K+ sensors based on supported alkanethiol/phospholipid bilayers

A novel kind of K+ sensor with valinomycin-incorporated bilayers supported on a gold electrode consisting of self-assembled alkanethiol monolayers (SAMs) and a lipid monolayer has been fabricated successfully. The lipid monolayer is deposited on the alkylated surface of the first alkanethiol monolayer through three different methods, such as the Langmuir-Blodgett (LB) technique, painted method and painted-frozen method. The response of K + sensors produced by a painted or painted-frozen lipid monolayer on an alkanethiol alkylated gold electrode is larger than that by the LB method, which is due to the difference in fluidity of the three kinds of bilayers. Selectivity coefficients KK+, Na+, KK+, Li+, KK+, Ca2+ and KK+, Mg2+ are 10(-4), 10(-4), 2 x 10(-5) and 3 x 10(-5) respectively, and there is no obvious difference among different fabricating methods. A linear response toward the potassium ion was found in the range from 10(-1) M to 10(-5) M with the detection limit of 10(-6) M. The sensor has a slope of 60 mV per decade. Meanwhile, the longevity of the sensor was improved obviously for at least two months at about -10 degrees C. The higher stability shows the possibility to fabricate a practical biosensor.

Supported phospholipid membranes: Comparison among different deposition methods for a phospholipid monolayer

Supported lipid membranes consisting of self-assembled alkanethiol and lipid monolayers on gold substrates could be produced by three different deposition methods: the Langmuir-Blodgett (L-B) technique, the painted method, and the paint-freeze method, By using cyclic voltammetry, chronoamperometry/chronocoulometry and a.c. impedance measurements, we demonstrated that lipid membranes prepared by these three deposition methods had obvious differences in specific capacitance, resistance and thickness. The specific capacitance of lipid membranes prepared by depositing an L-B monolayer on the alkanethiol alkylated surfaces was 0.53 mu Fcm(-2), 0.44 mu Fcm(-2) by the painted method and 0.68 mu Fcm(-2) by the paint-freeze method. The specific conductivity of lipid membranes prepared by the L-B method was over three times lower than that of the painted lipid membranes, while that of the paint-freeze method was the lowest. The difference among the three types of lipid membranes was ascribed to the influence of the organic solvent in lipid films and the changes in density of the films. The lipid membranes prepared by the usual painted method contained a trace amount of the organic solvent. The organic solvent existing in the hydrocarbon core of the membrane reduced the density of the membrane and increased the thickness of the membrane. The membrane prepared by depositing an L-B monolayer containing no solvent had higher density and the lowest fluidity, and the thickness of the membrane was smaller. The lipid membrane prepared by the paint-freeze method changed its structure sharply at the lower temperature. The organic solvent was frozen out of the membrane while the density of the membrane increased greatly. All these caused the membrane to exist in a ''tilted'' state and the thickness of this membrane was the smallest. The lipid membrane produced by the paint-freeze method was a membrane not containing organic solvent. This method was easier in manipulation and had better reproducibility than that of the usual painting method and the method of forming free-standing lipid film. The solvent-free membrane had a long lifetime and a higher mechanical stability. This model membrane would be useful in many areas of scientific research.

SPREADING AND TRANSFER BEHAVIOR OF POLY(2-ACRYLAMIDOHEXADECYLSULFONIC ACID-CO-STYRENE) MONOLAYERS

The spreading behavior of poly(2-acrylamidohexadecylsulfonic acid-co-styrene) (PAMC16SSt) random co-polymers with various compositions was investigated by measurements of the surface pressure-area (pi-A) isotherms. The random copolymers formed stable cond

ELECTROCHEMICAL-BEHAVIOR OF N-METHYL-N'-HEXADECYLVIOLOGEN MONOLAYERS ON SILVER ELECTRODES - EFFECTS OF COUNTERIONS

N-Methyl-N'-hexadecylviologen (C16MV) has been the subject of several electrochemical and spectroelectrochemical studies which characterized the species present in various redox states for C16MV monolayers on silver electrode surfaces. Both self-assembled monolayers (SA) and Langmuir-Blodgett (LB) transferred systems have been studied. These indicated inconsistencies regarding the presence or absence of splitting of the first reduction peak in its cyclic voltammogram (CV). The present study demonstrates the important influence of the specific anionic species present in the supporting electrolyte. Splitting may or may not take place, depending on the size and relative strength of the adsorption of specific anions contributed by the supporting electrolyte. Small, strongly adsorbing anions such as iodide produced peak splitting in the CV of C16MV monolayers; bulky but weakly adsorbing anions such as perchlorate may disrupt the ordered structure of monolayers but produce no splitting. Ancillary data provided by surface enhanced Raman spectroscopy (SERS) was consistent with the electrochemical measurements.

稀土配合物分子组装及其性质研究

分子组装技术是一种在分子水平上进行的有序薄膜组装技术,包括Langmuir-Blodgett(LB)膜技术及自组装技术.该论文中,对稀土配合物及稀土杂多化合物的分子组装进行了系统的研究,取得了一些令人感兴趣的研究结果:合成了Na<,9>EuW<,10>O<,36>,Na<,9>DyW<,10>O<,36>,Na<,9>SmW<,10>O<,36>,K<,13>Eu(SiW<,11>O<,39>)<,2>,K<,13>Eu(GeW<,11>O<,39>)<,2>,K<,15>Eu(BW<,11>O<,39>)<,2>等稀土多金属氧酸盐,用LB膜技术将其组装入双十八烷基二甲基溴化铵(DODA)和十八胺(ODA)分子中,得到稀土杂多化合物LB膜.以稀土离子为亚相,制备了邻十六酰基苯甲酸-稀土(铽和铕)和对十六烷氧基苯甲酸铽LB膜.以1,2-二羟基苯-3,5-二磺酸铽(Tiron-Tb)为亚相,制备了DODA/Tiron-TbLB膜.以3-氨丙基三乙氧基硅烷为前驱体,制备了Na<,9>EuW<,10>O<,36>,Na<,9>DyW<,10>O<,36>的自组装膜.荧光光谱研究表明,在自组装膜中配体能将能量有效地传递给稀土离子.

Fabrication of fibril like aggregates by self-assembly of block copolymer mixtures via interpolymer hydrogen bonding

This paper describes the formation of fibril like aggregates from the self-assembly of block copolymer mixture (polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) and polystyrene-b-poly(acrylic acid) (PS-b-PAA)) via interpolymer hydrogen bonding in nonselective solvent. The hydrogen bonding between P4VP and PAA in chloroform leads to the formation of complex. When all the pyridine units in P4VP were all hydrogen bonded to acrylic acid in PAA, the formed complex is insoluble, resulting in the formation of spherical micellar aggregates and nanorods.

电荷转移配合物薄膜制备方法和结构表征的研究进展

回顾了与Langmuir-Blodgett(LB)技术有关的电荷转移配合物薄膜的各类制备方法、结构表征结果,并比较了制备方法对薄膜结构的影响.例如,将LB膜C18H37TCNQ(电子受体)插入到电子给体3,3',5,5'-tetramethylbenzidine(四甲基联苯胺,TMB)的石油醚溶液中进行掺杂,制备了TMB·C18H37TCNQ电荷转移配合物薄膜.在这种薄膜中,给体和受体以面对面的方式堆积,两者的环平面与基片平面接近垂直.而采用硬脂酸和C18H37TCNQ的混合LB膜通过类似的掺杂路线制备的TMB·C18H37TCNQ薄膜的结构发生了一些变化,例如其长的烃链C18H37更加垂直于基片平面.通过比较以前的各种实验结果可以得出以下结论:电荷转移配合物的结构可以通过制备方法得到控制.

利用LB技术以寡聚DNA为模板构建CdS纳米结构

利用Langmuir Blodgett技术制备了十八胺 (ODA) /十聚腺嘌呤 (oligo A10 )单分子膜 ,并以其为模板制备了不同形状的CdS纳米结构 .结果表明以在低膜压下转移的寡聚DNA单层膜为模板可诱导生成线形的CdS纳米结构 ,而以在高膜压下转移的寡聚DNA单层膜为模板得到的是CdS的球形结构聚集体.

Preparation and properties of conducting polymer of doped polyaniline LB film

Stable monolayer of polyaniline doped with camphor sulfonic acid at the air-water interface has been obtained and has been successfully deposited by Langmuir-Blodgett technique onto CaF2 substrate. IR and UV-Vis-NIR spectra show that the doped molecules dedoped partially from the PANI backbone during the monolayer compression or deposition. Gas-sensing measurement indicates that the doped polyaniline LB film was sensitive to ethanol vapor at room temperature.

掺杂态聚苯胺LB膜的制备与性质

掺杂樟脑磺酸的聚苯胺在纯水表面可以形成稳定的单分子层 ,采用Langmuir Blodgett技术可以将其较好地转移到氟化钙基片上制成薄膜.对其LB膜的红外和紫外 可见 近红外光谱研究表明 ,在膜的压缩或转移过程中有少量的樟脑磺酸分子发生脱掺杂的现象.并且该LB膜在室温下对乙醇有较好的气敏性.

酞菁铜衍生物在酞菁铜氧化铁纳米粒子交替LB膜中的分子取向

通过Langmuir Blodgett技术制备了酞菁铜 氧化铁纳米粒子交替LB膜 ,利用偏振紫外 可见光谱对酞菁铜衍生物在不同制膜条件下所制得的交替膜中的分子取向进行了研究。结果表明 ,在同一氧化铁溶胶亚相中 ,随着表面压的增大 ,或在相同的表面压下 ,随着亚相中氧化铁浓度的减小 ,酞菁铜分子在其复合LB膜中倾斜程度变大。

可溶性聚酰亚胺LB膜对碳钢的缓蚀作用的研究

应用可溶性聚酰亚胺(PI)Langmuir-Blodgett(LB)膜沉积在碳钢电极上，研究其在中性及酸性介质中对碳钢的缓蚀作用．结果表明PILB膜在中性及酸性介质中对碳钢有较好的缓蚀作用，单分子层数目对缓蚀效率有很大的影响.

The synthesis of dendrimers bearing alkyl chains and their behavior at air-water interface

A new kind of amphiphilic polyether dendrimer bearing eight alkyl chains at the periphery were synthesized step by step using the convergent method. Their structures were confirmed by FT-IR spectra, H-1 NMR spectra and mass spectra etc. The pi-A isotherms, hysteresis and molecular area-time curves at air water interface were reported. These results showed that they could form stable monolayers at water surface.

邻苯二甲酸正十八醇单酯稀土配合物发光LB膜的研究

Langmuir-Blodgett膜以其超薄、均匀及在分子水平上进行组装等特点,在分子电子学、集成光学、信息存储、化学与生物传感器等方面有着潜在的应用前景。功能稀土配合物引入LB膜已开始引起人们的重视,但通常情况下其成膜性能较差,稀土羧酸配合物是一类具有无限链状结构的聚合物,它不仅具有良好的发光性能,同时还有热稳定性好,耐紫外光等优点。如果能把这些稀土羧酸配合物组装成有序的分子组合体,则很有可能在分子光学技术、光

聚酰亚胺修饰电极

聚酰亚胺(PI)是一类耐热性最好的聚合物,其性能和应用已得到极为广泛的研究,近年来发现这类聚合物可以进行电化学氧化还原反应;这对于金属/PI界面性质和PI的功能有重要的意义,本文评述了聚酰亚胺修饰电极的电化学行为、影响电极上的离子转移的因素、光谱特征及PI修饰电极的应用等方面的研究概况,讨论了聚酰亚胺电化学性质在分析化学方面应用的可能性.