Accelerated target capture by dynamic magnetic particle actuation

Particle-based capture is a widely used process for target enrichment. The upcoming generation of integrated biosensing systems need target capture technologies that are as efficient and as rapid as possible. Here, we study the effect of magnetic actuation of streptavidin-coated magnetic capture particles on the capture reaction of 200 nm sized biotinylated fluorescent target particles. To overcome limitations due to volume transport and near-surface alignment of reactive particles, and thus to accelerate target capture, various magnetic actuation techniques were developed. Stationary rotation of capture particles was found to increase the rate to obtain near-surface. Furthermore, dynamic actuation of particle chains was found to effectively accelerate both volume transport and near-surface alignment in the capture reaction. We conclude that rotational magnetic particle actuation can be effectively applied to achieve rapid microfluidic particle-based affinity capture.