Solid-State Electronics, The Ångström Laboratory, Uppsala University , SE-751 21 Uppsala, Sweden.
ACS Sens. 2017 Oct 27;2(10):1523-1530. doi: 10.1021/acssensors.7b00576. Epub 2017 Oct 17.
Nanopores have been explored for various biochemical and nanoparticle analyses, primarily via characterizing the ionic current through the pores. At present, however, size determination for solid-state nanopores is experimentally tedious and theoretically unaccountable. Here, we establish a physical model by introducing an effective transport length, L, that measures, for a symmetric nanopore, twice the distance from the center of the nanopore where the electric field is the highest to the point along the nanopore axis where the electric field falls to e of this maximum. By [Formula: see text], a simple expression S = f (G, σ, h, β) is derived to algebraically correlate minimum nanopore cross-section area S to nanopore conductance G, electrolyte conductivity σ, and membrane thickness h with β to denote pore shape that is determined by the pore fabrication technique. The model agrees excellently with experimental results for nanopores in graphene, single-layer MoS, and ultrathin SiN films. The generality of the model is verified by applying it to micrometer-size pores.
纳米孔已被广泛用于各种生化和纳米颗粒分析，主要是通过表征通过孔的离子电流来实现。然而，目前固态纳米孔的尺寸确定在实验上繁琐且在理论上不可解释。在这里，我们通过引入有效传输长度 L 来建立物理模型，对于对称纳米孔，L 测量从纳米孔中心到纳米孔轴上电场降至最大值的 e 的点的两倍距离，该点电场最高。通过 [公式：见正文]，推导出一个简单的表达式 S = f (G, σ, h, β)，将纳米孔的最小横截面积 S 与纳米孔电导 G、电解质电导率 σ 和膜厚 h 与 β 相关联，β 表示由孔制造技术决定的孔形状。该模型与石墨烯、单层 MoS 和超薄 SiN 薄膜中的纳米孔的实验结果非常吻合。通过将其应用于微米级孔，验证了该模型的通用性。
