Highly sensitive and selective coumarin-based fluorescent chemosensor for Cu2+ detection

Abstract

Our research resulted in the development of a new synthetic semicarbazide derivative based on coumarin (CS1) as a fluorescent chemosensor for Cu2+ detection. The probe demonstrated an “on–off” fluorescence response at 492 nm in the presence of Cu2+ with a detection limit of 5.80 ± 0.01 nM. A copper existence diminished visible fluorescence under UV light. The binding ratio of the CS1 probe to Cu2+ was found to be 1:1, resulting from the ESI-MS, Job’s method, and density functional theory (DFT) calculation. The probe exhibited acceptable Cu2+ sensitivity, within nanomolar scale, and selectivity, even in the presence of other important metal ions. Apart from the laboratory study, CS1 was also capable of real water sample measurement with great accuracy.