Histidine-dialkoxyanthracene dyad for selective and sensitive detection of mercury ions

Histidine-dialkoxyanthracene (HDA) was synthesised as a turn off type fluorescent sensor for fast and sensitive detection of mercury ions (Hg2+) in aqueous media. The two histidine moieties act as 'claws' to selectively complex Hg2+. The binding ratio of HDA to Hg2+ was 1: 1 (metal-to-ligand ratio). The association constant for Hg2+ towards the receptor HDA obtained from Benesi-Hildebrand plot was found to be 3.22 x 10(4) M-1 with detection limit as low as 4.7 nM (0.94 mu g/L). [GRAPHICS] .