Tunable Membranes for Free-Flow Zone Electrophoresis in PDMS Microchip Using Guided Self-Assembly of Silica Microbeads
Author(s)Song, Yong-Ak; Wu, Lidan; Wishnok, John S.; Han, Jongyoon; Tannenbaum, Steven Robert
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In this paper, we evaluate the strategy of using self-assembled microbeads to build a robust and tunable membrane for free-flow zone electrophoresis in a PDMS microfluidic chip. To fabricate a porous membrane as a salt bridge for free-flow zone electrophoresis, we used silica or polystyrene microbeads between 3–6 μm in diameter and packed them inside a microchannel. After complete evaporation, we infiltrated the porous microbead structure with a positively or negatively charged hydrogel to modify its surface charge polarity. Using this device, we demonstrated binary sorting (separation of positive and negative species at a given pH) of peptides and dyes in standard buffer systems without using sheath flows. The sample loss during sorting could be minimized by using ion selectivity of hydrogel-infiltrated microbead membranes. Our fabrication method enables building a robust membrane for pressure-driven free-flow zone electrophoresis with tunable pore size as well as surface charge polarity.
DepartmentMassachusetts Institute of Technology. Department of Biological Engineering; Massachusetts Institute of Technology. Department of Chemistry; Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
American Chemical Society (ACS)
Song, Yong-Ak, Lidan Wu, Steven R. Tannenbaum, John S. Wishnok, and Jongyoon Han. “Tunable Membranes for Free-Flow Zone Electrophoresis in PDMS Microchip Using Guided Self-Assembly of Silica Microbeads.” Anal. Chem. 85, no. 24 (December 17, 2013): 11695–11699.
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