Compartmentalization within Nanofibers of Double‐Decker Phthalocyanine Induces High‐Performance Sensing in both Aqueous Solution and the Gas Phase

The functionalization of natural 1D architectures is dependent on hierarchically inner nanostructures. However, the artificial supramolecular nanofibers or nanotubes were rarely developed with complex inner structures. Inspired by a biomimetic strategy, single‐molecule‐diameter nanofibers of double‐decker phthalocyanine (EuPc2) with compartmentalized internal space and fantastic electrochemical features were developed upon air/water interfacial assembly with poly‐l‐lysine. EuPc2/poly‐l‐lysine nanofibers can be electrochemical sensors both in water and the gas phase and have the best analytical performances for nitrite among all the porphyrins or phthalocyanines monomers and assemblies. Imbedding nitrite in compartments not only promotes the sensing but also changes the supramolecular chirality of nanofibers, and the morphological‐dependent sensing properties of EuPc2 assemblies in water are different from that in the gas phase. These results suggest the unprecedented properties for diverse applications of artificial 1D architectures containing complex inner nanostructures. Sensors: The nature of double‐decker phthalocyanine induces the formation of 1D architectures with compartmentalized inner structures upon co‐assembly with simple polypeptide, and produces high‐performance sensing both in water and the gas phase (see figure).