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/导电聚合物络合物。这种高度有序的结构络合物显示出独特的光电功能。结果表明，用该配合物成功地实现了有机电致发光二极管(OLED)的发光。在本研究中，为了在单个大分子水平上探索配合物的创新功能，并应用功能分子导线，我们用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。在研究DNA/导电聚合物(聚苯胺；PAn)配合物之前，用AFM研究了DNA/Ru(Bpy)_3^&lt；2+&gt；低摩尔质量Ru(Bpy)_3^&lt；2+&gt；的大分子结构。制备了该络合物的稀溶液，并将其浇铸在云母表面的原子水平上。从dna分子…的原子力显微镜图像当DNA(POP)/Ru(Bpy)3^&lt；2+&gt；浓度比达到1/1时，含Ru(Bpy)3^&lt；2+&gt；的络合物分子相互缠绕，形成普通DNA分子常见的网络结构。每根纤维的高度均小于1 nm，表明该网络是由单个大分子DNA复合体形成的。在染料嵌入的DNA分子中没有观察到这样的网络，形成了粗棒和簇状结构。由于DNA/Ru(Bpy)3^&lt；2+&gt；络合物具有光电功能，DNA/Ru(Bpy)32+络合物有望成为功能分子线的材料，以光电功能分子线为目标，利用介电拉伸技术实现了DNA/Ru(Bpy)3^&lt；2+&gt；和DNA/PAN络合物分子在电极间的桥联。众所周知，DNA分子可以通过在DNA溶液中施加高频(&gt；1 MHz)和高压(&gt；1 mV/m)交流电场而在电极之间伸展。通过改进工艺和结合其他技术，我们成功地实现了DNA/Ru(Bpy)_3~(2+)和DNA/PAn络合物分子在电极之间的桥联。尤其对于DNA/PAN复合体，在一定的偏置电场下，DNA/PAN复合体的电极间电流比普通DNA中的要大。这一结果清楚地表明，具有高度有序结构的DNA/导电聚合物络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者。较少

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