Nitrogen-Doped Carbon Quantum Dots for Tannic Acid Analysis in Complex Food Matrices

Area of Science:

• Analytical Chemistry
• Materials Science
• Food Science

Background:

• Accurate detection of tannic acid (TA) in food is crucial for safety.
• Existing methods may lack sensitivity, speed, or cost-effectiveness.

Purpose of the Study:

• To develop a novel, sensitive, and cost-effective fluorescent sensor for tannic acid detection.
• To utilize nitrogen-doped carbon quantum dots (N-CDs) for this purpose.

Main Methods:

• Synthesized N-CDs via a one-pot hydrothermal reaction using L-malic acid, citric acid, and tris(2-aminoethyl) amine.
• Characterized N-CDs using TEM, AFM, XPS, FT-IR, and XRD.
• Developed a fluorescence quenching-based assay for TA detection.

Main Results:

• N-CDs exhibited uniform morphology and a nitrogen-rich surface.
• The sensor showed high selectivity for TA via fluorescence quenching.
• Achieved a linear detection range of 0.500–250 µM and a detection limit of 0.15 µM.
• Demonstrated practical applicability in beer, red wine, and apple juice with high recoveries (101–116%).

Conclusions:

• The N-CDs-based fluorescent sensor is simple, sensitive, and reliable for TA detection.
• This platform is a promising tool for routine tannic acid monitoring in food safety.
• The method offers accurate results comparable to HPLC-DAD validation.