Microfluidics and Nanofluidics

, 11:429

Microfluidic continuous magnetophoretic protein separation using nanoparticle aggregates

  • Su Hui Sophia Lee
  • T. Alan Hatton
  • Saif A. Khan
Research Paper

DOI: 10.1007/s10404-011-0808-3

Cite this article as:
Lee, S.H.S., Hatton, T.A. & Khan, S.A. Microfluid Nanofluid (2011) 11: 429. doi:10.1007/s10404-011-0808-3


We demonstrate a microfluidic continuous-flow protein separation process in which silica-coated superparamagnetic nanoparticles interact preferentially with hemoglobin in a mixture with bovine serum albumin, and the resulting hemoglobin-nanoparticle aggregates are recovered online using magnetophoresis. We present detailed modeling and analysis of this process yielding quantitative estimates of the recovery of both proteins, validated by experiments. While several previous studies utilize an average particle size in modeling magnetophoretic particle trajectories or process design, in this study we emphasize the importance of accounting for particle size distributions in calculating particle recovery, and therefore in estimating separation efficiency. We combine experimentally measured size distributions of protein-nanoparticle aggregates with simulations of particle trajectories and provide a simple analytical method to calculate the efficiency of separation at various flow speeds, which fully accounts for heterogeneity in particle sizes. Our method can potentially be used for affinity based biomolecular separations at both analytical and preparative scales by exploiting well-established techniques to functionalize nanoparticle surfaces with selective ligands. Further, the modeling methodology presented here may be applied to provide better estimates of particle recovery in a broad range of magnetophoretic separation processes involving heterogeneity in particle sizes.


Magnetic nanoclustersMagnetic nanoparticlesMagnetophoretic separationProtein separationMicrofluidics

Supplementary material

10404_2011_808_MOESM1_ESM.docx (341 kb)
Supplementary material 1 (DOCX 342 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Su Hui Sophia Lee
    • 1
  • T. Alan Hatton
    • 1
    • 2
  • Saif A. Khan
    • 1
    • 3
  1. 1.Chemical and Pharmaceutical Engineering ProgramSingapore-MIT Alliance, National University of SingaporeSingaporeSingapore
  2. 2.Department of Chemical EngineeringMassachusetts Institute of TechnologyCambridgeUSA
  3. 3.Department of Chemical and Biomolecular EngineeringNational University of SingaporeSingaporeSingapore