A highly sensitive and selective fluorescent probe for determination of Cu (II) and application in live cell imaging

A highly sensitive fluorescent probe, 2‑butyl‑6‑(2‑ethylidenehydrazinyl)‑1H‑benzo[de]isoquinoline‑1,3(2H)‑dione (P) has been designed and synthesized to detect Cu²⁺ in CH₃CN-HEPES (4:1, v/v, pH = 7.4) solution. This probe functions via a distinctive hydrolysis mechanism through Cu²⁺-promoted accompany by extinction of the fluorescent and other competing metal ions did not showed any interference. The limit of detection toward Cu²⁺ was calculated of 320 nM. Probe P was not only successfully used for the determination of trace level Cu²⁺ in the CH₃CN-HEPES (4:1, v/v, pH = 7.4) solution, but also valid for fluorescence imaging of Cu²⁺ in lysosomes of 293T cells and it was applied in real water samples. This work indicated that P would be of great application prospect in environmental monitoring and medical diagnosis.