Al3+ selective an efficient colorimetric receptor derived from 5-aminouracil

Area of Science:

• Analytical Chemistry
• Materials Science
• Chemical Sensing

Background:

• Schiff bases are versatile ligands with applications in coordination chemistry and sensing.
• Intramolecular charge transfer (ICT) probes offer sensitive detection mechanisms based on electronic transitions.
• Developing selective and interference-free sensors for metal ions like aluminum is crucial for environmental and biological monitoring.

Purpose of the Study:

• To develop a naked-eye sensor for the selective and sensitive detection of aluminum ions (Al3+).
• To investigate the sensing mechanism of a Schiff base probe based on intramolecular charge transfer (ICT).
• To evaluate the probe's performance in the presence of potential interfering ions.

Main Methods:

• Synthesis and characterization of a novel Schiff base derivative (receptor 1).
• Spectroscopic studies (UV-Vis absorption) to monitor the interaction between the receptor and Al3+.
• Investigation of the probe's response to other metal ions and anions to assess selectivity.

Main Results:

• Receptor 1, a Schiff base, acts as an ICT probe with an absorption band at 434 nm (olive green).
• Addition of Al3+ ions caused a significant hypsochromic shift to 395 nm (colorless), enabling naked-eye detection.
• The probe showed minimal interference from common anions (F-, CH3COO-, H2PO4-) and other metal ions.

Conclusions:

• The developed Schiff base probe allows for interference-free, naked-eye recognition of Al3+ at micromolar concentrations.
• The sensing mechanism involves a distinct color change due to Al3+ binding and modulation of ICT.
• This probe represents a promising tool for simple and rapid Al3+ detection in aqueous media.