A selective detection approach for copper(ii) ions using a hydrazone-based colorimetric sensor: spectroscopic and DFT...

Area of Science:

• Analytical Chemistry
• Materials Science
• Computational Chemistry

Background:

• Developing sensitive and selective analytical methods for toxic ions in aqueous media is crucial.
• Hydrazone-based chemosensors show promise for detecting heavy metal ions due to their sensitivity and selectivity.
• Computational chemistry aids in understanding ligand-metal interactions for sensor design.

Purpose of the Study:

• To develop a highly sensitive, quick, and reusable colorimetric sensor for copper(II) ions in aqueous solutions.
• To investigate the ligand-metal interactions using DFT calculations.
• To evaluate the sensor's selectivity, detection limit, and regeneration capabilities.

Main Methods:

• Synthesis and characterization of 3-hydroxy-5-nitrobenzaldehyde-4-hydroxybenzoylhydrazone (3-HNHBH) ligand.
• Colorimetric detection of copper(II) ions.
• Density Functional Theory (DFT) calculations to model ligand-metal complexation.
• Investigation of interference, pH, and solvent effects on sensor performance and regeneration.

Main Results:

• The 3-HNHBH ligand demonstrated highly sensitive and selective colorimetric detection of copper(II) ions.
• A low detection limit of 0.34 μg L⁻¹ for copper(II) was achieved.
• DFT calculations indicated a seesaw coordination geometry for the copper(II) complex with favorable electronic properties.
• The ligand was successfully regenerated using dilute HCl, confirming its reusability.

Conclusions:

• The developed hydrazone-based chemosensor provides an efficient and reusable method for detecting trace copper(II) ions in aqueous media.
• The combination of experimental and computational approaches offers valuable insights into the sensing mechanism.
• This sensor shows potential for practical applications in environmental monitoring and water quality assessment.