Numerical simulations of electrokinetically-driven capture of viral particles inside media of high ionic strength

The increasing frequency of virus-related disease outbreaks creates a growing need for methods that permit rapid detection of infectious biological agents, such as viruses, within small sample volumes and without amplification of the agent. Surface-based biosensors emerge as a promising set of detection devices that are suitable for this purpose. Moreover, recent experimental studies have demonstrated that the detection capabilities of these sensors can be significantly enhanced when their operation is aided by AC electrokinetic effects (dielectrophoretic and AC electrohydrodynamic forces), which can cause accelerated transport and capture of biological agents on microelectrode platforms situated on the sensor's surface. The present study is concerned with the 3D modeling and simulation of the phenomena that govern viral transport to, and capture on, a microelectrode surface inside media of physiological ionic strength under the influence of a spatially non-uniform AC electric field. More specifically, the resulting force patterns (viscous and dielectrophoretic) on particles are assessed by using a finite element method-based simulation package (COMSOL Multiphysics®). The validity of the computer simulations is confirmed through experiments involving electrokinetically-directed capture of fluorescent sub-micron latex particles under the same conditions.