葡萄球菌肠毒素B基因的膜片电极支撑双层类脂膜核酸传感器的研究

本研究用膜片电极支撑双层类脂膜(BLMs)核酸传感器,检测葡萄球菌肠毒素B(SEB)基因。BLMs在膜片钳尖端形成后,传感器的检测电流大小和施加的电压成正比。通过在BLMs上固定针对SEB基因特异的直链十二烷烃链(0～273.65μg/L)修饰的单链寡核苷酸(C12-ssDNA)探针与膜片钳系统一同构建成膜片电极支撑BLMs核酸传感器。电流大小与探针的浓度呈正相关,线性回归方程I=5.49 2.94C;相关系数r=0.9962。SEB基因浓度在20～5000μg/L范围时,检测的电流信号与SEB基因浓度的自然对数呈负相关,线性回归方程I=1103.26-103.62lnC,相关系数r=0.9977;同时,核酸传感器有很好的特异性,与不产SEB的金葡菌属、其它食物中毒菌的基因组DNA和空白对照组反应无明显电信号响应。应用原子力显微镜对BLMs表面微观结构、ssDNA固定于BLMs上和BLMs上杂交洗脱后的表面微观结构进行观察。本研究构建的膜片电极支撑BLMs核酸传感器为SEB基因的检测提供了一种快速、灵敏、特异性强的方法。     

双层类脂膜及其在电化学生物传感器中的应用

详细评述了各种双层类脂膜包括传统的双层类脂膜（ＢＬＭ）、固体载体支撑的自组双层类脂膜（ｓ－ＢＬＭ）、固体载体支撑的混合双层类脂膜（ｅ－ＢＬＭ）的制备方法和特性,比较了其优缺点。介绍了双层类脂膜在电化学生物传感器中的应用,并展望了发展前景。     

直流偏压对于在玻碳电极上双层类脂膜成膜过程的影响

应用循环伏安法和电化学阻抗谱研究了直流偏压对卵磷脂在玻碳电极表面自组装成膜过程及其结构的影响.实验发现:无论在正偏压还是负偏压条件下,卵磷脂在玻碳电极上均可组装成膜.施加正偏压时,由于玻碳电极表面所带的正电荷与卵磷脂端基之间的静电作用,使得卵磷脂在电极表面倾向于形成双层的类脂膜,并在0.4V偏压下电极阻抗达到最大值.继续增大电极正向偏压,s-BLM缺陷增加,以至趋于被击穿.提出了适宜的等效电路,并据此非线性拟合电极过程,求得部分阻抗的模型参数.研究发现:膜电容和电荷传递电阻呈现良好的互补效应.     

肉豆蔻酸-双层类脂膜修饰玻碳电极研究氯化血红素的电化学行为

报道了氯化血红素在肉豆蔻酸-双层类脂膜修饰玻碳电极上的电化学行为。在0.1~-0.7 V(vs.Ag/AgCl)电位范围内,扫描速率为40 mV/s时,氯化血红素在-0.4 V处产生很灵敏的还原峰电流。于pH7.50.01 mol/L KH2PO4-Na2HPO4底液中,该氧化峰电流与氯化血红素浓度在7.32×10-9~1.57×10-6mol/L范围内呈良好线性关系。该电极可作为检测氯化血红素的新型的高灵敏度电化学生物传感器。     

平板双层磷脂膜中伏安行为的研究

未经修饰的双层类脂膜（BLM）是很好的绝缘体，不能进行离子和电子传导。但是，经过适当的修饰，如嵌入碘分子或者富含π-电子的有机化合物（四氰代二甲基苯醌TCNQ，四硫富瓦烯TTF），BLM显示出双偶电极的行为，也就是BLM一侧是进行氧化还原反应的阴极，另一侧是进行氧化还原反     

槲皮素修饰的双层脂膜的伏安研究

槲皮素修饰的从层脂膜作为研究抗病毒药物的一种模型体系,用循环伏安法测定了槲皮素在脂膜界面上的氧化还原性质和配位性质。在电位扫描过程中,微量铜离子能催化槲皮素的氧化,当双层脂膜的两侧存在着合适的氧化还原偶时,就会产生跨膜的电子传递。     

双层磷脂膜的电化学性质及其在生物传感器中的应用

由于双层磷脂膜（BLM）可模仿自然界的生物细胞膜的生物相容性，成为物分子的天然固定化材料，因此生物传感器的研制领域显示出广泛的应用前景，本文介绍了BLM、s-BLM的电化学性质，制备技术，并评述了其在生物传感器的应用研究进展。     

基于双层类脂膜的去甲肾上腺素传感器

报道了去甲肾上腺素 (NE)在月桂酸 -双层类脂膜修饰的玻碳电极上的电化学行为 ,在 +0.6～ -0.2V(vs.Ag/AgCl)电位范围内 ,于pH7.0的0.01mol/L的KH2PO4-Na2HPO4 底液中 ,去甲肾上腺素产生很灵敏的氧化峰电流。氧化峰电流与去甲肾上腺素浓度在1.7×10 -5～5.9×10 -4mol/L范围内呈良好线性关系。该电极可作为检测去甲肾上腺素的新型高灵敏度电化学生物传感器     

双层类脂膜核酸传感器的研究进展

对近几年发展起来的双层类脂膜（BLM）核酸传感器的研究工作进行了讨论，详细论述了该传感器的特性、工作原理以及在核酸杂交、序列分析研究中的应用，并与其它核酸传感器的研究作了对比；展望了其发展方向，引文31篇。     

自组装ITO/双层磷脂膜的制备及其光电行为研究

在ITO(Indium-tin-oxide)导电玻璃电极上制备上自组装双层磷脂膜和经C60修饰的双层磷脂膜,研究了这种自组装双层磷脂膜的光电行为,考察了偏压、溶液中的给体和受体的浓度对自组装膜光电流强度的影响,讨论了C60分子对光电子跨膜传递过程的促进作用。     

Transmembrane Signaling with Lipid‐Bilayer Assemblies as a Platform for Channel‐Based Biosensing

Artificial and natural lipid membranes that elicit transmembrane signaling is are useful as a platform for channel‐based biosensing. In this account we summarize our research on the design of transmembrane signaling associated with lipid bilayer membranes containing nanopore‐forming compounds. Channel‐forming compounds, such as receptor ion‐channels, channel‐forming peptides and synthetic channels, are embedded in planar and spherical bilayer lipid membranes to develop highly sensitive and selective biosensing methods for a variety of analytes. The membrane‐bound receptor approach is useful for introducing receptor sites on both planar and spherical bilayer lipid membranes. Natural receptors in biomembranes are also used for designing of biosensing methods.     

脂双层膜表面结构与稳定性的原子力显微镜研究

用原子力显微镜研究了1,2－二油酸甘油－3－磷酸－1甘油（DOPG）脂双层膜 的表面结构与稳定性。实验结果表明,原子力显微镜的探针与脂双层膜的相互作用 导致脂双层膜表面产生一个永久的损伤。静电相互作用对脂双层膜结构和稳定性的 影响表明,在NaCl溶液中制成的脂质体,随着NaCl浓度的增加,它们的双层膜更稳 定。在低的NaCl浓度则经常被损伤,在1 mol/L NaCl溶液中制备的指双层变得更稳 定。在KCl溶液中结果恰好相反。在高的KCl浓度中经常被损伤,随着KCl浓度的降 低,它们的双层膜更稳定。葡萄糖和蔗糖对脂双层膜结构有稳定作用。     

平板双分子层脂膜的制备及锌离子跨该膜的输运过程

制备了氧化胆固醇 卵磷脂(脑磷脂)平板双分子层脂膜,研究了膜配方对双分子层脂膜的稳定性和离子通透性的影响,得到了最佳制膜工艺,建立了锌离子跨卵 (脑 )磷脂膜的吸附 -扩散模型,其计算值与实验值基本吻合.     

Agar-supported lipid bilayers — basic structures for biosensor design. Electrical and mechanical properties

The lipid bilayer is widely accepted as the basic structure of all biological membranes. Known as BLM (bilayer lipid membrane), it can be prepared artificially. Suitably modified, the BLM serves as a very appropriate model for biological membranes. Recent investigations have verified the high analytical potential of artificial lipid membranes. With a structure and composition almost identical to the lipid moiety of biomembranes, the BLM may serve as an ideal host for receptor molecules of biological origin, thus becoming a transducer which could “see” the environment the way the living cell does. For the construction of lipid bilayer based biosensors; however, stable, easy to prepare and long-lasting lipid membranes are required. With this aim in mind, we have prepared lipid bilayer membranes which use an agar gel as support. This as-BLM (agar-supported BLM) has been shown to possess the same electrical, mechanical and dynamic properties the conventional BLM is famous for, along with the benefits of long-term stability and considerably elevated breakdown voltages. Its preparation on the tip of an agar-filled Teflon tube of 0.5 mm diameter is easy and can be performed even by less-skilled personnel.

In an attempt of further miniaturization the concept of the as-BLM was applied to thin-film micro-systems manufactured by standard micro-electronic techniques. The result is a lipid bilayer system, which, while preserving all the essential properties of the bilayer lipid membrane, can serve as a basic building block for cheap, disposable biosensoric systems.     

Mixed hybrid bilayer lipid membrane incorporating valinomycin: improvements in preparation and functioning

The paper deals with the reconstruction of lipid bilayer membranes on a Au-covered polycarbonate membrane. Such a kind of like-biomembranes (namely mixed hybrid bilayer lipid membrane (MHBLM)) are characterised by appreciable long-term stability. Here we describe changes that have been made in the geometry of the experimental device in order to avoid artefacts and render membrane reproduction easier. Incorporation of valinomycin was performed to check the membrane and its stability: conductance and membrane potential following the changes of ion concentration were recorded. This new approach permits increase of successful trials and renders possible, when it breaks, easily formation of a new MHBLM on the same Au-covered polycarbonate membrane support. Finally, the stability shown by the MHBLM renders this system a promising tool for use under flowing conditions.     

Highly reproducible method of planar lipid bilayer reconstitution in polymethyl methacrylate microfluidic chip

We developed a highly reproducible method for planar lipid bilayer reconstitution using a microfluidic system made of a polymethyl methacrylate (PMMA) plastic substrate. Planar lipid bilayers are formed at apertures, 100 microm in diameter, by flowing lipid solution and buffer alternately into an integrated microfluidic channel. Since the amount and distribution of the lipid solution at the aperture determines the state of the lipid bilayer, controlling them precisely is crucial. We designed the geometry of the fluidic system so that a constant amount of lipid solution is distributed at the aperture. Then, the layer of lipid solution was thinned by applying an external pressure and finally became a bilayer when a pressure of 200-400 Pa was applied. The formation process can be simultaneously monitored with optical and electrical recordings. The maximum yield for bilayer formation was 90%. Using this technique, four lipid bilayers are formed simultaneously in a single chip. Finally, a channel current through gramicidin peptide ion channels was recorded to prove the compatibility of the chip with single molecule electrophysiology.     

冠醚修饰的固体支撑双层类脂膜的形成及性能研究

用饱和了胆固醇和饰用冠醚的角鲨烷／氯仿溶液作成膜液，制备了冠醚修饰的固体支撑双层类脂分子膜。重点考察了成膜物种及技术对膜稳定性及电特生影响。其膜电势随接触水相中的变化呈现Ｎｅｒｎｓｔ响应，线性范围１０＾－４－１０＾－１ｍｏｌ／Ｌ。     

Biosensors for the Rapid Repetitive Detection of Adrenaline Using Stabilized Bilayer Lipid Membranes (BLMs) with Incorporated Calix[4]resorcinarene Receptor

This work uses lipid film based biosensors with incorporated calix[4]resorcinarene receptor (lipophilic macrocyclic host molecule) for the rapid electrochemical detection of adrenaline. Freely‐suspended and metal supported BLMs (composed of egg phosphatidylcholine (PC) and 35% (w/w) dipalmitoyl phosphatidic acid) modified with the resorcin[4]arene receptor were used as one shot sensors to rapidly detect this catecholamine. The interactions of this compound with freely‐suspended BLMs were found to be electrochemically transduced in the form of a transient current signal with duration of seconds, which reproducibly appeared about 14 s after exposure of the membranes to adrenaline. The response time for these BLMs without incorporated receptor for adrenaline was about 1.5 min. The magnitude of the transient current signal was related to the concentration of adrenaline in bulk solution in the micromolar range. Differential scanning calorimetric (DSC) experiments were performed to explore the mechanism of interactions of BLMs with incorporated receptor with adrenaline. The interactions of adrenaline with surface‐stabilized bilayer lipid membranes (sBLMs) with incorporated receptor produced electrochemical ion current increases, which reproducibly appeared within a few seconds after exposure of the membranes to the stimulant. The use of the receptor in sBLMs increased the sensitivity of the method 6‐fold. The current signal increases were related to the concentration of adrenaline in bulk solution in the micromolar range. Stabilized lipid membranes formed by polymerization on glass fiber microfilters were used as practical chemical biosensors for the rapid detection of adrenaline. The interactions of polymerized lipid films with adrenaline were also found to provide transient current signals similar to those of freely‐suspended BLMs. The magnitude of the transient current signal was also related to the concentration of the stimulating agent in bulk solution in the micromolar range and these stabilized lipid films can be used again after storage in air. No interferences from ascorbic acid were noticed because of the negatively charged lipids in membranes. The effect of other compounds such as proteins and other compounds closely related to adrenaline was also investigated. Results of recovery experiments using human urine have shown recoveries ranged between 94 to 105%, which shows no interferences from matrix effects due to the presence of urine constituents. The present sensor based on stabilized lipid films can be used for the rapid repetitive detection of this pharmaceutical substance and keep prospects for the selective determination of catecholamines in biofluids.     

硫醇－磷脂混合双层膜的电化学性质及其与蜂毒素的相互 作用研究

报道了硫醇－磷脂混合双层膜的循环伏安和电化学交流阻抗行为研究,并用电化学方法考察了蜂毒素与其相互作用,实验中通过冷冻表面沾有磷脂溶液的硫醇单层膜制备混合双层膜,研究表明双层膜在电极表面形成致密的绝缘层,阻碍了电极表面的电子传递,在双层膜体系上引入的蜂毒素可在膜表面上形成孔洞,破坏膜的绝缘性,降低膜电阻,增加膜电容,使带负电的探针Fe(CN)6^3-的氧化还原反应速度加快。     

Stabilization of bilayer lipid membranes on solid supports by trehalose

Using the electrostriction method the effect of the glucose and trehalose on the elasticity modulus perpendicular to the membrane plane, E_⊥, and the electrical capacitance, C, of supported bilayer lipid membranes (s-BLM) formed on the freshly cut tip of Teflon-coated Ag wire was studied. Addition of saccharides into the electrolyte resulted in a decrease in the elasticity modulus of the s-BLM formed from the soybean phosphatidylcholine in n-hexadecane, while the capacitance was increased. In addition, the trehalose has a considerable stabilizing effect on the above parameters of the s-BLM. Treatment of the s-BLM in an electrolyte containing 0.3 M of the trehalose allowed storage of the s-BLM under dry conditions and under refrigeration, with the subsequent recovery of membrane parameters after the wire had been dipped into the electrolyte.