Multi-Copper-Mediated DNA Base Pairs Acting as Suitable Building Blocks for the DNA-Based Nanowires

作者：Li Genqin; Liu Haiying; Chen Xiaohua; Zhang Laibin; Bu Yuxiang^*

来源：Journal of Physical Chemistry C, 2011, 115(6): 2855-2864.

DOI：10.1021/jp107605k

Transition-metal-mediated base pairs are under intense research because of their potential application in nanoscale molecular devices. To pursue suitable building blocks for DNA-based molecular wires, a three-copper-mediated guanine cytosine (G(3Cu)C) and a two-copper-mediated adenine-thymine (A(2Cu)T) base pair were designed by equi-stoichiometric H-by-Cu replacements in this Article. Their structural and electronic properties were examined by theoretical methods. Geometrically, G(3Cu)C and A(2Cu)T have great resemblances to the natural GC and AT with a size-expansion of about 1.0 angstrom due to the larger radii of Cu(I). Their significantly larger binding energies promise them to be structurally suitable for DNA helix construction. Electronically, the equi-number H-by-Cu replacement not only leads to considerable reductions of the HOMO-LUMO gaps and ionization potentials, but also enhances transverse electronic communication within isolated G(3Cu)C and A(2Cu)T pairs, revealed by the charge-transfer transitions in the UV absorption spectra of G(3Cu)C and A(2Cu)T. To further examine the effect of H-by-Cu substitution on conductivity, three-layer-stacked G(3Cu)C and A(2Cu)T of repeat and cross sequences were studied with positive results obtained. It can be reasonably concluded that the multi-Cu-mediated G(3Cu)C and A(2Cu)T pairs are promising candidates for building blocks of the Cu(m)-DNA nanowires. This work would open a new prospective for rational design of the DNA-based molecular wires by multimetal incorporation.

• 出版日期2011-2-17
• 单位山东大学