Rapid quantification of thiocyanate in milk samples using a universal paper-based SERS sensor

Area of Science:

• Analytical Chemistry
• Materials Science
• Biochemistry

Background:

• Sodium thiocyanate (NaSCN) is a natural antibacterial agent in milk.
• Excessive thiocyanate intake poses health risks.
• Existing detection methods for NaSCN lack sensitivity and are expensive.

Purpose of the Study:

• To develop a robust and cost-effective method for detecting NaSCN.
• To utilize surface-enhanced Raman spectroscopy (SERS) for sensitive NaSCN quantification.
• To enable reliable NaSCN analysis in milk samples.

Main Methods:

• Fabrication of a paper-based sensor with in situ reduced silver nanoparticles (AgNPs).
• Utilizing densely packed multilayer AgNPs to create uniform nanogaps for signal enhancement.
• Employing SERS for sensitive detection and quantification of NaSCN.

Main Results:

• Achieved a high sensitivity with a limit of detection of 10^-12 mol L^-1.
• Demonstrated a wide linear detection range from 10^-9 mol L^-1 to 10^-4 mol L^-1.
• Exhibited excellent reproducibility (coefficient of variation of 6.5%) and high recovery rates (95.1%-108.0%) in spiked milk samples.

Conclusions:

• The developed paper-based SERS sensor is a sensitive and cost-effective tool for NaSCN detection.
• This method shows great potential for routine milk analysis and health risk assessment.
• The robust design ensures reliable and reproducible results for thiocyanate quantification.