Unimolecular artificial transmembrane channel with terminal dihydrogen phosphate groups showing transport selectivity for ammonium

A new artificial transmembrane channel molecule bearing dihydrogen phosphate groups has been synthesized. The terminal dihydrogen phosphate groups enable the channel to be highly negatively charged at both ends of the channel structures. The artificial channel could incorporate into the lipid bilayer efficiently under low concentration. The channel displays high NH₄⁺/K⁺ selectivity due to the electrostatic interaction and hydrogen bonding between NH₄⁺ and the terminal dihydrogen phosphate groups.