Highly Selective and Reversible Chemosensor for Pd²⁺ Detected by Fluorescence, Colorimetry, and Test Paper

Abstract

A “turn-on” fluorescent and colorimetric chemosensor (RBS) for Pd2+ has been designed and synthesized through introduction of sulfur as a ligand atom to Rhodamine B. RBS exhibits high selectivity (freedom from the interference of Hg2+ in particular) and sensitivity toward Pd2+ with a detection limit as low as 2.4 nM. RBS is also a reversible sensor, and it can be made into test paper to detect Pd2+ in pure water. Compared to the chemosensors that introduced phosphorus to Rhodamine to detect Pd2+, RBS can be synthesized more simply and economically.