[Study on Detection of Prohibited Pigments in Drinks Using Paper-Based SERS Substrates]

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Food safety regulations require accurate detection of synthetic pigments.
• Existing methods for pigment detection can be complex and time-consuming.
• Development of rapid, sensitive, and cost-effective analytical tools is crucial for food quality control.

Purpose of the Study:

• To develop a novel, low-cost paper-based Surface-Enhanced Raman Spectroscopy (SERS) substrate.
• To demonstrate the substrate's high sensitivity and uniformity for pigment detection.
• To validate the method for semi-quantitative analysis of pigments in food products.

Main Methods:

• Fabrication of a paper-based SERS substrate using a liquid/liquid interface self-assembly technique.
• Detection of three common food pigments (rhodamine B, sunset yellow, chrysoidine) using a portable Raman spectrometer.
• Investigation of pigment structures and assignment of characteristic vibrational modes.
• Analysis of pigment solutions and real food samples without pretreatment.

Main Results:

• The developed paper-based SERS substrate exhibited high sensitivity, good uniformity, and affordability.
• Successful detection and structural investigation of rhodamine B, sunset yellow, and chrysoidine.
• Established concentration-dependent Raman peak intensities, showing index curve and linear relationships for different pigments.
• Achieved high recovery rates for pigment detection in drinks, indicating suitability for semi-quantitative analysis.

Conclusions:

• The novel paper-based SERS substrate offers a sensitive, rapid, and cost-effective platform for pigment detection.
• This technique is well-suited for the semi-quantitative analysis of multiple pigments in beverages.
• The method holds significant potential for routine quality control and market surveillance of food and drink products.