Selective and sensitive turn-on fluorescent sensing of arsenite based on cysteine fused tetraphenylethene with AIE characteristics in aqueous media.

Herein, a cysteine-functionalized derivative of TPE is presented as the first fluorescent organic dye for selective, label-free, sub-ppb level detection of As(3+) in aqueous media by taking the advantage of the aggregation induced emission feature. Besides, the first discrimination between the most toxic As(3+) and less toxic As(5+) was obtained.