ABSTRACT
Biological ion channels are made up of proteins that have matured over about 4 billion years in living systems. During this period, they have perfected the precision chemical modification of the interior of the pore wall through chemical selection processes. Thus, those pores possess specific selectivity criteria. Convergent multidimensional self-assembly strategies have been used over decades for the synthesis of unimolecular ion channels or noncovalent self-organized channels. Comparable investigations among amphiphiles and peptide channels about two decades ago also led to the discovery of artificial channels using synthetic materials and various derivatives. The possibility of constructing self-organized channels based on heteroditopic alkylureido crown ethers has been tried for almost two decades. Solid-state nanopores in silicon nitride have been developed to take advantage of the potentially improved stability offered by semiconductor materials. Solid-state nanopores were initially used to detect individual double-stranded DNA molecules, which are too large to transport through many ion channels.
