Colorimetric detection of Cu(II) in aqueous solutions using a novel chemosensor: 2-((2-chloroquinolin-3yl)methylidene]amino)phenol

A spectrophotometric technique based on a selective colorimetric approach is presented in this study for the determination of Cu(II) ions using 2-([(2-chloroquinolin-3-yl)methylidene]amino)phenol (BHMOS) as a detection agent. NMR and FT-IR spectroscopy were used to characterize the compound thoroughly, ensuring accuracy in terms of its molecular structure. As a chemosensor in aqueous solutions, BHMOS has demonstrated a very high level of sensitivity and specificity, even in the presence of other cations. During the interaction between Cu(II) ions and BHMOS, a noticeable colour change was observed to pale green, which is a visual indicator of Cu(II) ions. The method demonstrated linearity for Cu(II) concentrations ranging from 5 to 60 µM, with a detection limit of 1.50 µM. The binding constant for the Cu(II)-BHMOS complex was determined to be 1.14 × 106 M−1, reflecting the strength and stability of the interaction. This method proved to be effective for detecting Cu(II) ions in both natural and simulated water samples, showing its potential utility in environmental monitoring applications.