Determination of nitrite in saliva using microfluidic paper-based analytical devices

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Point-of-Care Diagnostics

Background:

• Point-of-care platforms offer rapid, cost-effective diagnostics, particularly microfluidic paper-based analytical devices (μPADs).
• Nitrite in saliva is a potential biomarker for periodontitis, necessitating accurate quantification methods.

Purpose of the Study:

• To develop and characterize μPADs for identifying and quantifying nitrite levels in saliva.
• To address limitations of traditional Griess reactions for improved color development and stability.

Main Methods:

• Fabrication of μPADs using wax printing.
• Colorimetric detection of nitrite via a modified Griess reaction.
• Design, characterization, and application of the developed devices.

Main Results:

• Optimized μPADs detect nitrite in the 10-1000 μmol L(-1) range.
• Achieved a limit of detection of 10 μmol L(-1) and sensitivity of 47.5 AU [log (μmol L(-1))](-1).
• Demonstrated successful application in analyzing real saliva samples across the clinical range.

Conclusions:

• The developed μPADs provide a stable, efficient, and accurate method for salivary nitrite quantification.
• This technology holds significant potential for point-of-care periodontitis screening and management.
• The modified Griess reaction on a paper platform enhances diagnostic capabilities.