An Instrument-free Detection of Antioxidant Activity Using Paper-based Analytical Devices Coated with Nanoceria.

Area of Science:

• Analytical Chemistry
• Materials Science
• Biochemistry

Background:

• Antioxidant activity assessment is crucial for food and health analysis.
• Traditional methods often require sophisticated instrumentation and are time-consuming.
• Development of rapid, portable, and instrument-free detection methods is needed.

Purpose of the Study:

• To develop a portable, distance-based detection paper device for instrument-free determination of antioxidant activity.
• To utilize a nanoceria assay for quantifying antioxidant levels in samples.
• To validate the device's performance against traditional antioxidant assays.

Main Methods:

• A thermometer-like paper device with nanoceria deposited on a detection channel was fabricated.
• Antioxidants in samples partially reduce Ce4+ to Ce3+ on nanoceria, forming colored complexes.
• The distance of color change on the channel, proportional to antioxidant activity, was measured with an integrated ruler.

Main Results:

• The paper device demonstrated a color change (yellow to brown) proportional to antioxidant activity.
• Performance was validated against traditional assays for 11 tea samples, showing good correlation (95% confidence level).
• The sensor exhibited high recovery, tolerance, and stability for 50 days at various temperatures.

Conclusions:

• The developed paper device offers a fast, simple, instrument-free, and portable method for high-throughput screening of antioxidant activity.
• This technology provides a cost-effective alternative for analyzing antioxidant content in real-world samples.
• The device shows significant potential for widespread application in food analysis and quality control.