Cellulose-based paper is a versatile material with a diverse array of applications. While paper is not commonly thought of as a material that shrinks, here we present a method for miniaturizing paper via periodate oxidation. Chromatography paper was exposed to varying concentrations of periodate (0.1–0.5 M) over a 96-h period. Following optimization of miniaturization parameters, fourteen different types of paper were miniaturized and reductions in surface area ranging from 60 to 80% were observed. All cellulose paper types, but not cellulose-derivatives, displayed successful miniaturization. Results were highly tunable dependent upon periodate concentration and reaction time. Potential applications of the technique are discussed, including its use as a microfabrication method.
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Fabrication of Miniaturized Paper-Based Microfluidic Devices (MicroPADs)
Microfluidic paper-based analytical devices (microPADs) are emerging as cost-effective and portable platforms for point-of-care assays. A fundamental limitation of microPAD fabrication is the imprecise nature of most methods for patterning paper. The present work demonstrates that paper patterned via wax printing can be miniaturized by treating it with periodate to produce higher-resolution, high-fidelity microPADs. The optimal miniaturization parameters were determined by immersing microPADs in various concentrations of aqueous sodium periodate (NaIO4) for varying lengths of time. This treatment miniaturized microPADs by up to 80% in surface area, depending on the concentration of periodate and length of the reaction time. By immersing microPADs in 0.5-M NaIO4for 48 hours, devices were miniaturized by 78% in surface area, and this treatment allowed for the fabrication of functional channels with widths as small as 301 µm and hydrophobic barriers with widths as small as 387 µm. The miniaturized devices were shown to be compatible with redox-based colorimetric assays and enzymatic reactions. This miniaturization technique provides a new option for fabricating sub-millimeter-sized features in paper-based fluidic devices without requiring specialized equipment and could enable new capabilities and applications for microPADs.
more » « less- Award ID(s):
- 1709740
- PAR ID:
- 10153592
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Scientific Reports
- Volume:
- 9
- Issue:
- 1
- ISSN:
- 2045-2322
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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