A novel colorimetric and ratiometric fluorescent Cu2+ sensor based on hydrazone bearing 1,8-naphthalimide and pyrrole moieties

A 1,8-naphthalimide hydrazone derivative bearing a pyrrole unit is a highly selective ratiometric fluorescent Cu 2+ probe used to monitor intracellular Cu 2+ in HeLa cells. This probe functions via a unique hydrolysis mechanism through Cu 2+ -promoted electrophilic substitution. Binding is confirmed through UV–vis absorption, fluorescence measurements, mass spectroscopy, IR, X-ray single crystal diffraction, and DFT calculation.