https://doi.org/10.1140/epje/s10189-021-00133-7
Regular Article – Soft Matter
Temperature profile characterization with fluorescence lifetime imaging microscopy in a thermophoretic chip
1
IBI-4:Biomacromolecular Systems and Processes, Forschungszentrum Jülich GmbH, D-52428, Jülich, Germany
2
Technische Universität Dresden Center for Molecular and Cellular Bioengineering, D-01062, Dresden, Germany
3
Neuroelectronics, Munich School of Bioengineering, Department of Electrical and Computer Engineering, Technical University of Munich, D-85748, Garching bei München, Germany
4
Chemistry Department-Physical Chemistry, University Cologne, D-50939, Cologne, Germany
Received:
29
June
2021
Accepted:
1
October
2021
Published online:
19
October
2021
This study introduces a thermophoretic lab-on-a-chip device to measure the Soret coefficient. We use resistive heating of a microwire on the chip to induce a temperature gradient, which is measured by fluorescence lifetime imaging microscopy (FLIM). To verify the functionality of the device, we used dyed polystyrene particles with a diameter of 25 nm. A confocal microscope is utilized to monitor the concentration profile of colloidal particles in the temperature field. Based on the measured temperature and concentration differences, we calculate the corresponding Soret coefficient. The same particles have been recently investigated with thermal diffusion forced Rayleigh scattering (TDFRS) and we find that the obtained Soret coefficients agree with literature results. This chip offers a simple way to study the thermophoretic behavior of biological systems in multicomponent buffer solutions quantitatively, which are difficult to study with optical methods solely relying on the refractive index contrast.
Supplementary Information The online version contains supplementary material available at https://doi.org/10.1140/epje/s10189-021-00133-7.
Copyright comment corrected publication 2021
© The Author(s) 2021. corrected publication 2021
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
