Novel “turn-on” fluorescent chemodosimeters based on thioxanthen-9-thione for the selective detection of mercuric ions in aqueous media

Two Hg2+-selective chemodosimeters based on thioxanthen-9-thione (DP-TXT and BDPA-TXT) were synthesized and structurally characterized. The highly sensitive and selective chemodosimetric behaviors of thioxanthen-9-thione towards Hg2+ ions were investigated. Significant chromogenic and fluorogenic signaling occurred from the transformation of thioxanthen-9-thione to thioxanthen-9-one by Hg2+-induced selective desulfurization. Both of the two probes exhibit excellent Hg2+-specific fluorescence enhancement over various competitive cations in aqueous media.