(179a) Deterministic Absolute Negative Mobility for Sub-Micrometer Bioparticle Separation

Deterministic Absolute Negative Mobility for sub-micrometer Bioparticle Separation

Jinghui Luo¹, Katherine Muratore³, Edgar Arriaga^2,3 & Alexandra Ros¹

¹Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, USA.

²Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA.

³Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA. (Alexandra.Ros@asu.edu)

Efficient particle separation in the micron- and submicron range is required for the various analytical challenges related to nanotechnology and microbiology. Here, we demonstrate a non-intuitive, yet efficient migration mechanism for µm- and sub-µm colloidal particles and organelles, taking advantage of particle transport in a nonlinear post array in a microfluidic device under the periodic action of electrokinetic and dielectrophoretic forces. We reveal regimes in which deterministic particle migration opposite to the average applied force occurs for a larger particle – a typical signature of deterministic absolute negative mobility (dANM) -whereas normal response is obtained for smaller particles. The coexistence of dANM and normal migration was characterized and optimized in numerical modeling and subsequently implemented in a microfluidic device demonstrating at least two orders of magnitude higher migration speeds as compared to previous ANM systems. We could also induce dANM for mouse liver mitochondria and envision that the efficient size selectivity can be advantageously employed in organelle sub-population studies, for nanotechnological applications, or in fractionating protein nanocrystals.