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Evaporation-Driven Micromixing in Sessile Droplets for Miniaturized Absorbance-Based Colorimetry
[Image: see text] We demonstrate the use of an evaporating, sessile droplet on a nonwetting substrate as a miniature micromixing device to conduct sample–dye reactions for absorbance-based colorimetry. The nonwetting substrate supports buoyancy-induced mixing inside the droplet for rapid completion...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical
Society
2019
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6941180/ https://www.ncbi.nlm.nih.gov/pubmed/31909320 http://dx.doi.org/10.1021/acsomega.9b02784 |
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author | Chandramohan, Aditya Chakraborty, Monojit Weibel, Justin A. Garimella, Suresh V. |
author_facet | Chandramohan, Aditya Chakraborty, Monojit Weibel, Justin A. Garimella, Suresh V. |
author_sort | Chandramohan, Aditya |
collection | PubMed |
description | [Image: see text] We demonstrate the use of an evaporating, sessile droplet on a nonwetting substrate as a miniature micromixing device to conduct sample–dye reactions for absorbance-based colorimetry. The nonwetting substrate supports buoyancy-induced mixing inside the droplet for rapid completion of the measurement. The Bradford assay is used as a proof of concept, where a protein-containing sample is reacted with a reagent dye to measure the protein concentration. Viability of absorbance measurement through the droplet is first established using droplets in which the reactants are mixed prior to their deposition onto the substrate. In a second set of experiments involving in situ mixing, the reagent is directly added to a sessile droplet of the protein-containing sample, allowing the reactants to mix while the absorbance is being measured. Interplay between buoyancy-induced mixing, protein–reagent reaction, and protein adsorption onto the substrate leads to a complex temporal absorbance measurement signal. Videos corresponding to the signal data show that each of these mechanisms dominates during different phases of droplet evolution, causing a signal pattern containing peaks and valleys having a strong monotonic trend with the protein concentration. Overall, the second absorbance peak at which the reaction nears completion is the most sensitive to sample concentration. Heating of the substrate is demonstrated to dramatically speed up the mixing process. These protein concentration measurements, obtained with a simpler system and low reactant volumes, demonstrate that this droplet micromixing concept is a viable alternative to microtiter plates for colorimetric applications. |
format | Online Article Text |
id | pubmed-6941180 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | American Chemical
Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-69411802020-01-06 Evaporation-Driven Micromixing in Sessile Droplets for Miniaturized Absorbance-Based Colorimetry Chandramohan, Aditya Chakraborty, Monojit Weibel, Justin A. Garimella, Suresh V. ACS Omega [Image: see text] We demonstrate the use of an evaporating, sessile droplet on a nonwetting substrate as a miniature micromixing device to conduct sample–dye reactions for absorbance-based colorimetry. The nonwetting substrate supports buoyancy-induced mixing inside the droplet for rapid completion of the measurement. The Bradford assay is used as a proof of concept, where a protein-containing sample is reacted with a reagent dye to measure the protein concentration. Viability of absorbance measurement through the droplet is first established using droplets in which the reactants are mixed prior to their deposition onto the substrate. In a second set of experiments involving in situ mixing, the reagent is directly added to a sessile droplet of the protein-containing sample, allowing the reactants to mix while the absorbance is being measured. Interplay between buoyancy-induced mixing, protein–reagent reaction, and protein adsorption onto the substrate leads to a complex temporal absorbance measurement signal. Videos corresponding to the signal data show that each of these mechanisms dominates during different phases of droplet evolution, causing a signal pattern containing peaks and valleys having a strong monotonic trend with the protein concentration. Overall, the second absorbance peak at which the reaction nears completion is the most sensitive to sample concentration. Heating of the substrate is demonstrated to dramatically speed up the mixing process. These protein concentration measurements, obtained with a simpler system and low reactant volumes, demonstrate that this droplet micromixing concept is a viable alternative to microtiter plates for colorimetric applications. American Chemical Society 2019-12-18 /pmc/articles/PMC6941180/ /pubmed/31909320 http://dx.doi.org/10.1021/acsomega.9b02784 Text en Copyright © 2019 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes. |
spellingShingle | Chandramohan, Aditya Chakraborty, Monojit Weibel, Justin A. Garimella, Suresh V. Evaporation-Driven Micromixing in Sessile Droplets for Miniaturized Absorbance-Based Colorimetry |
title | Evaporation-Driven
Micromixing in Sessile Droplets
for Miniaturized Absorbance-Based Colorimetry |
title_full | Evaporation-Driven
Micromixing in Sessile Droplets
for Miniaturized Absorbance-Based Colorimetry |
title_fullStr | Evaporation-Driven
Micromixing in Sessile Droplets
for Miniaturized Absorbance-Based Colorimetry |
title_full_unstemmed | Evaporation-Driven
Micromixing in Sessile Droplets
for Miniaturized Absorbance-Based Colorimetry |
title_short | Evaporation-Driven
Micromixing in Sessile Droplets
for Miniaturized Absorbance-Based Colorimetry |
title_sort | evaporation-driven
micromixing in sessile droplets
for miniaturized absorbance-based colorimetry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6941180/ https://www.ncbi.nlm.nih.gov/pubmed/31909320 http://dx.doi.org/10.1021/acsomega.9b02784 |
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