title: A novel strategy to construct a flat-lying DNA monolayer on a mica surface.
abstract: Flat-lying, densely packed DNA monolayers in which DNA chains are well organized have been successfully constructed on a mica surface by dropping a droplet of a DNA solution on a freshly cleaved mica surface and subsequently transferring the mica to ultrapure water for developing. The formation kinetics of such monolayers was studied by tapping mode atomic force microscopy (TMAFM) technique. A series of TMAFM images of DNA films obtained at various developing times show that before the sample was immersed into water for developing the DNA chains always seriously aggregated by contacting, crossing, or overlapping and formed large-scale networks on the mica surface. During developing, the fibers of DNA networks gradually dispersed into many smaller fibers up to single DNA chains. At the same time, the fibers or DNA chains also experienced rearrangement to decrease electrostatic repulsion and interfacial Gibbs free energy. Finally, a flat-lying, densely packed DNA monolayer was formed. A formation mechanism of the DNA monolayers was proposed that consists of aggregation, dispersion, and rearrangement. The effects of both DNA and Mg2+ concentration in the formation solution on DNA monolayer formation were also investigated in detail.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of the Chinese Academy of Sciences, Changchun 130022, Jilin Province, People's Republic of China.
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
authors.forename: Cunlan
authors.initials: C
authors.lastname: Guo
authors.forename: Yujing
authors.initials: Y
authors.lastname: Sun
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation
chemical_list: D000538:Aluminum Silicates; D004247:DNA; C011934:mica