Nonplanar Perylene Monoimide‐Based Fluorescent Film for Enhanced BTX Sensing

Abstract

Film-based fluorescent sensors have been adapted into portable devices for the vapor phase detection. The satisfactory sensing performance (e.g., sensitivity, selectivity, reusability) largely benefits from fluorophores. Here we report a new nonplanar perylene monoimide derivative (PMI-CB) and demonstrate its application in a miniaturized film-based fluorescent sensor for BTX (i.e., benzene, toluene, xylene) detection. The fluorophore of PMI-CB is obtained through incorporating a three-dimensional o-carborane with the perylene monoimide (PMI). Compared to a planar PMI derivative (PMIA), the nonplanar PMI-CB with reduced intermolecular aggregation exhibits enhanced fluorescence intensities in both solvents and film state. The PMI-CB film exhibited fluorescence enhancements for BTX, while fluorescence quenching for commonly interfering compounds like ethanol, triethylamine, and acetone. Such opposite response behavior endows the PMI-CB-based sensor with the ability for selective detection of BTX. Importantly, our PMI-CB film is not sensitive to water. The sensitivity test shows that the PMI-CB film can detect benzene vapor at a concentration of as low as 3.3 mg/m 3 without any preconcentration procedures, and exhibits a good linear relationship from 3.3 to 425.9 mg/m 3 . On the basis of this work, a portable detector with high selectivity, sensitivity, reusability, and low power consumption can be adapted for the on-site BTX detection.