Jongyoon Han, Ph.D.
Department of Electrical Engineering and Computer Science
Department of Biological Engineering
Research Scientist 2001-2002 Sandia National Laboratories, Livermore, CA
Ph.D. Applied Physics 2001 Cornell University, Ithaca, NY
M. S. Physics 1994 Seoul National University, Seoul, Korea
B. S. Physics 1992 Seoul National University, Seoul, Korea
Just as electrical circuits process information in the form of
collective motion of electrons that form electrical currents, biological
systems transmit and process information mediated by nucleic acids,
proteins and small effector molecules. The Han laboratory leverages new
advances in microelectromechanical systems (MEMS), microfluidics, and
nano- and micro-fabrication to develop new technologies for analyzing
complex biological systems.
Nanofluidic Biomolecular Preconcentration and Concentration-Enhanced Assays
Sample preparation is one of the bottlenecks in molecular detection and
analysis. During the past decades, significant progress has been made
both in binding assays (immunoassays) and mass spectrometry (MS).
However, issues related to limited sample capacity and low abundance
target create challenges in fully utilizing the power of these new
analysis platform. In general, only high-abundance species of a given
sample could be detected, while reliable analysis of low-abundance
targets is still challenging. To address these problems, our group has
sought ways to efficiently concentrate biomolecules in order to enhance
the detection sensitivity for both large and small sample volumes. The
nanofluidic electrokinetic concentration devices serve as;
- Ideal world-to-microchip coupling system: It can collect
biomolecules from ~µL fluidic samples (addressable by pipettes)
and concentrate them into ~nL plug (addressable by microfluidics).
- Generic sensitivity enhancement scheme for many biochemical
assays: Wide variety of biochemical assays can be enhanced simply
by collecting the reactants and / or target molecules.
Advanced Micro-Nanofluidic Biomolecule / Cell Separation
Bioanalysis is often compared to finding "a needle in a haystack", so
the importance of biosample fractionation cannot be exaggerated.
Traditionally, Gel electrophoresis, gel-exclusion chromatography and
other filtration techniques have been used for bioseparation. In
addition to well-known drawbacks such as manual operation, slow
separation rate, and need for large equipments, the science behind the
molecular sieving and filtration is still yet to be fully clarified. One
issue is that most molecular sieves and filters are random nanoporous
materials, making it difficult to control / optimize the separation
process. In our group, patterned regular sieving structures and
nanofilters have been sought as an alternative to conventional
separation method: recent developments in micro-nanofluidic sieves and
filters have demonstrated superior performance for both analytical and
preparative separation of various physiologically relevant
macromolecules, including proteins. In addition, recent development in
inertial microfluidics and other biomimetic separation techniques (such
as cell margination) allow microfluidic cell separation from a complex
sample (e.g. raw blood) at very high throughput (~1mL/min), by utilizing
physical characteristics of cells (deformability, size, and others).
- Bow, H., Pivkin, I., Diez-Silva, M., Goldfless, S.J., Dao, M.,
Niles, J.C., Suresh, S. & Han, J. A microfabricated
deformability-based flow cytometer with application to malaria. Lab on a Chip, 2011, *accepted for publication (*DOI:
- Han Wei Hou, Ali Asgar S. Bhagat, Alvin Guo Lin Chong, Pan Mao,
Kevin Shyong Wei Tan, Jongyoon Han, Chwee Teck Lim, "Deformability
based cell margination - A simple microfluidic design for malaria
infected erythrocyte separation," Lab on a Chip, 2010, 10, 2605 - 2613.
- Cheow, L. F.; Ko, S. H.; Kim, S. J.; Kang, K. H.; Han, J., “Increase of Sensitivity and Dynamic Range of ELISA using
Multiplexed Electrokinetic Concentrator,” Analytical Chemistry,
82, 3383-3388, 2010.
- Yamada, M., P. Mao, J. Fu, and J. Han, “Rapid quantification of
disease-marker proteins using continuous-flow immunoseparation in
a nano-sieve fluidic device.” Analytical Chemistry, 81,
- Lee, J.H., B. Cosgrove, A.D. Lauffenburger, and J. Han, “Microfluidic concentration-enhanced cellular kinase activity
assay.” Journal of the American Chemical Society, 131,
- Ying-Chih Wang and Jongyoon Han, “Pre-binding dynamic range and
sensitivity enhancement for immuno-sensors using nanofluidic
preconcentrator,” Lab on a Chip, 8, 392-394, 2008.
- J. Fu, R. R. Schoch, A. L. Stevens, S. R. Tannenbaum, and J. Han, “Patterned anisotropic nanofluidic sieving structure for
continuous-flow separation of DNA and protein,” Nature
Nanotechnology, 2, 121-128, 2007.
- Y.-C. Wang, A. L. Stevens, and J. Han, (2005) "Million-fold
Preconcentration of Proteins and Peptides by Nanofluidic Filter," Analytical Chemistry, 77, 4293-4299.
Last Updated: February 7, 2011