A Rhodamine B-Based "Turn-On" Fluorescent Probe for Selective Fe³⁺ Ions Detection

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Heavy metal ion detection is critical for environmental safety, industrial quality control, and public health.
• Development of sensitive and selective fluorescent probes is essential for accurate metal ion sensing.

Purpose of the Study:

• To synthesize and characterize a novel Rhodamine B-based fluorescent probe, RhB-DCT, for sensitive and selective detection of Fe3+ ions.
• To evaluate the probe's performance, including response time, pH stability, reversibility, and detection limit.

Main Methods:

• Synthesis of Rhodamine B-based fluorescent probe functionalized with 2,4-dichloro-1,3,5-triazine (DCT).
• Investigation of the "turn-on" fluorescence mechanism triggered by Fe3+ ions via spiro-lactam ring opening.
• Spectroscopic analysis to determine probe sensitivity, selectivity, pH stability, and reversibility.

Main Results:

• The RhB-DCT probe exhibited a rapid "turn-on" fluorescence response within seconds, with a distinct color change.
• The probe demonstrated broad pH stability (4-13), excellent reversibility, and a low detection limit of 0.0521 μM for Fe3+.
• RhB-DCT showed significant selectivity for Fe3+ over other competing metal ions.

Conclusions:

• The RhB-DCT probe is a highly sensitive, selective, rapid, and stable tool for Fe3+ detection.
• This probe shows great potential for real-time Fe3+ monitoring in aqueous environments.
• RhB-DCT can be effectively applied in environmental monitoring, water quality assessment, and analytical sensing platforms.