Nanofluidic devices for the separation of biomolecules

Chathurika Rathnayaka, Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA; Center of BioModular Multiscale Systems for Precision Medicine, USA.
Charuni A. Amarasekara, Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA; Center of BioModular Multiscale Systems for Precision Medicine, USA.
Khurshed Akabirov, Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA; Center of BioModular Multiscale Systems for Precision Medicine, USA.
Michael C. Murphy, Center of BioModular Multiscale Systems for Precision Medicine, USA; Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70810, USA.
Sunggook Park, Center of BioModular Multiscale Systems for Precision Medicine, USA; Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70810, USA.
Malgorzata A. Witek, Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA; Center of BioModular Multiscale Systems for Precision Medicine, USA.
Steven A. Soper, Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA; Center of BioModular Multiscale Systems for Precision Medicine, USA; Department of Mechanical Engineering, The University of Kansas, Lawrence, KS 66045, USA; Bioengineering Program, The University of Kansas, Lawrence, KS 66045, USA; KU Cancer Center and Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA. Electronic address: ssoper@ku.edu.

Abstract

Over the last 30-years, microchip electrophoresis and its applications have expanded due to the benefits it offers. Nanochip electrophoresis, on the other hand, is viewed as an evolving area of electrophoresis because it offers some unique advantages not associated with microchip electrophoresis. These advantages arise from unique phenomena that occur in the nanometer domain not readily apparent in the microscale domain due to scale-dependent effects. Scale-dependent effects associated with nanochip electrophoresis includes high surface area-to-volume ratio, electrical double layer overlap generating parabolic flow even for electrokinetic pumping, concentration polarization, transverse electromigration, surface charge dominating flow, and surface roughness. Nanochip electrophoresis devices consist of channels with dimensions ranging from 1 to 1000 nm including classical (1-100 nm) and extended (100 nm - 1000 nm) nanoscale devices. In this review, we highlight scale-dependent phenomena associated with nanochip electrophoresis and the utilization of those phenomena to provide unique biomolecular separations that are not possible with microchip electrophoresis. We will also review the range of materials used for nanoscale separations and the implication of material choice for the top-down fabrication and operation of these devices. We will also provide application examples of nanochip electrophoresis for biomolecule separations with an emphasis on nano-electrophoresis (nEP) and nano-electrochromatography (nEC).