Modifying the surface charge of single track-etched conical nanopores in polyimide
Modifying the surface charge of single track-etched conical nanopores in polyimide
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DOI：
10.1088/0957-4484/19/8/085713
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发表时间：
2008-02-27
期刊：
影响因子：
3.5
通讯作者：
Ensinger, Andw
中科院分区：
文献类型：
--
作者：
Ali, M.;Schiedt, B.;Ensinger, Andw
纳米孔表面的化学修饰引起了人们的极大兴趣，因为这意味着表面组成不再由基材材料的选择所固定，甚至达到大生物分子可以附着在孔壁上的程度。控制纳米孔传输特性是表面改性的一项重要应用，鉴于人们对基于离子和分子通过纳米孔传输的传感器的巨大兴趣，这一应用非常重要。这里报道了一种改变聚酰亚胺中单径迹蚀刻锥形纳米孔的表面电荷极性的方法，该方法还具有将更复杂的分子附着到纳米孔壁上的羧基上的潜力。这些羧基首先通过用 N-(3-二甲基氨基丙基)-N-乙基碳二亚胺 (EDC) 和 N-羟基琥珀酰亚胺 (NHS) 活化，然后与乙二胺共价偶联，转化为末端氨基。这导致表面电荷极性改变。通过氨基与琥珀酸酐的反应，羧基封端表面的再生也是可能的。通过测量化学改性前后孔的 pH 敏感电流-电压 (I-V) 特性（取决于表面电荷），证实了这些反应的成功。孔隙的选择性渗透率也随着修饰而发生相应的变化。
Chemical modification of nanopore surfaces is of great interest as it means that the surface composition is no longer fixed by the choice of substrate material, even to the point where large biomolecules can be attached to the pore walls. Controlling nanopore transport characteristics is one important application of surface modification which is very relevant given the significant interest in sensors based on the transport of ions and molecules through nanopores. Reported here is a method to change the surface charge polarity of single track-etched conical nanopores in polyimide, which also has the potential to attach more complex molecules to the carboxyl groups on the nanopore walls. These carboxyl groups were converted into terminal amino groups, first by activation with N-(3-dimethylaminopropyl)-N-ethylcarbodiimide (EDC) and N- hydroxysuccinimide (NHS) followed by the covalent coupling of ethylenediamine. This results in a changed surface charge polarity. Regeneration of a carboxyl-terminated surface was also possible, by reaction of the amino groups with succinic anhydride. The success of these reactions was confirmed by measurements of the pore's pH sensitive current-voltage ( I-V) characteristics before and after the chemical modification, which depend on surface charge. The permselectivity of the pores also changed accordingly with the modification.