DNA sequencing techniques are critical in order to investigate genes’ functions. Obtaining fast, accurate, and affordable DNA bases detection makes it possible to acquire personalized medicine. In this article, a semi-empirical technique is used to calculate the electron transport characteristics of the developed z-shaped graphene device to detect the DNA bases. The z-shaped transistor consists of a pair of zigzag graphene nanoribbon (ZGNR) connected through an armchair graphene nanoribbon (AGNR) channel with a nanopore where the DNA nucleobases are positioned. Non-equilibrium Green’s function (NEGF) integrated with semi-empirical methodologies are employed to analyze the different electronic transport characteristics. The semi-empirical approach applied is an extension of the extended Hückel (EH) method integrated with self-consistent (SC) Hartree potential. By employing the NEGF+SC-EH, it is proved that each one of the four DNA nucleobases positioned within the nanopore, with the hydrogen passivated edge carbon atoms, results in a unique electrical signature. Both electrical current signal and transmission spectrum measurements of DNA nucleobases inside the device’s pore are studied for the different bases with modification of their orientation and lateral translation. Moreover, the electronic noise effect of various factors is studied. The sensor sensitivity is improved by using nitrogen instead of hydrogen to passivate the nanopore and by adding a dual gate to surround the central semiconducting channel of the z-shaped graphene nanoribbon.

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通过具有纳米孔的石墨烯纳米带场效应晶体管检测 DNA 碱基：半经验模型


DNA 测序技术对于研究基因功能至关重要。获得快速、准确且经济实惠的 DNA 碱基检测使获得个性化医疗成为可能。在本文中，使用半经验技术来计算所开发的 z 形石墨烯装置的电子传输特性，以检测 DNA 碱基。 Z形晶体管由一对锯齿形石墨烯纳米带（ZGNR）组成，它们通过扶手椅石墨烯纳米带（AGNR）通道与DNA核碱基所在的纳米孔连接。采用非平衡格林函数（NEGF）与半经验方法相结合来分析不同的电子传输特性。所采用的半经验方法是扩展 Hückel (EH) 方法与自洽 (SC) Hartree 势相结合的扩展。通过使用 NEGF+SC-EH，证明位于纳米孔内的四个 DNA 核碱基中的每一个，以及氢钝化的边缘碳原子，都会产生独特的电信号。研究了装置孔内 DNA 核碱基的电流信号和透射光谱测量，针对不同的碱基，修改了它们的方向和横向平移。此外，还研究了各种因素对电子噪声的影响。通过使用氮气代替氢气来钝化纳米孔，并添加双栅极来包围 z 形石墨烯纳米带的中央半导体通道，从而提高了传感器的灵敏度。