Nanogap dielectrophoresis combined with buffer exchange for detecting protein binding to trapped bioparticles

Avijit Barik, Xiaoshu Chen, L. James Maher, Arthur E. Warrington, Moses Rodriguez, Sang Hyun Oh, Nathan J. Wittenberg

Research output: Contribution to journalArticlepeer-review


We demonstrate a gold nanogap electrode platform that can rapidly create a linear array of biological particles by low-voltage dielectrophoresis (DEP). We further combine microfluidic buffer exchange to introduce protein molecules in high-conductivity solutions while trapping and immobilizing particles. The nanogap between the gold electrodes enables low operating voltages that prevent unwanted Joule heating in high-conductivity buffers. This platform is used to trap bioparticles composed of lipid membranes such as spherical supported lipid bilayers and brain-derived myelin particles, followed by detection of protein binding to specific membrane-bound receptors. We use bioparticles with different sizes, physicochemical properties, and origins to demonstrate a platform that can be used to study a variety of biomolecular interactions. The low-power linear DEP trap combined with microfluidic buffer exchange has potential to enable a portable biosensing platform to rapidly concentrate rare biological particles and perform on-chip binding assays with improved detection limits in physiological buffers.

Original languageEnglish (US)
Article number125829
JournalColloids and Surfaces A: Physicochemical and Engineering Aspects
StatePublished - Feb 20 2021

Bibliographical note

Funding Information:
This work was supported by a grant from the Minnesota Partnership for Biotechnology and Medical Genomics (A.B., N.J.W., L.J.M., A.E.W., M.R., S.-H.O.), the National Science Foundation (Award Number: 1610333 to X.S.C. S.-H.O.), and the University of Minnesota MnDRIVE Initiative (N.J.W. and S.-H.O.). A.B. and X.S.C. also acknowledge support from the Doctoral Dissertation Fellowship from the University of Minnesota . N.J.W. acknowledges support from Lehigh University and the National Institutes of Health ( R21GM134414 ). A.E.W acknowledges support from Regenerative Medicine Minnesota.


  • Dielectrophoresis
  • Fluorescence
  • Lipid bilayer
  • Microfluidics
  • Myelin
  • Particle trapping

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