A novel supramolecular AIE gel acts as a multi-analyte sensor array

Abstract

A novel organic gelator (WJ) based on benzimidazole and acylhydrazone naphthol moities has been designed and synthesized. The organic gelator (WJ) could form a stable organogel (WJG) with strong aggregation-induced emission (AIE). Interestingly, the WJG shows multi-stimuli-response for many analytes such as CN⁻, Al³⁺ and Fe³⁺ and L-Cys. Therefore, a multi-analyte sensor array based on WJG has been successfully developed. The WJG presents selective fluorescent and colorimetric response for CN⁻. Meanwhile, the WJG could selectively identify Fe³⁺ and Al³⁺ in the gel state. With the addition of Fe³⁺ the yellow-green AIE of WJG was quenched. In addition, the AIE of WJG could be selectively recovered by adding L-Cys. So the AIE presents an “on–off–on” type by alternatively adding Fe³⁺ and L-Cys. Moreover, upon the addition of Al³⁺, the yellow-green AIE of WJG shows a blue shift and changes to blue. The detection limits of the sensor array for CN⁻, Al³⁺ and Fe³⁺ are 3.02 × 10⁻⁶ M, 5.78 × 10⁻⁸ M, and 3.81 × 10⁻⁹ M, respectively. The WJG could act as a multi-analyte detection and fluorescent display material.