title: Scanning tunneling microscopy study of DNA-chromophore motif on solid surfaces.
abstract: 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.
authors.affiliation: College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China. wldeng@scut.edu.cn
authors.forename: Wenli
authors.initials: W
authors.lastname: Deng
authors.forename: Zhanwen
authors.initials: Z
authors.lastname: Xiao
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Alexander D Q
authors.initials: AD
authors.lastname: Li
mesh_terms: D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties; D014965:X-Rays
chemical_list: D006046:Gold; D006108:Graphite; D004247:DNA