Vohra Rajan, Sawhney Ravinder Singh
Department of Electronics Technology, Guru Nanak Dev University, Amritsar, India.
J Mol Model. 2018 Nov 1;24(11):330. doi: 10.1007/s00894-018-3856-8.
The feasibility of electron transport conduction through a guanine base of DNA was investigated and then compared with another component of DNA, i.e., cytosine. A mathematical approach based on the jellium model using non-equilibrium Green's function combined with semi empirical extended Huckel theory was applied using the Atomistik Tool Kit. This was further used to measure significant transport parameters such as current, conductance, transmission spectra and the HOMO-LUMO gap of the suggested molecular system. An important revelation from our research work is that the cytosine-based molecular device exhibits metallic behavior with current ranging up to 70 μA, and hence establishes itself as a good conductor. On the other hand, the guanine-based device is comparatively less conductive, exhibiting current in the order of 3 μA. Another interesting observation about the guanine-based device is the visibility of a prominent negative differential resistance effect during the positive bias and a tunneling effect during negative bias. The uniform charge transfer through the cytosine device confirms its application as a molecular wire. The observations on the guanine-based device give better insights into its application as a memory device for nano-scale devices.
研究了电子通过DNA鸟嘌呤碱基进行传输传导的可行性，然后将其与DNA的另一种成分，即胞嘧啶进行比较。使用Atomistik工具包，应用了一种基于凝胶模型的数学方法，该方法使用非平衡格林函数并结合半经验扩展休克尔理论。这进一步用于测量重要的传输参数，如电流、电导、传输光谱以及所建议分子系统的最高占据分子轨道（HOMO）-最低未占分子轨道（LUMO）能隙。我们研究工作的一个重要发现是，基于胞嘧啶的分子器件表现出金属行为，电流高达70 μA，因此确立了其作为良好导体的地位。另一方面，基于鸟嘌呤的器件导电性相对较差，电流约为3 μA。关于基于鸟嘌呤的器件的另一个有趣观察结果是，在正偏压期间出现明显的负微分电阻效应，在负偏压期间出现隧穿效应。通过胞嘧啶器件的均匀电荷转移证实了其作为分子导线的应用。对基于鸟嘌呤的器件的观察结果为其作为纳米级器件的存储器件的应用提供了更好的见解。
