Review
Biochemical Research Methods
Blanca H. Lapizco-Encinas
Summary: This review article discusses the evolution of insulator-based dielectrophoresis (iDEP) and insulator-based electrokinetic (iEK) systems, highlighting recent studies that suggest particle trapping in these systems is mainly due to a balance between electroosmotic and electrophoretic effects under DC and low-frequency AC potentials, rather than dielectrophoresis. The proposed renaming of the field from DC-iDEP to DC-iEK reflects the shift in understanding particle manipulation and separation mechanisms in these systems.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Review
Biochemical Research Methods
Jared P. Smithers, Mark A. Hayes
Summary: The development of microfluidic manipulations has led to significant advances in the processing and detection of small volume samples. Effective isolation of single cells and manipulation of complex biomolecule mixtures allows for the utilization of information-rich detection methods. Delivering sub-nanoliter volumes of samples to a detection scheme has been achieved through spraying, meniscus-defined volumes, constrained volumes, and phase changes. This review presents selected publications highlighting the advancements and historical perspectives of these delivery techniques.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Review
Biochemical Research Methods
Cinthia J. Ramirez-Murillo, J. Martin de los Santos-Ramirez, Victor H. Perez-Gonzalez
Summary: Dielectrophoretically driven microfluidic devices have various applications in biomedical engineering, diagnostic medicine, and biological research, with a potential field being point-of-care devices. Two main approaches for inducing dielectrophoresis on suspended particles are electrode-based and insulator-based DEP, each with its own advantages and disadvantages. Input voltage plays a crucial role in determining the portability of microfluidic devices utilizing DEP.
Review
Biochemical Research Methods
Adrian Lomeli-Martin, Nuzhet Ahamed, Vinay V. V. Abhyankar, Blanca H. H. Lapizco-Encinas
Summary: This review provides an overview of the progress in electropatterning research during the last 5 years in the microfluidics arena. It discusses the advances in electropatterning of colloids, droplets, synthetic particles, cells, and gels using electrokinetic techniques such as electrophoresis and dielectrophoresis. The conclusions summarize recent advances and provide an outlook on the future of electropatterning in various fields of application, especially those with 3D arrangements as their end goal.
Article
Chemistry, Analytical
Md Nazibul Islam, Nicholas Mavrogiannis, Zachary Gagnon
Summary: Using fluidic dielectrophoresis, the motion of a polarizable liquid-liquid interface can be used to quantify reaction rate kinetics in solution. By controlling the electric field and frequency, the direction and magnitude of interface displacement can provide information about the binding dynamics. The measurement of the crossover frequency allows for quantitative analysis of the binding kinetics.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Chemistry, Analytical
Jose Eladio Flores-Mena, Pablo Garcia-Sanchez, Antonio Ramos
Summary: In this study, we investigate the scattering of metal colloids by an insulating circular post under the influence of an alternating current (AC) electric field. We analyze the effects of electrical forces such as induced dipole-repulsion, induced-charge electroosmotic (ICEO) flow, and dielectrophoresis on the particles. The relative influence of these forces is examined in relation to the frequency of the AC field, particle size, and distance to the post. Numerical simulations are performed to model the scattering of metal colloids in a microchannel with an insulating circular post under alternating current electric fields. The simulation results show that the maximum particle deviation occurs when the applied electric field is parallel to the flow direction, and this deviation is more significant at low electric field frequencies where the ICEO interaction dominates over other mechanisms.
Review
Chemistry, Analytical
Blanca H. Lapizco-Encinas
Summary: This review article discusses the latest advancements in microscale electrokinetics for the analysis of cells and subcellular materials in clinical applications. It covers the potential of electrokinetic-based methods in liquid biopsies, circulating tumor cells, blood components, stem cells, and subcellular particles. The conclusions summarize the main advancements and future prospects in this field.
Review
Biochemical Research Methods
Fabian O. Romero-Soto, Maria Polanco-Oliva, Roberto C. Gallo-Villanueva, Sergio O. Martinez-Chapa, Victor H. Perez-Gonzalez
Summary: Cancer is a leading cause of global deaths, with metastasis being the main cause of patient mortality. The scientific community is focused on early cancer detection and prevention of metastatic tumors.
Review
Biochemical Research Methods
Victor H. Perez-Gonzalez
Summary: Electrokinetically driven insulator-based microfluidic devices offer a way to manipulate particle suspensions, with the concept of insulator-based dielectrophoresis (iDEP) being developed two decades ago. Recent studies challenge the assumption that dielectrophoresis (DEP) is solely responsible for particle trapping in these devices.
Article
Chemistry, Analytical
Josie L. Duncan, Mathew Bloomfield, Nathan Swami, Daniela Cimini, Rafael V. Davalos
Summary: Aneuploidy is common in cancer, and tetraploidy often occurs during the evolution of aneuploid tumors. High-frequency DEP can distinguish cell subpopulations based on their ploidy and nuclear size, providing insight into their roles in cancer progression.
Article
Chemistry, Analytical
Abbi Miller, Nicole Hill, Kel Hakim, Blanca H. Lapizco-Encinas
Summary: The study focused on developing optimized EK sample injection schemes for direct current insulator-based EK systems, utilizing mathematical modeling and experimental methods to investigate sample injection schemes considering nonlinear electrokinetic effects.
Article
Chemistry, Analytical
Fang Yang, Wei Zhao, Cuifang Kuang, Guiren Wang
Summary: In this study, a quasi T-channel electrokinetics-based micromixer with electrically conductive sidewalls was investigated. It was found that this micromixer configuration achieved faster mixing compared to another widely studied micromixer configuration. The effects of Re numbers, applied AC voltage and frequency, and conductivity ratio of the two fluids on mixing results were explored. The study of this micromixer could provide new insights into electrokinetic phenomena and offer new tools for sample preparation in applications requiring fast mixing.
Article
Chemistry, Analytical
Taekeon Jung, Young-Ran Yun, Jaehyun Bae, Sung Yang
Summary: By integrating magnetic particle conjugation for bacteria concentration and separation, a new impedimetric bacteria-detection sensor has been developed for rapid and accurate detection of low bacteria concentrations in food samples.
ANALYTICA CHIMICA ACTA
(2021)
Article
Chemistry, Analytical
Qiang Zhao, Yunjiao Wang, Bangyong Sun, Deqiang Wang, Gang Li
Summary: This research presents a dielectrophoretic manipulation technique based on nanogap electrodes, which allows for the capture, enrichment, and sorting of nanometer-sized objects in liquids. The technique shows potential applications in micro/nanofluidics and provides an alternative method for the non-invasive manipulation and characterization of nanoparticles such as DNA, proteins, and viruses.
Article
Chemistry, Analytical
Maria Dimaki, Mark Holm Olsen, Noemi Rozlosnik, Winnie E. Svendsen
Summary: This paper introduces a novel microfluidic chip that utilizes electrical forces generated by a DC or AC field to achieve upconcentration of sub-100 nm nanoparticles in a flow. Two optimized electrode designs were tested using particles as small as 47 nm, and inclined electrodes with a zig-zag three-tooth configuration in a 20 μm width channel were found to generate the highest gradient and force. The chip design based on AC dielectrophoresis successfully upconcentrated sub-100 nm particles by a factor of 11 using a flow rate of 2-25 μL/h. The paper presents theoretical and experimental results, and discusses the potential for massively parallelizing the chip design to significantly increase throughput.
Article
Biochemical Research Methods
Grant Korensky, Xinye Chen, Mengdi Bao, Abbi Miller, Blanca Lapizco-Encinas, Myeongkee Park, Ke Du
Summary: A planar, transparent, and adaptable nanosieve device has been developed for efficient separation of microalgae and bacteria. This device can trap almost all microalgae cells while allowing bacteria cells to pass through, and is capable of single-cell auto-fluorescence tracking. It is a valuable method for purifying microalgae samples containing contaminations and studying single-cell heterogeneity.
Editorial Material
Biochemical Research Methods
Blanca H. Lapizco-Encinas
Review
Chemistry, Analytical
Blanca H. Lapizco-Encinas
Summary: This review article discusses the latest advancements in microscale electrokinetics for the analysis of cells and subcellular materials in clinical applications. It covers the potential of electrokinetic-based methods in liquid biopsies, circulating tumor cells, blood components, stem cells, and subcellular particles. The conclusions summarize the main advancements and future prospects in this field.
Review
Biochemical Research Methods
Blanca H. Lapizco-Encinas
Summary: This review article discusses the evolution of insulator-based dielectrophoresis (iDEP) and insulator-based electrokinetic (iEK) systems, highlighting recent studies that suggest particle trapping in these systems is mainly due to a balance between electroosmotic and electrophoretic effects under DC and low-frequency AC potentials, rather than dielectrophoresis. The proposed renaming of the field from DC-iDEP to DC-iEK reflects the shift in understanding particle manipulation and separation mechanisms in these systems.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Review
Biochemical Research Methods
Alaleh Vaghef-Koodehi, Blanca H. Lapizco-Encinas
Summary: This article summarizes three types of electrokinetic-based methodologies, discusses the fundamentals of each method, examines relevant examples from recent reports, and provides an overview of the latest advancements in using microscale electrokinetic techniques for analyzing intact cells and viruses.
Article
Chemistry, Analytical
Alaleh Vaghef-Koodehi, Curran Dillis, Blanca H. Lapizco-Encinas
Summary: This study reports a charge-based microparticle separation technique that can achieve separation even with a small difference in particle zeta potentials of only 3.6 mV (less than 10% of the difference in previous studies). By building an accurate COMSOL Multiphysics model and experimental verification, the feasibility and reproducibility of highly similar microparticle separation were demonstrated.
ANALYTICAL CHEMISTRY
(2022)
Review
Biochemical Research Methods
Blanca H. Lapizco-Encinas, Yan Victoria Zhang
Summary: The use of microfluidic devices in biomedical and clinical assessments has great potential. This review article discusses the applications of these devices in three main fields and provides an overview of the novel systems and microdevices developed in the last 5 years.
Article
Chemistry, Analytical
Alaleh Vaghef-Koodehi, Olivia D. Ernst, Blanca H. Lapizco-Encinas
Summary: This paper presents the first continuous separation of microparticles and cells with similar characteristics using linear and nonlinear electrokinetic phenomena in an insulator-based electrokinetic (iEK) system. By combining mathematical modeling and experimentation, four distinct binary mixtures of particles and cells were successfully separated. The results demonstrate good reproducibility and illustrate the potential of the iEK system for efficient separation.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Olivia D. Ernst, Alaleh Vaghef-Koodehi, Curran Dillis, Adrian Lomeli-Martin, Blanca H. Lapizco-Encinas
Summary: This study experimentally assessed the relationship between the nonlinear electrophoretic migration of colloidal polystyrene microparticles and their size and electrical charge. The results showed that both particle size and charge had similar effects on the nonlinear electrophoretic velocity, with an increase in size or decrease in charge leading to an increase in velocity. However, the trends were not perfect. These findings provide valuable information for the design of future separations based on size and charge.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Nuzhet Nihaar Nasir Ahamed, Carlos A. Mendiola-Escobedo, Olivia D. Ernst, Victor H. Perez-Gonzalez, Blanca H. Lapizco-Encinas
Summary: This study demonstrates that electrokinetic phenomena can be used to develop rapid and reliable methods for microparticle and cell assessments in a cost-effective and label-free manner. By using direct current (DC)-biased low-frequency alternating current (AC) voltages in an insulator-based electrokinetic (iEK) system, microparticles with a small difference in zeta potentials can be effectively separated.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Adrian Lomeli-Martin, Olivia D. Ernst, Braulio Cardenas-Benitez, Richard Cobos, Aditya S. Khai, Blanca H. Lapizco-Encinas
Summary: Recent findings suggest that in insulator-based electrokinetics under direct current fields, dielectrophoresis is not the main mechanism responsible for particle manipulation. Instead, the combined effects of electroosmosis, linear and nonlinear electrophoresis play a more significant role. A new methodology has been developed to estimate the nonlinear electrophoretic mobility of colloidal particles, but it is limited to particles with specific properties. This study aims to expand on this methodology and investigate the properties of particles with different characteristics, as well as identify current limitations in experimental determination of nonlinear electrophoresis.
ANALYTICAL CHEMISTRY
(2023)
Review
Biochemical Research Methods
Adrian Lomeli-Martin, Nuzhet Ahamed, Vinay V. V. Abhyankar, Blanca H. H. Lapizco-Encinas
Summary: This review provides an overview of the progress in electropatterning research during the last 5 years in the microfluidics arena. It discusses the advances in electropatterning of colloids, droplets, synthetic particles, cells, and gels using electrokinetic techniques such as electrophoresis and dielectrophoresis. The conclusions summarize recent advances and provide an outlook on the future of electropatterning in various fields of application, especially those with 3D arrangements as their end goal.
Review
Biochemical Research Methods
Finja Krebs, Holger Zagst, Matthias Stein, Ratih Ratih, Robert Minkner, Mais Olabi, Sophie Hartung, Christin Scheller, Blanca H. Lapizco-Encinas, Cari Sanger-van de Griend, Carlos D. Garcia, Hermann Waetzig
Summary: This article supports the development of selective, precise, fast, and validated capillary electrophoresis (CE) methods. It follows a similar article from 1998 and highlights the continuing relevance of its fundamentals while showcasing the significant achievements made in the last 25 years. With a focus on pharmaceutical and biological applications, the successful use of CE is demonstrated through over 600 carefully selected references, providing a comprehensive overview of the field. The article also includes sections on sample pretreatment, microchip CE, and a revised section on method development for protein analytes and biomolecules.
Review
Chemistry, Analytical
Blanca H. Lapizco-Encinas, Y. Victoria Zhang, Putuma P. Gqamana, Jana Lavicka, Frantisek Foret
Summary: Capillary electrophoresis (CE) is a powerful separation technique that offers high resolution, great sensitivity, and short processing times. When combined with mass spectrometry (MS), CE-MS systems provide accurate characterization of ionized species and significantly enhance the capabilities of MS. This review article introduces the analytical potential of CE-MS systems and discusses recent advances and future developments.
TRAC-TRENDS IN ANALYTICAL CHEMISTRY
(2023)
