Abstract Artificial single nanopore as a promising tool for chemical and biological studies, such as ionic detection, DNA sequencing, molecular sensing/separation, nanofluidics and biomimetics, has been attracting great attention. Here we show a reliable functional single glass nanopore system with tannic acid to provide polyphenolic functional groups that possess specific binding affinities able to achieve metal ions recognition and ultra-trace level detection (e.g., limit of Fe3+ detection is down to 10−15 M). This system displays fast and high sensing ability features for detecting multivalent metal ions. Theoretical calculation (Gaussian 16) and experiments demonstrate that the specific binding energy between the trihydroxy phenolic groups of the inner surface of the nanopore and multiple metal ions can effectively distinguish trivalent, divalent, and monovalent metal ions. Therefore, our new system could promote a potential to conveniently recognize multivalent metal ions in nanoconfined space, and spark efforts to mimic ionic transport in biological nanopore systems and exploit smart nanofluidic devices.

中文翻译：

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具有多价金属离子识别和超痕量检测的单宁酸修饰单纳米孔

摘要 人造单纳米孔作为一种有前途的化学和生物学研究工具，如离子检测、DNA 测序、分子传感/分离、纳米流体和仿生学，一直受到广泛关注。在这里，我们展示了一种具有单宁酸的可靠功能性单玻璃纳米孔系统，以提供具有特定结合亲和力的多酚官能团，能够实现金属离子识别和超痕量水平检测（例如，Fe3+ 检测限低至 10-15 M） . 该系统显示出用于检测多价金属离子的快速和高传感能力特征。理论计算（Gaussian 16）和实验表明，纳米孔内表面的三羟基酚基与多种金属离子之间的比结合能可以有效区分三价、二价和一价金属离子。因此，我们的新系统可以促进在纳米受限空间中方便地识别多价金属离子的潜力，并激发在生物纳米孔系统中模拟离子传输和开发智能纳米流体装置的努力。