Highly Selective and Sensitive Detection of Arsenite Ions (III) Using a Novel Tetraphenylimidazole-based Probe

More than 200 million people in the world are exposed to areas where the arsenic concentration exceeds the limit allowed for living species, which urges people to develop low-cost methods for selective and fast detection of arsenic ions in environmental samples. Herein, we reported a novel tetraphenylimidazole-based probe (TBAB) functionalized with Schiff base for sensing and detecting arsenic ions in the aqueous media. Upon addition of arsenic ions, an obvious fluorescence change from faint yellow to green can be observed by bare eyes. The probe can detect arsenic selectively in the presence of interfering substances, with a lower detection limit than 0.7 ppb, a value which is far lower than the limit set by the WHO. The detailed mechanism revealed that the chelation of TBAB with arsenic activated the AIE characteristic, leading to the enhanced fluorescence, which was verified by Job’s plot experiment and HRMS. The further practicality was validated by the analysis of real water samples, demonstrating its potential application for on-site detection and biological application.