A novel rhodamine-based turn-on probe for fluorescent detection of Au3+ and colorimetric detection of Cu2+

Abstract

In this work, we design and synthesize the novel probe RC through introduction the 1-aza-4,13-dithia-15-crown-5 ring into the structure of rhodamine 6G hydrazide, where the N atom of crown ring is responsible for quenching of rhodamine fluorescence. The compound obtained behaves as multifunctional cation sensor providing selective fluorescent response to Au3+ and selective colorimetric response to Cu2+ ions in aqueous acetonitrile (1/1, v/v) at pH 7.0. The use of 10−5 M RC solution allowed reliable determination of target cations in the presence of a wide range of environmentally relevant ions with detection limits of 2 × 10−6 M and 5 × 10−7 M for gold and copper, respectively.