Rotkin Slava V
Physics Department and Center for Advanced Materials and Nanotechnology, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
Annu Rev Phys Chem. 2010;61:241-61. doi: 10.1146/annurev.physchem.012809.103304.
Helical wrapping of single-strand DNA around single-wall nanotubes (SWNTs) results in the symmetry breaking and modification of the nanotube band structure. Empirical tight-binding theory was employed to investigate this symmetry breaking and modulation of the electronic and optical properties of a SWNT in the field of an ionized DNA. The model allows the computation of the polarization component of the hybrid's energy of cohesion, with a typical value of 0.5 eV per DNA base. A screening parameter that quantifies the response of the SWNT electrons to the DNA perturbation was obtained. SWNT symmetry breaking shows up in the optical absorption for light polarized across the SWNT axis. In addition, circular dichroism is predicted for DNA-SWNT hybrids, even when the nanotube itself is achiral. These optical effects may be used for experimental determination of the DNA wrapping.
单链DNA围绕单壁纳米管（SWNTs）的螺旋缠绕导致纳米管能带结构的对称性破缺和改变。采用经验紧束缚理论来研究在电离DNA场中SWNT的这种对称性破缺以及其电子和光学性质的调制。该模型能够计算杂化物凝聚能的极化分量，每个DNA碱基的典型值为0.5电子伏特。得到了一个量化SWNT电子对DNA微扰响应的屏蔽参数。SWNT的对称性破缺在垂直于SWNT轴偏振的光的光吸收中表现出来。此外，即使纳米管本身是非手性的，也预测DNA - SWNT杂化物会有圆二色性。这些光学效应可用于实验确定DNA的缠绕情况。
