A Colorimetric and Fluorescent Probe for the Detection of Cu²⁺ in a Complete Aqueous Solution

The fluorescent probe has become an important method for the detection of heavy metal ions. In the present work, a new and simple fluorescent probe, Cu-P, for detecting copper ion (Cu²⁺) was designed and synthesized. The probe has shown high sensitivity and selectivity toward Cu²⁺. The detection limit was 13 nM (based on the 3σ/slope). A significant color change from yellow to pink was observed; thus, the probe Cu-P could serve as a "naked-eye" indicator for Cu²⁺. Furthermore, the proposed probe was used to detect Cu²⁺ in real water and soil extract samples, with the result being satisfactory. Therefore, our proposed probe would provide a promising method for the detection of Cu²⁺ in the environment.