Microfluidic, electrochemical devices

• US 9,192,933 B2
• Filed: 03/08/2010
• Issued: 11/24/2015
• Est. Priority Date: 03/06/2009
• Status: Expired due to Fees

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Inventors: Whitesides, George M., Nie, Zhihong, Nijhuis, Christian, Chen, Xin, Martinez, Andres W., Narovlyansky, Max
• Primary Examiner(s): Kaur, Gurpreet
• Application Number:
  US13/254,967
• Publication Number:
  US 20120181184A1
• Time in Patent Office: 2,087 Days
• US Class Current: 1/1
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 3/502 with fluid transport, e.g. in multi-compartment structures centrifugal-type cuvettes G01N21/07; analysis by separation into components G01N30/00; automatic analysers G01N35/00
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

Microfluidic, electrochemical devices are described. The microfluidic, electrochemical device comprises one or more electrode(s) on a substrate and a patterned porous, hydrophilic layer having a fluid-impermeable barrier which substantially permeates the thickness of the porous, hydrophilic layer and defines boundaries of one or more hydrophilic channels within the patterned porous, hydrophilic layer, wherein the hydrophilic channel(s) comprises a hydrophilic region which is in fluidic communication with the electrode(s). In some embodiments, the electrodes comprise a working electrode, a counter electrode, and a reference electrode. In some embodiments, the microfluidic, electrochemical device further comprises a fluid sink. The method of assembling the microfluidic, electrochemical device is described. The method of using the device for electrochemical analysis of one or more analytes is also described.

Claims

1. A microfluidic, electrochemical analysis device comprising:

plural porous, hydrophilic layers, respectively separated by a fluid impermeable layer defining one or more openings in alignment with at least a portion of one or more hydrophilic channels within a hydrophilic layer to permit vertical fluidic communication through said fluid impermeable layer between said hydrophilic layers, wherein a porous, hydrophilic layer comprises a fluid sample deposition region and a patterned, fluid impermeable boundary that substantially permeates the thickness of the hydrophilic layer and defines the one or more hydrophilic channels therewithin in fluidic communication with said deposition region which permit fluidic flow within the one or more channels; and

an electrode assembly comprising one or more electrodes in fluidic communication with said deposition region through the one or more hydrophilic channels, wherein said electrode assembly is disposed in fluidic communication with the one or more hydrophilic channels on one hydrophilic layer and a sample deposition region disposed on another hydrophilic layer.

2. The device of claim 1 wherein the electrode assembly is supported by or comprises a portion of said porous, hydrophilic layer.

3. The device of claim 1 wherein the device further comprises a substrate layer supporting the electrode assembly.

4. The device of claim 3 wherein the substrate comprises paper or plastic film.

5. The device of claim 1 wherein the fluid impermeable boundary further defines said sample deposition region.

6. The device of claim 1 further comprising a filter or an assay reagent in a hydrophilic channel.

7. The device of claim 1 wherein a said fluid impermeable layer comprises a polymer sheet or an adhesive sheet.

8. The device of claim 1 wherein said porous, hydrophilic layer comprises paper.

9. The device of claim 1 wherein said porous, hydrophilic layer comprises chromatography paper.

10. The device of claim 1 further comprising a fluid sink in fluidic communication with and downstream of one end of the hydrophilic channel and said electrode assembly enabling flow of a fluid through the hydrophilic channel and across said electrode assembly.

11. The device of claim 1 wherein the electrode assembly comprises an electrically conductive region of said hydrophilic layer surrounded at least in part by a fluid impermeable boundary.

12. The device of claim 1 wherein the fluid impermeable boundary comprises a wax or a polymerized photoresist.

13. The device of claim 1 wherein the electrode assembly comprises a working electrode and a counter electrode.

14. The device of claim 13 wherein the electrode assembly further comprises a reference electrode.

15. The device of claim 1 wherein the electrodes of said electrode assembly are arranged side by side on one of said hydrophilic layers.

17. The device of claim 3 wherein an electrode of the electrode assembly is screen-printed on the substrate layer.

18. A method of determining the presence or concentration of one or more analytes in a fluid sample using a microfluidic, electrochemical device of claim 1, comprising:

depositing a fluid sample onto said deposition region;

permitting the sample to wick along a hydrophilic channel to provide fluidic contact of the sample with said electrode assembly; and

measuring an electrochemical parameter with said electrode assembly as an indicator of the presence or concentration of an analyte in the sample.

19. The method of claim 18 wherein the electrochemical parameter is correlated with a concentration of an analyte.

20. The method of claim 18 wherein the electrochemical parameter is correlated with the presence of the one or more analytes.

21. The method of claim 18 wherein said sample deposition region is positioned over said electrode assembly.

22. The method of claim 18 wherein the microfluidic, electrochemical device further comprises

a fluid sink in fluidic communication with a distal end of a said hydrophilic channel comprising a hydrophilic region in fluidic communication with the electrode assembly;

and

the method further comprising;

depositing a fluidic sample onto said deposition region disposed at a proximal end of a said hydrophilic channel; and

permitting transport of fluid in the sample through capillary action over the electrode assembly and into the fluid sink.

23. The method of claim 18 wherein measuring an electrochemical parameter comprises measuring impedance, current, or voltage.

24. The method of claim 18 wherein the step of measuring an electrical parameter is done by a method selected from the group consisting of amperometry, biamperometry, stripping voltammetry, differential pulse voltammetry, cyclic voltammetry, coulometry, chronoamperometry, and potentiometry.

25. The method of claim 18 wherein the analyte comprises glucose, cholesterol, uric acid, lactate, blood gases, DNA, haemoglobin, nitric oxide, or blood ketones.

26. The method of claim 18 wherein measuring an electrochemical parameter comprises anodic stripping voltammetry.

16. A microfluidic, electrochemical analysis device comprising:

plural porous, hydrophilic layers, respectively separated by a fluid impermeable layer defining one or more openings in alignment with at least a portion of one or more hydrophilic channels within a hydrophilic layer to permit vertical fluidic communication through said fluid impermeable layer between the hydrophilic layers, wherein a porous, hydrophilic layer comprises a fluid sample deposition region and a patterned, fluid impermeable boundary that substantially permeates the thickness of the hydrophilic layer and defines the one or more hydrophilic channels therewithin in fluidic communication with said deposition region which permit fluidic flow within the one or more hydrophilic channels; and

an electrode assembly comprising one or more electrodes in fluidic communication with said deposition region through the one or more hydrophilic channels, wherein the electrode assembly comprises electrodes arranged facing one another in adjacent layers.