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From the first issue of 2016, Chromatography has changed its name to Separations.

Open AccessArticle
Chromatography 2015, 2(3), 436-451;

Poly(N-isopropylacrylamide) Hydrogels for Storage and Delivery of Reagents to Paper-Based Analytical Devices

Department of Chemistry and Biochemistry, California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, CA 93407, USA
Author to whom correspondence should be addressed.
Academic Editor: Carlos D. Garcia
Received: 4 May 2015 / Revised: 29 June 2015 / Accepted: 10 July 2015 / Published: 17 July 2015
(This article belongs to the Special Issue Microfluidic Paper-Based Analytical Devices)
Full-Text   |   PDF [2519 KB, uploaded 17 July 2015]   |  


The thermally responsive hydrogel N,N'-methylenebisacrylamide-cross-linked poly(N-isopropylacrylamide) (PNIPAM) was developed and evaluated as a reagent storage and delivery system for microfluidic paper-based analytical devices (microPADs). PNIPAM was shown to successfully deliver multiple solutions to microPADs in specific sequences or simultaneously in laminar-flow configuration and was found to be suitable for delivering four classes of reagents to the devices: Small molecules, enzymes, antibodies and DNA. PNIPAM was also able to successfully deliver a series of standard glucose solutions to microPADs equipped to perform a colorimetric glucose assay. The results of these tests were used to produce an external calibration curve, which in turn was used to determine the concentration of glucose in sample solutions. Finally, PNIPAM was used to store the enzyme horseradish peroxidase for 35 days under ambient conditions with no significant loss of activity. The combination of PNIPAM and microPADs may allow for more complex assays to be performed on paper-based devices, facilitate the preparation of external calibration curves in the field, and extend the shelf life of microPADs by stabilizing reagents in an easy-to-use format. View Full-Text
Keywords: paper; microfluidics; PNIPAM; microPAD paper; microfluidics; PNIPAM; microPAD

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Mitchell, H.T.; Schultz, S.A.; Costanzo, P.J.; Martinez, A.W. Poly(N-isopropylacrylamide) Hydrogels for Storage and Delivery of Reagents to Paper-Based Analytical Devices. Chromatography 2015, 2, 436-451.

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