A novel fluorescent sensor based on triphenylamine with AIE properties for the highly sensitive detection of CN−

Abstract

In this study, a novel fluorescent sensor 1 built on triphenylamine was designed for the extremely sensitive detection of trace cyanide anions. The UV absorbance and fluorescence emission intensity of sensor 1 with aggregation-induced emission (AIE) properties vary with water fraction (fw). In the 1% DMSO aqueous solution, sensor 1 exhibits the optimal aggregation state and fluorescence intensity, and has high selectivity and sensitivity for cyanide ions (CN−). From formula 3δ/S, it is clear that sensor 1 has an extremely low limit of detection (LOD) for CN− (LOD = 2.95 × 10−8 mol/L). Excellent anti-interference performance and broad pH response scope (1.0–9.0) are also advantages of sensor 1. Fluorescence spectroscopy, 1H NMR, 13C NMR spectroscopy, HRMS, Job's plot analysis and density functional theory calculations have been employed to elucidate the sensing mechanism between TPEB and CN−. Through colorimetry and fluorescence approach, the sensor 1 test strip can easily detect CN−. Therefore, the novel sensor 1 provides a broad application prospect for detecting toxic environmental pollutants.