ELECTROPHORESIS最新文献

This study investigates dynamic electrohydrodynamic (EHD) interactions between two identical colloidal microspheres in rotating electric fields using a fully coupled three-dimensional transient model. Long-range dielectrophoretic (DEP) attraction drives radial convergence; upon near-contact, tangential EHD sliding further induces asynchronous co-field orbital revolution. Crucially, individual electrorotation (ER) not only retains its original direction but also maintains a stable rate—with the rate deviating by <5% from that of isolated particles, matching single-particle behavior. High-frequency DEP force polarity reversal establishes stable noncontact equilibria via short-range repulsion. Spectral analyses reveal collective dynamics (radial mobility, orbital motion) stem from rotating electric field-mediated gap modulation rather than altered particle polarization. This dynamic decoupling—governed by the Kramers–Kronig relationship between real (radial DEP) and imaginary (rotational ER) components of polarizability—enables independent positional and rotational control, opening new avenues for noncontact colloidal manipulation in microfluidic mixers and dynamically reconfigurable active matter systems, where conventional DEP-based approaches are limited by coupled dynamics.

High-performance capillary electrophoresis (CE) has been widely applied in the analysis of organic acids, especially monocarboxylic acids (MAs), but no studies on the CE analysis of dissociated states of MAs have been reported. Here, 15 MAs were analyzed by the newly developed universal interface-induced current detector (IICRD). Two current signal peaks were observed in current electrophoretograms (CR-EGs), whereas only one peak with low sensitivity can be obtained by diode array detector (DAD). The current signal peaks of MAs were accurately identified by adding a charge-neutral marker and calculating by pK_a. The qualitative analysis indicated that the two current signal peaks of MAs were charge-neutral forms [MA^±] and monovalent anions [MA⁻] in order. Quantitative analysis showed that CE-IICRD can enhance the sensitivity of MA analytes to 40 µM in limit of detection (LOD), with a linear range from 10⁻⁶ to 10⁻² M. Furthermore, interactions between different dissociated states of MAs and monocarboxylate transporter 1 (MCT1) were studied by combined application of nonimmobilized cell CE (NICCE) method for the first time. The binding kinetic parameters and mole number of MCT1 on cell membranes can also be obtained. Besides, competitive binding experiments proved that BAY-8002 (MCT1-specific inhibitor) and lactic acid shared the same binding site. CE-IICRD provides a new method to reveal the interaction between different dissociated forms of MAs or other biomolecules and essential receptors.

Electrokinetic phenomena play a vital role in the study of colloidal nanoparticles, offering significant insights and applications across a wide range of fundamental research and practical uses. It is crucial to recognize the extensive research on various types of nanomaterials, including polymer latexes, quantum dots, and biomolecules. However, there is a significant gap in the study of magnetic systems. Such materials have immense potential and can greatly benefit from both magnetophoretic and electrophoretic techniques. In this work, the electrophoretic behavior of water-based magnetic fluids was investigated, focusing on how additional magnetic field exposure affects their properties. The studies conducted utilized magnetic measurements that emerged from the presence of colloidal particles within the examined systems, which exhibited both charge and magnetic moment. The magnetic susceptibility and magnetization of colloidal particles precipitate formed on one of the electrodes were measured. The thickness of the formed precipitate on the electrode can be confidently estimated through micrometric measurements as well as by analyzing its magnetic susceptibility during electrophoresis. A formula for calculating the electrophoretic velocity based on the results of magnetic measurements was obtained. Estimates of zeta potential and charge of colloidal particles were carried out. The electrophoresis process in these systems can be effectively regulated by an inhomogeneous magnetic field, leading to complete compensation.

Current Y-chromosomal single-nucleotide polymorphism (Y-SNP) detection technologies in forensic genetics often rely on bulky equipment, complex procedures, and lack adaptability to field conditions. To address these limitations, we developed an 89-plex microfluidic Y-SNP system comprising a disposable DNA extraction/amplification chip and a capillary electrophoresis chip. Using in situ lyophilization, the reagents are stabilized for long-term storage. Integrated with a portable device, the system enables a fully automated “sample-in-answer-out” workflow and delivers complete 89-locus Y-SNP genotyping within 139 min. The system includes two panels—AIYSNP42 for global high-frequency haplogroups and AIYSNP47 for East Asian O-haplogroup subclades—designed on the basis of the International Society of Genetic Genealogy (ISOGG) phylogenetic tree for multi-level resolution. Validation showed a detection sensitivity of 2.5 ng of DNA, with a 93.6% genotyping success rate across 94 forensic samples. It maintained performance under environmental inhibitors (humic acid ≤ 100 ng/µL, hemin ≤ 300 µM, indigo ≤ 15 mM) and moderate UV-induced DNA degradation. The system demonstrated excellent reproducibility (coefficient of variation, CV < 0.5%) and reliably detected male DNA in mixtures (≥2% in male–female, ≥33% in male–male). This microfluidic system reduces the reliance on the need for conventional laboratory workflows and supports rapid, on-site Y-SNP analysis for pedigree tracing, ancestry inference, and mixture interpretation.