Microscale electrokinetic‐based analysis of intact cells and viruses

Vaghef-Koodehi, Alaleh; Lapizco‐Encinas, Blanca H.

doi:10.1002/elps.202100254

Cited by 12 publications

(17 citation statements)

References 135 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This experimental observation is in agreement with the particle properties (Table 1), theory, and model predictions, which are listed in detail in Table S3 and plotted in Figure 2c. Since particle 1 (red) has a lower-magnitude negative ζ P , i.e., a lower-magnitude EP (1) force toward the inlet is exerted on the red particle (Figure 1b), which allows the red particle to have a higher overall velocity toward the outlet. The small difference in ζ P of 3.6 mV between the particles allows the red particle to migrate forward faster than the green particle, as illustrated in Figure 2a,b.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…In iEK systems under DC electric potentials, EO and EP (1) are the dominant linear EK mechanisms, while DEP and EP (3) are the main nonlinear phenomena. The expressions for the EO and EP (1) velocities are as follows:…”

Section: ■ Theory and Computational Modelmentioning

confidence: 99%

“…The E EEC parameter is needed for estimating μ EP (3) of particles. The particles employed in this study were characterized in terms of their EP mobilities (μ EP (1) and μ EP (3) ) and E EEC (Table 1). Equation 6 illustrates the expression for E EEC which is obtained by setting v P = 0 in eq 5, and eq 7 contains the expression for estimating μ EP (3) used in this study.…”

Section: ■ Theory and Computational Modelmentioning

confidence: 99%

“…In those studies, DEP was considered strong enough to balance other EK forces in the systems and generate particle trapping. 21 Recent studies 16−19 revealed that particle trapping in iEK systems, stimulated with direct current (DC) potentials, is mainly the result of a balance between electroosmotic (EO) flow and electrophoresis (linear EP (1) and nonlinear EP (3) ). DEP is still a force present in DC-iEK systems, but it is not dominant, representing less than 6% of the magnitude of EP (3) .…”

mentioning

confidence: 99%

“…10−15 This study pushes the limit of the discriminatory capabilities of iEK systems. By employing computational modeling with COMSOL Multiphysics, which properly considers EP (1) , EP (3) , EO flow, and DEP, it was possible to accurately predict the electrical potentials required for the charged-based separation of almost identical microparticles. The COMSOL model also predicted particle retention times (t R,p ) which were compared with experimental particle retention times (t R,e ), where deviations of −32% and 2%, were obtained.…”

mentioning

confidence: 99%

See 4 more Smart Citations

High-Resolution Charge-Based Electrokinetic Separation of Almost Identical Microparticles

2022

Self Cite

View full text Add to dashboard Cite

Well-established techniques, e.g., chromatography and capillary electrophoresis, are available for separating nanosized particles, such as proteins. However, similar techniques for separating micron-sized particles are still needed. Insulator-based electrokinetic (iEK) systems can achieve efficient microparticle separations by combining linear and nonlinear EK phenomena. Of particular interest are charge-based separations, which could be employed for separating similar microorganisms, such as bacterial cells of the same size, same genus, or same strain. Several groups have reported charge-based separations of microparticles where a zeta potential difference of at least 40 mV between the microparticles was required. The present work pushes the limit of the discriminatory capabilities of iEK systems by reporting the charged-based separation of two microparticles of the same size (5.1 μm), same shape, same substrate material, and with a small difference in particle zeta potentials of only 3.6 mV, which is less than 10% of the difference in previous studies. By building an accurate COMSOL Multiphysics model, which correctly accounts for dielectrophoresis and electrophoresis of the second kind, it was possible to identify the conditions to achieve this challenging separation. Furthermore, the COMSOL model allowed predicting particle retention times (t R,p) which were compared with experimental values (t R,e). The separations results had excellent reproducibility in terms of t R,e with variations of only 9% and 11% between repetitions. These findings demonstrate that, by following a robust protocol that involves modeling and experimental work, it is possible to discriminate between highly similar particles, with much smaller differences in electrical charge than previously reported.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Theory and Computational Modelmentioning

confidence: 99%

Section: ■ Theory and Computational Modelmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

High-Resolution Charge-Based Electrokinetic Separation of Almost Identical Microparticles

2022

Self Cite

View full text Add to dashboard Cite

show abstract

A correlation of conductivity medium and bioparticle viability on dielectrophoresis‐based biomedical applications

et al. 2023

View full text Add to dashboard Cite

Dielectrophoresis (DEP) bioparticle research has progressed from micro to nano levels. It has proven to be a promising and powerful cell manipulation method with an accurate, quick, inexpensive, and label-free technique for therapeutic purposes. DEP, an electrokinetic phenomenon, induces particle movement as a result of polarization effects in a nonuniform electrical field. This review focuses on current research in the biomedical field that demonstrates a practical approach to DEP in terms of cell separation, trapping, discrimination, and enrichment under the influence of the conductive medium in correlation with bioparticle viability. The current review aims to provide readers with an in-depth knowledge of the fundamental theory and principles of the DEP technique, which is influenced by conductive medium and to identify and demonstrate the biomedical application areas. The high conductivity of physiological fluids presents obstacles and opportunities, followed by bioparticle viability in an electric field elaborated in detail. Finally, the drawbacks of DEP-based systems

show abstract

Nonlinear electrophoresis of dielectric particles in Newtonian fluids

et al. 2022

View full text Add to dashboard Cite

In classical electrokinetics, the electrophoretic velocity of a dielectric particle is a linear function of the applied electric field. Theoretical studies have predicted the onset of nonlinear electrophoresis at high electric fields because of the nonuniform surface conduction over the curved particle. However, experimental studies have been left behind and are insufficient for a fundamental understanding of the parametric effects on nonlinear electrophoresis. We present in this work a systematic experimental study of the effects of buffer concentration, particle size, and particle zeta potential on the electrophoretic velocity of polystyrene particles in a straight rectangular microchannel for electric fields of up to 3 kV/cm. The measured nonlinear electrophoretic particle velocity is found to exhibit a 2(±0.5)-order dependence on the applied electric field, which appears to be within the theoretically predicted 3-and 3/2-order dependences for low and high electric fields, respectively. Moreover, the obtained nonlinear electrophoretic particle mobility increases with decreasing buffer concentration (for the same particle) and particle size (for particles with similar zeta potentials) or increasing particle zeta potential (for particles with similar sizes). These observations are all consistent with the theoretical predictions for high electric fields.

show abstract

Microscale electrokinetic‐based analysis of intact cells and viruses

Cited by 12 publications

References 135 publications

High-Resolution Charge-Based Electrokinetic Separation of Almost Identical Microparticles

High-Resolution Charge-Based Electrokinetic Separation of Almost Identical Microparticles

A correlation of conductivity medium and bioparticle viability on dielectrophoresis‐based biomedical applications

Nonlinear electrophoresis of dielectric particles in Newtonian fluids

Contact Info

Product

Resources

About