Microfluidic Paper-Based Preconcentration and Retrieval for Rapid Ribonucleic Acid Biomarker Detection and...

Area of Science:

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

Background:

• Microfluidic paper-based analytical devices (μPADs) are crucial for point-of-care (POC) diagnostics.
• Paper's heterogeneity can limit the detection of low-abundance targets.
• On-site sample preconcentration is a viable strategy to overcome detection limits.

Purpose of the Study:

• To develop a 3D μPADs preconcentrator (3D-μP²).
• To enhance the limit of detection (LOD) of downstream assays.
• To demonstrate the device's application in sample concentration for POC diagnostics.

Main Methods:

• Development of a 3D-μP² device with stacked absorbent pads and an ion-selective membrane (PEDOT:PSS).
• Utilized electrokinetic trapping for sample preconcentration.
• Validated the device with a colorimetric assay for a single-stranded DNA target.

Main Results:

• Achieved up to 170-fold concentration of DNA targets in 80 seconds.
• Increased the LOD of the colorimetric assay by 3 orders of magnitude.
• Demonstrated a portable and cost-effective preconcentration method.

Conclusions:

• The 3D-μP² effectively increases sample concentration for improved assay sensitivity.
• This device offers a powerful solution for sample pretreatment in resource-limited POC settings.
• The technology has the potential to advance accessible diagnostics.