Engineered Artificial Nanochannels for Nitrite Ion Harmless Conversion

Inspired by the delicate functions of living organisms to transport or transform nitrite ions (NO₂ ^-), a bioinspired smart nanochannel that can realize harmless conversion of NO₂ ^- into N₂ is developed by immobilizing a NO₂ ^--responsive functional molecule, p-phenylenediamine, onto a single conical polyethylene terephthalate nanochannel. Subsequently, the aromatic primary amine groups could be triggered to transform into a phenyldiazonium molecule based on the acid-activated NO₂ ^--binding process. The nanochannel exhibits specific selectivity and highly ultratrace recognition of NO₂ ^-. Fascinatingly, the transformed phenyldiazonium molecules could be triggered to generate phenol groups and release N₂ by ultraviolet light activation, achieving NO₂ ^- harmless conversion. This system could provide inspiration to construct artificial nanofluidic devices for ion-sensing and nitrogen cycle fields.