Novel Carbonothioate-Based Colorimetric and Fluorescent Probe for Selective Detection of Mercury Ions

The development of probes for selective detection of mercury ions (Hg2+) is an important mission to accomplish because of the toxicity and ubiquity of Hg2+. Herein, we designed and synthesized a novel fluorescent probe O-(N-butyl-1,8-naphthalimide)-4-yl-O-phenyl carbonothioate (CBONT) for selective and sensitive detection of Hg2+ by turn-on fluorescence spectroscopy. Probe CBONT exhibited a fast response for Hg2+ with excellent sensitivity (limit of detection = 1.9 nM, 3 sigma/slope), and it might be attributed to the adoption of a new recognition receptor of carbonothioate moiety. Additionally, probe CBONT could serve as a "naked-eye" indicator for Hg2+. Finally, probe CBONT could be successfully applied to detect the concentrations of Hg2+ in real water samples. Our proposed recognition receptor would open up new, exciting opportunities for designing highly selective and ultrasensitive fluorescent probes for the determination of Hg2+ in real water samples.