Novel 2-(hydroxy)-naphthyl imino functionalized pillar[5]arene: a highly efficient supramolecular sensor for tandem fluorescence detection of Fe3+ and F− and the facile separation of Fe3+

Abstract

A highly efficient supramolecular sensor based on 2-(hydroxy)-naphthyl imino-functionalized pillar[5]arene (AP5N) for the tandem fluorescence detection of Fe³⁺ and F⁻ in H₂O/DMSO (1/9, v/v) solution was successfully synthesized. On addition of Fe³⁺ to AP5N, the blue fluorescence was quenched. The detection limit of fluorescence for Fe³⁺ was estimated to be 1.21 × 10⁻⁷ M with short detection duration. Moreover, the AP5N–Fe³⁺ complex could selectively exhibit “turn-on” fluorescence on sensing F⁻ (LOD = 1.34 × 10⁻⁷ M). In addition, the sensor AP5N could separate Fe³⁺ from aqueous solution with excellent ingestion capacity, and the Fe³⁺ separation rate was up to 98.25%. Moreover, the fluorescence changes of AP5N upon addition of Fe³⁺ and F⁻ could be utilized as an IMPLICATION logic gate. Furthermore, as a practical application, ion test strips based on AP5N were fabricated, which can act as convenient and efficient test kits for detecting Fe³⁺ and F⁻.