Novel selective "on-off" fluorescence sensor based on julolidine hydrazone-Al³⁺ complex for Cu²⁺ ion: DFT study

Area of Science:

• Coordination Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Hydrazone complexes are explored for sensing applications.
• Aluminum complexes offer unique properties for metal ion detection.
• Copper ion (Cu²⁺) detection is crucial for environmental and health monitoring.

Purpose of the Study:

• To synthesize and characterize a novel aluminum-hydrazone complex (T1-Al³⁺).
• To evaluate the T1-Al³⁺ complex as a selective sensor for copper ions (Cu²⁺).
• To investigate the anticancer properties of the synthesized hydrazone (T1).

Main Methods:

• Synthesis of hydrazone (T1) and its aluminum complex (T1-Al³⁺) in aqueous solution.
• Utilizing paramagnetic quenching for Cu²⁺ selective sensing.
• Computational analysis using Gaussian software for selectivity explanation.
• Anticancer activity evaluation using MTT assay on HeLa and U251 cells.

Main Results:

• The T1-Al³⁺ complex demonstrated high sensitivity and selectivity for Cu²⁺ detection.
• A broad linear detection range (10-110 µM) and a low detection limit (0.62 µM) for Cu²⁺ were achieved.
• The sensor successfully detected Cu²⁺ in mineral and tap water samples.
• The parent hydrazone (T1) showed anticancer efficacy against tested cell lines.

Conclusions:

• The T1-Al³⁺ complex is a promising sensor for Cu²⁺ detection, even below EPA thresholds.
• Computational studies support the observed selectivity of the sensor.
• The hydrazone ligand (T1) possesses potential anticancer properties.