Spectroscopic and Photoelectrochemical Properties of Biomacromolecules-Semiconductor Nanoparticles Composites

近年来，半导体纳米粒子与生物学的结合应用成为生物和医学领域的研究热点。其中，关于生物大分子—半导体纳米粒子缀合体系的研究，在生物学研究和医学诊断上，及纳米电子器件和生物传感器的研发，均具有指导意义。同时，基于半导体纳米粒子的量子点荧光探针在生物学标记、成像、检测等方面均具有重大的应用前景。 本文的工作围绕着生物大分子—半导体纳米粒子缀合体系和半导体纳米粒子荧光探针的研究展开，主要进行了以下两方面的工作： 1.以DNA作为模板及保护剂，构建DNA/半导体纳米粒子复合体系，研究DNA对复合体系的光谱和光电化学性质的影响，进一步探讨DNA与半导体纳米粒子之间的相互作用。 2.构建不同类型的半导...In recent years, the integration of semiconductor nanoparticles and biological systems has attracted a great many concerns in biology and medicine field. Investigations of biomacromolecules-semiconductor nanoparticles conjugates(composites) will provide significant theoretical foundation for the biological study and medical diagnosis and assist the construction and operation of nano-molecular devi...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：1912005130190

自组装单层保护金纳米团簇的量子化电容充电

本文研究自组装单层保护金纳米团簇(C12Au MPC)在常温下二氯甲烷溶液中的量子化电容充电效应.示差脉冲伏安曲线显示金核平均直径为2.0 nm的C12Au MPC在-0.6~0.6 V电位区间内有9个明显的量子化电容充电峰,其双电层电容总的变化趋势为在零电荷电位附近最小,随着电位正移或负移电容变大.而且随着该金核尺寸的增大,MPC双电层电容值也变大

DNA/CdS纳米粒子复合体系的光谱和光电化学性质

在水溶液中以DNA作为模板和稳定剂,构筑了DNA与CdS纳米粒子复合体系(DNA/CdSNPC),研究DNA的含量,单双链等对复合体系光电响应的影响,并综合TEM,UV-Vis,IR和荧光光谱等对其形貌和光谱性质进行表征.结果表明,CdS纳米粒子(CdSNPs)与DNA链之间主要通过静电作用结合;DNA模板对CdSNPs的禁带宽度没有影响;以DNA模板合成的CdSNPs具有较高的表面态密度,其对CdSNPs的荧光有增强作用,而对光电流响应有抑制作用,并且DNA在复合体系中的含量影响荧光增强和光电流减弱的程度.该复合体系在荧光标记检测和DNA的定量分析方面可能具有应用前景

Spectroscopic and photoelectrochemical properties of DNA/CdS nanoparticle composites

DNA/CdS nanoparticle composites (DNA/CdS NPC) containing single or double strands and different concentrations of DNA were constructed in aqueous solutions. The effect of DNA on the photoelectrochemical properties of DNA/CdS NPC was investigated and the spectroscopic properties of DNA/CdS NPC were characterized by TEM, UV-Vis, IR, and fluorescent spectrometry. The results showed that CdS nanoparticles (CdS NPs) were combined with DNA strands through the electrostatic interaction; DNA templates did not affect the band gap of CdS NPs; DNA-templated CdS NPs had a higher density of surface states than that stabilized by Na4P2O7, which enhanced the photoluminescence (PL) intensity whereas restrained the photocurrent response of CdS NPs. Besides, there was certain dependency of both the increase of PL intensity and the decrease of photocurrent response on DNA concentrations in DNA/CdS NPC. The composites were hopeful for applications in both fluorescent tagged detections and quantitative analysis of DNA

电化学石英晶体微天平研究界面电场对DNA杂交的影响

采用电化学石英晶体微天平,现场监测不同界面电场下完全匹配的靶标DNA和不完全匹配的靶标DNA分别与寡聚核苷酸探针分子杂交的过程.结果表明,电极表面荷正电时DNA表观杂交效率比电极表面荷负电时高,但假阳性比较显著;而电极表面荷负电时能有效地抑制错配杂交.探讨了引入界面电场后探针分子取向和微观作用力对DNA杂交的影响

Quantized Capacitance Charging of Self-Assembled Monolayer Protected Gold Clusters

本文研究自组装单层保护金纳米团簇(C12Au MPC)在常温下二氯甲烷溶液中的量子化电容充电效应.示差脉冲伏安曲线显示金核平均直径为2.0 nm的C12Au MPC在-0.6~0.6 V电位区间内有9个明显的量子化电容充电峰,其双电层电容总的变化趋势为在零电荷电位附近最小,随着电位正移或负移电容变大.而且随着该金核尺寸的增大,MPC双电层电容值也变大.Quantized capacitance charging was observed for the C12Au monolayer-protected clusters self-assembled on a gold electrode surface in CH2Cl2 solution at room temperature.The result from differential pulse voltammetry(DPV) of C12Au MPC with average core diameter of 2.0 nm showed that which appear nine entries well-defined quantized capacitance charging peaks within the potential range of-0.6 to +0.6 V.The change trend of MPC double-layer capacitances(CMPC) was that the value of CMPC was smallest near zero charge potential and increased with potential positive or negative transfer.In addition,the effect of Au core size on quantized capacitance charging of C12Au MPC was studied.The results showed that the value of CMPC increased with increasing Au core size.作者联系地址：厦门大学化学化工学院化学系,厦门大学固体表面物理化学国家重点实验室,厦门大学化学化工学院化学系,厦门大学化学化工学院化学系,厦门大学固体表面物理化学国家重点实验室 福建厦门361005,福建厦门361005,福建厦门361005Author's Address: 1.State Key Laboratory of Physical Chemistry of the Solid Surface,2.Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,Fujian,Chin

Effect of interface electric field on DNA hybridization studied by electrochemical quartz crystal microbalance

The hybridization of oligonucleotide probe with matched or mismatched DNA target was monitored by a combination of electrochemical control and in situ quartz crystal microbalance technique. The results indicated that the apparent efficiency of hybridization for matched DNA target at a positive potential was higher than that at a negative potential. But an obvious response of "false positives" may be obtained at the positive potential. Application of negative potential can availably halt hybridization for mismatched target DNA. The effect of the orientation of oligonucleotide probe and micro forces on DNA hybridization under interface electric field was discussed