聚糖联乙炔类脂肪生膜与大肠杆菌的识别作用研究

生物膜是生物进化的产物 .生物膜中的脂类 (糖脂、磷脂、胆固醇 )的组成极为复杂 ,种类繁多 ,分子结构也各不相同 ,但全部属于极性分子 ,即在分子中都含有一个亲水头部基团和一个疏水尾部基团 .它们在膜中有一定的排列方向 ,形成脂双层或微团 ,与膜的生物学功能密切相关 .糖脂在生物膜中所含的比例虽然不是很高 ,约占 2 %～ 5% ,但它在细胞间识别和分子识别过程中具有十分重要的作用 .如 GM1是所有细胞中霍乱毒素的真正受体 [1] ,幽门螺旋杆菌的配体是一些糖脂上的唾液酸 [2 ] .L angmuir- Blodgett(L B)薄膜技术 [3,4 ] 在分子水平上制…     

糖脂功能化聚二乙炔Langmuir-Schaefer薄膜与大肠杆菌的分子识别及动力学过程研究

在气液界面上研究了α-D-甘露糖苷-十六烷(MC₁₆)与10,12-二十五碳双炔酸混合单分子膜行为,二者具有较好的互溶性.在疏水的玻璃衬底上用Langmuir-Schaefer(LS)薄膜技术制备单层MC₁₆/PDA薄膜,研究了这种仿生薄膜与大肠杆菌jm109的相互作用.大肠杆菌jm109对MC₁₆修饰的聚二乙炔LS薄膜的吸附,使薄膜颜色由蓝色变为红色,用紫外-可见吸收光谱可进行定量检测.动力学研究显示比色响应值随时间的增加而增加,3min内即有显著变化,15min后趋于饱和,20min后CR值达到28%,进一步探讨了分子识别的动力学过程.     

一种新型糖脂单分子膜与伴刀豆蛋白A的分子识别

一种新型糖脂单分子膜与伴刀豆蛋白Ａ的分子识别张希，沈家骢ＲｕｍｐＥ．，ＲｉｎｇｓｄｏｒｆＨ．（吉林大学化学系，长春，１３００２３）（德国Ｍａｉｎｚ大学有机化学研究所）关键词糖脂，单分子膜，分子识别糖与蛋白质、核酸相比，直到六十年代还只当作贮能和结构的...     

仿生聚合物的制备及其分子识别作用

本文评述了仿生聚合物的制备及其对分子的识别作用和在分离和生物医用材料方面的应用。     

环糊精与烷基钴配合物分子识别作用的DFT研究

用密度泛函理论(DFT)的B3LYP方法对Costa型烷基钴配合物[n-C6H13Co(C11H19N4O2)·H2O]+(A)和烷基钴肟配合物n-C6H13Co(C8H14N4O4)·H2O(B)进行计算研究,探讨了环糊精对它们的分子识别作用与其电荷分布之间的关系.结果表明,由于A和B的轴向烷基都是中性的,而且它们的烷基均插入环糊精腔内,而使A或B与环糊精形成包结物,因此,在环糊精边上修饰负离子不能加强其对+1价的Costa型配合物的识别作用,平面配体的类型及电荷对分子识别影响也不大.     

CdS薄膜及其光电化学电池阳离子识别特性的研究

半导体材料CdS薄膜具有优良的光电特性,一直受到人们的关注,广泛用于许多无机薄膜太阳电池的n型窗口层[1,2]。用CdS薄膜组装的光电化学电池也一度引起人们的极大兴趣。二十世纪七十年代以来,半导体光电化学在光能-电能转换、光能-化学能转换和太阳能的光电化学利用方面得到了蓬     

荧光素衍生物LB膜对TiO2电极的光敏化作用

合成了三种荧光素长碳链衍生物，通过LB技术将它们组装成单分子薄膜，修饰在用溶胶-凝胶法制备的TiO2透明电极上，研究了这些LB膜的结构和特性及它对TiO2的光增感作用．并对其光敏化机理作了阐述．     

蒽衍生物自组装膜的制备及其对金属离子的识别作用

本文制备了石英基片表面的蒽甲基胺自组装膜，荧光光谱测试结果表明该膜在450～500 nm波段产生较强的excimer发射峰，这应与成膜分子的有序排列加强了蒽环间的相互作用有关。利用该自组装膜通过固/液界面相互作用实现了Zn^Ⅱ和Ag^Ⅰ的荧光识别。不同金属离子与膜分子结合对蒽环排列产生的不同影响是实现识别的主要机制。     

光谱法研究羟基葫芦[6]脲与对氨基苯磺酸的分子识别作用

光谱法研究羟基葫芦[6]脲与对氨基苯磺酸的分子识别作用;紫外光谱法;荧光光谱法;分子识别;包结作用;羟基葫芦[6]脲;对氨基苯磺酸     

荧光法研究羟基葫芦[6]脲与水溶性苯胺蓝的分子识别作用

采用荧光光谱法研究羟基葫芦[6]脲(HOCB6)与水溶性苯胺蓝(AB)、荧光素(FS)和甲基紫(MV)之间的包结作用。结果表明,HOCB6与FS和MV无相互作用,而与AB能形成1∶1型的HOCB6-AB内包结物,并测得HOCB6-AB包结物的包结常数为1.02×103L.mol-1。考察了溶液的pH值、常见有机溶剂、表面活性剂和金属离子等对该包结物的形成及荧光强度的影响,初步探讨了它们之间的作用机理。通过选用不同荧光探针作客体,揭示客体分子的大小和空间位阻对主客体包结物的形成具有决定性的影响,在空间匹配的条件下,通过疏水和氢键作用形成稳定的包结物。     

Piezoelectric Crystal Biosensor System for Detection of Escherichia Coli

Abstract

A piezoelectric crystal biosensor system was applied to the detection of Escherichia coli. the system consists of an oscillator, a frequency counter, a flow cell and a modified piezoelectric crystal. Anti-E. coli antibody is immobilized on the surface of the crystal. It is used as an E. coli detection by measuring its resonant frequency shift due to a mass change caused by specific binding of the micro organisms to the surface. the frequency shift correlates with an E. coli concentration in the range of 10⁶?10⁸ cells·cm^?3. the resonant frequency shift is increased by further treatment to bind micro-particles modified with anti-E. coli antibody. This method allows us to improve the determination limit to 10⁵ cells · cm^?3.     

Interaction and Interfacial Molecular Recognition of Calix[4] arene Derivatives Bearing Nucleobases for Complementary Nucleoside

The p-tert-butyl calix[4] arene derivatives la with uracils and 1b with adenines at the lower rim were synthesized.The Interaction between 1a and 1b in CDCl3 solution was demonstrated by ^1H NMR spectra.The interfacial molecular recognitions of la and 1b for the complementary nucleosides in aqueous subphases were investigated by Langmuir-Blodgett technique.     

Functionalized Gold Nanoparticles – Octadecylamine Hybrid Langmuir‐Blodgett Film for Enzyme Sensor

Mediator free enzyme sensor has been fabricated by covalently immobilizing cholesterol oxidase (ChOx) onto 11‐mercaptoundecanoic acid functionalized gold nanoparticles (MUDA‐AuNPs) – octadecylamine (ODA) hybrid Langmuir–Blodgett film. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies reveal that MUDA‐AuNP/ODA LB film has good affinity for ChOx and provides favorable microenvironment for direct electron transfer between enzyme and electrode. Interference free estimation of cholesterol has been realized at 0.3 V with linear range from 25 to 500 mg/dL, detection limit of 23.38 mg/dL, sensitivity of 1.085 μA mM^?1 and response time of 20 s at pH 7.0.     

Preparation and characterization of 5,10,15,20‐tetraphenylporphyrin Langmuir films for gas chemsensor applications

In this work is reported the preparation and characterization of 5,10,15,20‐tetraphenylporphyrin (H₂TPP) films at the water‐air interfaces. The surface pressure‐area isotherms (π‐A) and UV‐Vis spectroscopy were used to investigate the effect of the spreading methods and parameters on the porphyrin monolayer formation. Also, Langmuir‐Blodgett (LB) and Langmuir‐Schaefer (LS) films were deposited onto glass substrates in order to study the conformation changes in porphyrin molecular packing. Quartz crystal microbalance (QCM) was utilized as the active solid substrate for the development of the NO₂ gas sensor based on the H₂TPP molecular films. The results of π‐A curves have clearly shown the significant contribution of the preparation methods and processing parameters on the conformation of porphyrin molecular films. The UV‐Vis spectroscopy results using polarized absorption dichroism have indicated different molecular packing for porphyrin films deposited by LB and LS methods, with relative tilted angles of 50° ± 5° and 35° ± 5°, respectively. Moreover, the QCM response has given strong evidence that H₂TPP porphyrin molecular films have performed as NO₂ chemsensor. Copyright © 2011 John Wiley & Sons, Ltd.     

聚酰亚胺LB膜真空热解制备β-SiC膜的STM观察

扫描隧道显微镜 ( STM)是一种基于量子隧道效应对样品进行高分辨无损测试的表面测试技术 [1] ,它可以在原子水平上反映表面分子或原子的排列分布情况 ,在物理、化学、生物和微电子界受到高度的重视 .STM技术以及其后发展起来的原子力显微镜 ( AFM)特别适合 LB膜的研究 ,能直观地反映出 LB膜中分子排列的微观结构以及表面缺陷 [2 ,3] .我们曾通过真空热解沉积在单晶硅片上的聚酰亚胺L B膜制得了准单晶β- Si C超薄膜 [4～ 6 ] .本文利用 STM技术对聚酰亚胺 LB膜以及由它真空热解而成的 Si C膜的表面形态结构进行了初步观察和分析 .…     

Inner membrane lipids of Escherichia coli form domains

In prokaryotic cells, the hypothesis of the existence of lipid domains was considered. In order to test this hypothesis and study the organization of lipids in the inner membrane of Escherichia coli, we elaborated Langmuir films mimicking the inner leaflet of this membrane by considering lipids extracted from the inner membrane of E coli by Folch protocol.

Lipid monolayers were elaborated by using these extracts (Langmuir technique); the organization of the resulting films was studied at the air–water interface by Brewster angle microscopy and after transfer onto muscovite by atomic force microscopy. The existence of domains was demonstrated for different interfacial pressures of biological interest, and their stability was studied.     

一种新型的铕络合物/TiO2发光薄膜

研究了Eu(DBM)3(DiBut-bpy)/TiO2/AA 单分子膜的表面压－分子面积(π－A)曲线和稳定性,单层膜中的TiO2纳米粒子是经TBT（tetrabutyloxyltitanium ,钛酸四丁酯）二维溶胶-凝胶法得到的.TiO2纳米粒子和铕络合物都被成功地转移到固体基片上，得到了具有良好的机械和热稳定性的新型发光薄膜.小角度X射线衍射结果证明这种复合膜具有层状有序的周期性结构.讨论了TiO2基质对复合膜发光机理的影响.