Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
ACS Nano. 2014 Aug 26;8(8):7914-22. doi: 10.1021/nn5029295. Epub 2014 Jul 15.
Nanopore-based DNA sequencing has led to fast and high-resolution recognition and detection of DNA bases. Solid-state and biological nanopores have low signal-to-noise ratio (SNR) (< 10) and are generally too thick (> 5 nm) to be able to read at single-base resolution. A nanopore in graphene, a 2-D material with sub-nanometer thickness, has a SNR of ∼3 under DNA ionic current. In this report, using atomistic and quantum simulations, we find that a single-layer MoS2 is an extraordinary material (with a SNR > 15) for DNA sequencing by two competing technologies (i.e., nanopore and nanochannel). A MoS2 nanopore shows four distinct ionic current signals for single-nucleobase detection with low noise. In addition, a single-layer MoS2 shows a characteristic change/response in the total density of states for each base. The band gap of MoS2 is significantly changed compared to other nanomaterials (e.g., graphene, h-BN, and silicon nanowire) when bases are placed on top of the pristine MoS2 and armchair MoS2 nanoribbon, thus making MoS2 a promising material for base detection via transverse current tunneling measurement. MoS2 nanopore benefits from a craftable pore architecture (combination of Mo and S atoms at the edge) which can be engineered to obtain the optimum sequencing signals.
基于纳米孔的 DNA 测序技术能够快速、高分辨率地识别和检测 DNA 碱基。固态纳米孔和生物纳米孔的信噪比（SNR）较低（<10），且通常太厚（>5nm），无法实现单碱基分辨率的读取。石墨烯中的纳米孔厚度为亚纳米级，在 DNA 离子电流下具有约 3 的 SNR。在本报告中，我们通过原子和量子模拟发现，单层 MoS2 是一种非凡的材料（SNR>15），可用于两种竞争技术（纳米孔和纳米通道）的 DNA 测序。MoS2 纳米孔在低噪声下显示出用于单核苷酸检测的四个独特的离子电流信号。此外，单层 MoS2 显示出总态密度在每个碱基上的特征变化/响应。与其他纳米材料（例如石墨烯、h-BN 和硅纳米线）相比，当碱基置于原始 MoS2 和扶手椅 MoS2 纳米带的顶部时，MoS2 的带隙发生了显著变化，这使得 MoS2 成为通过横向电流隧穿测量进行碱基检测的有前途的材料。MoS2 纳米孔得益于可定制的孔结构（边缘处的 Mo 和 S 原子组合），可通过工程设计获得最佳测序信号。
