Low-frequency flicker noise in stochastic ionic transport across atomically thin graphene nanopores
Low-frequency flicker noise in stochastic ionic transport across atomically thin graphene nanopores
复制标题
DOI：
10.1016/j.xcrp.2022.101210
复制
发表时间：
2022-12
影响因子：
8.9
通讯作者：
Ruiyang Song;Haiou Zeng;Shengping Zhang;Ying Wang;Xiao Han;Xiaobo Chen;Luda Wang
中科院分区：
文献类型：
--
作者：
Ruiyang Song;Haiou Zeng;Shengping Zhang;Ying Wang;Xiao Han;Xiaobo Chen;Luda Wang
从纳米流体研究到实际应用，原子薄的二维纳米孔已经成为一个有前途的平台。二维纳米孔中的低频闪烁噪声限制了纳米孔传感器的检测精度和性能。然而，低频噪声的物理机制仍然存在争议，在二维纳米孔中实现低频噪声的控制仍然具有挑战性。在这里，我们报道了石墨烯纳米孔中的多价阳离子调制的低频噪声，并证明低频噪声源于离子的可逆吸附-解吸引起的表面电荷波动。出乎意料的是，它的振幅可以通过痕量的多价阳离子（混合物溶液中至少0.1%的浓度）大大控制到约3个数量级。此外，通过加入具有高介电常数的有机溶剂来抑制表面电荷和离子之间的相互作用，可以将低频噪声抑制2个数量级。我们的发现将有助于理解纳米流体中的低频噪声，以及设计包括超灵敏纳米流体器件在内的相关应用。
Atomically thin 2D nanopores have emerged as promising platforms from nanofluidics research to practical applications. Low-frequency flicker noise in 2D nanopores limits detection accuracy and performance of nanopore sensors. However, the physical mechanisms of low-frequency noise are still under debate and achieving its control in 2D nanopores remains challenging. Here, we report multivalent-cations-modulated low-frequency noise in graphene nanopores and demonstrate that low-frequency noise originates from surface charge fluctuations induced by reversible adsorption-desorption of ions. Unexpectedly, its amplitude can be greatly controlled up to about 3 orders of magnitude by a trace of multivalent cations (at least 0.1% of concentration in mixture solutions). Moreover, low-frequency noise can be suppressed by 2 orders of magnitude via adding organic solvents with a high dielectric constant based on suppressing interactions between surface charge and ions. Our findings will facilitate understanding of low-frequency noise in nanofluidics and design of related applications including ultrasensitive nanofluidic devices.