Addressable Electrode Arrays in Multiple Fluidic Compartments and Uses Thereof

Abstract

Methods and apparati for performing measurements of electrical signals in a multi-compartmented fluidic array format where the signal to noise ratio is improved are disclosed.

What is claimed is: 
     
         1 . An apparatus for measuring a signal, comprising:
 a plurality of working electrodes, the plurality of working electrodes comprising a first working electrode and a second working electrode;   a conductive path between the first and second working electrodes;   a plurality of compartments for containing a fluid, the compartments comprising a first compartment in which the first working electrode is located and a second compartment in which the second working electrode is located;   a plurality of reference electrodes, the plurality of reference electrodes comprising a first reference electrode located in the first compartment and a second reference electrode located in the second compartment, the first reference electrode not being in direct contact with the first working electrode, the second reference electrode not being in direct contact with the second working electrode; and   circuitry configured to selectively enable and disable the first and second working electrodes based on (1) a first controllable voltage potential relationship between the first reference electrode and the first working electrode and (2) a second controllable voltage potential relationship between the second reference electrode and the second working electrode.   
     
     
         2 . The apparatus of  claim 1  wherein the circuitry comprises a plurality of switches, the switches configured to switch the reference electrodes between a plurality of voltage potentials in response to a control signal. 
     
     
         3 . The apparatus of  claim 1  wherein the plurality of switches comprises a first switch and a second switch, the first switch configured to switch the first reference electrode between a ground voltage and a first voltage potential in response to a control signal, the second switch configured to switch the second reference electrode between a ground voltage and a second voltage potential in response to a control signal. 
     
     
         4 . The apparatus of  claim 3  wherein the first and second voltage potentials are the same voltage amount. 
     
     
         5 . The apparatus of  claim 1  wherein the circuitry further comprises a controller, the controller configured to provide a control signal to the switches, the control signal configured to vary over time, the control signal comprising a first control signal state and a second control signal state, the first control signal state configured to enable the first working electrode while disabling the second working electrode, the second control signal state configured to disable the first working electrode while enabling the second working electrode. 
     
     
         6 . The apparatus of  claim 5  wherein the controller is configured to vary the control signal over time in accordance with a sequence that causes each working electrode to become enabled while a plurality of the working electrodes located in compartments other than the enabled working electrode are disabled. 
     
     
         7 . The apparatus of  claim 5  wherein the circuity further includes a first and second multiplexer, the first multiplexer configured to receive the first control signal state and determine whether to pass a ground voltage or a first control voltage contained within a first register to selectively drive the first reference electrode to either ground or the first control voltage and the second multiplexer configure to receive the second control signal state and determine whether to pass the ground voltage or a second control voltage contained within a second register to selectively drive the second reference electrode to either ground or the second control voltage. 
     
     
         8 . The apparatus of  claim 1  wherein the circuitry comprises measuring circuitry, the measuring circuitry configured to connect the enabled working electrode to a voltage potential to measure a signal via the enabled working electrode. 
     
     
         9 . The apparatus of  claim 8  wherein the circuitry is further configured to vary the voltage potential to which the enabled working electrode is connected over time. 
     
     
         10 . The apparatus of  claim 8  wherein the measuring circuitry is further connected to a controller, the controller providing a control signal to a multiplexer to select one of a plurality of voltage potentials to be passed to the measuring circuity. 
     
     
         11 . The apparatus of  claim 1  wherein the first working electrode, the second working electrode, and the conductive path are formed from a conductor having an insulated covering, the insulating covering having a plurality of openings, the openings defining the first and second working electrodes. 
     
     
         12 . The apparatus of  claim 1  further comprising a plurality of N of conductors and a plurality M of the compartments, a plurality M of the reference electrodes, and a plurality N×M of the working electrodes, each working electrode being located on a conductor, each compartment having N working electrodes located therein, wherein one of the conductors comprises the conductive path, wherein N and M are each greater than 2. 
     
     
         13 . The apparatus of  claim 1  further comprising a fluid contained within the first and second compartments, the fluid in the first compartment causing a fluid connection between the first working electrode and the first reference electrode, the fluid in the second compartment causing a fluid connection between the second working electrode and the second reference electrode. 
     
     
         14 . The apparatus of  claim 13  wherein the first working electrode is at a first voltage potential and the fluid in the first compartment is at a second voltage potential via the first reference electrode located in the same compartment as the first working electrode, wherein the first controllable voltage potential relationship is formed based on the first voltage potential and the second voltage potential causing a current to flow through the fluid in the first compartment via the first working electrode. 
     
     
         15 . The apparatus of  claim 14  wherein the first working electrode is at a first voltage potential and the fluid within the second compartment is at a third voltage potential via the second reference electrode located in the same compartment as the second working electrode, wherein the second controllable voltage potential relationship is formed based on the first voltage potential and the third voltage potential preventing an appreciable current from flowing through the fluid in the second compartment via the second working electrode. 
     
     
         16 . The apparatus of  claim 1  further comprising a plurality of counter electrodes, the plurality of counter electrodes comprising a first counter electrode and a second counter electrode, the first counter electrode being located in the first compartment, the second counter electrode being located in the second compartment. 
     
     
         17 . A method for measuring a signal via an apparatus, the apparatus comprising (1) a plurality of conductors, (2) a plurality of electrodes arranged as an electrode array, and (3) a plurality of compartments for containing a fluid, and wherein each compartment contains at least one of the electrodes, the method comprising:
 filling a plurality of the compartments with a fluid;   enabling a selected electrode of the electrode array;   while the selected electrode is enabled and while the compartments are filled with the fluid, electrically blocking a current path through the fluid compartments that do not contain the enabled electrode;   measuring a signal from the enabled electrode while the current path is electrically blocked.   
     
     
         18 . The method of  claim 17 , further comprising repeating the enabling, electrically blocking, and measuring steps for different selected electrodes of the electrode array. 
     
     
         19 . A method for measuring a signal via an apparatus, the apparatus comprising (1) a plurality of conductors, (2) a plurality of electrodes arranged as an electrode array, and (3) a plurality of compartments for containing a fluid, wherein each conductor contacts a plurality of the electrodes, and wherein each compartment contains a plurality of the electrodes, the method comprising:
 filling a plurality of the compartments with a fluid;   within a fluid compartment containing a selected electrode of the electrode array, disabling a reaction by the fluid;   while the fluid reaction is disabled within the fluid compartment containing the selected electrode, enabling a fluid reaction in the fluid compartments that contain a plurality of the electrodes other than the selected electrode;   measuring a signal from the selected electrode while (1) the fluid reaction within the fluid compartment containing the selected electrode is disabled and (2) the fluid reaction within the fluid compartments containing the electrodes other than the selected electrode is enabled.   
     
     
         20 . The method of  claim 19 , further comprising repeating the enabling, electrically blocking, and measuring steps for different selected electrodes of the electrode array.