Understanding the disorder of the DNA base cytosine on the Au(111) surface.
Using ultrahigh vacuum scanning tunneling microscopy (STM) and ab initio density functional theory, we have investigated in detail structures formed by cytosine on the Au(111) surface in clean ultrahigh vacuum conditions. In spite of the fact that the ground state of this DNA base on the surface is shown to be an ordered arrangement of cytosine one-dimensional branches (filaments), this structure has never been observed in our STM experiments. Instead, disordered structures are observed, which can be explained by only a few elementary structural motifs: filaments, five- and sixfold rings, which randomly interconnect with each other forming bent chains, T junctions, and nanocages. The latter may have trapped smaller structures inside. The formation of such an unusual assembly is explained by simple kinetic arguments as a liquid-glass transition.
Kelly
Ross E A
RE
Department of Physics, School of Physical Sciences and Engineering, King's College London, Strand, London WC2R 2LS, United Kingdom. ross.kelly@ucl.ac.uk
Lukas
Maya
M
Kantorovich
Lev N
LN
Otero
Roberto
R
Xu
Wei
W
Mura
Manuela
M
Laegsgaard
Erik
E
Stensgaard
Ivan
I
Besenbacher
Flemming
F
D003596:Cytosine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D019281:Dimerization; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D036103:Nanotechnology; D011789:Quantum Theory; D013499:Surface Properties
D006046:Gold; D003596:Cytosine; D004247:DNA