Zwolak Michael, Lagerqvist Johan, Di Ventra Massimiliano
Theoretical Division, MS-B213, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2009 Sep 18;103(12):128102. doi: 10.1103/PhysRevLett.103.128102. Epub 2009 Sep 17.
Ionic transport in nanopores is a fundamentally and technologically important problem in view of its occurrence in biological processes and its impact on novel DNA sequencing applications. Using molecular dynamics simulations we show that ion transport may exhibit strong nonlinearities as a function of the pore radius reminiscent of the conductance quantization steps as a function of the transverse cross section of quantum point contacts. In the present case, however, conductance steps originate from the break up of the hydration layers that form around ions in aqueous solution. We discuss this phenomenon and the conditions under which it should be experimentally observable.
鉴于离子在生物过程中的存在及其对新型DNA测序应用的影响，纳米孔中的离子传输是一个具有根本重要性和技术重要性的问题。通过分子动力学模拟，我们表明离子传输可能表现出强烈的非线性，这是作为孔径半径的函数，类似于作为量子点接触的横向横截面函数的电导量子化步骤。然而，在当前情况下，电导步骤源于在水溶液中围绕离子形成的水合层的破裂。我们讨论了这种现象以及在实验中可观察到它的条件。
