Towards an electrowetting-based digital microfluidic platform for magnetic immunoassays

Lab Chip. 2009 Dec 7;9(23):3433-6. doi: 10.1039/b912646e. Epub 2009 Oct 1.

Abstract

We demonstrate ElectroWetting-On-Dielectric (EWOD) transport and SQUID gradiometer detection of magnetic nanoparticles (MNPs) suspended in a 2 microl de-ionized water droplet. This proof-of-concept methodology constitutes the first development step towards a highly sensitive magnetic immunoassay platform with SQUID readout and droplet-based sample handling. Magnetic AC-susceptibility measurements were performed on MNPs with a hydrodynamic diameter of 100 nm using a high-Tc dc Superconducting Quantum Interference Device (SQUID) gradiometer as detector. We observed that the signal amplitude per unit volume is 2.5 times higher for a 2 microl sample droplet compared to a 30 microl sample volume.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrowetting / instrumentation*
  • Equipment Design
  • Immunoassay / trends*
  • Magnetics*
  • Microfluidic Analytical Techniques / instrumentation*
  • Nanoparticles / chemistry