A Novel C-glycosyl Rhodamine-based Fluorescent Sensor with a Thiourea Receptor for the Detection of Hg²⁺

A novel C-glycosyl rhodamine-based fluorescent sensor with a thiourea receptor has been readily synthesized and its fluorogenic behavior towards various metal ions was fully studied. It was found that the obtained target sensor exhibited good selectivity for Hg2+ over many other metal ions, which has been attributed to a binding mode of thiourea with thiophilic Hg2+, the sensor showed high selectivity and sensitivity to Hg2+ with a violent fluorescence enhancement at 580 nm. The sensing mechanism was explored by spectroscopic techniques and the IR analysis results demonstrated that a 1:1 mixture was formed between Hg2+ and the sensor.