A red fluorescent turn-on chemosensor for Al3+ based on dimethoxy triphenylamine-benzothiadiazole derivative with aggregation-induced emission
Aluminum is a known neurotoxin to organisms and believed to cause Alzheimer's disease, osteomalacia and breast cancer. Effective tools for Al3+ recognition are thus in great demand. In this paper, a new sensitive and highly selective red turn-on chemosensor (TB-COOH) for Al3+ was presented by combining the dimethoxy triarylamine- benzothiadiazole motif and carboxyl group, where the benzothiadiazole-derivative as aggregation-induced emission (AIE) moiety and the carboxyl motif functions as the recognition site with Al3+. It shows significant fluorescence enhancement upon addition of the selective Al3+ with a relatively low detection limit (1.5 10-7 M). The fluorescence turn on mechanism is ascribed to the aggregation of TB-COOH after complexation with Al3+, which has been confirmed by the 1H NMR, FT-IR spectra and scanning electronic microscope measurements. Furthermore, benefiting from its good water solubility and biocompatibility, imaging detection and real-time monitoring of Al3+ in living HeLa cells were successfully achieved.