A selective fluorogenic chemodosimeter for Hg2+ based on the dimerization of desulfurized product

A simple Hg2+-selective chemodosimetric system based on thiosemicarbazone was investigated. The transformation of thiosemicarbazone into semicarbazone selectively exerted by Hg2+ ions and the dimerization of semicarbazone resulted in a pronounced OFF–ON-type fluorescent signaling behavior. The coexistent metal ions, such as Fe3+, Ca2+, Cu2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+, Cr3+, Mg2+, Na+, K+, and Fe2+, had no obvious interference with the detection of Hg2+. In addition, S12–Hg2+ plays a high sensitivity for basic anions to form an ‘OFF–ON–OFF’ type signaling behavior, with the Hg2+-induced emission spectra can be quenched. Moreover, test strips based on S12 exhibited a good selectivity to Hg2+. We believe the test strips could act as a convenient and efficient Hg2+ test kit.