Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs)
Microfluidic paper-based analytical devices (microPADs) have emerged as a promising platform for point-of-care diagnostic devices. While the inherent wicking properties of microPADs allow for fluid flow without supporting equipment, this also presents a major challenge in achieving robust fluid cont...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-03-01
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| Series: | Inventions |
| Subjects: | |
| Online Access: | http://www.mdpi.com/2411-5134/4/1/20 |
| _version_ | 1818299828082311168 |
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| author | E. Brandon Strong Carsten Knutsen Jay T. Wells Aditya R. Jangid Megan L. Mitchell Nathaniel W. Martinez Andres W. Martinez |
| author_facet | E. Brandon Strong Carsten Knutsen Jay T. Wells Aditya R. Jangid Megan L. Mitchell Nathaniel W. Martinez Andres W. Martinez |
| author_sort | E. Brandon Strong |
| collection | DOAJ |
| description | Microfluidic paper-based analytical devices (microPADs) have emerged as a promising platform for point-of-care diagnostic devices. While the inherent wicking properties of microPADs allow for fluid flow without supporting equipment, this also presents a major challenge in achieving robust fluid control, which becomes especially important when performing complex multi-step assays. Herein, we describe an ideal method of fluid control mediated by wax-printed fluidic time delays. This method relies on a simple fabrication technique, does not utilize chemicals/reagents that could affect downstream assays, is readily scalable, and has a wide temporal range of tunable fluid control. The delays are wax printed on both the top and bottom of pre-fabricated microPAD channels, without subsequent heating, to create hemi-/fully-enclosed channels. With these wax printed delays, we were able to tune the time it took aqueous solutions to wick across a 25 mm-long channel between 3.6 min and 13.4 min. We then employed these fluid delays in the sequential delivery of four dyes to a test zone. Additionally, we demonstrated the automation of two simple enzymatic assays with this fluid control modality. This method of fluid control may allow future researchers to automate more complex assays, thereby further advancing microPADs toward real-world applications. |
| first_indexed | 2024-12-13T04:57:25Z |
| format | Article |
| id | doaj.art-e7dd98a5c64b42048b2dd2902e06606e |
| institution | Directory Open Access Journal |
| issn | 2411-5134 |
| language | English |
| last_indexed | 2024-12-13T04:57:25Z |
| publishDate | 2019-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Inventions |
| spelling | doaj.art-e7dd98a5c64b42048b2dd2902e06606e2022-12-21T23:58:52ZengMDPI AGInventions2411-51342019-03-01412010.3390/inventions4010020inventions4010020Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs)E. Brandon Strong0Carsten Knutsen1Jay T. Wells2Aditya R. Jangid3Megan L. Mitchell4Nathaniel W. Martinez5Andres W. Martinez6Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USADepartment of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USADepartment of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USADepartment of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USADepartment of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USADepartment of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USADepartment of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407, USAMicrofluidic paper-based analytical devices (microPADs) have emerged as a promising platform for point-of-care diagnostic devices. While the inherent wicking properties of microPADs allow for fluid flow without supporting equipment, this also presents a major challenge in achieving robust fluid control, which becomes especially important when performing complex multi-step assays. Herein, we describe an ideal method of fluid control mediated by wax-printed fluidic time delays. This method relies on a simple fabrication technique, does not utilize chemicals/reagents that could affect downstream assays, is readily scalable, and has a wide temporal range of tunable fluid control. The delays are wax printed on both the top and bottom of pre-fabricated microPAD channels, without subsequent heating, to create hemi-/fully-enclosed channels. With these wax printed delays, we were able to tune the time it took aqueous solutions to wick across a 25 mm-long channel between 3.6 min and 13.4 min. We then employed these fluid delays in the sequential delivery of four dyes to a test zone. Additionally, we demonstrated the automation of two simple enzymatic assays with this fluid control modality. This method of fluid control may allow future researchers to automate more complex assays, thereby further advancing microPADs toward real-world applications.http://www.mdpi.com/2411-5134/4/1/20microfluidic paper-based analytical devicesmicroPADsµPADswax printingmulti-step assaysfluid control |
| spellingShingle | E. Brandon Strong Carsten Knutsen Jay T. Wells Aditya R. Jangid Megan L. Mitchell Nathaniel W. Martinez Andres W. Martinez Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs) Inventions microfluidic paper-based analytical devices microPADs µPADs wax printing multi-step assays fluid control |
| title | Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs) |
| title_full | Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs) |
| title_fullStr | Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs) |
| title_full_unstemmed | Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs) |
| title_short | Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs) |
| title_sort | wax printed fluidic time delays for automating multi step assays in paper based microfluidic devices micropads |
| topic | microfluidic paper-based analytical devices microPADs µPADs wax printing multi-step assays fluid control |
| url | http://www.mdpi.com/2411-5134/4/1/20 |
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