A novel Schiff-base as a Cu(II) ion fluorescent sensor in aqueous solution

Area of Science:

• Analytical Chemistry
• Materials Science
• Organic Chemistry

Background:

• Schiff bases are versatile ligands for metal ion complexation.
• Development of selective fluorescent sensors for heavy metal detection is crucial.
• Copper(II) ion detection is important in environmental and biological monitoring.

Purpose of the Study:

• To synthesize and characterize a new fluorescent sensor for Cu(II) ions.
• To investigate the selectivity and sensitivity of the sensor towards Cu(II).
• To apply the sensor for the determination of copper in real samples.

Main Methods:

• Synthesis of Schiff base ligand (L) from 5,5'-methylene-bis-salicylaldehyde and 2,4-diaminophenol.
• Characterization using FT-IR, MS, 1H NMR, and 13C NMR.
• Fluorescence spectroscopy for metal ion sensing in DMSO/H2O buffer (pH 6.5).
• Quantum chemical computations for structural and electronic properties of the Cu(II) complex.

Main Results:

• A new fluorescent Cu(II) sensor (L) was successfully synthesized and characterized.
• The sensor exhibits high sensitivity and selectivity for Cu(II) over other tested metal ions.
• A stable 2:1 complex of Cu(II) with L was formed at pH 6.5.
• The sensor was effectively applied to determine copper in a standard reference material.

Conclusions:

• The synthesized Schiff base acts as an efficient fluorescent sensor for Cu(II) detection.
• The sensor demonstrates excellent selectivity and sensitivity, making it suitable for practical applications.
• Quantum chemical calculations provide insights into the electronic structure of the Cu(II)-sensor complex.