Developing cysteamine-modified SERS substrate for detection of acidic pigment with weak surface affinity

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Acidic pigments often exhibit weak affinity with gold nanoparticles (Au NPs), complicating their detection.
• Sensitive and reproducible detection methods are crucial for ensuring food safety and quality.

Purpose of the Study:

• To develop a cysteamine-modified SERS substrate for enhanced detection of trace acidic pigments.
• To investigate the interaction mechanisms enabling sensitive pigment detection.

Main Methods:

• Preparation of a SERS substrate by modifying Au NPs with cysteamine (CA).
• Utilizing multi-hydrogen-bond and electrostatic interactions for pigment adsorption.
• Employing SERS spectroscopy for pigment quantification.

Main Results:

• The cysteamine-modified SERS substrate achieved sensitive detection of five acidic pigments down to 1.0 ppm.
• The method demonstrated high reproducibility and good universality across different pigment types.
• The substrate enabled reliable and accurate detection of trace pigments in real samples.

Conclusions:

• The developed cysteamine-modified SERS substrate offers a simple, reproducible, and versatile platform for trace acidic pigment detection.
• This method meets stringent safety limits and shows promise for practical applications in food safety monitoring.