Fluorogenic bis-triazolyl galactoprobe–metal complex for full-aqueous analysis of sulfide ion

Abstract

As a common environmental pollutant, the sulfide anion (S2−) is toxic to the human body. We report here the simple preparation of a selective fluorogenic glycoprobe–metal complex for the rapid analysis of S2− in full aqueous solution and real water samples. The probe was synthesized by “clicking” a dipropargyl naphthalimide dye with a water-soluble azido β-d-galactoside. Fluorescence spectroscopic analyses showed that the probe had an on–off response to Cu2+, forming a fluorogenic probe–Cu2+ complex. The subsequent addition of S2− selectively recovered the fluorescence of the complex over other anions tested, probably because of the high-affinity association between Cu2+ and S2−. The complex showed a good linear range and a nanomolar limit of detection with S2− in full aqueous solution, and has also proven to be suitable for accurate recovery of spiked S2− in real water samples.