Highly selective, sensitive and quantitative detection of Hg2+ in aqueous medium under broad pH range

Amidothiourea linked acridinedione derivatives selectively detect Hg2+ in unbuffered aqueous solution under broad pH range with both single- and two-photon excitation. The observed linear fluorescence intensity change allows the quantitative detection of Hg2+ in the concentration range of 22 nM-0.33 mu M with the lower detection limit of 2 nM.