A near-infrared “turn-on” fluorescent probe for selective detection of copper(II) ions in aqueous media and its application in cell imaging

Abstract

Copper (II) is considered the third most essential trace element for life, following iron and zinc, and plays a vital role in various physiological and pathological processes. The fluorescent probe has become an important method for the detection of heavy metal ions. This investigation involved the development and synthesis of a near-infrared “turn-on” fluorescent probe, DCX-Cu, with a significant Stokes shift (156 nm), specifically to identify Cu²⁺ compared other ions. A detection limit (LOD) of 19.47 nM for Cu²⁺ was demonstrated by probe DCX-Cu. A strong linear correlation was observed between the fluorescence intensities measured at 746 nm and the concentrations of Cu²⁺. Furthermore, the current probe successfully visualized Cu²⁺ in water samples and HepG2 cells.