Construction of a coumarin based fluorescent sensing platform for palladium and hydrazine detection

摘要

Graphical abstractDisplay OmittedHighlights•Two coumarin-based fluorescent probesC1andC2were designed and synthesized.•C1andC2showed high selectivity for Pd0detection over other 22 tested metal ions with nanomolar level sensitivity.•The high selectivity ofC1towards Pd0was further utilized to construct a Pd2+assisted system for hydrazine detection.AbstractDesigning high performance signal turn on or ratiometric fluorescent probes for detecting hazardous substances is of great importance and challenging. In this paper, two coumarin-based fluorescent probesC1andC2with allyl carbonate and propargyl as their respective fluorescence masking groups were designed and synthesized for detecting both palladium and hydrazine. ProbeC1showed highly selective and sensitive fluorescence turn on response towards Pd0over all other tested metal ions including Pd2+. Whereas a large ratiometric fluorescence response towards Pd0was observed for probeC2. The detection limits for Pd0were determined to be 33nM and 14nM forC1andC2, respectively. Taking advantages of the high Pd0selectivity ofC1and the metal ion reducing ability of hydrazine, we further successfully developed a new strategy for hydrazine detection, which is based on the reduction of Pd2+to Pd0by hydrazine and subsequent Pd0-induced removal of the allyl carbonate fluorescence masking group inC1. TheC1-Pd2+sensing system was determined to be selective for hydrazine detection over other tested amines with a detection limit calculated to be 37nM (∼1.2ppb).