Novel fluorescent chemosensor for Ag+ based on coumarin fluorophore

A novel chemosensor 1 (CS1) bearing one coumarin and two carbodithioate groups was synthesized and its fluorescent sensing behavior toward metal ions was investigated. Ag+ addition to a CH3COCH3/H2O (3:7, v:v) solution of CS1 gave a significantly quenched fluorescence. Other ions including Pb2+, Zn2+, Cu2+, Ca2+, Cd2+, Co2+, Mg2+, Mn2+, Hg2+, Ag+, Ni2+ induced no or much smaller spectral changes. This constitutes an ON–OFF Ag+-selective fluorescent chemosensor.