Single Molecule Channels Water

Abstract

Chinese researchers have made the first nanoscale artificial water channels that selectively transport water across lipid membranes. Such a system could be used for applications such as water purification and desalination. Jun-Li Hou and coworkers at Fudan University, in Shanghai, constructed the channels from single pillar[5]arene molecules with hydrazide-containing side chains (J. Am. Chem. Soc., DOI: 10.1021/ja302292c). Intramolecular hydrogen bonds between side chains turn the molecules into tubes. Hou and coworkers inserted these tubes into vesicles to form membrane-spanning channels. The researchers induced water flow via salt concentration and osmosis. “The osmotic pressure difference prevents water inside the vesicles from coming back out,” Hou says. Although several groups had previously reported water-trapping molecules, none had demonstrated a synthetic channel that could selectively transport water, says Huaqiang Zeng of the National University of Singapore. The new work of Hou and coworkers “...