Electrokinetic concentration devices
The present invention provides a device and methods of use thereof in concentrating a species of interest and/or controlling liquid flow in a device. The methods make use of a device comprising a fluidic chip comprising a planar array of channels through which a liquid comprising a species of interest can be made to pass with at least one rigid substrate connected thereto such that at least a portion of a surface of the substrate bounds the channels, and a high aspect ratio ion-selective membrane is embedded within the chip, attached to at least a portion of the channels. The device comprises a unit to induce an electric field in the channel and a unit to induce an electrokinetic or pressure driven flow in the channel.
1. A concentrating device comprising:
a fluidic chip comprising a planar array of channels through which a liquid comprising a species of interest can be made to pass;
at least one rigid substrate connected thereto such that at least a portion of a surface of said substrate bounds said channels;
a high aspect ratio ion-selective membrane, embedded within said chip, attached to at least a portion of said channels, said membrane being formed by introducing said liquid to a portion in said chip;
a unit to induce an electric field in said channels; and
a unit to induce an electrokinetic or pressure driven flow in said channels.
2. The device of claim 1 , wherein said unit to induce an electric field in said channel is a voltage supply.
3. The device of claim 2 , wherein a voltage applied by said voltage supply is between 50 mV and 1500 V.
4. The device of claim 2 , wherein said voltage supply applies equal voltage to opposing sides of said channel.
5. The device of claim 2 , wherein said voltage supply applies greater voltage to an anodic side of said channel, as compared to a cathodic side of said channel.
6. The device of claim 1 , wherein a width of said channel is between 0.1-500 μm.
7. The device of claim 1 , wherein a depth of said channel is between 5-50 μm.
8. The device of claim 1 , wherein a depth of said channel is between 50-150 μm.
9. The device of claim 1 , wherein said rigid substrate comprises pyrex, silicon, silicon dioxide, silicon nitride, quartz, PMMA, PC or acryl.
10. The device of claim 1 , wherein said fluidic chip comprises polydimethylsiloxane.
11. The device of claim 1 , wherein said high aspect ratio ion-selective membrane comprises polytetrafluoroethylenes (PTFEs), polyphosphazenes, polybenzimidazoles (PBIs), poly-zirconia, polyethyleneimine- poly(acrylic acid), perfluorosulfonates, non-fluorinated hydrocarbon polymers, polymer-inorganic composites or poly(ethylene oxide).
12. The device of claim 1 , wherein said liquid comprises sulfonated tetrafluorethylene copolymer.
13. The device of claim 12 , wherein said sulfonated tetrafluorethylene comprises a Nafion solution.
14. The device of claim 1 , wherein said high aspect ratio membrane comprises microparticles or beads.
15. The device of claim 14 , wherein said microparticles or beads comprising silica or polystyrene.
16. The device of claim 1 , wherein said high aspect ratio ion-selective membrane has a width of 1-10 μm.
17. The device of claim 1 , wherein said ion-selective membrane has a depth of 550-1050 μm.
18. The device of claim 1 , wherein a surface of said channel has been functionalized to reduce or enhance adsorption of said species of interest to said surface.
19. The device of claim 1 , wherein the surface of the channel has been functionalized to enhance or reduce the operation efficiency of the device.
20. The device of claim 1 , wherein said high aspect ratio ion selective membrane is not in contact or is in minimal contact with said rigid substrate.
21. The device of claim 1 , wherein said unit to induce an electric field in said channel comprises at least a pair of electrodes and a power supply.
22. The device of claim 1 , wherein said device is coupled to a separation system, detection system, analysis system or combination thereof.
23. The device of claim 1 , wherein the device is coupled to a mass spectrometer.