Selective microorganism concentration using a dielectrophoresis-based microfabricated device

Abstract

Detection of pathogenic microorganisms is a significant challenge in medicine, environmental protection and biological threat safety because samples are often contaminated. This work presents a method of separating bacterial spores from typical air contaminants such as sand or soot by means of dielectrophoresis. Spores of B. subtilis as well as model airborne interferents are characterized electrically; based on their properties, schemes of their electrical separation are proposed. The separation based on the frequency of applied electric field is implemented using microfabricated chips. To relate the data obtained from these microtools to particle concentration, a computer program is designed, implemented and validated. Experiments show that separation of bacterial spores from soot and sand suspended in water based on electrical properties of particles is possible and may serve as a way of enhancing spore concentration in mixtures.