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Pathogen contamination of water has a massive impact on global human health. In particular, viruses pose unique challenges to water treatment techniques due to their small size and presence in water as both individual virions and when absorbed onto larger particles. Low-energy water treatment processes such as media filtration are not capable of completely removing viruses owing to their small size. Hence, less sustainable processes with high chemical or energy consumption such as chemical disinfection, ultraviolet irradiation, and membrane filtration are usually required. To overcome high energy and/or chemical requirements for virus treatment, designs for sustainable fiber filters fabricated from minimally processed natural materials for efficient virus (MS2) and bacteria (E. coli) removal are presented in this work. These filters were created by functionalizing readily accessible natural fibers including cotton, silk, and flax with a simple aqueous extract containing cationic proteins fromMoringa oleiferaseeds. The proposed filters offer a comprehensive low cost, low energy, and low environmental impact solution for pathogen removal from water with removals of >7log₁₀(99.99999%) for viruses and bacteria.

Unlike many other biologically relevant ions (Na⁺, K⁺, Ca²⁺, Cl⁻, etc) and protons, whose cellular concentrations are closely regulated by highly selective channel proteins, Li⁺ion is unusual in that its concentration is well tolerated over many orders of magnitude and that no lithium‐specific channel proteins have so far been identified. While one naturally evolved primary pathway for Li⁺ions to traverse across the cell membrane is through sodium channels by competing with Na⁺ions, highly sought‐after artificial lithium‐transporting channels remain a major challenge to develop. Here we show that sulfur‐containing organic nanotubes derived from intramolecularly H‐bonded helically folded aromatic foldamers of 3.6 Å in hollow cavity diameter could facilitate highly selective and efficient transmembrane transport of Li⁺ions, with high transport selectivity factors of 15.3 and 19.9 over Na⁺and K⁺ions, respectively.

Unlike many other biologically relevant ions (Na⁺, K⁺, Ca²⁺, Cl⁻, etc) and protons, whose cellular concentrations are closely regulated by highly selective channel proteins, Li⁺ion is unusual in that its concentration is well tolerated over many orders of magnitude and that no lithium‐specific channel proteins have so far been identified. While one naturally evolved primary pathway for Li⁺ions to traverse across the cell membrane is through sodium channels by competing with Na⁺ions, highly sought‐after artificial lithium‐transporting channels remain a major challenge to develop. Here we show that sulfur‐containing organic nanotubes derived from intramolecularly H‐bonded helically folded aromatic foldamers of 3.6 Å in hollow cavity diameter could facilitate highly selective and efficient transmembrane transport of Li⁺ions, with high transport selectivity factors of 15.3 and 19.9 over Na⁺and K⁺ions, respectively.