Deng Wenli, Xiao Zhanwen, Wang Wei, Li Alexander D Q
College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
J Phys Chem B. 2007 Jun 14;111(23):6544-8. doi: 10.1021/jp0708188. Epub 2007 May 17.
We focus our studies on DNA-chromophore motif on surfaces using samples prepared by the synthetic methods described by Wang and Li in a recent publication (J. Am. Chem. Soc. 2003, 125, 5248-5249). Scanning tunneling microscope (STM) was used to investigate the DNA-chromophore hybrids adsorbed on Au(111) and highly oriented pyrolytic graphite (HOPG) surfaces at room temperature in air. Experiments found that the DNA-chromophore hybrid molecules easily formed multimolecule aggregations on gold surface. On HOPG surfaces, however, DNA-chromophore hybrids were usually adsorbed as single molecules. STM images further showed DNA-chromophore hybrids adsorbed on Au(111) surfaces existed in the form of single molecule, dimer, trimer, tetramer, etc. The occurrence of molecular aggregations indicates that molecular interactions are comparable or stronger than molecule-substrate interactions; such weak interactions control the geometrical sizes and topographical shapes of the self-assembled DNA-chromophore hybrids on surfaces.
我们使用王和李在最近一篇出版物（《美国化学会志》2003年，125卷，5248 - 5249页）中描述的合成方法制备的样品，将研究重点放在表面的DNA - 发色团基序上。使用扫描隧道显微镜（STM）在室温空气中研究吸附在Au(111)和高度取向热解石墨（HOPG）表面的DNA - 发色团杂化物。实验发现，DNA - 发色团杂化分子在金表面容易形成多分子聚集体。然而，在HOPG表面，DNA - 发色团杂化物通常以单分子形式吸附。STM图像进一步显示，吸附在Au(111)表面的DNA - 发色团杂化物以单分子、二聚体、三聚体、四聚体等形式存在。分子聚集体的出现表明分子间相互作用与分子 - 底物相互作用相当或更强；这种弱相互作用控制着表面自组装的DNA - 发色团杂化物的几何尺寸和形貌。
