Scholarlink

<p>The pervasive model for a solvated, ion-filled nanopore is often a resistor in parallel with a capacitor. For conical nanopore geometries, here we propose the inclusion of a Warburg-like element, which is necessary to explain otherwise anomalous observations such as negative capacitance and low-pass filtering of translocation events (we term this phenomenon as Warburg filtering). The negative capacitance observed here has long equilibration times and memory (that is, mem-capacitance) at negative voltages. We used the transient occlusion of the pore using λ-DNA and 10 kbp DNA to test whether events are being attenuated by purely ionic phenomena when there is sufficient amplifier bandwidth. We argue here that both phenomena can be explained by the inclusion of the Warburg-like element, which is mechanistically linked to concentration polarization and activation energy to generate and maintain localized concentration gradients. We conclude the study with insights into the transduction of molecular translocations into electrical signals, which is not simply based on pulse-like resistance changes but instead on the complex and nonlinear storage of ions that enter dis-equilibrium during molecular transit.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Negative memory capacitance and ionic filtering effects in asymmetric nanopores

  • 期刊论文

  • 发表日期：

    2025年1月2日

查看全文
  • Nasim Farajpour,
  • Y. M. Nuwan D. Y. Bandara,
  • Lauren Lastra,
  • Kevin J. Freedman

摘要

The pervasive model for a solvated, ion-filled nanopore is often a resistor in parallel with a capacitor. For conical nanopore geometries, here we propose the inclusion of a Warburg-like element, which is necessary to explain otherwise anomalous observations such as negative capacitance and low-pass filtering of translocation events (we term this phenomenon as Warburg filtering). The negative capacitance observed here has long equilibration times and memory (that is, mem-capacitance) at negative voltages. We used the transient occlusion of the pore using λ-DNA and 10 kbp DNA to test whether events are being attenuated by purely ionic phenomena when there is sufficient amplifier bandwidth. We argue here that both phenomena can be explained by the inclusion of the Warburg-like element, which is mechanistically linked to concentration polarization and activation energy to generate and maintain localized concentration gradients. We conclude the study with insights into the transduction of molecular translocations into electrical signals, which is not simply based on pulse-like resistance changes but instead on the complex and nonlinear storage of ions that enter dis-equilibrium during molecular transit.