magnetism & microfluidics

Exploitation of Magnetic Attraction Forces

Magnetic particles are commonly used in bioanalysis but conventional tube-based procedures are cumbersome. In our research group, we have developed continuous flow approaches for particle sorting and on-particle processing. These include continuous flow separation of magnetic microparticles and magnetically labelled cells based on their size and magnetic loading. More recently, we have presented platforms for continuous flow processing on particle surfaces allowing for entire analysis procedures to be conducted within one minute in an automated fashion. Processes studied so far include immunoassays and DNA hybridisation assays and layer-by-layer deposition.

FFM - pathogens    chemistry - pamme - continuous flow processing schematic Ali - snakes and ladders chip principle

Selected References

  • C. Phurimsak, M.D. Tarn, S.A. Peyman, J. Greenman, N Pamme, On-chip determination of C-reactive protein using magnetic particles in continuous flow, Analytical Chemistry, 2014, 86, 10552-10559. doi: 10.1021/ac5023265
  • M. Vojtisek, A. Iles, N. Pamme, Rapid, multi-step on-chip DNA hybridisation in continuous flow on magnetic particles, Biosensors and Bioelectronics, 2010, 25, 2172-2176. doi: 10.1016/j.bios.2010.01.034.
  • S.A. Peyman, A. Iles, N. Pamme, Mobile magnetic particles as solid-supports for rapid surface-based bioanalysis in continuous flow, Lab on a Chip, 2009, 9, 3110-3117. doi: 10.1039/b904724g
  • S.A. Peyman, A. Iles, N. Pamme, Rapid on-chip multi-step (bio)chemical reactions in continuous flow – manoeuvring particles through co-laminar flow streams. Chemical Communications, 2008, 10, 1220-1222. doi: 10.1039/B716532C
  • N. Pamme, A. Manz, On-Chip Free-Flow Magnetophoresis: Continuous flow separation of magnetic particles and agglomerates. Analytical Chemistry, 2004, 76, 7250-7256. doi: 10.1021/ac049183o

Exploitation of Magnetic Repulsion Forces

Polymer particle and biologoical cells are usually diamagnetic and thus weakly repelled from magnetic fields. This repulsion force can be enhanced by suspending particles or cells in a paramagnetic medium such as a gadolinium or manganese salt. In our research we have applied this principle for the trapping, focussing and deflection of polymer particles and cells and performed bioassays, pre-concentration and separation processes.

chemistry - pamme - diamagnetic repulsion

Selected References:

  • M.D. Tarn, L.T. Elders, S.A. Peyman, N. Pamme, Diamagnetic repulsion of particles for multilaminar flow assays, RSC Advances, 2015, 5, 103776-103781. doi: 10.1039/C5RA21867E
  • M.D. Tarn, S.A. Peyman, N. Pamme, Simultaneous trapping of magnetic and diamagnetic particle plugs for separations and bioassays, RSC Advances, 2013, 3, 7209–7214. doi: 10.1039/C3RA40237A
  • M. Vojtisek, M.D. Tarn, N. Hirota, N. Pamme, Microfluidic devices in superconducting magnets: on-chip free-flow diamagnetophoresis of polymer particles and bubbles, Microfluidics and Nanofluidics, 2012, 13, 625-635. doi: 10.1007/s10404-012-0979-6
  • A.I. Rodríguez-Villarreal, M.D. Tarn, L.A. Madden, J.B. Lutz, J. Greenman, J. Samitier, N. Pamme, Flow focussing of particles and cells based on their intrinsic properties using a simple diamagnetic repulsion setup, Lab on a Chip, 2011, 11, 1240-1248. doi: 10.1039/c0lc00464b
  • S.A. Peyman, E-Y. Kwan, O. Margarson, A. Iles, N. Pamme, Diamagnetic repulsion – a versatile tool for on-chip label-free particle handling, Journal of Chromatography A, 2009, 1216, 9055-9062.