A microscopic physical analysis of the various resistive effects involved in the electronic detection of single biomolecules in a nanopore of a MoS2 nanoribbon is presented. The analysis relies on a combined experimental-theoretical approach, where the variations of the transverse electronic current along the two-dimensional (2D) membrane due to the translocation of DNA and proteins molecules through the pore are compared with model calculations based on molecular dynamics (MD) and Boltzmann transport formalism for evaluating the membrane conductance. Our analysis that points to a self-consistent interaction among ions, charge carriers around the pore rim and biomolecules, emphasizes the effects of the electrolyte concentration, pore size, nanoribbon geometry, but also the doping polarity of the nanoribbon on the electrical sensitivity of the nanopore in detecting biomolecules, which agrees well with the experimental data.
Invariant ionic conductance in an atomically thin polar nanopore
National Key Laboratory of Advanced Micro and Nano Manufacture Technology, School of Integrated Circuits, Peking University（北京大学集成电路学院先进微纳制造技术国家重点实验室）；Academy for Advanced Interdisciplinary Studies and Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Peking University（北京大学前沿交叉学科研究院纳米化学中心北京纳米碳科学与工程研究中心）；State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University（北京大学物理学院介观物理国家重点实验室）；Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin（德克萨斯大学奥斯汀分校沃克机械工程系奥登计算工程与科学研究所）；School of Mechanics and Engineering Science, Peking University（北京大学力学与航空航天工程学院）；Beijing Advanced Innovation Center for Integrated Circuits（北京集成电路先进创新中心）；Beijing Graphene Institute（北京石墨烯研究院）
Ionic transport through sub-10 nm diameter hydrophobic high-aspect ratio nanopores: experiment, theory and simulation
在纳米尺度上离子传输的基本理解是必不可少的开发基于纳米孔技术和新一代高性能纳滤膜分离和纯化应用的生物传感器。我们在这里研究了离子通过具有高纵横比（长度L=6 μm，直径范围从1到10 nm）和具有良好控制的圆柱形几何形状的单个纯中性疏水纳米孔的传输。我们开发了一个详细的混合介观理论方法的纳米孔内的电解质电导率，明确考虑离子平流电渗流和可能的流动滑移在孔表面。通过拟合实验电导数据，我们表明，对于纳米孔直径大于4 nm的恒定弱表面电荷密度约10 $^{-2}$ C m $^{-2}$需要纳入模型中，以考虑在低盐浓度的几个皮西门子的电导平台。对于更紧密的纳米孔，我们的分析导致更高的表面电荷密度，这可以归因于靠近孔表面的离子溶剂化结构的改变，正如我们进行的分子动力学模拟中观察到的那样。
