title: Using nonuniform electric fields to accelerate the transport of viruses to surfaces from media of physiological ionic strength.
abstract: Nonuniform ac (alternating current) electric fields created by microelectrodes are investigated for their influence on the transport of the vesicular stomatitis virus (VSV) from aqueous suspensions of physiological ionic strength to surfaces on which the VSV is captured. Whereas passive diffusion did not lead to detectable levels of virus captured on a surface when using titers of VSV as high as 107 PFU/mL, nonuniform electric field-mediated transport led to the detection of 105 PFU/mL of virus in 2 min. An order-of-magnitude analysis of the time scales associated with virus transport to the microelectrodes inside media of physiological relevance indicates that electrothermal fluid flow (and the resulting viscous drag forces on the virus) rather than dielectrophoresis likely constitutes the major mechanism for virus transport far from the electrodes. The influence of dielectrophoresis was calculated to be confined to a region within a few micrometers of the electrodes and to lead to collection patterns of both virus and fluorescently labeled particles near the electrodes that were found to be in qualitative agreement with experiments. These observations and conclusions are discussed within a theoretical framework presented in the paper. The results presented in this work, when combined, suggest that ac electrokinetic phenomena can be used to expeditiously transport and capture viruses onto surfaces from solutions of high ionic strength, thus providing a potentially useful approach to addressing a bottleneck in the development of devices that allow for rapid sampling and detection of infectious biological agents.
authors.affiliation: Department of Chemical Engineering, Queen's University at Kingston, Kingston, Ontario K7L 3N6, Canada. docoslis@ chee.queensu.ca
authors.forename: Aristides
authors.initials: A
authors.lastname: Docoslis
authors.forename: Luis A Tercero
authors.initials: LA
authors.lastname: Espinoza
authors.forename: Bingbing
authors.initials: B
authors.lastname: Zhang
authors.forename: Li-Lin
authors.initials: LL
authors.lastname: Cheng
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Israel
authors.forename: Paschalis
authors.initials: P
authors.lastname: Alexandridis
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Abbott
mesh_terms: D004563:Electrochemistry; D007477:Ions / Q000737:chemistry; D008839:Microelectrodes; D044085:Microfluidics; D014721:Vesicular stomatitis Indiana virus / Q000737:chemistry*
chemical_list: D007477:Ions