A novel colorimetric and fluorescent probe based on a core-extended perylene tetra-(alkoxycarbonyl) derivative for the selective sensing of fluoride ions

Abstract

A novel fluoride (F⁻) colorimetric and fluorescent probe (P1) based on a core-extended perylene tetra-(alkoxycarbonyl) (PTAC) derivative was developed. The probe exhibited high sensitivity and selectivity for distinguishing F⁻ from other common anions through significant changes of the UV-Vis and fluorescence spectra. Job's plot analysis revealed that the stoichiometry of the P1–F⁻ interaction is 1 : 1. The association constant between P1 and F⁻ was estimated to be 9.7 × 10² M⁻¹ and the detection limit of F⁻ was about 0.97 μM. An approximately 76 nm red-shift in the absorption and fluorescent quenching response was observed when F⁻ was associated with P1. The emission intensity (I₅₇₄) decreased linearly along with the F⁻ concentration from 3 × 10⁻⁵ M to 2 × 10⁻⁴ M. The mechanism of intermolecular proton transfer (IPT) was deduced based on the changes in the absorption, fluorescence, electrochemistry, and ¹H NMR titration spectra. The density functional theory (DFT) theoretical results of the P1–F⁻ complex are in good agreement with the experimental results. The rapid detection of F⁻ ions in the solid state and living cells was also studied.