Direct current dielectrophoretic simulation of proteins using an array of circular insulating posts

Abstract

This paper presents a mathematical model for the manipulation of proteins using insulator-based dielectrophoresis (iDEP) and direct current (DC) electric fields. Simulations via COMSOL v4.1 Multiphysics software are implemented to study the response of moderately sized proteins on a lab-on-a-chip platform. The geometry of the device is incorporated in a model that solves current and mass conservation equations within an array of circular insulating silicon posts embedded in a channel. Both micro- and nano-scale geometries are utilized to investigate the protein concentration distributions in the iDEP device. Our results indicate that the trapping of proteins is independent of the scale with respect to the geometry of a device as long as the applied electric field remains constant. DC voltage dependency on concentration distributions has also been explored in both micro- and nano-scale device geometries. To achieve DEP trapping of the proteins, nano-scale geometry is a better selection, as the voltage necessary to generate the required electric field (2.5 MV/cm) is 10(5) × lower compared with the voltage required to generate the same field in the micro-scale device.

Dielectrophoresis‐Based Protein Enrichment for a Highly Sensitive Immunoassay Using Ag/SiO2 Nanorod Arrays

“…More recently, high cost e‐beam lithography has been utilized to fabricate nanogaps for enhanced local fields and protein trapping . Besides experimental endeavor, theoretical attempts by Ivory and Srivastava in 2011 reveal that, to realize the protein concentration, nanoscale posts are routinely required for adequate DEP forces . Thus, it is of utmost priority that a robust, simple, and inexpensive iDEP device with nanosized insulating posts needs to be developed so as to effectively enrich proteins under low voltage schemes.…”

Modelling of electrokinetic phenomena for capture of PEGylated ribonuclease A in a microdevice with insulating structures

“…26 So far, there is lack of literature reporting conductivity of proteins, especially for RNase A, although there are some reported values available for other proteins that vary in a very wide range. 22,[28][29][30] As we experimentally observed streaming or trapping DEP for both proteins (native and PEGylated) in positive mode, we set r p ¼ 1000 lS/cm, one order of magnitude higher than r m , to guarantee positive DEP theoretical predictions. Besides, we varied r p up to 10 000 lS/cm with no significant changes in the EK velocity response (data not shown).…”

Theoretical investigation on nanoparticle concentrations in optoelectrofluidic chip based on diffusion, convection, and migration

“…Therefore, the micro-/nanoparticle movement can be expressed in terms of the diffusion, convective, electrophoresis (EP), and DEP mobilities [14] ,…”

“…In the second step, the transport Equation including an approximate boundary condition is used to analyze the velocity of particle concentration in the time domain. It relies on the both Equations to calculate the physical convection, diffusion, and migration similar to Ivory's model [14] . Furthermore, the effect of electroosmotic flow is analyzed in the model.…”