title: Continuous flow nanoparticle concentration using alternating current-electroosmotic flow.
abstract: Achieving real-time detection of environmental pathogens such as viruses and bacterial spores requires detectors with both rapid action and a suitable detection threshold. However, most biosensors have detection limits of an order of magnitude or more above the potential infection threshold, limiting their usefulness. This can be improved through the use of automated sample preparation techniques such as preconcentration. In this paper, we describe the use of AC electroosmosis to concentrate nanoparticles from a continuous flow. Electrodes at an optimized angle across a flow cell, and energized by a 1 kHz signal, were used to push nanoparticles to one side of a flow cell, and to extract the resulting stream with a high particle concentration from that side of the flow cell. A simple model of the behavior of particles in the flow cell has been developed, which shows good agreement with experimental results. The method indicates potential for higher concentration factors through cascading devices.
authors.affiliation: Faculty of Engineering and Physical Sciences, Centre for Biomedical Engineering, University of Surrey, Guildford, Surrey, UK.
authors.forename: Kai F
authors.initials: KF
authors.lastname: Hoettges
authors.forename: Martin B
authors.initials: MB
authors.lastname: McDonnell
authors.forename: Michael P
authors.initials: MP
authors.lastname: Hughes
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D053841:Electroosmosis / Q000295:instrumentation*; D004783:Environmental Microbiology; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D036103:Nanotechnology
keywords: AC-electroosmotic flow; Bioparticle detection; Dielectrophoresis; Lab on a chip; Particle separation