Flexible Single‐Chain‐Heteropolymer‐Derived Transmembrane Ion Channels with High K+ Selectivity and Tunable pH‐Gated Characteristics.

A series of single‐chain random heteropolymer (RHP)‐derived artificial ion channels with both high K+ selectivity and controllable pH‐gated behaviors were fabricated by a facile "one‐pot" polymerization method. The benzo‐18‐crown‐6 moieties appended on lateral chains of RHPs can form ion‐permeable nanopores and transport K+ over Na+ through the lipid bilayers. The ion permeation selectivity was significantly enhanced by incorporating a cholesterol group to serve as a membrane anchor. Interestingly, similar to natural gated protein channels, on–off switchable characteristics were also realized by integrating an additional acid‐sensitive alkylamine group into the RHP‐derived channel. The unique design strategies have endowed the RHP‐derived ion channels with facile synthetic procedures, desirable membrane compatibility, high K+ selectivity, and tunable pH‐gated properties. This work provides an entry point for future design of novel functional nanochannels. [ABSTRACT FROM AUTHOR]