Apparatus for and method of separating polarizable analyte using dielectrophoresis

A method of separating a target analyte in a sample using an apparatus for separating a polarizable analyte using dielectrophoresis, the apparatus comprising a vessel including a membrane having a plurality of nano- to micro-sized pores, the membrane disposed inside the vessel wherein the vessel is a microchannel and the membrane is disposed in a direction substantially perpendicular to a flowing direction of a fluid in the vessel, electrodes for generating spatially non-uniform electric fields in the nano- to micro-sized pores of the membrane when an AC voltage is applied to the electrodes, and a power source for applying the AC voltage to the electrodes, wherein a sectional area of the pores, formed in a surface of the membrane or in a plane parallel to the surface of the membrane, varies along a depth of the pores, the method comprising:

• contacting the membrane with the sample;
• and
• dielectrophoretically separating the polarizable analyte in the sample based on the permittivity of the analyte by applying the AC voltage to the electrodes from the power source to generate spatially non-uniform electric fields in the membrane in which target analyte is either attracted to or repelled from the electric field.