A Selective and Sensitive “Turn‐on” Fluorescent Chemosensor for Recognition of Hg²⁺ Ions in Water

Abstract

Based upon highly selective and irreversible Hg2+-promoted deprotection of the dithioacetal reaction, a new water-soluble “turn-on” fluorescent chemosensor (1) was prepared and exhibited high selectivity and sensitivity towards the Hg2+ ion over other heavy and transition-metal ions in pure water by transforming a weakly fluorescent precursor (colorless) to a highly fluorescent aldehyde (yellow–green; see figure) with a 155-fold increase in fluorescent intensity.