Modification of microfluidic paper-based devices with silica nanoparticles

Area of Science:

• Analytical Chemistry
• Materials Science
• Biotechnology

Background:

• Microfluidic paper-based analytical devices (μPADs) offer low-cost, portable diagnostics.
• Colorimetric assays on μPADs can suffer from poor color uniformity due to enzyme washout.
• Improving enzyme immobilization is crucial for reliable μPAD performance.

Purpose of the Study:

• To develop silica nanoparticle-modified μPADs for enhanced enzymatic bioassays.
• To investigate the effect of silica nanoparticles on color intensity and uniformity.
• To assess the performance of modified μPADs for detecting clinically relevant analytes.

Main Methods:

• Fabrication of μPADs using filter paper and CO2 laser engraving.
• Modification of μPADs with 3-aminopropyltriethoxysilane-functionalized silica nanoparticles.
• Enzymatic reactions for lactate, glucose, and glutamate detection.
• Colorimetric analysis and limit of detection determination.

Main Results:

• Silica nanoparticle modification significantly improved color intensity and uniformity in enzymatic reactions.
• The modified μPADs achieved limits of detection of 0.63 mM (lactate), 0.50 mM (glucose), and 0.25 mM (glutamate).
• Successful semi-quantitative detection of analytes in artificial urine demonstrated practical applicability.

Conclusions:

• Silica nanoparticles effectively prevent enzyme washout in μPADs.
• The modified μPADs provide enhanced colorimetric signal and improved assay reliability.
• This approach holds significant potential for developing advanced paper-based diagnostic tools.