Analysis of heavy metal ions (Pb, Hg, Cr, Cd, As) capture & detection based on quinoline probe binding data

This research employs the density functional theory method to study the coordination and capture of the "five toxic" heavy metal ions (Pb, Hg, Cr, Cd, and arsenic) by quinoline-derivative molecular probes. The study has determined the microscopic molecular configurations, structural parameters, and natural charge distributions of the coordinating atoms in the optimal structures of the complexes formed by the probes and each heavy metal ion. Additionally, the coordination bond orders of all the complexes have been calculated and analyzed. Furthermore, by calculating the infrared vibration frequencies of the optimal structures, the stability of the structures has been verified. Moreover, the binding energies, frontier molecular orbital energy levels, and energy gap values of the complexes formed by the probes and each heavy metal ion through capture have been further obtained, and the changes in the ultraviolet-visible absorption spectra and molecular fluorescence spectra of the probes have been analyzed. The study also investigated the probe's ability to capture and detect the "five toxic" heavy metal ions.