easily achieved by the ZnO nanorod/Au electrode. Data of amperometric responses demonstrated that a linear amperometric response to hydrogen peroxide was observed on the ZnO nanorod/Au electrodes after adsorbing cyt c.国家自然科学基金(20603027,21021002,20973134); 国家高技术研究发展专项经费项目(2009AA03Z327)资