Porous polymer electrodes
Porous polymer electrode assemblies are useful in the detection or quantification of a variety of analytes. By preparing a porous monolith, and applying a conductive polymer to the monolith, a porous matrix is prepared that combines favorable conductive properties, by virtue of the presence of the conductive polymer, with the porous character of the underlying monolith. The resulting porous electrode can be used for qualitative or quantitative analysis, and the capture and/or release of selected charged materials, such as nucleic acids. The pores of the electrode matrix may also be filled with nonconductive material, yielding electrodes having a plurality of discrete conductive surfaces.
1 . A porous polymer electrode assembly, comprising:
a porous monolith;
a conductive polymer applied to at least a portion of the porous monolith, so that the surface of the conductive polymer defines a porous topography; and
a conductive material in electrical contact with at least a portion of the conductive polymer adapted to provide an electrical connection to a potential source.
2 . The electrode assembly of claim 1 , wherein the conductive material includes a conductive metal.
3 . The electrode assembly of claim 1 , further comprising a substrate adapted to support the porous monolith and conductive polymer.
4 . The electrode assembly of claim 1 , wherein the porous monolith includes a poly(acrylic acid) polymer or copolymer.
5 . The electrode assembly of claim 4 , wherein the porous monolith is prepared using phase separation and precipitation techniques.
6 . The electrode assembly of claim 4 , wherein the monolith is prepared by sintering polymeric microparticles.
7 . The electrode assembly of claim 1 , wherein the porous monolith is a porous carbon monolith.
8 . The electrode assembly of claim 1 , wherein the porous monolith has a macroporous topography.
9 . The electrode assembly of claim 1 , wherein the porous monolith includes pores having diameters of about 2 μm to about 100 μm.
10 . The electrode assembly of claim 1 , wherein the conductive polymer includes conductive polythiophene polymers or copolymers.
11 . The electrode assembly of claim 1 , wherein the applied conductive polymer has a thickness of about 10 Å to about 5 μm.
12 . The electrode assembly of claim 1 , wherein the applied conductive polymer has a thickness of about 5 nm to about 1000 nm.
13 . A porous polymer electrode assembly, comprising:
a macroporous monolith;
a conductive polymer applied to at least a portion of the macroporous monolith, so that the surface of the conductive polymer defines a macroporous topography; and
a conductive material in electrical contact with at least a portion of the conductive polymer adapted to provide an electrical connection to a potential source.
14 . The electrode assembly of claim 13 , wherein the macroporous monolith includes pores having diameters of about 2 μm to about 100 μm.
15 . A porous polymer electrode assembly, comprising:
a substrate;
a conductive layer disposed on the substrate;
a porous monolith disposed on the conductive layer; and
a conductive polymer applied to the porous monolith, so that the conductive polymer at least partially defines the pores present in the porous monolith, and so that an electrical connection is formed between the conductive layer and the conductive polymer.
16 . An electrode assembly, comprising
a porous nonconductive monolith;
a nonporous and nonconductive filler material filling the pores of the porous monolith; and
a conductive polymer disposed in the pores of the monolith, and interposed between the monolith and the filler material.
17 . The electrode assembly of claim 16 , wherein a surface of the electrode assembly exposes a plurality of conductive domains at least partially isolated by nonconductive filler material and nonconductive monolith.
18 . The electrode assembly of claim 16 , wherein channels present in the assembly expose a plurality of conductive domains at least partially isolated by nonconductive filler material and monolith.
19 . An electrochemical device comprising a porous polymer electrode, where the porous polymer electrode includes:
a porous monolith;
a conductive polymer applied to at least a portion of the porous monolith, so that the surface of the conductive polymer defines a porous topography; and
a conductive material in electrical contact with at least a portion of the conductive polymer adapted to provide an electrical connection to a potential source.
20 . The electrochemical device of claim 19 , further comprising a controller adapted to control the potential applied to the electrode assembly.
21 . The electrochemical device of claim 19 , further comprising fluidics for bringing a sample solution into contact with the electrode assembly.
22 . A method of manufacturing a porous polymer electrode assembly, comprising
applying a macroporous monolith to a substrate;
applying a conductive polymer to the macroporous monolith, so that the topography of the conductive polymer is defined by pores present in the monolith..
23 . The method of claim 22 , further comprising applying a conductive material to the substrate so that the conductive material is interposed between the substrate and the monolith, and an electrical connection is established between the conductive material and the conductive polymer.
24 . The method of claim 23 , further comprising modifying the surface of the conductive material to enhance binding of the monolith.
25 . The method of claim 22 , further comprising modifying the surface of the monolith to enhance binding of the conductive polymer.
26 . The method of claim 22 , wherein applying the porous monolith to the substrate includes phase separation and precipitation of a polymer.
27 . The method of claim 22 , wherein applying the porous monolith to the substrate includes sintering polymeric microparticles on the substrate.
28 . The method of claim 22 , wherein applying the porous monolith includes applying a carbon composition to the substrate.
29 . The method of claim 22 , wherein applying the conductive polymer surface includes oxidative polymerization of a suitable monomer.
30 . The method of claim 29 , wherein applying the conductive polymer surface includes chemical oxidation.
31 . The method of claim 29 , wherein applying the conductive polymer surface includes electrochemical oxidation.
32 . A method of analyzing a sample, comprising
contacting a sample that contains an analyte of interest with an electrode assembly;
wherein the electrode assembly includes:
a porous monolith;
a conductive polymer applied to at least a portion of the porous monolith, so that the surface of the conductive polymer defines a porous topography; and
a conductive material in electrical contact with at least a portion of the conductive polymer adapted to provide an electrical connection to a potential source;
and
applying an electrical potential to the electrode assembly.
33 . The method of claim 32 , wherein the analyte of interest is a charged biomolecule.
34 . The method of claim 32 , wherein the applied electrical potential is selected to capture the charged biomolecule at the electrode.
35 . The method of claim 32 , further comprising removing the applied electrical potential wherein the charged biomolecule is released.
36 . The method of claim 32 , further comprising removing the applied electrical potential wherein the charged biomolecule is not released.
37 . The method of claim 32 , wherein the applied electrical potential is a positive electrical potential.
38 . The method of claim 32 , wherein the analyte of interest includes an electrochemically active tag.
39 . The method of claim 32 , wherein the analyte is a nucleic acid polymer.
40 . The method of claim 39 , wherein the analyte is DNA.
41 . The method of claim 39 , wherein the nucleic acid polymer is produced during an amplification procedure.
42 . The method of claim 41 , where the amplification procedure includes PCR, OLA, RPA, HAD, NASBA, LAMP, EXPAR, or SDA.
43 . The method of claim 32 , wherein the porous polymer electrode includes a surface having pores that are appropriately sized to interact with the analyte of interest.