Selective Detection of Fe(III) and Al(III) Using an Azo-Functionalized Rhodamine B Chemosensor: Expansion to F- Ion...

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Rhodamine-B derivatives are widely used as fluorescent probes.
• Development of selective chemosensors for metal ions and anions is crucial for environmental and biological monitoring.
• Azo-functionalized compounds offer versatile platforms for designing chemosensors.

Purpose of the Study:

• To develop and characterize a novel azo-functionalized Rhodamine-B based chemosensor (HL).
• To investigate the sensor's ability to detect specific metal cations (Al(III) and Fe(III)) and anions (F⁻).
• To evaluate the practical applicability of the chemosensor in real-world samples.

Main Methods:

• Spectroscopic characterization of the synthesized chemosensor (HL).
• Optical and fluorescence spectroscopy for cation and anion detection.
• Nuclear Magnetic Resonance (NMR), Mass Spectrometry, and Job's plot analysis for structural validation and stoichiometry determination.

Main Results:

• The chemosensor HL selectively detects Al(III) and Fe(III) in a methanol-water medium, exhibiting color change and fluorescence enhancement.
• The HL-Al(III) complex selectively detects F⁻ ions via fluorescence quenching, indicating a turn-off sensing mechanism.
• Low limit of detection (LOD) of 72 µM for Al(III) and reproducibility were confirmed, along with 1:1 probe-analyte stoichiometry.

Conclusions:

• The developed azo-functionalized Rhodamine-B chemosensor (HL) demonstrates excellent selectivity and sensitivity for Al(III) and Fe(III) detection.
• The HL-Al(III) complex serves as an effective probe for selective F⁻ ion detection.
• The chemosensor shows practical applicability for quantifying Al(III) in pharmaceutical samples and F⁻ in water samples.