超分子有机薄膜

Supramolecular Organic Thin Films

利用超分子有机薄膜技术能制成新的传感分子电子器件、光学器件和生物分子器件等 ,受到跨学科高技术研究领域的重视。本文描述了超分子有机薄膜的制备方法以及在各应用领域的研究状况。重点介绍了我们研究组在近 2 0年工作中 ,利用LB膜技术 ,在光电器件、气体传感技术和光学非线性 ,特别是在生物传感技术方面的研究成果。按照生物体系提供的信息 ,模拟合成功能分子 ,建造有组织的分子组装体 ,以便用来研究依赖于分子排列的生物物理化学效应。

The Langmuir-Blodgett (LB) technique is a way of preparing supramolecular organic thin films, which possess high order, uniformity, super thinness and a accurate control of film thickness, it is also harmless to substrates. Therefore, the films have shown considerable promise in frontiers of high technology research. In fact, the special functional systems can be assembled by LB technique on the basis of requirement molecular structures and the molecular packing and aligment are realized. The structure of the films as well as its physical properties are investigated and controlled at molecular level. At present, the LB films with specific functions have been successfully obtained such as monomolecular ultra thin insulating film, semiconducting film, conducting film and biological film, etc. In the early part studies of LB film were focused on the topochemistry. Since 1980's LB film technique is developed rapidly, it has been incorporatied with the research fields of condense state physics, material science, synthesis chemistry, microelectronic, biology and induced significant interest of scientists. The people desires to make novel sensitive mole electronic devices, optical non-linear devices, solar battery, optical switches of the information stores, bio-sensors, etc. We introduce mainly the history and preparation of LB films and research work of our group in over past ten years in this paper. The research results are described as follows. Firstly, we synthesized the substituted silicon phthalocyanine prepared, LB films, and obtained potential use in electronic device for the first time, and also reported the luminance diode with Au/LB film/ZnSe. Secondly, we have made great progresses in the synthesis of gas-sensitive materials and preparation of the films, and gas sensitive elements. We have synthesized firstly asymmetric and symmetric substituted copper phthslocyanine derivatives, and substituted phthalocyaninato-polysiloxane, the above materials were prepared for the gas-sensors used in detection of NH 3. The sensitivity to NH 3 is 1×10 -7 and it reached the world levels of similar devices. Thirdly, we also studied on optical bistability of an optical waveguide coated with nonlinear Langmuir-Blodgett films by a prism coupling technique for the first time. The obtained threshold power densities of bistabilities were estimated to be 20MW/cm 2, 32MW/cm 2 and 40MW/cm 2, respectively. The switching time is approximately 24ps. Fourthly, LB technique was applied in the biosensors and colorimetric transition process of polydiacetylene mannoside derivative LB films by binding Escherichia (E.coli) was investigated via UV-visible absorption spectra. The interfacial behaviors of the mixture at the air/water exhibited a good miscibility. In addition, we have analyzed the dynamical process of colorimetric transition caused by binding the E.coli to the mannoside derivative for the first time. It was estimated that one E.coli could only bind two mannoside molecules. We also describe a new method for using supramolecular assemblies composed of polydiacetylene supported on a electrode, which can provide easy and direct detection of bacteria through electrochemical technology. It utilizes an open platform to host biosensory elements allowing fast recognition and binding with the target molecules.