A Highly Selective and Sensitive Fluorescent Chemosensor for Detecting Al³⁺ Ion in Aqueous Solution and Plant Systems

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Aluminum ions (Al³⁺) are toxic to plants and animals in acidic soils.
• Accurate detection and quantification of Al³⁺ are crucial for environmental and biological monitoring.
• Existing methods for Al³⁺ detection may require improvement in terms of sensitivity and ease of use.

Purpose of the Study:

• To synthesize and characterize a novel Schiff-based fluorescent turn-on sensor (probe L) for selective Al³⁺ detection.
• To evaluate the sensing performance of probe L for Al³⁺ in various conditions.
• To demonstrate the practical application of probe L in real-world samples, including water and plant systems.

Main Methods:

• Synthesis of the Schiff-based fluorescent probe L via coupling of 2-hydroxy-1-naphthaldehyde and 2-aminoisoindoline-1,3-dione.
• Characterization of the probe's structure using nuclear magnetic resonance (NMR) spectroscopy.
• Fluorescence spectroscopy was employed to assess the probe's selectivity and sensitivity towards Al³⁺ in a DMSO-H₂O mixture.

Main Results:

• The synthesized probe L exhibited high selectivity and sensitivity for Al³⁺ ions over other tested metal ions.
• Fluorescence quantification confirmed the probe's effectiveness in detecting and measuring Al³⁺ levels.
• Al³⁺ treatment (25–200 μM) was shown to inhibit rice seedling growth and induce reactive oxygen species in roots.

Conclusions:

• Probe L is a promising fluorescent sensor for the selective and sensitive detection of Al³⁺.
• The developed method provides a simple and effective alternative for quantifying Al³⁺ in aqueous solutions and plant systems.
• The fluorescent probe L has significant potential for environmental and biological monitoring of aluminum contamination.