Novel supramolecular sensors constructed from pillar[5]arene and a naphthalimide for efficient detection of Fe3+ and F− in water

Abstract

As we all know, due to the high hydration enthalpy of F⁻, the detection of F⁻ in water is a very difficult task. Herein, we report a novel water soluble self-assembled supramolecular sensor P5B1 for fluorescence detection of Fe³⁺ and F⁻ in water. The supramolecular sensor P5B1 was constructed by the self-assembly of water soluble cationic pillar[5]arene (P5) and a novel N-(pyridinium-4-yl)-naphthalimide derivative (B1). P5B1 could selectively detect Fe³⁺; more interestingly, by adding Fe³⁺ to P5B1, competitive coordination was introduced into P5B1 to form a new Fe³⁺ complexed supramolecular sensor, P5B1Fe. P5B1Fe showed high selectivity and sensitivity for F⁻ in water solution. Moreover, P5B1-based silica gel plates and test strips for selective detection Fe³⁺ and F⁻ were prepared, which could not only act as Fe³⁺ and F⁻ test kits, but also as Fe³⁺ and F⁻ controlled fluorescent display materials.