A simple levulinate-based ratiometric fluorescent probe for sulfite with a large emission shift

Area of Science:

• Analytical Chemistry
• Organic Chemistry
• Spectroscopy

Background:

• Sulfite is an important analyte in various industrial and biological processes.
• Accurate and sensitive detection methods for sulfite are crucial.
• Existing methods may lack selectivity, sensitivity, or ease of use.

Purpose of the Study:

• To design and synthesize a novel 4-hydroxynaphthalimide-derived probe for sulfite detection.
• To develop a colorimetric and ratiometric fluorescent method for quantitative sulfite monitoring.
• To validate the probe's performance and explore its practical applications.

Main Methods:

• Synthesis of a 4-hydroxynaphthalimide-based probe with a levulinate moiety.
• Utilizing ratiometric fluorescence spectroscopy for sulfite detection.
• Employing Nuclear Magnetic Resonance (NMR) and Electrospray Ionization Mass Spectrometry (ESI-MS) for mechanism elucidation.

Main Results:

• The probe exhibited a significant 100 nm red-shifted absorption spectrum and color change from colorless to yellow upon sulfite addition.
• A 103 nm red-shifted emission spectrum was observed, confirming ratiometric detection capabilities.
• High selectivity and sensitivity were achieved for sulfite quantification.
• Mechanism studies confirmed the recognition of sulfite by the probe.

Conclusions:

• The developed probe provides a simple, selective, and sensitive method for sulfite detection.
• The probe functions as a "naked-eye" sensor, facilitating rapid visual assessment.
• This approach offers a promising tool for practical sulfite determination in various samples.