A novel fluorescent chemosensor based on a rhodamine 6G derivative for the detection of Pb2+ ion

A new selective fluorescent chemosensor based on rhodamine 6G derivative (R1) has been designed and synthesized, which displayed highly selective and sensitive detecting for lead ion in aqueous solution. Sensor R1 was selective toward Pb2+ ion by a light yellow to pink change for the visual detection of Pb2+ ion. The fluorescence recognition processes of Pb2+ was based on a binding induced ring-opening from the spirolactam (nonfluorescent) to acyclic xanthenes (fluorescent). Sensor R1 was excited with a 1:1 binding ratio and the linear response in the range of 1.0 × 10−8–1.0 × 10−5 mol L−1with the limit of detection of 2.7 × 10−9 mol L−1 (3σ/slope).