A Chemically Patterned Microfluidic Paper-based Analytical Device (C-µPAD) for Point-of-Care Diagnostics

Area of Science:

• Analytical Chemistry
• Materials Science
• Biotechnology

Background:

• Microfluidic paper-based analytical devices (µPADs) offer potential for low-cost diagnostics.
• Creating precise fluidic networks on paper remains a challenge for complex assays.

Purpose of the Study:

• To develop a chemically patterned microfluidic paper-based analytical device (C-µPAD) using chemical vapor deposition (CVD).
• To optimize CVD conditions for creating stable hydrophobic barriers and controlled fluidic networks on chromatography paper.
• To demonstrate the device's utility in various bioassays and environmental monitoring applications.

Main Methods:

• Hydrophobic barriers were fabricated on chromatography paper via CVD of trichlorosilane (TCS).
• Optimal patterning conditions (temperature, size, duration) were determined by analyzing hydrophobicity and fluid flow.
• Glucose assay, immunoassay (TNFα), and heavy metal (Ni) detection were performed on developed C-µPADs.

Main Results:

• Achieved a limit of detection (LOD) of 13 mg/dL for glucose assays, comparable to commercial sensors.
• Demonstrated an LOD of 3 ng/mL for tumor necrosis factor alpha (TNFα) detection.
• Successfully detected Ni down to 150 μg/L by immobilizing a colorimetric agent on functionalized C-µPADs.

Conclusions:

• The developed C-µPADs enable simple, rapid, and cost-effective bioassays and environmental monitoring.
• The technology provides practically relevant LODs with high expandability and adaptability for diverse analytical needs.
• Chemically patterned paper devices represent a promising platform for point-of-care diagnostics and field testing.