Fabrication of Metal/Molecule/Metal Junctions and Their Characterization by a Combined MCBJ-SERS Method

本论文主要针对当前分子电子学研究中的二个关键性问题开展方法学研究，一是如何将目标分子与宏观世界可靠的连接，即在芯片上形成金属电极/目标分子/金属电极组成的分子结；二是如何对分子结的电学性质与化学结构进行关联研究。迄今为止，有关分子结中的电子传输过程和详细机理仍不清楚，甚至存在着较多互相矛盾的解释。因此，亟待发展可构筑分子结和在分子水平上表征其结构特征的各种新方法。在本论文工作中，我们通过结合机械可控裂结法(MCBJ)和表面增强拉曼光谱(SERS)的各自优势，成功构筑了多种分子的金属/分子/金属结的结构，并通过I/V、G/V特性曲线、电导统计图和拉曼光谱等测量手段对分子结进行了表征。我们所提出和...This dissertation aims to take two challenges in the field of molecular electronics with emphasize on methodology. The first one is how to connect the target molecules with the macro-world on a chip, i.e., to form molecular junctions with the metal electrode/target molecules/metal electrode structure reliably. The second one is how to correlate the electrical property of the molecular junction dir...学位：理学博士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：B20032503

Optimization of Fermentation Conditions of Marine Algicidal Bacterium Microbulbifer sp. BS03 by Uniform Design

通讯作者 Corresponding author (E-mail: [email protected]; [email protected])[中文文摘]采用均匀设计法设计和二次多项式逐步回归分析,对一株高效杀塔玛亚历山大藻微泡菌BS03(Microbulbifer sp.)产杀藻活性物质的发酵培养条件进行优化.通过单因素实验筛选出碳源、氮源、pH、培养时间和接种量为显著影响因子,并对5个显著影响因子采用U15(155)水平对培养基进行优化.结果表明BS03最适发酵培养条件为:蔗糖8 g/L,蛋白胨10.50 g/L,初始pH值7.5,培养时间32 h,接种量3.00%.验证试验结果显示,在此条件下该菌发酵液的干重为4.725 g/L,较优化前增加了31.35%,LD50为0.768%,较优化前降低了25.14%.研究结果为杀藻活性物质以及杀藻机理的研究奠定了理论基础.[英文文摘]The optimal parameters of fermentation conditions of marine bacterium Microbulbifer sp.BS03 producing algicidal substances against Alexandrium tamarense were obtained by using Uniform Design and quadric polynomial regression methods.Five main factors were achieved through single factor experiments,that is,carbon source,nitrogen source,pH,incubation time and inoculum size.The U15(155) design result showed the optimum conditions of experiment were as follows: sugar 8 g/L,peptone 10.5 g/L,initial pH 7.5,incubation time 32 h, and inoculum size of 3.00%. According to the verifi cation experiment, under the optimal conditions, the dry biomass was 4.725 g/L which was increased by 31.35% and LD50 was 0.768% which was decreased by 25.14% compared with those of the basic fermentation conditions. This outcome will help us to separate active substances from complex components in medium and thus to reveal the mechanism of algicidal activity in the future. Fig 7, Tab 5, Ref 20.国家自然科学基金项目(Nos.40930847,31070442); 福建省自然科学基金项目(Nos.2012J01150,2010J01223);; 福建省教育厅项目(No.JA10232);莆田市科技计划项目[No.2011S09(4)]资助

悬空纳米间隔电极对的制备并应用于单分子电学性质测量

将普通光刻技术和电化学技术相结合,在微芯片上制备得到了机械可控断裂结法(MCBJ)所需的悬空纳米间隔金属电极对,并分别用热氧化二氧化硅和聚酰亚胺(PI)作为牺牲层使得电极对悬空,明显提高了可控断裂的实验成功率,并延长了微芯片使用寿命。利用分子自组装和MCBJ方法成功构筑了金属/分子/金属结,并实施了对巯基苯胺(BDT)单分子的电学性质测量,得到了BDF的电导值和I-V特性曲线

Fabrication, characterization and electric properties of a gold nanowire containing 4,4 ‘-azopyridine molecular junction

A study on the fabrication and characterization of gold nanowires containing a 4,4′-azopyridine monolayer junctions was reported. Au nanowires were prepared by using a two-step alternative current(AC) electrodeposition inside the pores of AAO. Azopyridine molecules were adsorbed on the top of Au layer by self-assembly and electroless plating was done to introduce Au caps on the top of the SAMs. The top Au segments were prepared by using AC electrodeposition, too. The HRTEM image shows the thickness of the SAM is approximately 1.5 nm, which is in good agreement with the theoretical length of azopyridine. It is demonstrated that direct AC electrodeposition was more effective than chemical deposition on strengthening the electronic device. Utilizing 4,4′-azopyridine as the active component, current-voltage characterization of nanowires containing molecules was done at room temperature by a two-point probe method by using a Keithley 4200 semiconductor characterization system. A good conductive behavior at room te..

两步电沉积法制备单晶Au纳米线阵列

　以多孔阳极氧化铝为模板,采用两步交流电脉冲沉积法制备具有单晶结构的有序金纳米线阵列.实验表明:在氧化铝模板中由交流电沉积制备的金属纳米线,其成核电压直接影响模板内纳米线的填充率,而生长电压则控制纳米线的结构和形貌均一性.在最佳沉积条件下得到的金纳米线阵列,其填充率高达95%,且具有单晶结构

Studies on Graphite Anode During Electrochemical Scan Cycles by EIS,Raman Spectroscopy and XRD

运用电化学阻抗谱(EIS)、Raman光谱和XRD研究了石墨负极在1 mol/L LiPF6-EC∶DEC∶DMC电解液中的电化学循环扫描过程.EIS研究结果表明,在电化学循环扫描4~10周范围内,SEI膜(固体电解质相界面膜)电阻随循环扫描周数增加近似线性增长,但石墨负极/电解液界面总阻抗由于电荷传递电阻的降低而减小.Raman光谱研究结果表明,在经历电化学循环扫描后,活性材料表层发生粉化和无定形化,石墨化程度降低;但XRD研究结果显示,石墨材料的本体结构没有发生变化,仍然保持着完整的石墨层状结构.The graphite anode during electrochemical scan cycles in 1 mol/L LiPF6-EC-DEC-DMC electrolyte solutions was investigated by EIS,Raman spectroscopy and XRD.It was found that the resistance of the SEI film increases almost linearly during the prolonged cycling in the 4—10 electrochemical scan cycles.However,the interface resistance between the graphite anode and the electrolyte solution decreases due to the decrease of the charge transfer resistance.After the electrochemical scan cycles,the active material on the surface of graphite anode is exfoliated and pulverized,and become amorphous,while the bulk of the active material remains unchanged.国家“九七三”计划(批准号:2002CB211804)资