Energy Band Gap and Optical Transition of Metal Ion Modified Double Crossover DNA Lattices
Energy Band Gap and Optical Transition of Metal Ion Modified Double Crossover DNA Lattices
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DOI：
10.1021/am503614x
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发表时间：
2014-10-22
影响因子：
9.5
通讯作者：
Park, Sung Ha
中科院分区：
文献类型：
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作者：
Dugasani, Sreekantha Reddy;Ha, Taewoo;Park, Sung Ha
报道了用衬底辅助生长（SAG）方法在熔融石英衬底上制备的一系列二价金属离子（Cu ~（2+）、Ni ~（2+）、Zn ~（2+）和Co ~（2+））修饰的DNA（M-DNA）双交叉（DX）晶格的能带隙和光学跃迁。我们展示了DX晶格的覆盖度如何受到DX单体浓度的影响，并分析了M-DNA晶格的带隙。通过光学跃迁判断，M-DNA的最低未占分子轨道（LUMO）和最高已占分子轨道（HOMO）之间的能带隙在4.67至4.98 eV的范围内。相对于原始DNA分子的带隙（4.69 eV），M-DNA晶格的带隙随着金属离子掺杂增加到临界浓度，然后随着进一步掺杂而减小。有趣的是，除了Ni 2+的情况下，第二吸收带的开始移动到一个较低的能量，直到临界浓度，然后移动到一个较高的能量，进一步增加金属离子的浓度，这是一致的电输运特性的演变。我们的研究结果表明，可控的金属离子掺杂是一种有效的方法来调整DNA基纳米结构的带隙能量。
We report on the energy band gap and optical transition of a series of divalent metal ion (Cu2+, Ni2+, Zn2+, and Co2+) modified DNA (M-DNA) double crossover (DX) lattices fabricated on fused silica by the substrate-assisted growth (SAG) method. We demonstrate how the degree of coverage of the DX lattices is influenced by the DX monomer concentration and also analyze the band gaps of the M-DNA lattices. The energy band gap of the M-DNA, between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO), ranges from 4.67 to 4.98 eV as judged by optical transitions. Relative to the band gap of a pristine DNA molecule (4.69 eV), the band gap of the M-DNA lattices increases with metal ion doping up to a critical concentration and then decreases with further doping. Interestingly, except for the case of Ni2+, the onset of the second absorption band shifts to a lower energy until a critical concentration and then shifts to a higher energy with further increasing the metal ion concentration, which is consistent with the evolution of electrical transport characteristics. Our results show that controllable metal ion doping is an effective method to tune the band gap energy of DNA-based nanostructures.