3D Multilayered paper- and thread/paper-based microfluidic devices for bioassays

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Materials Science

Background:

• Microfluidic paper-based analytical devices (μPADs) offer low-cost, portable platforms for diagnostics.
• 3D fabrication techniques enhance μPAD functionality and sample handling.
• Colorimetric assays provide visual and quantifiable detection methods.

Purpose of the Study:

• To fabricate and characterize novel 3D microfluidic paper-based analytical devices (3D-μPADs) and 3D microfluidic thread/paper-based analytical devices (3D-μTPADs).
• To evaluate the performance of these devices for the colorimetric detection of glucose and bovine serum albumin (BSA).
• To assess the accuracy of the developed platforms using artificial urine samples.

Main Methods:

• Fabrication of 3D-μPADs (three layers) and 3D-μTPADs (four layers) using wax printing, heat pressing, and single-sided tape.
• Colorimetric assays utilizing glucose oxidase (GOx) for glucose detection and tetrabromophenol blue for BSA detection.
• Quantitative analysis of color intensity (yellow for glucose, cyan for BSA) via scanning and correlation with analyte concentration.

Main Results:

• Saturation curves were generated for both glucose and BSA assays on all fabricated platforms.
• The glucose assay showed a correlation between yellow color intensity and glucose concentration.
• The BSA assay demonstrated a correlation between cyan color intensity and BSA concentration.
• Glucose detection in artificial urine samples showed good correlation (percent differences <10%) with theoretical concentrations.

Conclusions:

• The developed 3D-μPADs and 3D-μTPADs are effective platforms for sensitive and quantitative colorimetric bioassays.
• These novel devices offer potential for simplified and accessible point-of-care diagnostics.
• The 3D architecture enhances the utility of paper-based devices for complex bioanalysis.