Electrokinetic Bioprocessor for Concentrating Cells and Molecules

Abstract

Bioprocessors for concentrating bioparticles, such as cells and molecules, are commonly needed in bioanalysis systems. In this microfluidic processor, a global flow field generated by ac electroosmosis transports the embedded particles to the regions near the electrode surface. The processor then utilizes electrophoretic and dielectrophoretic forces, which are effective in short range, to trap the target cells and molecules on the electrode surface. By optimizing the operating parameters, we have concentrated various biological objects in a large range of sizes, including Escherichia coli bacteria, lambda phage DNA, and single-stranded DNA fragments as small as 20 bases that have a radius of gyration of only 3 nm.

Analytical Solutions of Time Periodic Electroosmotic Flow in a Semicircular Microchannel

“…In other words, the electroosmotic flow generated by the AC electric field is quasi-periodic. The generating part of the solution is very important, since it explains both the characteristics of electroosmotic flow and the practical applications due to rapid development of the Biochiptechnology (Wong, Chen, Wang, and Ho 2004).…”

Enhancing the Performance of Surface-based Biosensors by AC Electrokinetic Effects - a Review

“…Fluorescence is by far the most frequently used optical signalling method for the monitoring and detection of AC-electrokinetically trapped bioparticles due to its high level of sensitivity and low background noise (Hübner et al, 2007;Wong et al, 2004b;Cui et al, 2002;Yang et al, 2008). Using fluorescent imaging, Docoslis et al (2007) detected captured virus (vesicular stomatitis virus) and later explored numerical simulations of the system to better understand the processes involved (Wood et al, 2007).…”

Induced charge effects on electrokinetic entry flow

“…28 This flow has a nonlinear quadratic dependence on electric field and often consists of counter-rotating rolls. [29][30][31] It has been extensively studied around conducting surfaces of, for instance, metal electrodes and particles, which can be either electrically activated [32][33][34] or left floating [35][36][37][38][39][40][41][42][43][44][45] as reviewed by Bazant and Squires. 46 ICEO also takes place around an inert but polarizable object where the surface charge is induced by the electric field leaked into the object.…”