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Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets

Rapid biosensing requires fast mass transport of the analyte to the surface of the sensing element. To optimize analysis times, both mass transport in solution and the geometry and size of the sensing element need to be considered. Small dielectric spheres, tens of microns in diameter, can act as la...

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Detalles Bibliográficos
Autores principales: Wildgen, Sarah M., Dunn, Robert C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4384086/
https://www.ncbi.nlm.nih.gov/pubmed/25806835
http://dx.doi.org/10.3390/bios5010118
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author Wildgen, Sarah M.
Dunn, Robert C.
author_facet Wildgen, Sarah M.
Dunn, Robert C.
author_sort Wildgen, Sarah M.
collection PubMed
description Rapid biosensing requires fast mass transport of the analyte to the surface of the sensing element. To optimize analysis times, both mass transport in solution and the geometry and size of the sensing element need to be considered. Small dielectric spheres, tens of microns in diameter, can act as label-free biosensors using whispering gallery mode (WGM) resonances. WGM resonances are sensitive to the effective refractive index, which changes upon analyte binding to recognition sites on functionalized resonators. The spherical geometry and tens of microns diameter of these resonators provides an efficient target for sensing while their compact size enables detection in limited volumes. Here, we explore conditions leading to rapid analyte detection using WGM resonators as label-free sensors in 10 μL sample droplets. Droplet evaporation leads to potentially useful convective mixing, but also limits the time over which analysis can be completed. We show that active droplet mixing combined with initial binding rate measurements is required for accurate nanomolar protein quantification within the first minute following injection.
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spelling pubmed-43840862015-05-04 Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets Wildgen, Sarah M. Dunn, Robert C. Biosensors (Basel) Article Rapid biosensing requires fast mass transport of the analyte to the surface of the sensing element. To optimize analysis times, both mass transport in solution and the geometry and size of the sensing element need to be considered. Small dielectric spheres, tens of microns in diameter, can act as label-free biosensors using whispering gallery mode (WGM) resonances. WGM resonances are sensitive to the effective refractive index, which changes upon analyte binding to recognition sites on functionalized resonators. The spherical geometry and tens of microns diameter of these resonators provides an efficient target for sensing while their compact size enables detection in limited volumes. Here, we explore conditions leading to rapid analyte detection using WGM resonators as label-free sensors in 10 μL sample droplets. Droplet evaporation leads to potentially useful convective mixing, but also limits the time over which analysis can be completed. We show that active droplet mixing combined with initial binding rate measurements is required for accurate nanomolar protein quantification within the first minute following injection. MDPI 2015-03-23 /pmc/articles/PMC4384086/ /pubmed/25806835 http://dx.doi.org/10.3390/bios5010118 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
Wildgen, Sarah M.
Dunn, Robert C.
Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets
title Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets
title_full Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets
title_fullStr Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets
title_full_unstemmed Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets
title_short Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets
title_sort whispering gallery mode resonators for rapid label-free biosensing in small volume droplets
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4384086/
https://www.ncbi.nlm.nih.gov/pubmed/25806835
http://dx.doi.org/10.3390/bios5010118
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