Biological sodium channels ferry sodium ions across the lipid membrane while rejecting potassium ions and other metal ions. Realizing such ion selectivity in an artificial solid-state ionic device will enable new separation technologies but remains highly challenging. In this work, we report an artificial sodium-selective ionic device, built on synthesized porous crown-ether crystals which consist of densely packed 0.26-nm-wide pores. The Na+ selectivity of the artificial sodium-selective ionic device reached 15 against K + , which is comparable to the biological counterpart, 523 against Ca2 + , which is nearly two orders of magnitude higher than the biological one, and 1128 against Mg2 + . The selectivity may arise from the size effect and molecular recognition effect. This work may contribute to the understanding of the structure-performance relationship of ion selective nanopores.

Glass micropipette has characteristics of easy fabrication, excellent flexibility and stable properties. The HKUST-1 and MIL-68(In) in-situ grow into the tip of micropipette to construct the porous nanochannel. After absorbing...

With the inspiration of biological ion channels from nature, the scientific community started to build up biomimetic nanochannels/nanopores, especially for the functional modification of the nanochannels/nanopores. However, there is no detailed explanation for the dominant reason that influences transmembrane ionic current in the modification process. Here, we studied the poly(N-isopropylacrylamide) (PNIPAM) by the atom transfer radical polymerization (ATRP) method into an anodic aluminum oxide (AAO) membrane. There are detailed explanations for the dominant reason, including the steric and hydrophilic−hydrophobic effects that influence transmembrane ionic current in the modification process. The findings pointing to the modified membrane provide a general and convenient method for the migration behavior of hydrophilic and hydrophobic ions, which has a potential application prospect.

Zeolitic imidazolate framework-8 (ZIF-8)-modified micropipets can be an effective sensing platform for zinc finger peptides, which the limit of detection reach 10-2 µg/ml. A series of techniques for detecting biomolecules...

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