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Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices

Integrated microfluidic devices with nanosized array electrodes and microfiltration capabilities can greatly increase sensitivity and enhance automation in immunoassay devices. In this contribution, we utilize the edge-patterning method of thin aluminum (Al) films in order to form nano- to micron-si...

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Autores principales: Doan, Nhi M., Qiang, Liangliang, Li, Zhe, Vaddiraju, Santhisagar, Bishop, Gregory W., Rusling, James F., Papadimitrakopoulos, Fotios
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4435220/
https://www.ncbi.nlm.nih.gov/pubmed/25774709
http://dx.doi.org/10.3390/s150306091
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author Doan, Nhi M.
Qiang, Liangliang
Li, Zhe
Vaddiraju, Santhisagar
Bishop, Gregory W.
Rusling, James F.
Papadimitrakopoulos, Fotios
author_facet Doan, Nhi M.
Qiang, Liangliang
Li, Zhe
Vaddiraju, Santhisagar
Bishop, Gregory W.
Rusling, James F.
Papadimitrakopoulos, Fotios
author_sort Doan, Nhi M.
collection PubMed
description Integrated microfluidic devices with nanosized array electrodes and microfiltration capabilities can greatly increase sensitivity and enhance automation in immunoassay devices. In this contribution, we utilize the edge-patterning method of thin aluminum (Al) films in order to form nano- to micron-sized gaps. Evaporation of high work-function metals (i.e., Au, Ag, etc.) on these gaps, followed by Al lift-off, enables the formation of electrical uniform nanowires from low-cost, plastic-based, photomasks. By replacing Al with chromium (Cr), the formation of high resolution, custom-made photomasks that are ideal for low-cost fabrication of a plurality of array devices were realized. To demonstrate the feasibility of such Cr photomasks, SU-8 micro-pillar masters were formed and replicated into PDMS to produce micron-sized filters with 3–4 µm gaps and an aspect ratio of 3. These microfilters were capable of retaining 6 µm beads within a localized site, while allowing solvent flow. The combination of nanowire arrays and micro-pillar filtration opens new perspectives for rapid R&D screening of various microfluidic-based immunoassay geometries, where analyte pre-concentration and highly sensitive, electrochemical detection can be readily co-localized.
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spelling pubmed-44352202015-05-19 Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices Doan, Nhi M. Qiang, Liangliang Li, Zhe Vaddiraju, Santhisagar Bishop, Gregory W. Rusling, James F. Papadimitrakopoulos, Fotios Sensors (Basel) Article Integrated microfluidic devices with nanosized array electrodes and microfiltration capabilities can greatly increase sensitivity and enhance automation in immunoassay devices. In this contribution, we utilize the edge-patterning method of thin aluminum (Al) films in order to form nano- to micron-sized gaps. Evaporation of high work-function metals (i.e., Au, Ag, etc.) on these gaps, followed by Al lift-off, enables the formation of electrical uniform nanowires from low-cost, plastic-based, photomasks. By replacing Al with chromium (Cr), the formation of high resolution, custom-made photomasks that are ideal for low-cost fabrication of a plurality of array devices were realized. To demonstrate the feasibility of such Cr photomasks, SU-8 micro-pillar masters were formed and replicated into PDMS to produce micron-sized filters with 3–4 µm gaps and an aspect ratio of 3. These microfilters were capable of retaining 6 µm beads within a localized site, while allowing solvent flow. The combination of nanowire arrays and micro-pillar filtration opens new perspectives for rapid R&D screening of various microfluidic-based immunoassay geometries, where analyte pre-concentration and highly sensitive, electrochemical detection can be readily co-localized. MDPI 2015-03-12 /pmc/articles/PMC4435220/ /pubmed/25774709 http://dx.doi.org/10.3390/s150306091 Text en © 2015 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Doan, Nhi M.
Qiang, Liangliang
Li, Zhe
Vaddiraju, Santhisagar
Bishop, Gregory W.
Rusling, James F.
Papadimitrakopoulos, Fotios
Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices
title Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices
title_full Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices
title_fullStr Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices
title_full_unstemmed Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices
title_short Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices
title_sort low-cost photolithographic fabrication of nanowires and microfilters for advanced bioassay devices
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4435220/
https://www.ncbi.nlm.nih.gov/pubmed/25774709
http://dx.doi.org/10.3390/s150306091
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