Preparation of DNA/Conducting Polymer Nano-Hybrid by Template Photopolymerization and Application to Optoelectronic Device with High Efficiency

在DNA模板存在的情况下，利用Ru(bpy)_3^<2+>配合物与二聚苯胺进行光催化聚合，成功制备了DNA/聚苯胺（PAn）高度有序杂化物。由于DNA提供了特定的局部“低pH”环境，即使在pH为3.0-6.0的溶液中也能发生反应。在该杂交体中，PAn与DNA结合，并且PAn的链结构受到DNA螺旋结构的影响。得到的DNA/PAn配合物含有Ru(bpy)_3^<2+>光催化剂，其结构在纯化后仍保持不变。该复合物可作为新型有机红发二极管的材料。这种光聚合DNA/PAn杂化物的缺点之一是得到的PAn的摩尔质量低。为了提高DNA/PAn杂化产物的摩尔质量和电子性能，我们首先用更高摩尔质量的化学聚合PAn制备了DNA/PAn杂化产物。制备过程非常简单，只需将DNA溶液与化学聚合的PAn溶液混合即可。我们成功地找到了合适的混合条件来制备具有高度有序结构的DNA/PAn杂化物，与光聚合产物相似。我们已经报道了一种由DNA/PAn杂化物组成的电致发光器件，并分析了该杂化物的电荷输运机制。从这些结果可以清楚地看出，电荷载流子沿着DNA/PAn链迁移，并且杂交产物有望成为分子线。在本研究中，作为第二个目的，我们利用交流电场研究了DNA杂交的分子定位。最后，我们成功地展示了DNA/PAn杂化物在电极之间的分子排列，以研究其作为分子线的电子特性。

A DNA/polyaniline(PAn) highly ordered hybrid has been successfully prepared by the photopolymeization of dimeric aniline via photocatalytic reaction with Ru(bpy)_3^<2+> complex in the presence of DNA template, a reaction which occurs, even in the solution at pH 3.0-6.0,due to the specific local "lower-pH" environment provided by DNA. In this hybrid, the PAn was associated with DNA, and the chain structure of the PAn was revealed to be affected by the helical structure of the DNA. The resulting DNA/PAn complex contained Ru(bpy)_3^<2+> photocatalyst its structure even after purification. The complex was revealed to work as a material for novel organic red-emitting diode.One of shortcomings of this photopolymerized DNA/PAn hybrid is the low molar mass of the obtained PAn. In order to increase the molar mass and to improve the electronic properties of the resulting DNA/PAn hybrid, we first prepared DNA/PAn hybrid with chemically polymerized PAn with higher molar mass. The preparation procedure is very simple, just mixing the DNA solution with the chemically polymerized PAn solution. We successfully found out the adequate mixing condition to prepare the DNA/PAn hybrid with highly ordered structure similar to the photopolymerized one.We have already reported an EL device composed of DNA/PAn hybrid and analyzed the charge transport mechanism of the hybrid. From these results, it was clear that charge carriers migrated along DNA/PAn chain and that the hybrid was expected to be molecular wire. In this research, as the second purpose, we studied molecular alignment of DNA hybrid by means of ac field. Finally, we successfully demonstrated the molecular alignment of the DNA/PAn hybrid between electrodes to study the electronic properties as molecular wire.