Highly selective fluorescent sensing for CN− in water: utilization of the supramolecular self-assembly

Abstract

A simple 4-amino-3-hydroxynaphthalene-1-sulfonic acid is demonstrated to fluorescently sense CN⁻ in water based on the mechanism of supramolecular self-assembly. This work provides a novel approach for the selective recognition of CN⁻ anions. The detection limit of the sensor towards CN⁻ is 3.2 × 10⁻⁷ M, and other anions, including F⁻, Cl⁻, Br⁻, I⁻, AcO⁻, H₂PO₄⁻, HSO₄⁻ and ClO₄⁻, had nearly no influence on the probing behavior. Notably, the test strips based on S₄ were fabricated, which could act as convenient and efficient CN⁻ test kits.