title: Immobilization of DNA on 11-mercaptoundecanoic acid-modified gold (111) surface for atomic force microscopy imaging.
abstract: Immobilized DNA on preformed 11-mercaptoundecanoic acids (MUDA) self-assembled monolayers (SAMs) on a gold (111) surface was bound by a divalent cation bridges was imaged by atomic force microscopy (AFM). The DNA immobilization was attributed to the formation of ionic bridges between the carboxylate groups of MUDA and the phosphate groups of DNA. AFM images revealed that DNA molecules could be immobilized strongly enough to permit stable and reproducible imaging. The effect of different bridge cations, such as Mg(2+), Zn(2+) and Cu(2+), and the pH of DNA assembled solution on immobilization and conformation of DNA was studied. Plasmid DNA pBR 322/Pst I molecules were straightened by using a molecular combing technique on the MUDA surface.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences.
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Song
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Li
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Liu
authors.forename: Gang
authors.initials: G
authors.lastname: Wei
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Lanlan
authors.initials: L
authors.lastname: Sun
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D005227:Fatty Acids / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: C505222:11-mercaptoundecanoic acid; D005227:Fatty Acids; D013438:Sulfhydryl Compounds; D006046:Gold; D004247:DNA