A quinolimide-based reversible fluorescent sensor for Cu2+ and S2− and its applications

A quinolimide-based reversible fluorescent sensor QPC with carboxamidoquinoline as the receptor was prepared for the relay recognition of Cu2+ and S2−. QPC displayed the high selectivity and anti-interference ability to Cu2+ through the 1:1 binding mode. Subsequently, the selectively sensing S2− with the QPCCu2+ complex gave a remarkable recovery of the emission. The LODs of QPC and its Cu2+ complex for Cu2+ and S2− were calculated to be 47.8 nM and 0.178 µM, respectively. Moreover, QPC and its Cu2+ complex had the satisfactory recoveries 93.5–105.8% for Cu2+ and 97.7–104.0% for S2− in water samples, and exhibited low cytotoxicity, which enabled them to image Cu2+ and S2− in yeast cells.