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

Anal Chem. 2022 Aug 2;94(30):10764-10772. doi: 10.1021/acs.analchem.2c01442. Epub 2022 Jul 20.

Abstract

Microfluidic paper-based analytical devices (μPADs) have attracted significant attention in the field of point-of-care (POC) diagnostics. However, the heterogeneous structure of the paper often impairs the limit of detection (LOD) for low-abundance targets when those targets are directly analyzed. One viable solution to bypass this limitation is to elevate the target concentration above the LOD on-site to reach a valid readout. Here, we developed a 3D μPADs preconcentrator (3D-μP2) to increase sample concentration by electrokinetic trapping and demonstrated its application in increasing the LOD of a downstream colorimetric assay. The three-dimensional (3D) structure of this device was composed of a loading pad, a vertical fluid path formed by stacked absorbent pads, and an ion-selective membrane of PEDOT:PSS. This novel design facilitates fast preconcentration, high capacity in sample processing, and easy target retrieval. The concentration of an exemplary target, a single-stranded DNA sequence, was increased up to 170-fold within 80 s. The LOD of the colorimetric assay to verify the DNA target was increased 3 orders of magnitude with a preconcentrated sample compared to the control. The device and its analysis equipment used in this study were all cheap and portable. Thus, the 3D-μP2 can be a powerful POC tool for sample pretreatment in resource-limited areas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers
  • Microfluidic Analytical Techniques*
  • Microfluidics*
  • Paper
  • RNA

Substances

  • Biomarkers
  • RNA