Function of DNA/Conducting Polymer Complex Single Molecules with Highly Ordered Structure

我们成功地制备了具有高度有序结构的DNA/导电聚合物复合物。高度有序结构的配合物表现出独特的光电功能。用该配合物成功地制备了有机发光二极管（OLED）。在本研究中，为了探索配合物在单个大分子水平上的创新功能，并应用功能分子线，我们利用AFM技术分析了DNA高度有序结构配合物的分子结构，总结了单个大分子配合物的分子结构与电子性质之间的关系。在处理DNA/导电聚合物（聚苯胺；PAn）配合物之前，用AFM研究了DNA/Ru(bpy)_3^<2+>配合物的大分子结构，其中较低摩尔质量的Ru(bpy)_3^<2+>通过非共价键与DNA结合。制备了络合物的稀释溶液，并将其浇铸在云母表面，使其达到原子水平。从DNA分子的AFM图像来看，含有Ru(bpy)_3^<2+>的DNA（磷酸盐）/ Ru(bpy)_3^<2+>浓度比达到1/1时，DNA复合物分子相互缠绕形成了普通DNA分子常见的网状结构。每根纤维的高度小于1 nm，表明该网络是由单个大分子DNA复合物形成的。在染料嵌入的DNA分子中没有观察到这种网络，形成了粗大的棒状和簇状结构。由于DNA/Ru(bpy)_3^<2+>配合物具有光电功能，因此DNA/Ru(bpy)32+配合物有望成为功能性分子线材料。以光电功能分子线为目标，采用介电拉伸技术将DNA/Ru(bpy)_3^<2+>和DNA/PAn复合物分子在一对电极之间桥接。众所周知，DNA分子可以通过在DNA溶液中施加高频（> 1mhz）和高压（>1MV/m）交流电场在电极之间拉伸。通过对技术的改进和其他技术的耦合，我们成功地在一对电极之间桥接了DNA/Ru(bpy)_3^<2+>和DNA/PAn复合物分子。特别是对于DNA/PAn复合物，在一定偏置电场下，DNA/PAn复合物的电极间电流高于普通DNA。这一结果清楚地表明，结构高度有序的DNA/导电聚合物复合物在单分子水平上具有独特的功能，是实现光电功能分子线的有力候选材料。少

We successfully prepared a DNA/conducting polymer complex with highly-ordered structure. The highly-ordered structure complex showed unique opt-electronic function. It was found that organic light emitting diode (OLED) was successfully demonstrated with this complex. In this research, in ordered to explore innovative function of the complex in a single macromolecular level and to apply a functional molecular wire, we analyzed the molecular structure of DNA highly ordered structure complex with AFM technique and summarized the relation between the molecular structure and electronic properties of the single macromolecular complex.Before tackling DNA/conducting polymer (polyaniline; PAn) complex, the macromolecular structure of DNA/Ru(bpy)_3^<2+> complex, where lower molar mass Ru(bpy)_3^<2+> was associated with DNA via non-covalent bond, was studied with AFM. A dilute solution of the complex was prepared and cast on mica surface flat in atomic level. From the AFM images of the DNA molecu … More les containing Ru(bpy)_3^<2+> with DNA (phosphate)/ Ru(bpy)_3^<2+> concentration ratio up to 1/1, the DNA complex molecules were entangled to each other forming network structure which could be commonly seen for plain DNA molecules. The height of each fiber was less than 1 nm, indicating the network was formed by single macromolecular DNA complex. Such a kind of networks was not observed in dye-intercalated DNA molecules which formed thick rod and cluster structure. Since DNA/Ru(bpy)_3^<2+> complex shows opt-electronic functions, DNA/Ru(bpy)32+ complex is expected to be a material for functional molecular wire.With the aim of opt-electronic functional molecular wire, bridging of DNA/Ru(bpy)_3^<2+> and DNA/PAn complex molecules between a pair of electrodes was carried out with dielectrophoretic stretching technique. It is well-known that DNA molecule can be stretched between electrodes by applying high-frequency (>1 MHz) and high-voltage (>1MV/m) ac electric fields to the DNA solution. By modifying the technique and coupling other techniques, we succeeded the bridging of DNA/Ru(bpy)_3^<2+> and DNA/PAn complex molecules between a pair of electrodes. Particularly for DNA/PAn complex, the current between electrodes under a certain bias electric field was higher in DNA/PAn complex than in plain DNA. This result clearly indicates that DNA/conducting polymer complex with highly-ordered structure has unique function in single molecular level and is a potent candidate to realize opt-electronic functional molecular wire. Less