Trace level detection of Pb ion using organic ligand as fluorescent-on probes in aqueous media.

In this study, an optical sensor, JA/(2,6-di((E)-benzylidene)cyclohexan-1-one), was synthesized and characterized using H NMR and FT-IR spectroscopy. The sensor exhibited high efficiency and selectivity in detecting Pb ions, even in the presence of potential interfering ions such as Mn, Cu, Co, Cr, Ni, Ce, Hg, and Cd in aqueous solutions. The interaction of JA with Pb resulted in a significant enhancement of fluorescence intensity, suggesting the formation of a stable complex. A 2:1 binding ratio between JA and Pb was confirmed through fluorometric analysis, absorption spectra, and theoretical calculations (DFT). The association constant for the complex was calculated to be 3 × 10 M. The sensor demonstrated high sensitivity towards Pb with a detection limit of 5 × 10 M. Additionally, JA was successfully reused by applying EDTA to release Pb from the sensor. Real sample analysis under optimized conditions of pH, time, and concentration of JA and Pb further validated the practical applicability of the sensor.