Analyte detection methods and apparatus using dielectrophoresis and electroosmosis

Abstract

Methods and apparatus for detection and/or identification of analytes including bacteria using dielectrophoresis and electroosmotic traps. Switching between different frequencies of an applied electric field results in movement of the analyte between dieiectrophoresis and electroosmotic trapping states. The use of edge-based sensing techniques enables the use of electrodes with a larger form factor than nanowire sensors. Signal modulation based on analyte contact with the electrode edge is also described.

1 - 88 . (canceled) 
     
     
         89 . In a microfluidic device adapted for filtering and analyzing analytes from an entity to be eliminated, said device comprising dielectrophoresis (DEP) and/or electroosmosis (EO) electrodes, a method for highly selective filtration, the method comprising:
 identifying a frequency and conductivity having a difference for a Clausius-Mossotti (CM) factor for said analytes and a CM factor for said entity to be eliminated; and   filtering said entity to be eliminated by introducing a solution of the identified conductivity and by imposing an electric field having the identified frequency so as to separate said entity to be eliminated from said analytes.   
     
     
         90 . The method of  claim 89 , the method further comprising:
 compiling data including the CM factor as a function of frequency and conductivity for said analytes and entities to be eliminated;   for each entity to be eliminated,
 identifying, based on the data, a frequency and conductivity having a largest difference for said CM factor for said analyte and said CM factor for said entity to be eliminated; and 
 filtering said entity to be eliminated by introducing a solution of the identified conductivity and by imposing an electric field of the identified frequency so as to separate said entity to be eliminated, 
 wherein separation for each entity to be eliminated is used to achieve said highly selective filtration. 
   
     
     
         91 . The method of  claim 90 , further comprising employing electroosmosis and/or dielectrophoresis. 
     
     
         92 . The method of  claim 90 , further comprising: communicating diagnostic information concerning said analyte identities and concentrations to a smartphone or other network-connected device. 
     
     
         93 . The method of  claim 90 , wherein the analytes comprise antibodies and/or viruses. 
     
     
         94 . The method of  claim 90 , further comprising storing in a database, information concerning said analyte identities and concentrations for purposes of diagnosing and tracking said analytes, and quantifying response of analytes to antibodies. 
     
     
         95 . The method of  claim 90 , wherein the microfluidic device is adapted for use inline for detection of analytes and/or toxins. 
     
     
         96 . The method of  claim 90 , wherein the microfluidic device is adapted for detection of sulfur-reducing bacteria or other bacteria which change their response to the electric field based on response to chemicals. 
     
     
         97 . The method of  claim 90 , wherein the microfluidic device is adapted for use in capturing and/or separating analytes from samples made in a bioreactor. 
     
     
         98 . The method of  claim 89 , wherein the frequency and the conductivity are chosen such that a separation force between the analytes and the entities in the solution is effective to separate the analytes from the entities. 
     
     
         99 . The method of  claim 98 , wherein an operating parameter for the separation force include one or more of electric field voltage, phase, solution conductivity, electrode metal, electrode geometry, electrode edge roughness, flow rate, height and/or geometry of a microfluidic channel, characteristics of an applied waveform, and chemical composition of the solution. 
     
     
         100 . The method of  claim 89 , wherein a circular assembly of coaxial- or circularly-shape electrodes or a partially center-symmetric electrodes are used. 
     
     
         101 . The method of  claim 89 , further switching between a first frequency and a second frequency, the first frequency for trapping the analytes in an electroosmotic trap and the second frequency for trapping the analytes in a dielectrophoretic trap. 
     
     
         102 . A microfluidic device adapted for filtering and analyzing analytes from an entity to be eliminated, said device comprising dielectrophoresis (DEP) and/or electroosmosis (EO) electrodes, the microfluidic device being adapted to:
 identify a frequency and conductivity having a difference for a Clausius-Mossotti (CM) factor for said analytes and a CM factor for said entity to be eliminated; and   filter said entity to be eliminated by introducing a solution of the identified conductivity and by imposing an electric field having the identified frequency so as to separate said entity to be eliminated from said analytes.   
     
     
         103 . The microfluidic device of  claim 102 , wherein the microfluidic device is further adapted to:
 compile data including the CM factor as a function of frequency and conductivity for said analytes and entities to be eliminated;   for each entity to be eliminated,
 identify, based on the data, a frequency and conductivity having a largest difference for said CM factor for said analyte and said CM factor for said entity to be eliminated; and 
 filter said entity to be eliminated by introducing a solution of the identified conductivity and by imposing an electric field of the identified frequency so as to separate said entity to be eliminated, 
 wherein separation for each entity to be eliminated is used to achieve said highly selective filtration. 
   
     
     
         104 . The microfluidic device of  claim 103 , wherein the microfluidic device is further adapted to employ electroosmosis and/or dielectrophoresis. 
     
     
         105 . The microfluidic device of  claim 103 , wherein the microfluidic device is further adapted to communicate diagnostic information concerning said analyte identities and concentrations to a smartphone or other network-connected device. 
     
     
         106 . The microfluidic device of  claim 103 , wherein the analytes comprise antibodies and/or viruses. 
     
     
         107 . The microfluidic device of  claim 103 , wherein the microfluidic device is further configured to store in a database, information concerning said analyte identities and concentrations for purposes of diagnosing and tracking said analytes, and quantifying response of analytes to antibodies. 
     
     
         108 . The microfluidic device of  claim 103 , wherein the microfluidic device is further adapted for use inline for detection of analytes and/or toxins.