DEVICES FOR INDUCED CHARGE DEIONIZATION AND USE THEREOF

[001] This application claims the benefit of priority from IL Application No. 247303, filed on August 16, 2016. The content of the above document is incorporated by reference in its entirety as if fully set forth herein. FIELD OF INVENTION

[002] The present invention, in some embodiments thereof, relates to the separation of charged species.

BACKGROUND OF THE INVENTION

[003] The separation of ions and impurities from electrolytes has heretofore been generally achieved using a variety of conventional processes including: ion exchange, reverse osmosis, electrodialysis, electrodeposition, and filtering.

[004] The conventional ion exchange process generates large volumes of corrosive secondary wastes that must be treated for disposal through regeneration processes. Existing regeneration processes are typically carried out following the saturation of columns by ions, by pumping regeneration solutions, such as concentrated acids, bases, or salt solutions through the columns. These routine maintenance measures produce significant secondary wastes, as well as periodic interruptions of the deionization process. Secondary wastes resulting from the regeneration of the ion exchangers typically include used anion and cation exchange resins, as well as contaminated acids, bases and/or salt solutions.

[005] Capacitive deionization (CDI) is a process in which ionic species are removed from liquid solution, into the electrical double layers (EDLs) formed around each one of the two oppositely placed porous carbon electrodes under applied electric potential difference. The employed electrodes in CDI setup are typically prepared from activated carbon materials which provide a very large internal areas (per mass) for ion adsorption, in the order of 1000 m ² per gram. Cations are stored in the negatively charged electrode (cathode) and anions are stored in the positively charged electrode (anode). After the ion adsorption capacity of the electrodes has been reached, the applied cell voltage is reduced to zero and a small concentrated salt stream is obtained in the ion release-step. In this way the fresh water and the concentrated salt stream are produced intermittently. The two geometries commonly employed for CDI are "flow through" and "flow between". In "flow through" the two electrodes are separated by a thin open structured spacer, through which the water flows in a direction perpendicular to the electrodes. In "flow between" setup, the liquid flows parallel to a pair of parallel electrodes and the ionic species electro -migrate towards the electrodes in a direction normal to the flow field.

[006] However, CDI technology suffers from some drawbacks. Firstly, the "RC time" at which a typical CDI devices charge and remove ionic species from liquid under a given electric potential difference, is inherently limited by the distance between the electrodes. Secondly, CDI devices are characterized by discontinuous operation: a typical cycle of CDI cell is composed of two stages. During the first stage the porous electrodes adsorb ionic species from the liquid, while during the second release-step the ions are released into brackish water. Thirdly, typical CDI cells require a direct electrical connection to the porous electrodes. For efficient operation, this connection (also termed "current collector") must have low resistance, and should be well-coupled to the porous electrodes to reduce parasitic resistance.

SUMMARY OF THE INVENTION

[007] According to one aspect, there is provided a process for removing charged species from a fluid, the process comprising:

(i) providing the fluid to a chamber, wherein the chamber contains at least one polarizable particle, wherein the at least one polarizable particle is characterized by a porosity of at least 0.01%; and

(ii) applying an electrical field via a direct current (DC) in the fluid, so as to induce a positive pole and a negative pole on the at least one polarizable particle, thereby electroadsorbing the charged species on the at least one particle.

[008] In some embodiments, the polarizable particle is devoid of contact with an external electrode.

[009] In some embodiments, the polarizable particle is affixed to an inner base of the chamber.

[010] In some embodiments, the particle is characterized by a surface capacitance of from 1 μ /cm ² to 50 μ¥ /cm ² .

[011] In some embodiments, the polarizable particle is a plurality of particles being in fluid communication with each other.

[012] In some embodiments, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 50%, at least 60%, at least 70%, or at least 80% of the particles are fully separated from each other by the fluid. [013] In some embodiments, the least 80% of the particles are separated from each other by a gap of the liquid of at least 1 μηι.

[014] In some embodiments, the particle comprises activated carbon. In some embodiments, the activated carbon is a material selected from the group consisting of carbide - derived carbons, carbon nanotubes, graphene and carbon black, and any combination thereof. In some embodiments, the particle is characterized by a specific surface area of at least 100 m ² per gram.

[015] In some embodiments, the plurality of particles have an average diameter of from 100 nm to 10 cm.

[016] In some embodiments, the particle further comprises a polymeric matrix. In some embodiments, the polymeric matrix comprises a material selected from a polyamide, a polyolefin, polyethylene, polystyrene, epoxy, and any combination thereof.

[017] In some embodiments, the process further comprises a step of removing the charged species from the particles.

[018] In some embodiments, the charged species is selected from cations, and anions.

[019] In some embodiments, the charged species is selected from proteins, peptides, toxins, metabolites, and nucleic acid.

[020] According to another aspect, there is provided a kit comprising (a) at least one polarizable particle characterized by at least one of: a porosity of at least 0.01%; a specific surface area of at least 100 m ² per gram; capacitance of from 1 μΡ /cm ² to 50 μΡ /cm ² ; or any combination thereof, and (b) housing comprising a chamber configured to contain a fluid, wherein the housing is configured to induce an electric field through the contained liquid, and wherein the at least one polarizable particle is affixed to an inner base of the chamber.

[021] In some embodiments, the kit further comprises one or more of an instruction sheet, and a label.

[022] According to another aspect, there is provided a system comprising a chamber configured to contain a fluid comprising charged species, wherein the chamber contains at least one polarizable particle, an is configured to be operably connected to a power source, so as to apply an electrical field in the fluid, thereby inducing a positive pole and a negative pole on the at least one polarizable particle.

[023] In some embodiments, the polarizable particle is devoid of contact with environment external to air, the fluid, the charged species, and the chamber. In some embodiments, the polarizable particle is devoid of contact with an external electrode. [024] In some embodiments, the polarizable particle is affixed to an inner base of the chamber.

[025] In some embodiments, the polarizable particle is allowed to disperse in the fluid.

[026] In some embodiments, the system further comprises one or more probing tools selected from: a microscope, a photodetector, a photomultiplier tube (PMT), a conductivity detector, a point detector a radioactive detector, a camera, and any combination thereof.

[027] Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

[028] Exemplary embodiments are illustrated in referenced figures. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.

[029] In the drawings:

[030] Figures 1A-B present a schematic description highlighting key differences between: a typical CDI "flow between" configuration where the electrolyte is placed between a pair of porous conducting electrodes, each connected to electric potential source (Figure 1A), and the disclosed induced charge deionization (ICCDI) configuration where under an external electric field, a dipole moment is induced on a porous conductor which leads to capacitive charging of both types of ions on two opposite sides of the porous particle (Figure IB).

[031] Figures 2A-C show schematic illustrations of an exemplary device, according to some embodiments described hereinbelow.

[032] Figures 3A-B present a photo of an exemplary device used for experimental study of ICCDI (Figure 3A) and the exemplary dimensions of the setup (Figure 3B).

[033] Figures 4A-I present images demonstrating the use of ICCDI for depletion of salt concentration in the bulk liquid. The images show fluorescence signal of 100 uM sodium fluorescence under applied electrical field 260 V/m oriented from left to right, around 1.2 mm diameter carbon disk. The corresponding times were: 6 s (Figure 4A), 48 s (Figure 4B) and 108 s (Figure 4C) and around 18 disks of identical radius at times: 6 s (Figure 4D), 78 s (Figure 4E), and 240 s (Figure 4F). Figures 4G-I present images showing the raw fluorescence images showing the combined effect of ICCDI with pressure-driven flow from left to right, at different flow velocities u: 600 μιη/s (Figure 4G), 1 cm/s (Figure 4H), 4 cm/s (Figure 41).

[034] Figures 5A-B present a comparative fluorescence microscopy images of sodium fluorescence around 1mm diameter porous carbon disk (Figure 5A) vis-a-vis non-porous aluminum disk having the same size (Figure 5B). Both experiments (porous vs. non-porous disks) share identical experimental conditions; ambient solution 100 uM sodium fluorescence in DI, 20 V potential difference between external electrodes and recording time of one minute after the electrical current was switched on.

[035] Figures 6A-C present images demonstrating the use of ICCDI for focusing DNA molecules on the electrodes outer surface. The images show the fluorescence signal emitted by fluorescently labeled DNA in deionized water, at an initial concentration of 100 nM. Upon application of a 1300 V/m electric field, DNA molecules focus around the positively charged pole of the electrode and a ~100x increase in concentration was observed within 60 s. The corresponding times were: 0 s (Figure 6A), 30 s (Figure 6B), and 60 s (Figure 6C).

[036] Figure 7 presents a scheme demonstrating the process of focusing of biomolecules for bioanalysis: focusing of ionic species, such as salts and biomolecules.

[037] Figures 8A-D present schemes demonstrating the process of buffer exchange showing the steps of providing a buffer (Figure 8A), focusing the species on the particle by applying an electric field (Figure 8B), replacing the buffer (Figure 8C), and releasing the species to the new buffer by changing the direction of the electric field (Figure 8D).

[038] Figures 9A-C present images showing raw fluorescence images showing the discharge process of 1.2 mm diameter carbon disk previously charged with 100 μΜ sodium fluorescein for 5 min. When the electric field is flipped, the initial discharge process results in release of fluorescein from the right pole resulting in an observable intensity increase. At later times, re-charging of the disk results in renewed depletion at the pole. The electrical field was 260 V/m, oriented from right to left (a) 3 s (Figure 9A), (b) 12 s (Figure 9B), and (c) 30 s (Figure 9C).

DETAILED DESCRIPTION OF THE INVENTION [039] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details set forth in the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. [040] The present invention, in some embodiments thereof, is directed to polarizable (conducting or dielectric) porous particle(s) (also referred to herein as "electrode") in an applied electric field, e.g., for the purpose of removing from (or injecting ions to) a fluid (e.g., liquid). In some embodiments, the particle(s) is dispersed in the liquid. In some embodiments, the particle(s) is floating in the liquid.

[041] In some embodiments, there is provided a process for removing charged species from a fluid. In some embodiment, the process comprises providing at least one particle in a fluid, and inducing an electrical field in the fluid, so as to induce a positive pole and a negative pole onto the particle, thereby adsorbing the charged species on the particle.

[042] In some embodiment, the process comprises filling a chamber (partially or fully) with a fluid, wherein the chamber contains one or more polarizable particles and applying an electric field in the fluid, so as to induce a positive pole and a negative pole on the one or more polarizable particles, thereby adsorbing the charged species on the one or more particles.

[043] In some embodiments, the kinetic process is driven by electric field between two or more electrodes. In exemplary embodiments, the electric field is derived from a direct current (DC). In exemplary embodiments, the electric field is derived from direct current (DC), thereby avoiding e.g., unfavorably alternating the direction of the electrical field. Without being bound by any particular mechanism, it is assumed that the electrical field having a defined direction allows the polarization of the polarizable particles and therefore the adsorption of charged species.

[044] In some embodiment, the fluid is gas. In some embodiment, the fluid is water. In some embodiment, the fluid is an aqueous solution.

The Particles

[045] In some embodiment, the particle is polarizable. The term "polarizable" as used herein may refer to any material whose internal charge distribution changes under an external electric field. Non-limiting examples of such materials include conductors and dielectric materials.

[046] In some embodiments, the conductor is characterized by free charge carriers moving to the boundaries of the material upon applying an electric field, thereby eliminating the electric field within the conductor's volume.

[047] In some embodiments, the conductivity of the conductor may vary between 1 to 10 ^s

S/m.

[048] In some embodiments, upon placing in an electric field, the dielectric material is characterized by electric charges slightly shifting from their average equilibrium positions causing dielectric polarization. That is, each molecule forms an electric dipole which leads on an effective charge on the boundaries.

[049] In some embodiments, dielectric materials are characterized by high polarizability, as further expressed by dielectric constant (also referred to as "relative permittivity"). Relative permittivity is the factor by which the electric field between the charges is decreased relative to vacuum.

[050] In some embodiments, the relative permittivity is between 1 to 250,000.

[051] In some embodiment, the particle is characterized by a defined porous structure, or porosity.

[052] The term "porous" as used herein refers to a particle that comprises pores, holes, or voids.

[053] The term "porosity" refers to a measure of the void spaces in the particle, and is measured as a fraction, between 0-1, or as a percentage between 0 to 100%.

[054] In some embodiment, porosity of the particle is between 0.01 to 0.99.

[055] In some embodiment, porosity of the particle is 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,

0.7, 0.8, 0.9, or 0.99, including any value and range therebetween.

[056] In some embodiment, the size (e.g., diameter, length) of the pores is between 0.5 nm to 500 nm, e.g., 0.5 nm, 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, or 500 nm, including any value or range therebetween.

[057] Therefore, in some embodiments, the electric field induces electric dipole in the porous solid, leading to capacitive charging of both cations and anions on two of its' opposite sides.

[058] In some embodiment, the applied electric voltage is smaller than e.g., 10V, 9V, 8V, 7V, 6V, 5V, 4V, 3V, 2V, or IV.

[059] In some embodiment, the applied electric voltage is IV. That is, the electric field is, for example, 1000 V/m (when applied on 1 mm particle), or, 10,000 V/m (when applied on 100 μιη particle).

[060] In some embodiment, the charging process results in local depletion of surrounding ionic species around the particle.

[061] In some embodiment, the particle is characterized by a surface capacitance of from

1 μΐ /cm ² to 50 μΈ /cm ² . In some embodiment, the capacitance is 1 μΐ/cm ² , 5 μΤ/cm ² , 10 μΤ/cm ² , 15 μΤ/cm ² , 20 μΤ/cm ² , 25 μΤ/cm ² , 30 μΤ/cm ² , 35 μΤ/cm ² , 40 μΤ/cm ² , 45 μΤ/cm ² , or 50 μΤ/cm ² , including any value and range therebetween. [062] As described hereinthroughout, the inventors have demonstrated a surprising phenomenon of induced charge deionization (referred to as "ICCDI") that occurs around a porous and conducting solid immersed in an electrolyte, under the action of an external electrical field.

[063] Reference is made to Figures 1A-B which present a typical CDI setup (Figure 1A), and, in sharp contrast, the porous particle in the disclosed ICCDI setup (Figure IB).

[064] In some embodiment, the porous particle is devoid of any connection or contact to any other external electrode (e.g., no current collector is used). In some embodiment, the porous particle is devoid of contact with environment external to air, the fluid, the charged species, and the chamber as described hereinbelow.

[065] In some embodiments, at least a portion of the plurality of particles is fully separated from each other by the fluid.

[066] By "a portion" it is meant to refer to, for example, a surface or a portion thereof, and/or a body or a portion thereof, or a volume or a part thereof. In some embodiments, by "a portion" as used herein throughout, it is meant e.g., at least 1 percent, at least 20 percent, at least 30 percent, at least 40 percent, at least 50 percent, at least 60 percent, at least 70 percent, at least 80 percent, at least 90 percent, and optionally all of the surface is coated by e.g., the adsorbed species (e.g., ions), as feasible, including any value therebetween.

[067] In some embodiments, the term "adsorbing", or any grammatical derivative thereof, as used herein, generally refers to the binding or adhesion of a molecule or ion to the surface of the particle.

[068] In some embodiments, the term "adsorbing" refers to "electroadsorbing" i.e., binding by applying an electric force.

[069] In some embodiments, the highly porous particle comprises carbon fibers. In some embodiments, the highly porous particle comprises graphite. In some embodiments, the highly porous particle comprises a particulate material having a high surface area, such as activated carbon, molecular sieves, zeolite, or any other material having a high surface area, porous polymer, metal hydroxide or hydrophobic particles.

[070] In some embodiments, a plurality of particles comprises more than one materials, wherein, in some embodiments, each particle comprises different materials or property (e.g., pore size).

[071] Non-limiting examples of activated carbons are selected from carbide-derived carbons, carbon nanotubes, graphene and carbon black.

[072] In some embodiments, the particle is characterized by a defined specific surface area. [073] In some embodiments, the particle comprises a highly porous surface. In some embodiments, the particle comprises or is made up from carbon.

[074] In some embodiments, the particle comprises a polymeric material. In some embodiments, the polymeric material comprises a crosslinked polymer. The polymeric material may comprise crosslinked monomer units and non-crosslinked monomer units. The crosslinked polymer may have a ratio of crosslinking monomer units to non-crosslinking monomer units. In some embodiments, the crosslinked monomer unit is derived from divinyl benzene. In some embodiments, the non-crosslinked monomer unit is derived from styrene or a derivative thereof.

[075] In some embodiments, the polymer is selected from, without being limited thereto, crystallizable side-chain polymers, degradable polymers, hybrids, bicontinuous polymers, organic- inorganic hybrids and polymers obtained from atom transfer radical polymerization.

[076] In some embodiments, the polymer is characterized by a porous structure e.g., micro-, meso-, and/or macroporous structure.

[077] By "microporous" it is meant to refer to pore length or diameter, d, of less than 2 nm. By "mesoporous" it is meant to refer to pore length or diameter, d, of 2 nm < d < 50 nm. By "macroporous" it is meant to refer to pore length or diameter, d, of above 50 nm.

[078] As used herein, the term "polymer" describes a substance (e.g., an organic substance) composed of a plurality of repeating structural units (monomeric units) covalently connected to one another.

[079] The term "specific surface area" as used herein is defined as the accessible area of solid surface per unit mass of material. The measurement of the specific surface areas may be performed by any method known in the art e.g., BET (Brunauer-Emmett-Teller).

[080] In some embodiments, the particle is characterized by a specific surface area of at least 100 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 150 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 200 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 250 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 300 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 350 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 400 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 450 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 500 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 550 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 600 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 650 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 700 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 750 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 800 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 850 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 900 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 950 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of at least 1000 m ² per gram. In some embodiments, the particle is characterized by a specific surface area of about 2000 m ² per gram.

[081] In some embodiments, the one or more particles are separated from an electrode by a gap, e.g., such that the fluid fills the gap between the one or more particles and the electrode. In some embodiments, the plurality of particles is separated from each other by a gap, e.g., such that the fluid fills the gap between the particles. In some embodiments, the gap features a size of at least 0.1 μηι. In some embodiments, the gap is at least 0.2 μιη. In some embodiments, the gap features a size of at least 0.3 μιη. In some embodiments, the gap features a size of at least 0.4 μιη. In some embodiments, the gap features a size of at least 0.5 μιη. In some embodiments, the gap features a size of at least 0.6 μιη. In some embodiments, the gap features a size of at least 0.7 μιη. In some embodiments, the gap features a size of at least 0.8 μιη. In some embodiments, the gap features a size of at least 0.9 μιη. In some embodiments, the gap features a size of at least 1 μιη. In some embodiments, the gap features a size of at least 1.5 μιη.

[082] In some embodiments, the size of the particle described herein represents an average size of a plurality of particles. In some embodiments, by "size" it is meant to refer to at least one dimension thereof (e.g., diameter, length).

[083] In some embodiments, the average size (e.g., diameter, length) ranges from about

100 nanometers (nm) to 10 cm. In some embodiments, the average size ranges from about 500 nm to about 100 mm. In some embodiments, the average size ranges from about Ιμιη to about 100 mm.

[084] The particle can be generally shaped as a sphere, a rod, a cylinder, a disc, a ribbon, a sponge, and any other shape, or can be in the form of a cluster of any of these shapes, or can comprises a mixture of one or more shapes.

[085] In some embodiment, the "at least one particle" refers to a plurality of particles. In some embodiments, at least some, and in some embodiments, most of the particles are generally shaped as spheres or discs. [086] In some embodiments, the plurality of particles are the same or are different, in some embodiments, at least 50 %, 60 %, 70 %, 80 %, 90 %, 95 %, 98 %, 99%, 99.9 %, or all of the particles are the same. In some embodiments, by "the same" it is meant comprising substantially the same material (e.g., polymer).

[087] In some embodiments, the particle is in the form of a bead.

[088] In some embodiments, the particle refers to cluster of particles being embedded to each other by a polymeric matrix.

[089] In some embodiments, the particle further comprises a polymeric material selected from, but not limited to, a polyamide, a polyolefin (e.g., polyethylene), polystyrene, epoxy, a conductive polymer and any combination thereof.

The Devices

[090] Reference is now made to Figure 2A, which shows a perspective view of an exemplary device 100A.

[091] Device 100A may have housing. The housing may fully encapsulate elements of device 100A and may be made of a rigid, durable material, such as aluminum, stainless steel, a hard polymer and/or the like. The housing may partially encapsulate elements of device 100A. The housing may prevent unwanted foreign elements from entering device 100A.

[092] Device 100A may have a chamber (e.g., a fluidic chamber) 110. Chamber 110 may be defined by a pair of panels, and has a height (H) extending between interior surfaces of the panels. Chamber 110 may allow storing a sample (e.g., a fluid) therein (e.g., between the panels). Device 100A may have a particle 120 as described and exemplified hereinthroughout, e.g., porous particle. Particle 120 may be a bead having a cylinder shape, having two ends 122, and 124, with a defined diameter. Particle 120 may be in contact with chamber 110 via one end thereof. Particle 120 may be fixed with chamber 110 via one end thereof. Particle 120 may have a defined range of dimension thereof (height, and diameter, referred to as "r" and "h" in this Figure, respectively). Chamber 110 may be disposable. Particle 120 may be disposable.

[093] Device 100A may have a plurality of particles 120 in chamber 110. Plurality of particles 120 may be substantially not in contact with each other (e.g., substantially are not packed or at least are not vertically packed in chamber 110, thereby allowing an optimum contact surface with the liquid).

[094] Particle 120 may have a height 126 (referred to as "h"). Height 126 may extend between two ends 122, and 124 of particle 120. Particle 120 may be fixed atop chamber 110 via end 122. Two ends 122, and 124 may have an average diameter ("r") 128. [095] Device 100A may allow adsorbing charged species (e.g., ions; cation and anions) from a fluid in chamber 110 on particle 120.

[096] Device 100A may be operable connected to at least one power source 130. Power source 130 may allow applying an electric field (via DC) through chamber 110 or content (liquid) therein. Electric field may induce a positive and negative pole on particle 120.

[097] Power source 130 may allow applying an electric field via external electrodes 132.

[098] External electrodes 132 may be porous (working in capacitive mode) or standard non-porous (working in Faradaic mode).

[099] That is, electric field may be accomplished through Faradaic reactions on the driving electrodes, or, alternatively, may be accomplished through capacitive charging the driving electrodes.

[0100] Accordingly, particle 120 may undergo Faradaic charging or capacitive charging (e.g., on its surface).

[0101] In some embodiments, external electrodes 132 are not in direct contact with particle 120.

[0102] In exemplary configurations the device is characterized by:

Particle sizes of 100 nm≤ r, h, H≤ 10 cm;

Pore sizes of the particle in the range of between 0.5 nm to 500 nm;

porosity of the particle in the rage of between 0.01 to 0.99;

Surface area of porous particles of between 100 m ² /gr to 2000 m ² / gr; and

Surface charge the particle 1 /cm ² to 50 /cm ² .

[0103] Reference is now made to Figure 2B, which shows a perspective view of another exemplary configuration (referred to as "device 100B") of device 100A.

[0104] Figure 2B presents device 100B having a plurality of fixed array of particles 120. By "fixed particle(s)" it is meant to refer to particle(s) being immobilized to an inner base of chamber 110.

[0105] The plurality of fixed particles or non-fixed particles 120 may be in fluid communication with each other.

[0106] Reference is now made to Figure 2C, which shows a perspective view of another exemplary configuration (referred to as "device lOOC") of device 100A.

[0107] Figure 2C presents device lOOC having a plurality of non-fixed particles 120. Non- fixed particles 120 may be disposable for a one cycle of adsorption. [0108] Device lOOC may allow adsorbing charged species (e.g., ions; cation and anions) onto particles 120 from a fluid in chamber 110 in a continuous regime (e.g., followed by filtration, release of adsorbed ions by reversing electric field and/or providing new particles 120), thereby increasing the local concentration of biological or organic molecules (e.g., nucleic acid such as DNA) on/near particles 120.

[0109] In additional exemplary configurations, a plurality of particles 120 are fixed to chamber 110, each one connected to power source 130. In these configurations the electric potential on each one of the particles is set directly by a different power source. Moreover, in these configurations, two different modes of operation are allowed for adsorbing biological or organic molecules (e.g., DNA) from the fluid:

The first mode comprises a step of applying an electric field so as to increase biological or organic molecule concentration ("also referred to as: "focusing") near one of particles 120 having a defined porous without being adsorbed onto particles 120.

The second mode comprises the step of applying an electric field so as to allow the biological or organic molecules to accumulate and penetrate porous particles 120.

[0110] In exemplary embodiments, after sufficient long time an electric field may be applied in an opposite direction, so as to allow releasing the molecules e.g., in a different chamber. The increased concentration can be observed e.g., via fluorescence.

[0111] As used hereinthroughout, the term "fluid communication" means fluidically interconnected, and refers to the existence of a continuous coherent flow path from one of the components of the system to the other if there is, or can be established. In some embodiments, liquid may flow through and between the ports or particles, which when desired, may impede fluid flow therebetween.

[0112] The term "array of particles" may refer to a plurality of electrodes (particles).

[0113] The terms "electrodes", "particles" "array of electrodes" or "arrangement of electrodes" do not necessarily refer to any specific geometric arrangement thereof.

[0114] The term "atop" as used herein is not restricted to a particular orientation with respect to the gravitational field of the local environment, but simply refers to one element being disposed on another element, optionally with one or more intermediate elements disposed therebetween, unless otherwise indicated.

Systems

[0115] In some embodiment, there is provided a system comprising the disclosed device or kit. [0116] In some embodiment, the system as described herein further comprises a photodetector.

[0117] In some embodiment, the system as described herein further comprises, or is configured to be operable with, a power source for inducing an electric field (e.g., via DC).

[0118] In some embodiments, the system described herein further comprises one or more probing tools. In some embodiments, the probing tool is a camera. In some embodiments, the probing tool is a radioactive probe or detector. In some embodiments, the probing tool is a calorimetric detector. In some embodiments, the probing tool is a point detector. In some embodiments, the probing tool is a photodetector. In some embodiments, the probing tool is a fluorescence detector.

[0119] In some embodiments, the disclosed system further comprises a computer program product.

[0120] In some embodiments, the computer program product comprises a computer- readable storage medium. The computer-readable storage medium may have program code embodied therewith. The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

[0121] Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.

[0122] Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.

[0123] These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified herein. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified hereinthroughout.

[0124] The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the schemes.

Applications

[0125] Unless otherwise indicated, as used herein, a "sample" refers to a fluid (e.g., liquid such as aqueous solution comprising an electrolyte) capable of flowing through, or being stored in, chamber 110. Thus, a sample can include a fluid suspension of biologically derived molecules (such as DNA) as further described hereinbelow.

[0126] A sample can generally include suspensions, or liquids, having at least one type of molecules, or ions, disposed therein.

[0127] In some embodiments, the device described herein can be adapted for various applications such as, water desalination systems, and/or water purification systems. For example, applying electric field in a solution with suspended or fixed porous and conducting particles (e.g., in the form of beads) may invoke ICCDI and fast removal of ionic species from a portion of or from the whole volume of the solution.

[0128] In some embodiments, and without being bound by any particular theory, by "fast removal" it is meant that typical desalination time needed to reach identical result as compared against standard CDI methods, is expected to be smaller by a factor r/L, where r is beads' radius, L is the size of the chamber, which leads to the conclusion that times desalination time may be reduced by few orders of magnitude.

[0129] In some embodiments, the porous particle may be separated from the liquid and discharged from the molecules or salt (e.g., in another chamber). In some embodiments, continuity of this process enables continuous operation of the desalination chamber.

[0130] In some embodiments, the device described herein can be adapted for increasing local concentration of species, such as salts and biomolecules.

[0131] In some embodiments, invoking ICCDI on a porous particle leads to accumulation of cations and anions either in/on or around the particle.

[0132] In some embodiments, a CDI device (see Figure 1A) is used for increasing local concentration of species, such as biomolecules, near a porous electrode.

[0133] In some embodiments, the disclosed device is used for invoking ICCDI on a porous particle leading to the accumulation of cations and anions either in/on or around the particle. In some embodiments, increasing local concentration of species enables rapid reaction between species.

[0134] In some embodiments, as exemplified hereinthroughout, the sample is a biological sample. [0135] The term "biological sample" as used herein refers to a sample that may originate, be obtained or isolated from any source of the animal kingdom, depending on the intended use of the disclosed process. For example, the sample may originate, be obtained or isolated from any subject of vertebrates, such as mammals, reptiles, fish, birds, and amphibians. In some embodiments, the biological sample is isolated or originating or obtained from a mammalian subject, such as a human being or a bovine subject. In other non-limiting examples, the sample is a sample originating, obtained or isolated from a ruminant, a ferret, a badger, a rodent, an elephant, a bird, a pig, a deer, a coyote, a camel, a puma, a fish, a dog, a cat, a non-human primate or a human.

[0136] In some embodiments, the biological sample is selected from a biological content e.g., a cell extract, tissue sample, blood sample, viruses, virus particles, protein, DNA, RNA or metabolites.

[0137] In some example the protein is selected from a growth factor, cytokine, chemokine, neurotransmitter, antibody or an enzyme.

[0138] In some embodiments, the term "isolated" refers to isolated from the natural environment. In some embodiments, this term relates to blood or tissue sample isolated from a subject to be diagnosed.

[0139] The sample may be diluted or concentrated prior to application to the device or it may be subject to pre- treatment steps to alter the composition, form or some other property of the sample. Pre-treatment steps may include, for example, cell lysis.

[0140] In some embodiments, the disclosed device and process are used for integrated nucleic acid (DNA, RNA, cDNA, etc.) adsorption on the particles, and extraction and fractionation of different molecular weight nucleic acid molecules, from biological and clinical samples.

[0141] In some embodiments, the extraction and fractionation of nucleic acid is used for downstream applications such as, without being limited to, polymerase chain reaction (PCR), helicase-dependent amplification (HDA), recombinase polymerase amplification (RPA), hybridization (such as southern blotting, microarrays, expression arrays, etc.), DNA sequencing (including integrated extraction and size selection for paired-end sequencing) and other related applications.

[0142] Methodologies for analyzing the sequence and biology of DNA or RNA presently used in the art merely collect all DNA present in a biological or clinical sample.

[0143] In some embodiments, separation of DNA as disclosed herein may provide a method for enriching samples for specific DNA of interest. For example, a molecular diagnostic test for a blood born bacterial infection would benefit from enriching the sample for molecular weight DNA of the bacterial genomic DNA (gDNA) and discarding smaller fragments of DNA and larger fragments of human DNA.

[0144] In some embodiments, the species or the molecules may be physically released from the disclosed particles by reversing DC electric field or by switching it off. In some embodiments, the species or molecules are analyzed by any method known in the art, as described hereinthroughout e.g., using a sample analysis by chromatograph and PCR.

[0145] In some embodiments, the device described herein is used for buffer exchange. That is, in some embodiments, species remain adsorbed in/on the porous particles, while the buffer outside the particles is replaced with a different one. In some embodiments, upon inversion of the field, species may be released into the new buffer.

[0146] In some embodiments, the disclosed device may be used as a biosensor. As used herein and in the art, biosensors are analytical devices that combine a biological material (e.g., tissues, microorganisms, enzymes, antibodies, nucleic acids etc.) or a biologically-derived material with a physicochemical transducer or transducing microsystem. This transducer may be e.g., optical, electrochemical, thermometric, piezoelectric, magnetic or radioactive. Biosensors may yield a digital electronic signal which is proportional to the concentration of a specific analyte or group of analytes (e.g., samples and species as described herein, such as biomolecules or a toxins).

[0147] While the signal may in principle be continuous, the disclosed devices may be configured to yield single measurements to meet specific application requirements. Biosensors may be used in a wide variety of analytical problems including those found in medicine, the environment, food processing industries, security and defense.

[0148] In some embodiment, the ionic species may be detected by standard methods known in the art e.g., by fluorescence microscopy.

Sample Analysis

[0149] In some embodiments, there is provided a method of sample analysis, the method comprising the steps of:

(a) depositing a fluid sample of interest to be analyzed in the device disclosed herein in an embodiment thereof;

(b) establishing an electric field, thereby inducing an electric dipole in the porous particle, leading to capacitive charging of both cations and anions on two of opposite sides of the particle; and

(c) detecting local depletion of charged or ionic species around the particle or on the particle, by a method known in the art. [0150] Herein, "sample analysis" may be chemical analysis on small volume such as micro- sized volume. The term "chemical analysis" can refer to, for example, the qualitative and/or quantitative detection and/or separation of molecules of interest. In some embodiments, the device and process disclosed herein enables processing large volumes of samples (e.g., hundreds of μΐ,) in short period of time, e.g., less than 1 min.

[0151] In some embodiments, the action performed in response to an electric field change is substantially modulating the electric field for a pre-determined period of time. In some embodiments, the modulating is enhancing the electric field. In some embodiments, the modulating is switching the electric field off. In some embodiments, the modulating is changing the direction of the electric field.

[0152] In some embodiments, the sample analysis is further assisted by labeling the particles or the species (e.g., ions) in the fluid e.g., using a labeling agent.

[0153] In some embodiments, the phrase "labeling agent" (or "labeling compound"), as used herein, describes a detectable moiety or a probe. Exemplary labeling agents which are suitable for use in the context of these embodiments include, but are not limited to, a fluorescent agent, a radioactive agent, a near infra-red (IR) dye (e.g., indocyamine green), a rhodamine dye, a fluorescein dye, a magnetic agent or nanoparticle, a chromophore, a photochromic compound, a bioluminescent agent, a chemiluminescent agent, a phosphorescent agent and a heavy metal cluster.

[0154] In some embodiments, the label is a dye. In some embodiments, the label is a fluorescent dye. In other embodiments, the label is a radioactive agent. In some embodiments, the label is a metal such as, without being limited thereto, gold or silver.

[0155] In some embodiments, the phrase "radioactive agent" describes a substance (i.e. radionuclide or radioisotope) which loses energy (decays) by emitting ionizing particles and radiation. When the substance decays, its presence can be determined by detecting the radiation emitted by it. For these purposes, a particularly useful type of radioactive decay is positron emission. Exemplary radioactive agents include ^99m Tc ¹⁸ F, ¹³ II and ¹²⁵ I.

[0156] As used herein, the term "chromophore" describes a chemical moiety that, when attached to another molecule, renders the latter colored and thus visible when various spectrophotometric measurements are applied.

[0157] In some embodiments, the term "bioluminescent agent" describes a substance which emits light by a biochemical process.

[0158] In some embodiments, the term "chemiluminescent agent" describes a substance which emits light as the result of a chemical reaction. [0159] In some embodiments, the phrase "fluorescent agent" refers to a compound that emits light at a specific wavelength during exposure to radiation from an external source.

[0160] In some embodiments, the term "fluorescent detection" refers to a process wherein, excitation is supplied in the form of optical energy to a particular molecule which will then absorb the energy and subsequently release the energy at another wavelength. In some embodiments, the fluorescent detection technique requires the use of an excitation source, excitation filter, detection filter and detector, which may be in-built e.g., in fluorescence microscopy.

[0161] In some embodiments, the term "chemiluminescence" refers to a process wherein certain molecules when catalyzed in the presence of an enzyme, undergo a specific biochemical reaction and emit light at a particular wavelength as a result of this reaction. In some embodiments, chemiluminescent detection techniques only require a detector without the need for an excitation source or filters.

[0162] In some embodiments, the phrase "phosphorescent agent" refers to a compound emitting light without appreciable heat or external excitation.

[0163] In some embodiments, a heavy metal cluster can be, for example, a cluster of gold atoms used, for example, for labeling for e.g., electron microscopy examination.

[0164] Detection of nucleic acid samples may be obtained by use of different tailored primers and probes, e.g., oligonucleotide primers and/or oligonucleotide primers and probes of any suitable lengths may be used, for example, oligonucleotides of 5-300 nucleotides, such as 10- 200, 20-100, or 20-50 consecutive nucleotides.

The Kits

[0165] In some embodiments, there is provided a kit comprising the disclosed device, in any embodiment thereof. In some embodiments, the kit may be used for certain medical uses including, without being limited thereto, diagnostics.

[0166] In some embodiments, the term "diagnosis" and any grammatical derivative thereof, as use herein, refers to a method of determining a disease or disorder in a subject.

[0167] For example, the method may comprise identifying a charged or a polar biomarker in a sample from the subject wherein the presence of the microorganism in the sample is e.g., indicative of the disease or the disorder.

[0168] In some embodiments, the term "diagnosis" may also refer to "prognosis" which may include monitoring the diagnosis and/or prognosis over time, and/or statistical modeling based thereupon. [0169] That is, in some embodiments, the diagnosis may include: a. prediction (e.g., determining if a patient will likely develop e.g., hyperproliferative disease) b. prognosis (predicting whether a patient will likely have a better or worse outcome at a pre-selected time in the future) c. therapy selection.

[0170] The term "diagnosing" as used herein may also refer to determining presence or absence of pathology, classifying pathology or a symptom or determining a severity of the pathology. In some embodiments, the term "diagnosis" also refers, to screening, e.g., for cancer.

[0171] In some embodiments, the term "prognosis" as used herein refers to forecasting an outcome of pathology and/or prospects of recovery including the efficacy of medication or treatment. In some embodiments, the term "prognosis" further refers to the determination of tumor progress.

[0172] In some embodiments, the terms "marker", or "biomarker", refer to a biomolecule that is generated in response to a specific physiological condition. Biomarkers may or may not be uniquely associated with a particular physiological condition.

[0173] In some embodiments, the disclosed device is used to assess the change in status of the expression of a biomarker (e.g., protein) according to their charge. In some embodiments, the term "status" in this context is used according to its art accepted meaning and refers to the condition or state of a gene and/or its products including mRNA and protein. Typically, but not exclusively, skilled artisans use a number of parameters to evaluate the condition or state of a gene and its products. These include, but are not limited to, the location of expressed gene products (including the location of the marker expressing cells) as well as the level, and biological activity of expressed gene products (such as mRNA and polypeptides). In some embodiments, an alteration in the status of biomarker exhibits a change in the location of the mRNA or protein and/or the cancer cell marker expressing cells and/or an increase in the cancer cell marker mRNA and/or protein expression, or any combination thereof.

[0174] In some embodiments, the device described herein is used for creating pH gradients. That is, in some embodiments, porous particle may adsorb and/or desorb all ionic species, including H ⁺ (or H ₃ 0 ⁺ ), and therefore modifies local pH distribution around the porous particle. In some embodiments, controlling local pH values may assist protein separation according to their isoelectric point (pi).

[0175] In some embodiments, the pi is the pH at which a particular molecule carries no net electrical charge. In another embodiment, the "charge" refers to the polymer in a medium having pH of about 7. [0176] In some embodiments, a predetermined reference value is obtained by measuring the level of a protein (or proteins) having a characteristic charge (or pi) in a parallel healthy tissue or cells. In some embodiments, a predetermined reference value is obtained by measuring the level of a protein (or proteins) in a parallel non-malignant tissue or cells. In some embodiments, a predetermined reference value is obtained by measuring the level of a protein (or proteins) in a parallel inflamed tissue.

[0177] In some embodiments, the term "level", as used herein, refers to the degree of gene expression and/or gene product expression or activity in the biological sample. Accordingly, the level of a protein of the invention serving as a marker is determined, in some embodiments, at the amino acid level using protein detection methods.

General

[0178] As used herein the term "about" refers to ± 10 %.

[0179] The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to". The term "consisting of means "including and limited to". The term "consisting essentially of means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0180] The word "exemplary" is used herein to mean "serving as an example, instance or illustration". Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.

[0181] The word "optionally" is used herein to mean "is provided in some embodiments and not provided in other embodiments". Any particular embodiment of the invention may include a plurality of "optional" features unless such features conflict.

[0182] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

[0183] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0184] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases "ranging/ranges between" a first indicate number and a second indicate number and "ranging/ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0185] As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.

[0186] As used herein, the term "treating" includes abrogating, substantially inhibiting, slowing or reversing the progression of a condition, substantially ameliorating clinical or aesthetical symptoms of a condition or substantially preventing the appearance of clinical or aesthetical symptoms of a condition.

[0187] In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

[0188] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. EXAMPLES

[0189] Reference is now made to the following examples which, together with the above descriptions disclosed herewith, illustrate the invention in a non-limiting fashion.

Exemplary Device

[0190] Figures 3A-B present a photo of an exemplary device used for experimental study of ICCDI (Figure 3A) and the dimensions of the setup (Figure 3B). The channel is formed by a 250 μηι thick gasket frame which is pressed between two 5 mm thick transparent acrylic plates by six screws. The top acrylic plate has two reservoirs around two circular apertures of 3 mm diameter, for injection and removal of liquid into the channel. 1 mm activated carbon, porous cylinder was placed at the center of the chamber.

[0191] In exemplary procedures the channel is filled with a liquid solution, and voltage is applied through two electrodes (particles) placed in each of the reservoirs.

Depletion of Salt Concentration:

[0192] Experimental results demonstrating the use of ICCDI for depletion of salt concentration in the bulk liquid are presented in Figures 4A-C. The images in this Figure show fluorescence signal of 100 uM sodium fluorescence under applied electrical field 260 V/m oriented from left to right, around 1.2 mm diameter carbon disk. The corresponding times were: (a) 6 s, (b) 48 s and (c) 108 s. At short time (t = 6 s), a thin depletion region is formed around the disk. Notably, depletion more significant around the poles of the disk, as predicted by the short-times analysis. At later times, (t s), the asymmetry of the depletion fronts is clearly visible, as expected from the difference in mobility between sodium and fluorescein. After 108 s, the depletion region is on the scale of the disk, and after another approximately 10 min the ionic flux from the surrounding bulk balanced with the charging rate of the micropores, which leads to a quasi-steady regime characterized by static depletion regions. Figures 4D-F present a similar time-lapse experiment performed on an array of 18 porous disks arranged in a staggered array, with a typical distance of 1 mm between the disks. At 78 s, clear interaction between the depletion fronts of the individual disks is observed, and by 240 s a continuous depletion region exists between the disks, i.e. a relatively large volume of the bulk can be processed using a set of porous electrodes, each sufficiently small to operate in an (induced) capacitive mode. Reversing the direction of the electric field leads to discharge of the Fluorescein, and increased fluorescence around one of the poles. In the presence of advection (Figure 4G, flow velocity 600 μητ/s), the charging time reduces to approximately 15 min, as indicated by gradual disappearance of the downstream deletion wake. [0193] Figures 5A-B present a comparative fluorescence microscopy images of sodium fluorescence around 1mm diameter porous carbon disk (Figure 5A) vis-a-vis non-porous aluminum disk having the same size (Figure 5B). Both experiments (porous vs. non-porous disks) share identical experimental conditions; ambient solution 100 uM sodium fluorescence in DI, 20 V potential difference between external electrodes and recording time of one minute after the electrical current was switched on. These Figures illustrate the role of the porosity on the absorbency of the disk: while the concentration field around the non-porous disk remains unchanged, the concentration field around the porous disk exhibits clear depletion due to electro soroption of fluorescein ions in to the disk.

Adsorbing DNA molecules:

[0194] Experimental results demonstrating the use of ICCDI for focusing DNA molecules on the electrodes outer surface are presented in Figures 6A-C.

[0195] The images in this Figures show the fluorescence signal emitted by fluorescently labeled DNA in deionized water, at an initial concentration of 100 nM. Upon application of a 1300 V/m electric field, DNA molecules focus around the positively charged pole of the electrode and a ~100x increase in concentration was observed within 60 s. The corresponding times were: (a) 0 (Figure 6A) s, (b) 30 (Figure 6B), and (c) 60 s (Figure 6C).

[0196] Figure 7 presents an illustrative scheme 300 demonstrating the process of focusing of biomolecules (DNA 320) for bioanalysis on a porous carbon 320 in a medium of polyacrylamide or agarose gel 330.

[0197] The focusing may also be of ionic species, such as salts and biomolecules.

[0198] In exemplary procedures, the device described herein is used for buffer exchange. That is, in, species adsorbed in/on the porous particles, while the buffer outside the particles is replaced with a different one. Upon inversion of the field, species may be released into the new buffer.

[0199] Figures 8A-D presents an illustrative scheme demonstrating the process of buffer exchange showing the steps of providing a buffer medium 410A (Figure 8A), focusing the species 420 on the particle 430 by applying an electric field (Figure 8B), replacing the buffer 410A (Figure 8C), and releasing the species to the new buffer 410B by changing the direction of the electric field (Figure 8D). Arrows denote the direction of the electric field.

Release Phase:

[0200] Additional experimental results demonstrating the use of ICCDI for discharge process are presented in Figures 9A-C. [0201] These Figures show raw fluorescence images showing the discharge process of 1.2 mm diameter carbon disk previously charged with 100 micro-Molar Sodium Fluorescein for 5 min. When the electric field is flipped, the initial discharge process results in release of fluorescein from the right pole resulting in an observable intensity increase. At later times, re-charging of the disk results in renewed depletion at the pole. The electrical field was 260 V/m, oriented from right to left (a) 3 s (Figure 9A), (b) 12 s (Figure 9B), (c) 30 s (Figure 9C).

[0202] Taken together, the electrokinetic response of a conducting porous particle to an externally applied electric field was studied. As demonstrated by the experimental results, the ICCDI phenomenon is characterized by charging time which is several orders of magnitude larger than that of a polarizable impermeable particle, and leads to significant changes in salt concentration in the electrically neutral bulk. Consequently, in ICCDI the processes of electrosorption, electromigration, diffusion, and advection are strongly coupled as they operate on similar time scales. Several nonlinear effects are triggered by the strong electrosorption of the porous particle. In the advection-free case, sharp concentration fronts propagating away from the particle were observed which are likely associated with conductivity and pH gradients induced by the particle.

[0203] The formation of these gradients is particularly interesting, as those affect the electrophoretic mobility of the participating ionic species and thus couple back to electromigration and electrosorption fluxes. The observed effects may be particularly important when considering the electrophoretic mobility of such particles. Moreover, the self-generated salt concentration gradient around the particle is expected to result in significant diffusiophoretic forces, which, depending on the species' diffusivities and the ζ (Zeta) potential of the surface, may either retard or advance the particle. Furthermore, the above-mentioned pH changes may also have a significant influence on the native ζ potential of the surface and also affect its mobility. From a practical perspective, ICCDI may be useful for the implementation of novel desalination methods, as it allows rapid removal of ionic species without requiring physical connection of the electrode.

[0204] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0205] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.