Laucirica Gregorio, Hernández Parra L Miguel, Huamani Angel L, Wagner Michael F, Albesa Alberto G, Toimil-Molares María Eugenia, Marmisollé Waldemar, Azzaroni Omar
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, CC 16 Suc. 4, La Plata B1904DPI, Argentina.
GSI Helmholtzzentrum für Schwerionenforschung, 64291, Darmstadt, Germany.
Nanoscale. 2024 Jul 4;16(26):12599-12610. doi: 10.1039/d3nr06212k.
In this study, the transport of salt with moderate solubility through bioinspired solid-state nanochannels was comprehensively investigated. For this purpose, bullet-shaped channels were fabricated and exposed to KClO, a monovalent salt with moderate solubility. These channels displayed the typical rectifying behavior characteristic of asymmetrical channels but with one remarkable difference, the iontronic output exhibited a negative incremental resistance phenomenon of high gating efficiency when the transmembrane voltage in the open state was increased enough, giving rise to an inactivated state characterized by a low and stable ion current. The behavior is attributed to salt precipitation inside the channel and remarkably, it is not observed in other geometries such as cylindrical or cigar-shaped channels. Considering the central role of the surface in precipitation formation, the influence of several parameters such as electrolyte concentration, pH, and channel size was studied. Under optimized conditions, this system can alternate among three different conductance states (closed, open, and inactivated) and exhibits gating ratios higher than 20. Beyond its potential application in fields related to electronics or sensing, this study provides valuable insight into the fundamental principles behind ion rectifying behavior in solid-state channels and highlights the implications of surface phenomena at the nanoscale.
在本研究中，对具有中等溶解度的盐通过仿生固态纳米通道的传输进行了全面研究。为此，制备了子弹形通道，并使其暴露于具有中等溶解度的单价盐KClO中。这些通道表现出不对称通道典型的整流行为，但有一个显著差异，当开放状态下的跨膜电压增加到足够程度时，离子电子输出表现出高门控效率的负增量电阻现象，从而产生以低且稳定的离子电流为特征的失活状态。这种行为归因于通道内部的盐沉淀，值得注意的是，在其他几何形状的通道（如圆柱形或雪茄形通道）中未观察到这种现象。考虑到表面在沉淀形成中的核心作用，研究了电解质浓度、pH值和通道尺寸等几个参数的影响。在优化条件下，该系统可以在三种不同的电导状态（关闭、开放和失活）之间切换，并且门控比高于20。除了在电子或传感相关领域的潜在应用外，本研究还为固态通道中离子整流行为背后的基本原理提供了有价值的见解，并突出了纳米尺度表面现象的影响。
