FRET‐based Fluorescent and Colorimetric Probe for Selective Detection of Hg(II) and Cu(II) with Dual‐mode

A dual‐function fluorescence resonance energy transfer (FRET)‐based fluorescent and colorimetric probe was rationally fabricated from an energy donor coumarin moiety and an energy acceptor rhodamine moiety linked by a thiohydrazide arm for selective detection of Hg²⁺ and Cu²⁺. Two distinct mechanisms were used for the selective detection. Results revealed that probe 1 showed high fluorescent selectivity towards Hg²⁺ and evident colorimetric selectivity for Cu²⁺, which was suitable for ‘naked‐eye’ detection.