Microfluidic paper-based analytical device for the determination of nitrite and nitrate

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Nitrite and nitrate are key water quality indicators.
• Accurate and accessible detection methods are crucial for environmental monitoring.

Purpose of the Study:

• To develop a low-cost, disposable colorimetric microfluidic paper-based analytical device (μPAD) for nitrite and nitrate determination.
• To enable user-friendly, on-site analysis of water samples.

Main Methods:

• Fabrication of μPADs using inkjet printing.
• Colorimetric determination of nitrite via Griess reaction.
• Reduction of nitrate to nitrite using immobilized zinc microparticles.
• Optimization of reaction conditions and validation of analytical performance.

Main Results:

• Achieved limits of detection (LOD) of 1.0 μM for nitrite and 19 μM for nitrate.
• Demonstrated high repeatability with relative standard deviation (RSD) < 2.9% for nitrite and < 5.6% for nitrate.
• Successfully applied the μPAD to analyze synthetic and natural water samples.

Conclusions:

• The developed μPAD is a cost-effective and efficient tool for on-site nitrite and nitrate monitoring.
• The device offers a user-friendly and environmentally sound approach for water quality assessment.
• This technology facilitates rapid and reliable analysis in diverse water matrices.