ABSTRACT
This chapter focuses on the dielectrophoretic detection of virus particles; these are structurally the most complex particles on the nanometer-scale, on a size scale cells and bacteria. Viruses are unique in the world of living organisms, in that there is debate over whether or not a virus actually is a living organism. The chapter examines the application of the Clausius–Mossotti relationship as a means of determining the dielectrophoretic response of a solid, homogeneous sphere. However, viruses are not solid, homogeneous spheres; while virus shape is often approximately spherical, it is never homogeneous throughout, instead it consists of a number of shells surrounding a central core. Viruses that have a membrane envelope are most sensitive to environmental conditions, which must, for example, be maintained in an iso-osmotic medium; both enveloped and nonenveloped viruses are sensitive to pH. In addition to the payload and the capsid, many viruses have an extra lipid membrane similar to that which encloses cells.
