BINOL-Based Fluorescent Sensor for Recognition of Cu(II) and Sulfide Anion in Water

A multifunctional fluorescent sensor based on a cyclen-appended BINOL derivative (<b>R-1</b>) was synthesized and characterized. It can display on–off-type fluorescence change with high selectivity toward Cu­(II) among 19 metal ions in 100% aqueous solution. Furthermore, the in situ generated <b>R-1–Cu­(II)</b> ensemble could recover the quenched fluorescence upon the addition of sulfide anion resulting in a off–on-type sensing with a detection limit of micromolar range in the same medium. No interference was observed from other biothiols and anions, including GSH, l-Cys, DTT, and sulfates, making it a highly sensitive and selective sulfide probe