Preparation of one-dimensional pi-electron system based on DNA-mimetics

由于DNA和DNA模拟物具有特定的分子识别、可控的碱基序列和分子量，因此选择DNA和DNA模拟物制备具有可控纳米结构（发色团排列、发色团数量、发色团取向等）的一维pi-电子系统。制备了两种在空气-水界面处与DNA分子络合的Langmuir单层膜，分别用于单DNA拉伸和DNA模拟物的模板聚合。利用传统的Langmuir-Blodgett技术，将双链DNA的离子络合物与阳离子单层缓慢地从水表面转移到亲水固体表面，可以在固体表面拉伸单个DNA分子。含有核碱基的二乙炔两亲体的表面单层可与单链dna在空气-水界面形成互补氢键。单链DNA分子可以作为DNA模拟物中二乙炔基团光聚合的模板。两种方法的结合将为具有一维pi电子系统的单分子器件的制备提供一种新的策略。

DNA and DNA-mimetics are chosen for preparation of one-dimensional pi-electron systems with controlled nanostructure (chromophore arrangement, number of chromophores, chromophore orientation, etc.) because of their specific molecular recognition, controlled base sequence and molecular wight. Two types of Langmuir monolayers complexed with DNA molecules at the air-water interface were prepared for single DNA stretching and template polymerization of the DNA-mimetics, respectively. Single DNA molecule can be stretched on the solid surface when the ionic complex of a double-stranded DNA and a cationic monolayer was transferred slowly from water surface to the hydrophilic solid surface by using conventional Langmuir-Blodgett technique. The surface monolayer of the diacetylene containing nucleobase amphiphiles parepared as DNA-mimetics can form complementary hydrogen bonds with single stranded DNAs at the air-water interface. The single-stranded DNA molecule can act as a template of photopolymerization of the diacetylene groups in the DNA-mimetics. Combination of two methods will provide a new preparation strategy of single molecular devices having one-dimensional pi-electron system.