Dual signaling of thallium(III) ions via oxidative cleavage of a sulfonhydrazide linkage

Abstract

The thallium is widely used in various research and industrial applications but is very toxic. In this work, we developed a novel reaction-based dual signaling probe for the selective and sensitive determination of Tl3+ via the oxidative cleavage of a rhodamine–dansylhydrazide conjugate. The designed probe showed pronounced colorimetric and fluorescence signaling behavior toward Tl3+ with a detection limit of 1.3 × 10–7 M (0.027 ppm), as well as selectivity over other common metal ions, anions, and oxidants. The Tl3+ signaling process required less than 2 min and was not influenced by the solution pH within the range of 4.0–5.5; however, the signal diminished significantly above pH 6.0. To demonstrate the practical applicability of the designed probe, a simple and convenient colorimetric assay for the determination of Tl3+ in commercial reagents was established using an office scanner as a readily available signal capturing device. © 2020 Elsevier B.V.