Sulfites detection by surface-enhanced Raman spectroscopy: A feasibility study.

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Food Science

Background:

• Wine production requires extensive chemical analysis for quality control.
• Quantification of total and free sulfur dioxide (SO₂) is crucial for wine production.
• Existing SO₂ detection methods often lack reproducibility and require extensive sample pre-treatment.

Purpose of the Study:

• To develop a novel, rapid, and pre-processing-free method for free SO₂ determination in wine.
• To explore the potential of Surface-Enhanced Raman Spectroscopy (SERS) for real-time wine analysis.
• To validate a new methodology using Density Functional Theory (DFT) calculations and chemometrics.

Main Methods:

• Utilized Surface-Enhanced Raman Spectroscopy (SERS) for direct free SO₂ detection in wine.
• Employed Density Functional Theory (DFT) calculations to identify key molecular vibrational modes.
• Integrated theoretical predictions with experimental data using chemometrics for real-time monitoring.

Main Results:

• Demonstrated a proof of concept for a SERS-based methodology for free SO₂ quantification.
• Identified active vibrational modes of molecules contributing to free SO₂ concentration.
• Achieved a simple and real-time free SO₂ monitoring system by combining SERS, DFT, and chemometrics.

Conclusions:

• SERS offers a promising, pre-processing-free alternative for free SO₂ determination in wine.
• The developed methodology, supported by DFT and chemometrics, enables real-time monitoring.
• This approach could lead to portable SERS modules for on-site wine analysis and quality control.