Sample pre-concentration with high enrichment factors at a fixed location in paper-based microfluidic devices

Shih Hao Yeh, Kuang Hua Chou, Ruey Jen Yang

Research output: Contribution to journalArticlepeer-review

52 Citations (Scopus)

Abstract

The lack of sensitivity is a major problem among microfluidic paper-based analytical devices (μPADs) for early disease detection and diagnosis. Accordingly, the present study presents a method for improving the enrichment factor of low-concentration biomarkers by using shallow paper-based channels realized through a double-sided wax-printing process. In addition, the enrichment factor is further enhanced by exploiting the ion concentration polarization (ICP) effect on the cathodic side of the nanoporous membrane, in which a stationary sample plug is obtained. The occurrence of ICP on the shallow-channel μPAD is confirmed by measuring the current-voltage response as the external voltage is increased from 0 to 210 V (or the field strength from 0 to 1.05 × 104 V m-1) over 600 s. In addition, to the best of our knowledge, the electroosmotic flow (EOF) speed on the μPAD fabricated with a wax-channel is measured for the first time using a current monitoring method. The experimental results show that for a fluorescein sample, the concentration factor is increased from 130-fold in a conventional full-thickness paper channel to 944-fold in the proposed shallow channel. Furthermore, for a fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) sample, the proposed shallow-channel μPAD achieves an 835-fold improvement in the concentration factor. The concentration technique presented here provides a novel strategy for enhancing the detection sensitivity of μPAD applications.

Original languageEnglish
Pages (from-to)925-931
Number of pages7
JournalLab on a Chip
Volume16
Issue number5
DOIs
Publication statusPublished - 2016

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Biochemistry
  • Chemistry(all)
  • Biomedical Engineering

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