A new Fe3+ fluorescent chemosensor based on aggregation-induced emission

A new tetraphenylethylene (TPE)-based sensor M1 bearing double 2-methylpyridyl-2-methylthiophenylamino units linked with triazole moieties was reported. Both UV–vis and fluorescence spectroscopic studies demonstrated that M1 was highly sensitive and selective toward Fe3+ over other metal ions in THF/H2O solution based on the aggregation-induced emission quenching mechanism. The lowest detection limit of M1 for Fe3+ is 0.7 μM. The detailed fluorescent titration study suggested that the binding stoichiometry of the M1–Fe3+ complex was 1:2, and the structure between M1 and the Fe3+ complex was confirmed by the 1H NMR titration.