Probing surface charge fluctuations with solid-state nanopores.
Probing surface charge fluctuations with solid-state nanopores.
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DOI：
10.1103/physrevlett.102.256804
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发表时间：
2009-06-26
影响因子：
8.6
通讯作者：
Golovchenko JA
中科院分区：
文献类型：
--
作者：
Hoogerheide DP;Garaj S;Golovchenko JA
我们发现固态纳米孔中离子电流噪声谱的贡献超过了 0.1-10 kHz 频段内的所有其他噪声源。对这种过量噪声与 pH 值和电解质浓度的依赖性的实验研究表明，噪声是由表面电荷波动引起的。基于表面官能团质子化的定量模型可以预测观察到的行为，并使我们能够局部测量质子化反应速率。通过在精心选择的 pH 值下操作纳米孔，可以最大限度地减少这种噪音。
We identify a contribution to the ionic current noise spectrum in solid-state nanopores that exceeds all other noise sources in the frequency band 0.1–10 kHz. Experimental studies of the dependence of this excess noise on pH and electrolyte concentration indicate that the noise arises from surface charge fluctuations. A quantitative model based on surface functional group protonization predicts the observed behaviors and allows us to locally measure protonization reaction rates. This noise can be minimized by operating the nanopore at a deliberately chosen pH.