Coumarin Derivative Fluorescent Probe for Highly Selective and Sensitive Sequential Detection of Cu2+/S2- and Cell imaging

Abstract Rapid detection of copper ion (Cu 2+ ) and sulfide anion (S 2− ) has become a research priority in view of their crucial roles in human health and environmental monitoring; therefore, there is an intense demand for highly effective detection of their concentrations in biological and environmental samples. In this work, a fluorescent probe Y based on the "ON-OFF-ON" strategy for sequential recognition of Cu 2+ and S 2− with high selectivity and anti-interference ability was developed. Probe Y can form a complex with Cu 2+ to realize Cu 2+ detection due to fluorescence quenching, and the Y +Cu 2+ complex can react with S 2− to achieve fluorescent recovery by generation of insoluble copper sulfide (CuS) to release probe Y . Probe Y toward Cu 2+ and its complex to S 2− detection exhibit good sensitivity with the detection limit (LOD) of 2.40×10 − 8 mol/L and 1.80×10 − 8 mol/L, respectively. Moreover, the detection process can be completed within 30 s to demonstrate rapid response capability over a wide pH range. Test strip, reversibility, and cell imaging experiments were also conducted to confirm their practical application capability in real environments.