Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide.

The chemosensor properties of a bimetallic terbium(III)/copper(II) complex functionalized with a 4-(2-pyridyl)-1,2,3-triazole ligand for the detection of Cu ions and, aqueous and gaseous hydrogen sulfide was investigated. The 4-(2-pyridyl)-1,2,3-triazole ligand functions both as an antenna chromophore and a receptor for Cu ions; the Cu complex was shown to be a chemosensor for the detection of aqueous hydrogen sulfide. The chemosensor exhibited significant reversibility over multiple cycles, observed with the sequential addition of NaS followed by Cu ions. The limit of detection for aqueous hydrogen sulfide was 0.63 μM (20 ppb). No luminescent changes of the bimetallic terbium(III)/copper(II) complex were observed in the presence of gaseous hydrogen sulfide, and thus this sensor can only be used for the detection of aqueous hydrogen sulfide.