Microfluidic Applications of Magnetic Particles for Biological Analysis and Catalysis

Advances in the fabrication, manipulation, detection, and application of magnetic particles in microfluidic systems were studied. Nearly all important functions in a bioassay can be realized using magnetic beads, raw sample purification, providing a solid substrate to the sample, mixing, labeling, manipulation, transport, and separation. Magnetic labeling permits one to select or deplete certain cell types from a complex matrix, because of the combination of magnetic labeling with magnetic separation principles. When introducing a raw cell sample on a microfluidic chip or cartridge, it is possible to capture the DNA, purify and process it, and detect a specific DNA sequence on-chip. Microfluidic chips for nucleic acid detection will be playing an important role for point-of-care diagnosis and infield testing. Optimized chemical reaction/washing protocols have been developed for magnetoresistive sensors, where the magnetic particles need to be immobilized specifically over the most sensitive part of the sensor area.