A new thiosemicarbazone fluorescent probe based on 9,9'-bianthracene for Hg2+ and Ag.

A new 9,9'-bianthracene-based thiosemicarbazone (D1) has been successfully synthesized and utilized for chemosensors. The properties of D1 were systematically investigated by UV-Vis, fluorescence titration and theoretical calculations. As a result, D1 exhibits a characteristic fluorescence quenching phenomenon in the presence of Hg2+ or Ag+ compared to other metal cations (Na+, K+, Mg2+, Ba2+, Al3+, Zn2+, Fe2+, Pb2+, Cu2+, Co2+, Cd2+, Ni2+ and Mn2+). The detection limits of Hg2+ and Ag+ reach 6.62×10-7M and 1.99×10-5M, respectively. This is mainly attributed to the Hg2+ (or Ag+) forms a stable five-membered ring with the N atom in Schiff base CN and the S atom in thiourea. The results suggest that the probe D1 is a promising candidate for chemosensors in aqueous media due to its highly selectivity for Hg2+ and Ag+.