界面可控硫醇SAMs纳米金修饰金电极的电化学行为研究

在裸金电极上自组装不同比例的4,4′-二甲基联苯硫醇（MTP）和硫辛酸（TA）混合液,形成自组装膜（MTP+TA/AuSAMs）,再修饰纳米金,制得纳米金混合巯基修饰金电极（AuNPs/MTP+TA/Au）。研究了纳米金混合巯基修饰金电极的电化学行为和阻抗行为,结果表明电极表面pH值的改变对电极表面的电子转移有重要影响。对葡萄糖传感器的制备条件、测定条件、抗干扰能力等进行了讨论,结果表明修饰电极的微结构和微环境有必要进一步研究。     

Electrochemical Impedance Study of Schiff Base by Means of Self-assembled Monolayer

Schiff base and its metal complex have attracted much attention because of their wide applications in biomedicine and their specific character in photochromic field1. Up to now, reports about Schiff base mainly covered its synthesis and structure2,3. To the best of our knowledge, there is no paper dealing with Schiff base using electrochemical impedance spectroscopy technique by forming self-assembled monolayer. The complexation of Schiff base with the transition metal ions has been confir…     

铁表面组装磷酸三乙酯缓蚀功能分子膜的研究

研究一种新型的自组装成膜物质—磷酸三乙酯(TEP).实验发现,TEP自组装膜能有效抑制铁在0.5mol.L-1硫酸溶液中的腐蚀.电化学测试显示,组装时间对成膜效果产生影响.在最初较短的组装时间内,TEP自组装膜的缓蚀效率随组装时间延长而快速增加,之后增加速率减慢直至恒定.     

铁表面自组装缓蚀功能膜的电化学阻抗谱研究

在铁表面自组装十四烷基胺膜.研究该膜在0.5 mol/LH2SO4溶液中对铁的缓蚀性能.电化学阻抗谱测试表明,随着组装时间的延长,缓蚀性能也随之增强,最大缓蚀效率为68.7%.而以十二烷基硫醇和十四烷基胺修饰的混合膜则更为致密、稳定,对铁的缓蚀能力也明显优于仅以十二烷基硫醇或十四烷基胺修饰的单一膜,其缓蚀效率可提高至78.2%.     

自组装双硫醇分子膜阻抗谱的研究

Dielectric properties of dithiol self-assemble monolayers (SAMs) under ac electric field were presented. Using a Hg-SAM/SAM-Hg junction, the ac impedances of dithiol SAMs were measured using a sinusoidal perturba- tion of 30 mV (peak-to-peak) with the frequency ranging from 1 Hz to 1 MHz at zero bias. The contributions from dithiol SAMs and solvent interlayers were separated due to their different behaviors at ac impedance. The peak position in the loss spectra (the plot of tg± vs: frequency) moves to low frequency with the increase of chain length of dithiols. Using a correlation of peak position with the chain length, the active energies of 23-39 meV for dithiol SAMs of C6-C10 under an ac electric field were derived.     

席夫碱大环铜配合物的化学核酸酶活性研究

对3种结构相近的席夫碱四氮大环草酰胺铜配合物（CuL^1～3）的化学核酸酶活性进行比较研究。结果表明：这类配合物的化学核酸酶活性与中心金属离子的类型、配体的结构、溶液的pH值、离子强度及配合物的浓度等都有关系。3种配合物表现出来的化学核酸酶活性顺序为CuL³＞CuL²＞CuL¹。CuL³的DNA切割反应表现为典型的假一级连续反应。在80 μmol·L^-1 CuL³和2 mmol·L^-1 H₂O₂的存在下,就超螺旋DNA向切口开环型DNA进而向线型DNA的转化而言,反应速率常数分别为0.044 0±0.001 5 min^-1(k₁)和0.003 52±0.000 18 min^-1(k₂)。     

Modification of Electrode Surfaces by Self‐Assembled Monolayers of Thiol‐Terminated Oligo(Phenyleneethynylene)s

The wire‐like properties of four S‐(4‐{2‐[4‐(2‐phenylethynyl)phenyl]ethynyl}phenyl) thioacetate derivatives, PhC≡CC₆H₄C≡CC₆H₄SAc ( 1 ), H₂NC₆H₄C≡CC₆H₄C≡CC₆H₄SAc ( 2 ), PhC≡CC₆H₂(OMe)₂C≡CC₆H₄SAc ( 3 ) and AcSC₆H₄C≡CC₆H₄C≡CC₆H₄SAc ( 4 ) (Figure 1 ), all of which possess a high degree of conjugation along the oligo(phenyleneethynylene) (OPE) backbone, were investigated as self‐assembled monolayers (SAMs) on gold and platinum electrodes by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The redox probe [Fe(CN)₆]₄^? was used in both the CV and impedance experiments. The results indicate that the thiolates derived from thioacetate‐protected precursor molecules 1 and 2 form well‐ordered monolayers on a gold electrode, whereas SAMs derived from 3 and 4 exhibit randomly distributed pinholes. The electron tunnelling resistance and fractional coverage of SAMs of all four compounds were examined using electron tunnelling theory. The analysis of the results reveal that the well‐ordered SAMs of 1 and 2 exhibit higher charge‐transfer resistance in comparison to the defect‐ridden SAMs of 3 and 4 . The additional steric bulk offered by the methoxy groups in 3 is likely to prevent efficient packing within the SAM, leading to a microelectrode behaviour, when assembled on a gold electrode surface. The protected dithiol derivative 4 probably binds to the surface through both terminal groups which prevents dense packing and leads to the formation of a monolayer with randomly distributed pinholes. Atomic force microscopy (AFM) was used to examine the morphology of the monolayers, and height images gave root‐mean‐square (RMS) roughness′s which are in agreement with the proposed SAM structures.     

阻抗滴定法测定巯基乙酸及其混合自组装膜表面酸度

采用循环伏安和交流阻抗法对巯基乙酸及其混合自组装膜的表面酸性基团的离解特性进行了研究,并利用阻抗滴定曲线得出了巯基乙酸及其混合自组装膜的表面酸度。研究了混合组装电极中其他组分含量的变化、支持电解质的离子强度等因素对表面酸度移动的影响,用氢键作用、疏水相互作用及分子间相互作用对实验结果进行了解释。     

全反式维甲酸合钇(Ⅲ)配合物对DNA的切割和键合作用(英)

以紫外光谱、荧光光谱、粘度法和凝胶电泳方法研究了全反式维甲酸合钇(Ⅲ)配合物与DNA的作用。结果表明,该配合物能在生理条件下比配体和金属离子更有效地切割质粒DNA,体系离子强度和pH值的变化对配合物的切割活性有较大影响,自由基捕捉剂的加入不影响配合物的切割活性。该配合物对DNA的切割可能通过水解机理进行。该配合物可使DNA的粘度增加,使EB-DNA体系的荧光强度和DNA溶液的紫外吸收强度降低。据此推断,该配合物主要以嵌入方式与DNA作用。     

Switchable Hydrophobic Valve for Controlled Microfluidic Processing

A simple microfluidic valve, without any moving parts, is presented that can control solution flow on demand in microchannels of many different materials using a low‐power electric signal. Many independently operating valves can easily be integrated into complex microfluidic systems. The valve consists of a self‐assembled monolayer (SAM) formed on a platinum electrode that is incorporated directly in the microchannel. The normally‐on valve stops the solution flow due to a hydrophobic SAM on the electrode surface. The solution is allowed to pass the valve by applying a potential to the electrode, which removes the SAM due to reductive desorption. The valve operation is highly stable and has switching times of the order of 1 s. The valve is ideal for controlled solution manipulation in integrated micro‐analytical systems and autonomous microfluidic systems.     

纳米半导体硫化银单层膜的自组装

本文使用Triton X-100作为模板剂制备半导体硫化银纳米颗粒,并研究了其吸收光谱的兰移特性。在金属铝或金基底上自组装有机双功能分子单层膜后,将其浸入所制备的纳米硫化银颗粒的微乳液中,自组装得到硫化银纳米颗粒单层膜并研究了其表面形貌特征。