Methods and devices for high-throughput dielectrophoretic concentration

Abstract

Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

1 . A substrate comprising a plurality of pores and a nonuniform electric field having local extrema located near the pores.  
     
     
         2 . The substrate of  claim 1 , wherein the substrate is a membrane, a film, or a filter.  
     
     
         3 . The substrate of  claim 1 , wherein the substrate is a woven structure of a plurality of fibers.  
     
     
         4 . The substrate of  claim 1 , wherein the substrate is a non-woven structure of a plurality of fibers.  
     
     
         5 . The substrate of  claim 1 , wherein the substrate is a plurality of aligned fibers.  
     
     
         6 . The substrate of  claim 1 , wherein the substrate comprises a material with insulative properties.  
     
     
         7 . The substrate of  claim 1 , wherein the substrate comprises a material with conductive properties.  
     
     
         8 . A method for assaying, inhibiting, or concentrating analytes in a fluid sample which comprises passing the fluid sample through or in the vicinity of a substrate having a plurality of pores and a nonuniform electric field having local extrema located near the pores.  
     
     
         9 . The method of  claim 8 , wherein the analytes having a size larger than the pores are physically entrapped on one side of the substrate.  
     
     
         10 . The method of  claim 8 , wherein the analytes having a size smaller than the pores pass though the pores of the substrate.  
     
     
         11 . The method of  claim 8 , wherein the analytes are immobilized on or constrained in a given area from the surface of the substrate due to dielectrophoretic forces.  
     
     
         12 . A device for assaying, inhibiting, or concentrating analytes in a fluid sample which comprises at least one assembly comprising at least one substrate having a plurality of pores capable of a nonuniform electric field gradient having local extrema located near the pores in the presence of an applied field and at least one electrode.  
     
     
         13 . The device of  claim 12 , wherein the substrate is a conductive material.  
     
     
         14 . The device of  claim 12 , wherein the assembly comprises at least one spacer.  
     
     
         15 . The device of  claim 12 , which comprises two or more assemblies.  
     
     
         16 . The device of  claim 12 , and further comprising at least one component selected from the group consisting of a fluid inlet, a fluid outlet, a substrate housing, a gasket, an insert, a viewing area, a delivery device, a collection device, a spacer, and a valve.  
     
     
         17 . The device of  claim 12 , wherein the electrode is a pin electrode or a wire mesh.  
     
     
         18 . The device of  claim 12 , wherein the electrode is a remote electrode.  
     
     
         19 . The device of  claim 12 , wherein the substrate is transverse to the flow of the fluid sample.  
     
     
         20 . The device of  claim 12 , wherein the substrate is substantially normal to substantially aligned with the flow of the fluid sample.  
     
     
         21 . The device of  claim 12 , wherein the substrate is about 80 degree incidence to about 10 degree incidence to the flow of the fluid sample.