Ultrasensitive and selective spectrofluorimetric determination of Hg(II) using a dimercaptothiadiazole fluorophore

► 2,5-Dimercpato-1,3,4-thiadiazole was used as a fluorophore for Hg(II) determination. ► 245-Fold increase in emission intensity was observed after the addition of 0.5 μM Hg(II). ► Using the present method, a detection limit of 18 p Hg(II) was achieved. ► Hg(II) was determined in the presence of 50,000-fold concentrations of interferences. ► The proposed method was utilized for the determination of Hg(II) in real samples.