Publications by authors named "Miguel Solsona"

4 Publications

  • Page 1 of 1

Positional dependence of particles and cells in microfluidic electrical impedance flow cytometry: origin, challenges and opportunities.

Lab Chip 2020 10 11;20(20):3665-3689. Epub 2020 Sep 11.

FEMTO-ST Institute, CNRS, Univ. Bourgogne Franche-Comté, AS2M Department, 24 rue Alain Savary, F-25000 Besançon, France.

Microfluidic electrical impedance flow cytometry is now a well-known and established method for single-cell analysis. Given the richness of the information provided by impedance measurements, this non-invasive and label-free approach can be used in a wide field of applications ranging from simple cell counting to disease diagnostics. One of its major limitations is the variation of the impedance signal with the position of the cell in the sensing area. Indeed, identical particles traveling along different trajectories do not result in the same data. The positional dependence can be considered as a challenge for the accuracy of microfluidic impedance cytometers. On the other hand, it has recently been regarded by several groups as an opportunity to estimate the position of particles in the microchannel and thus take a further step in the logic of integrating sensors in so-called "Lab-on-a-chip" devices. This review provides a comprehensive overview of the physical grounds of the positional dependence of impedance measurements. Then, both the developed strategies to reduce position influence in impedance-based assays and the recent reported technologies exploiting that dependence for the integration of position detection in microfluidic devices are reviewed.
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http://dx.doi.org/10.1039/d0lc00616eDOI Listing
October 2020

Ion Concentration Polarization for Microparticle Mesoporosity Differentiation.

Langmuir 2019 Jul 16;35(30):9704-9712. Epub 2019 Jul 16.

BIOS-Lab on a chip group, MESA+ Institute for Nanotechnology , Max Planck-University of Twente Center for Complex Fluid Dynamics University of Twente , Drienerlolaan 5 , Enschede , The Netherlands.

Microparticle porosity is normally determined in bulk manner providing an ensemble average that hinders establishing the individual role of each microparticle. On the other hand, single particle characterization implies expensive technology. We propose to use ion concentration polarization to measure differences in mesoporosity at the single particle level. Ion concentration polarization occurs at the interface between an electrolyte and a porous particle when an electric field is applied. The extent of ion concentration polarization depends, among others, on the mesopore size and density. By using a fluorescence marker, we could measure differences in concentration polarization between particles with 3 and 13 nm average mesopore diameters. A qualitative model was developed in order to understand and interpret the phenomena. We believe that this inexpensive method could be used to measure differences in mesoporous particle materials such as catalysts.
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http://dx.doi.org/10.1021/acs.langmuir.9b00802DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6671885PMC
July 2019

Gradient in the electric field for particle position detection in microfluidic channels.

Lab Chip 2019 03;19(6):1054-1059

BIOS Lab on a Chip Group, MESA+ Institute for Nanotechnology, University of Twente, Drienerlolaan 5, Enschede, The Netherlands.

In this work, a new method to track particles in microfluidic channels is presented. Particle position tracking in microfluidic systems is crucial to characterize sorting systems or to improve the analysis of cells in impedance flow cytometry studies. By developing an electric field gradient in a two parallel electrode array the position of the particles can be tracked in one axis by impedance analysis. This method can track the particle's position at lower frequencies and measure the conductivity of the system at higher frequencies. A 3-D simulation was performed showing particle position detection and conductivity analysis. To experimentally validate the technique, a microfluidic chip that develops a gradient in the electric field was fabricated and used to detect the position of polystyrene particles in one axis and measure their conductivity at low and high frequencies, respectively.
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http://dx.doi.org/10.1039/c8lc01333kDOI Listing
March 2019

Magnetophoretic Sorting of Single Catalyst Particles.

Angew Chem Int Ed Engl 2018 Aug 13;57(33):10589-10594. Epub 2018 Jul 13.

BIOS lab on a chip group, MESA+ Institute for Nanotechnology, University of Twente, Drienerlolaan 5, Enschede, The Netherlands.

A better understanding of the deactivation processes taking place within solid catalysts is vital to design better ones. However, since inter-particle heterogeneities are more a rule than an exception, particle sorting is crucial to analyse single catalyst particles in detail. Microfluidics offers new possibilities to sort catalysts at the single particle level. Herein, we report a first-of-its-kind 3D printed magnetophoretic chip able to sort catalyst particles by their magnetic moment. Fluid catalytic cracking (FCC) particles were separated based on their Fe content. Magnetophoretic sorting shows that large Fe aggregates exist within 20 % of the FCC particles with the highest Fe content. The availability of Brønsted acid sites decreases with increasing Fe content. This work paves the way towards a high-throughput catalyst diagnostics platform to determine why specific catalyst particles perform better than others.
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http://dx.doi.org/10.1002/anie.201804942DOI Listing
August 2018
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