A novel tetraphenylethene-based fluorescent sensor for uranyl ion detection with aggregation-induced emission character

Facile and efficient approaches for uranyl ion detection without tedious sample pretreatment and sophisticated instrumentation are in great demand in environmental monitoring and mitigation. In this work, a novel fluorescent sensor TPE-BSA with aggregation-induced emission (AIE) character was designed and synthesized for the uranyl ion detection, by incorporating salophen moiety into the AIE-active tetraphenylethene moiety. Fluorescence titrimetric studies revealed that TPE-BSA could detect uranyl ion in a simple way owing to the quenching of its aggregation-induced emission, with the limit of detection as low as 0.039 μM. According to the results of particle size distribution analysis, 1H NMR, Job's plot analysis, quantum chemical calculations and fluorescence lifetime measurement, the fluorescence quenching of TPE-BSA upon addition of uranyl ion could be ascribed to the complexation of TPE-BSA and uranyl ion as well as the heavy atom effect of uranyl ion. Furthermore, TPE-BSA was successfully used for the quantification of uranyl ion in drinking water, demonstrating that TPE-BSA has the potential to be employed in the detection of uranyl ion in the environmental system as an AIE-active sensor.