Diagnostic device

Abstract

This invention relates to a diagnostic device for quantitative or qualitative analysis of sample fluids comprising analytes, the device comprising at least two parts made of a hydrophilic material. The planar parts are stacked on top of each other, and each planar part occupies a different and substantially parallel plane to form a three-dimensional structure. At least one of the planar parts includes a hydrophobic region formed by applying a low surface energy material that extends from a first primary surface of the substrate part through its thickness to a second primary surface. The hydrophilic regions in the stacked, substantially parallel substrate parts can be aligned with each other such that fluid is passively transported between adjacent hydrophilic regions to provide a sample flow path between adjacent substrate parts.

Description

Background Technology

[0001] Simple, low-cost diagnostic technologies are an important component of strategies to improve health care and access to health care in developing countries and resource-constrained environments. According to the World Health Organization, diagnostic devices used in developing countries should be ASSURED (affordable, sensitive, specific, user-friendly, fast, reliable, equipment-free, and deliverable to the end user).

[0002] Inexpensive, portable, and easy-to-use diagnostic devices have been developed that utilize porous substrates containing reagents selected for rapid on-site quantitative or qualitative analysis of fluid samples (such as bodily fluids, industrial fluids, or water) when laboratory facilities are unavailable or inconvenient for sample analysis. In one example, a paper-based diagnostic device includes a colorimetric immunoassay reagent with a color change as a reading, and the color change reading can be detected visually or by machine to provide a rapid, low-cost diagnosis of the presence of infectious diseases. In various examples, analytes that can be rapidly detected in samples using diagnostic devices include viral antigens, bacterial antigens, fungal antigens, parasitic antigens, cancer antigens, metabolic markers, and combinations thereof. In one example, in an immunochromatographic diagnostic assay, an antibody acting as a binding protein can be used to capture disease-related biomarkers from a patient sample, then generate a visible diagnostic signal derived from the binding event.

[0003] In some examples, the diagnostic device comprises multiple layers of porous material disposed in planes that are parallel to each other and face-to-face. Each layer of the diagnostic device includes fluid-impermeable hydrophobic regions and hydrophilic hygroscopic regions, arranged to provide a sample flow path configured such that a fluid sample can be wicked or flow from one layer to another. At least some layers include reagents, buffer salts, analytes (e.g., antigens), and binders (e.g., antibodies) selected for performing multiplex assays.

[0004] To fabricate diagnostic devices comprising multiple planar regions with different reagents or different patterns of hydrophobic and hydrophilic regions, multiple layers must be manufactured individually, precisely stacked and aligned to provide a sample flow path, and adhered to maintain the continuity of the sample flow path and form a workable stack. In practice, producing low-cost diagnostic devices using this complex series of steps can be difficult, and manufacturing costs have so far limited the deployment of these types of diagnostic devices in resource-constrained environments, such as developing countries. To provide enhanced diagnostic resources and improve healthcare in these areas, there remains a need for inexpensive, portable, and easy-to-construct and-use multiplex assay devices. Summary of the Invention

[0005] Generally, this disclosure relates to inexpensive and easy-to-use diagnostic devices for quantitative or qualitative analysis of sample fluids including analytes. Suitable sample fluids include, but are not limited to, bodily fluids (e.g., blood, sputum, saliva, or urine), industrial fluids, water samples, etc. The diagnostic device comprises at least two parts, each made of a hydrophilic material such as paper. The planar parts are stacked on top of each other, and each planar part occupies different and substantially parallel planes to form a three-dimensional structure. At least one of the planar parts includes a hydrophobic region and a hydrophilic region. The hydrophobic region in each substrate part is formed by applying a low surface energy material (such as hydrophobic ink) extending from a first primary surface of the substrate part through its thickness to a second primary surface. The hydrophobic region in each substrate part includes an arrangement of interconnecting holes having at least one uninterrupted path extending between the first and second primary surfaces. The hydrophilic regions in the stacked substantially parallel substrate parts can be aligned with each other such that fluid is passively transported between adjacent hydrophilic regions to provide a sample flow path substantially perpendicular to the stacked plane of the substrate parts between adjacent substrate parts.

[0006] In some embodiments, certain surfaces of the stacked substrate portion may optionally include connection areas that maintain alignment of the hydrophobic and hydrophilic regions with the sample flow path. In some embodiments, the diagnostic device may include mechanical fasteners to maintain alignment of the hydrophobic and hydrophilic regions.

[0007] In various embodiments, the reagent is within the sample flow path, in fluid communication with the sample flow path, or may be applied to the sample flow path to provide an indication of at least one of the presence, absence, or concentration of the analyte in the sample. For example, in some embodiments, the indication includes an easily readable color change.

[0008] In one embodiment, the diagnostic device includes an elongated hydrophilic substrate with a folded region that divides the substrate into at least two portions, each occupying a different and substantially parallel plane. When the substrate is folded, the planar portions are stacked adjacent to each other to provide a diagnostic device with a three-dimensional structure.

[0009] The disclosed diagnostic devices are particularly well-suited for performing immunoassays, such as sandwich or competitive immunoassays, but they can also be readily adapted to perform assays including steps such as filtration, multiple incubations with different reagents or reagent combinations, continuous or timed addition of reagents, various incubation times, washing, etc. The diagnostic devices are especially effective for performing colorimetric assays, such as immunoassays that use color changes as readings, and are readily adaptable to performing multiple assays simultaneously. They are highly sensitive, simple to manufacture, inexpensive, and versatile.

[0010] In one aspect, this disclosure relates to a diagnostic device comprising a substantially flat, elongated porous substrate having a first end and a second end, wherein the substrate has at least one folded region between the first and second ends. A first portion of the substrate lies in a first plane relative to the folded region, wherein the first portion of the substrate includes a first hydrophobic region and a first hydrophilic region, wherein the first hydrophobic region includes a first low surface energy polymer material extending from a first primary surface of the first portion of the substrate to a second primary surface of the first portion of the substrate, and wherein the first hydrophobic region has an arrangement of interconnecting openings providing at least one uninterrupted path extending from the first primary surface of the first portion of the substrate to the second primary surface of the first portion of the substrate. A second portion of the substrate lies in a second plane relative to the folded region, wherein the second plane is substantially parallel to the first plane. The second portion of the substrate includes a second hydrophilic region and a second hydrophobic region having a second low surface energy polymer material, which may be the same as or different from the first low surface energy polymer material, extending from a first main surface of the second portion of the substrate to a second main surface of the second portion of the substrate. The second hydrophobic region has an arrangement of interconnecting openings that provide at least one uninterrupted path from the first main surface of the second portion of the substrate to the second main surface of the second portion of the substrate. At least one connecting region is located between the first portion and the second portion of the substrate, wherein the at least one connecting region is configured to maintain alignment of the first and second hydrophilic regions, such alignment being sufficient to provide a sample flow path between the first and second portions of the substrate in a direction perpendicular to the first and second planes. A reagent flows along the sample flow path, wherein the reagent is selected for detecting at least one of the presence, absence, or concentration of an analyte present in a sample applied to the diagnostic device.

[0011] In another aspect, this disclosure relates to a diagnostic device comprising a substantially flat, elongated, porous fiber substrate having a first end and a second end. The substrate includes a plurality of folded regions between the first and second ends, the plurality of folded regions dividing the flat porous substrate into a stack of substantially flat panels, wherein each panel in the stack occupies a different substantially parallel plane, and wherein each panel includes a hydrophobic region and a hydrophilic region, the hydrophobic region having fibers coated with a hydrophobic low surface energy polymer ink such that open regions are maintained between the fibers, the open regions between the fibers providing at least one uninterrupted open path between a first main surface and a second main surface of the panel. At least some of the panels include a reagent selected for detecting the presence of an analyte in a sample, and a connecting region configured to attach adjacent panels to each other; and wherein the hydrophobic and hydrophilic regions in the stacked adjacent panels are aligned with each other to provide a sample flow path between their hydrophilic regions in a direction perpendicular to the first and second planes, such that the sample contacts the reagent disposed in the flow path to provide an indication of at least one of the presence, absence, or concentration of an analyte in the sample.

[0012] In another aspect, this disclosure relates to a diagnostic method comprising: providing a diagnostic device comprising a substantially flat, elongated porous fiber substrate having a first end and a second end, wherein the substrate has a plurality of folded regions between the first and second ends, the plurality of folded regions dividing the flat porous substrate into a stack of stacked flat panels, each flat panel occupying a different substantially parallel plane, and wherein each of the panels comprises: a hydrophobic region and a hydrophilic region, the hydrophobic and hydrophilic regions being arranged such that the hydrophilic regions in the panels are aligned with each other to provide a sample flow path therebetween, the hydrophobic regions comprising fibers coated with a low surface energy polymer material such that open regions are maintained between the fibers, the open regions between the fibers providing at least one uninterrupted open path between a first main surface of the panel and a second main surface of the panel; a reagent disposed in the sample flow path; and a connector between at least some of the panels in the panel, the connector maintaining the alignment of the hydrophilic regions along the sample flow path; applying a sample to the sample flow path; and flowing the sample along the sample flow path by capillary action such that the reagent provides an indication of at least one of the presence, absence, or concentration of an analyte in the sample.

[0013] In another aspect, this disclosure relates to a method of manufacturing a diagnostic device, the method comprising: applying a hydrophobic curable polymer ink composition to an elongated web of fibrous material, wherein the hydrophobic curable polymer ink composition is applied to a plurality of adjacent web regions extending from a first edge of the web to a second edge of the web, wherein each web region is separated from adjacent web regions by a boundary region; and wherein each web region includes: a hydrophobic region containing the hydrophobic polymer ink composition, a hydrophilic region substantially free of the hydrophobic polymer ink composition, and at least partially curing the curable polymer ink composition in the hydrophobic region of each web region to provide hydrophobic ink on the fibers of the fibrous material and open regions between the fibers, the open regions between the fibers providing at least one uninterrupted open ink-free path between a first main surface and a second main surface of the web; and folding the porous material web along the boundary region to form a stack of stacked, substantially flat panels, wherein each of the stacked flat panels occupies a different substantially parallel plane, and wherein each of the stacked flat panels includes a registered hydrophilic region thereby forming a sample flow path therebetween.

[0014] In another aspect, this disclosure relates to a system comprising a diagnostic device having a substantially flat, elongated porous substrate having a first end and a second end, wherein the substrate has at least one folded region between the first end and the second end, and wherein: a first portion of the substrate lies in a first plane relative to the folded region, wherein the first portion of the substrate has a first hydrophobic region and a first hydrophilic region, wherein the first hydrophobic region comprises a hydrophobic polymeric low surface energy material extending from a first primary surface of the first portion of the substrate to a second primary surface of the first portion of the substrate, and wherein the first hydrophobic region includes an arrangement of interconnecting openings providing at least one uninterrupted path extending from the first primary surface of the first portion of the substrate to the second primary surface of the first portion of the substrate; and a second portion of the substrate differs from the first portion of the substrate, wherein the second portion of the substrate lies in a second plane relative to the folded region, wherein the second plane is substantially parallel to the first plane. The second portion of the substrate includes a second hydrophilic region and a second hydrophobic region, the second hydrophobic region comprising a hydrophobic polymeric low surface energy material and extending from a first main surface of the second portion of the substrate to a second main surface of the second portion of the substrate, wherein the second hydrophobic region has an arrangement of interconnecting openings providing at least one uninterrupted path from the first main surface of the second portion of the substrate to the second main surface of the second portion of the substrate; at least one connection region located between the first portion of the substrate and the second portion of the substrate, wherein the at least one connection region is configured to maintain alignment of the first hydrophilic region and the second hydrophilic region, the alignment being sufficient to provide a passive sample flow path between the first portion of the substrate and the second portion of the substrate in a direction perpendicular to the first plane and the second plane; and a reagent selected for detecting at least one of the presence, absence, or concentration of an analyte in the sample fluid applied to the flow path of the diagnostic device.

[0015] Details of one or more embodiments of the present invention are shown in the following drawings and description. Other features, objects, and advantages of the invention will become apparent from the description and drawings, as well as from the claims. Attached Figure Description

[0016] Figure 1A This is a schematic cross-sectional view of an embodiment of the diagnostic device according to the present disclosure.

[0017] Figure 1B This is a schematic cross-sectional view of an embodiment of the diagnostic device according to the present disclosure.

[0018] Figure 1C When the fluid is initially applied Figures 1A to 1B An enlarged schematic cross-sectional view of a portion of the implementation scheme of the diagnostic device.

[0019] Figure 1D After the fluid is passively delivered to and wets a portion of its substrate. Figure 1C An enlarged schematic cross-sectional view of the implementation scheme of the diagnostic device.

[0020] Figure 2A This is a schematic cross-sectional view of an embodiment of the diagnostic device according to the present disclosure.

[0021] Figure 2B This is a schematic cross-sectional view of an embodiment of the diagnostic device according to the present disclosure.

[0022] Figure 2C This is a schematic top view of an embodiment of a patterned adhesive applicable to the diagnostic device of this disclosure.

[0023] Figure 3A This is a schematic top view of the diagnostic device disclosed herein.

[0024] Figure 3B yes Figure 3A A schematic cross-sectional view of the diagnostic device.

[0025] Figure 4A This is a top view of the boundary surrounding the hydrophobic area of ​​Example 1, formed by the wicking of the components of the printing material in the lateral direction.

[0026] Figure 4B It is Example 1 and Figure 4A An enlarged cross-sectional view of the diagnostic device.

[0027] Figure 5 This is a graph showing the flow rate through the substrate of the diagnostic device of Example 1 in the unpatterned hydrophilic region and the patterned hydrophobic region.

[0028] In these accompanying figures, similar symbols represent similar elements. Detailed Implementation

[0029] Now for reference Figures 1A to 1B An embodiment of the diagnostic device 10 includes a substantially flat, elongated hydrophilic substrate 12 having a first end 13, a second end 15, and at least one folded region 14 between the first end 13 and the second end 15. The folded region 14 divides the hydrophilic substrate 12 into a first sheet-like portion 16 and a second sheet-like portion 18, each sheet-like portion occupying a substantially parallel plane relative to the folded region 14. The first substrate portion 16 includes a first main surface 17 and a second main surface 19, while the second substrate portion 18 includes a first main surface 21 and a second main surface 23. Figure 1A In one embodiment, the first portion of substrate 16 and the second portion of substrate 18 cover each other, such that the respective main surfaces 19 and 21 are adjacent to each other.

[0030] The first substrate portion 16 includes a first hydrophobic region 24 and a first hydrophilic region 26, while the second substrate portion 18 includes a second hydrophobic region 28 and a second hydrophilic region 30. The fibers of the substrate 12 in the hydrophobic regions 24, 28 have a low surface energy polymer material applied thereto, and thus resist unassisted capillary fluid flow or wicking of selected fluids (such as sample fluids including, for example, analytes, buffer solutions, or washing solutions) through them. Due to this resistance, the selected fluid is passively transported between the hydrophilic regions 26, 30 (without requiring external pressure gradients, gravity, or electrostatic forces). The hydrophobic regions 24, 28 substantially restrict fluid flow in the direction of arrow A, which is aligned along the thickness of the substrate portions 16, 18 or along the z-axis of the three-dimensional diagnostic device 10. The hydrophilic regions 26, 30 are sufficiently aligned with each other such that the first hydrophilic region 26 (in...) Figures 1A to 1B Not shown in the image, see [link / reference]. Figures 1C to 1D The fluid sample on the sample can be passively transported along the sample flow path 32 using, for example, wicking or capillary action, to provide fluid communication between the first substrate portion 16 and the second substrate portion 18, such that the fluid sample is wicked into the second hydrophilic region 30.

[0031] Now for reference Figures 1C to 1D Enlarged schematic cross-sectional view in the diagram. Figures 1A to 1B The diagnostic device 10 includes a hydrophilic substrate 12 having a first substrate portion 16. The substrate portion 16 of the hydrophilic substrate 12 includes a hydrophobic portion 24 and a hydrophilic portion 26. The hydrophilic portion 26 includes an arrangement of entangled fibers 80. In some exemplary embodiments (which are not intended to be limiting and are provided only as illustrative examples), the fibers 80 in the hydrophilic region 26 have a surface energy σ of about 40 dynes / cm to about 65 dynes / cm for a selected liquid 84 at a selected temperature. In the hydrophobic portion 24, at least a portion of the fibers 80 is coated with a low surface energy polymer material 82, which restricts the capillary flow (or wicking) of fluid into the hydrophobic portion 24. In some embodiments, if the low surface energy polymer material 82 is deposited on the fibers 80 such that it coats only the surface of the fibers, at least some interconnecting gap channels 83 are maintained between the fibers. The channels 83 remain open, allowing gas (which is a fluid) to move freely through the porous substrate 12 in the hydrophobic region 24. After being coated with a low surface energy polymer material 82, the fibers in the hydrophobic region 24 have a surface energy that is at least 10 dynes / cm less than the surface tension of the liquid 84.

[0032] If liquid 84 is applied to the surface 17 of the hydrophilic region 26 at time t=0, then after the saturation time t=0... satAfterward, the fluid 84 will be wicked and passively transported along the fiber 80, and occupy the gap region 85 in the hydrophilic region 26. The low surface energy polymer material in the hydrophobic region 24 tends to repel or resist the fluid 84 from intruding into the gap region 83, thereby forming a flow path 88 for the fluid 84 through the hydrophilic region 26.

[0033] Refer again Figures 1A to 1B All or a portion of one or both of the hydrophilic regions 26 and 30 may include a test area 42, in which the analytical results or output of the device 10 can be displayed to a user, and one or more reagents 40 are in or in fluid communication with the test area 42. The reagents 40 are selected to provide an indication of at least one of the presence, absence, or concentration of an analyte in a fluid sample disposed in a sample flow path 32. In various embodiments, the reagents 40 are applied to all or a portion of one or both of the hydrophilic regions 26 and 30, which may be in another part of the device 10 and in fluid communication with the flow path 32, or may be applied to the sample flow path 32 before or after the fluid sample is applied to the sample flow path 32.

[0034] In some embodiments, the diagnostic device 10 includes an optional first connection region 34 on a second main surface 19 of the first substrate portion 16. In some embodiments, the diagnostic device 10 also includes an optional second connection region 36 on a first main surface 21 of the second substrate portion 18. Any or both of the adjacent main surfaces 19, 21 of the stacked substrate portions 16, 18 may include a connection region that adheres the first substrate portion 16 to the second substrate portion 18 and maintains the registration of the hydrophilic regions 26, 30 to preserve the sample flow path 32. Figure 1B ).

[0035] In various embodiments, the elongated hydrophilic substrate 12 can be made of any porous hydrophilic adsorbent material capable of wicking sample fluids through capillary action. In one or more embodiments, the substrate 12 is a paper product, such as chromatography paper, filter paper, etc., but may also be selected from woven or nonwoven fabrics, or from polymer membranes, such as nitrocellulose, cellulose acetate, polyester, and polyurethane.

[0036] The first hydrophobic region 24 and the second hydrophobic region 28 can be formed by applying a low surface energy polymer material (such as a polymer ink composition) with the desired pattern to the substrate 12. Figures 1C to 1DAs schematically shown, the hydrophobic ink composition wicks and coats the fibers of the hydrophilic substrate 12, leaving at least some open gap regions between the fibers. Upon subsequent curing or hardening, the polymer ink composition provides open gap regions that form at least one uninterrupted open path between the respective main surfaces 17, 19 of the first substrate portion 16 and the main surfaces 21, 23 of the second substrate portion 18. Thus, the hydrophobic regions 24, 28 resist the absorption of liquid applied to, for example, the hydrophilic region 26 of the first substrate portion 16, and the liquid is passively transported between the hydrophilic regions 26, 30 via capillary action or wicking.

[0037] While not wishing to be bound by any theory, currently available evidence suggests that the relative absorption difference between hydrophobic regions 24, 28 and hydrophilic regions 26, 30 is a function of the difference between the surface energy of the fibers in the hydrophilic regions of the selected liquid (such as sample fluid, buffer solution, etc.) intended to flow between substrate portions 16, 18 and the surface energy of the fibers in the hydrophobic regions 24, 28 coated with a low surface energy ink. The larger this difference, the greater the absorption resistance of the selected fluid in the hydrophobic regions 24, 28. This difference can also depend on, for example, the uniformity of ink coverage, fiber structure, etc.

[0038] In one example, if the sample fluid selected for flow between substrate portions 16, 18 via wicking or capillary action is a body fluid, then the surface energy of the fibers of the low-surface-energy hydrophobic ink applied to the hydrophobic regions 24, 28 should be lower than the minimum surface tension of the body fluid. Because body fluids have a range of surface tensions, the surface energy of the fibers in the hydrophobic regions 24, 28 should be at least 10 dynes / cm lower, or at least 15 dynes / cm lower, or at least 20 dynes / cm lower, or even at least 30 dynes / cm lower than the minimum surface tension of the body fluid. For example, it has been reported that human urine has a minimum surface tension of about 55 dynes / cm and human saliva has a surface tension of about 40 dynes / cm. Therefore, in order to resist the absorption of these bodily fluids by wicking or capillary action, the surface energy of the hydrophobic regions 24 and 28 of the ink should have a surface tension of less than about 45 dynes / cm, or less than about 40 dynes / cm, or less than about 35 dynes / cm, or less than about 30 dynes / cm, or less than about 25 dynes / cm, or less than about 20 dynes / cm.

[0039] In another example, in order to resist capillary flow or wicking of the selected fluid, currently available evidence suggests that the hydrophobic ink compositions in zones 24 and 28 provide a contact angle greater than about 90°, or greater than about 95°, or greater than about 100°, or greater than about 105°, or greater than about 110°, or greater than about 115°, or greater than about 120°, or greater than about 125°, or greater than about 130°, or greater than about 135°, or even greater than about 140°, to the selected fluid upon curing.

[0040] Contact angle and wettability can be measured using techniques described in, for example, the following literature: Capillary and Wetting Phenomena: Droplets, Bubbles, Pearls, Waves (Francoise Brochard-Wyart; David Quere, hardcover, New York: Springer, September 12, 2003); Wettability (Surfactant Science), edited by John Berg, CRC Press, 1st edition, April 20, 1993. The full text of each of these literatures is incorporated herein by reference.

[0041] In various embodiments, the hydrophobic ink composition comprises at least one polymerizable low surface energy monomer, oligomer, or polymer that provides the desired resistance to absorption by a selected liquid or sample fluid. This low surface energy monomer, oligomer, or polymer may be fluorocarbon, silicone, or hydrocarbon. The low surface energy monomer, oligomer, or polymer is added to the formulation to reduce the surface energy of the cured hydrophobic coating to a wetting tension of about 30 mJ / m² to less than about 38 mJ / m², as measured by ASTM D2578-08. Examples of suitable polymerizable low surface energy monomers, oligomers, and polymers are described in WO2011 / 094342, the entire contents of which are incorporated herein by reference.

[0042] In some embodiments, the hydrophobic regions 24, 28 comprise a non-sticky cross-linked polymer layer. This polymer layer is prepared from a radiation-curable coating formulation containing at least one low-surface-energy monomer, oligomer, or polymer selected from polymerizable fluorocarbons, organosilicones, or hydrocarbon monomers.

[0043] The non-sticky crosslinked polymer layer can be formed from a polymeric precursor composition, but other methods can also be used (e.g., crosslinking of the polymer or its blends using chemical measures or ionizing radiation). Available precursor compositions typically comprise one or more polymerizable materials (e.g., monomers and / or oligomers, which may be monofunctional and / or multifunctional), a curing agent, and optional inorganic particles. The polymerizable materials can be, for example, radical-polymerizable, cationic-polymerizable, and / or polycondensation-polymerizable.

[0044] Available polymerizable materials include, for example, acrylates and methacrylates, epoxides, polyisocyanates, and trialkoxysilane-terminated oligomers and polymers. Preferably, polymerizable materials include materials that can be polymerized on a free radical basis.

[0045] Available free-radical polymerizable materials include, for example, free-radical polymerizable monomers and / or oligomers, any one or both of which may be monofunctional or polyfunctional. Exemplary free-radical polymerizable monomers include styrene and substituted styrene (e.g., α-methylstyrene); vinyl esters (e.g., vinyl acetate); vinyl ethers (e.g., butyl vinyl ether); N-vinyl compounds (e.g., N-vinyl-2-pyrrolidone, N-vinylcaprolactam); acrylamides and substituted acrylamides (e.g., N,N-dialkylacrylamide); and acrylates and / or methacrylates (i.e., collectively referred to herein as (meth)acrylates) (e.g., isooctyl (meth)acrylate, nonyl...). Phenolic ethoxylates (meth)acrylates, isononyl methacrylate, diethylene glycol methacrylate, isobornyl methacrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl methacrylate, butanediol mono(meth)acrylate, β-carboxyethyl (meth)acrylate, isobutyl methacrylate, 2-hydroxyethyl (meth)acrylate, (meth)acrylonitrile, isodecanyl methacrylate, dodecane (meth)acrylate methyl methacrylate, n-butyl methacrylate, methyl methacrylate, hexyl methacrylate, methacrylic acid, stearyl methacrylate, hydroxy-functionalized polycaprolactone (meth)acrylate, hydroxyethyl methacrylate, hydroxymethyl methacrylate, hydroxypropyl methacrylate, hydroxyisopropyl methacrylate, hydroxybutyl methacrylate, hydroxyisobutyl methacrylate, tetrahydrofurfuryl methacrylate, ethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, triethylene glycol Di(meth)acrylate, 1,3-propanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and neopentanediol di(meth)acrylate.

[0046] Exemplary free radical polymerizable oligomers include those sold by UCB Chemicals, Smyrna, Georgia (e.g., under the trade name "EBECRYL") and those sold by Sartomer Company, Exton, PA (e.g., under the trade names "KAYARAD" or "CN").

[0047] Depending on the choice of polymerizable material, the precursor composition may optionally contain one or more curing agents that facilitate the polymerization of the polymerizable material. For a particular polymerizable material, the choice of curing agent depends on the chemical properties of the copolymerizable material. For example, in the case of epoxy resins, curing agents known for use in epoxy resins (e.g., dicyandiamide, onium salts, or polythiols) are typically chosen. In the case of free radical polymerizable resins, free radical thermal initiators and / or photoinitiators are available curing agents.

[0048] Typically, the optional curing agent is used in an amount that effectively promotes monomer polymerization, said amount varying depending on, for example, the type of curing agent, the molecular weight of the curing agent, and the polymerization method. The optional curing agent is typically included in the precursor composition in an amount from about 0.01% by weight to about 10% by weight of the total weight of the precursor composition, but higher and lower amounts may also be used. The precursor composition can be cured, for example, by exposure to a heat source (e.g., heat, infrared radiation), electromagnetic radiation (e.g., ultraviolet and / or visible radiation), and / or particulate radiation (e.g., an electron beam of gamma radiation).

[0049] A variety of curing strategies can be readily selected, depending in part on the properties of the curable coating composition, other components of the article, and the manufacturing facility. Exemplary techniques for maximizing the curing of UV-curable coating compositions include curing under nitrogen, using a new UV bulb, cleaning the UV bulb before use, matching the output spectrum of the UV bulb to the absorption of the initiator, and processing at low speeds and / or for longer periods. In some embodiments, some post-exposure curing may occur over time due to the dry-rubbed article aging at room temperature.

[0050] In addition to the first curing process described above, a second curing treatment may be required. The second curing may use the same radiation source as the first curing or a different radiation source. Preferred second curing methods include thermal, electron beam, and gamma-ray treatments.

[0051] If the optional curing agent is a free radical initiator, the amount of curing agent is preferably in the range of about 1% to about 5% by weight of the total weight of the precursor composition, but higher and lower amounts may also be used. Available free radical photoinitiators include, for example, benzoin ethers (such as benzoin methyl ether and benzoin isopropyl ether), substituted benzoin ethers (e.g., anethole methyl ether), substituted acetophenones (e.g., 2,2-dimethoxy-2-phenylacetophenone), substituted α-keto alcohols (e.g., 2-methyl-2-hydroxyphenylacetone), benzophenone derivatives (e.g., benzophenone), and acylphosphine oxides. Exemplary commercially available photoinitiators include those available under the trade names “IRGACURE” (e.g., IRGACURE 651, IRGACURE 184, and IRGACURE 819) or “DAROCUR” (e.g., DAROCUR 1173, DAROCUR 4265) from Ciba Specialty Chemicals, Tarrytown, New York, and those available under the trade name “LUCIRIN” (e.g., “LUCIRINTPO”) from BASF, Parsippany, New Jersey.

[0052] Exemplary free radical thermal initiators include: peroxides, such as benzoyl peroxide, dibenzoyl peroxide, dilauryl peroxide, cyclohexane peroxide, methyl ethyl ketone peroxide, hydroperoxides (e.g., tert-butyl hydroperoxide) and cumene hydroperoxide, dicyclohexyl percarbonate, tert-butyl perbenzoate, and azo compounds (e.g., 2,2'-azobis(isobutyronitrile)).

[0053] Low surface energy monomers, oligomers, or polymers may be selected from fluorocarbons, silicones, or hydrocarbon monomers. Fluorocarbon monomers suitable for hydrophobic ink compositions include, but are not limited to, perfluoroacrylates or perfluoromethacrylates, such as C4F9-based sulfonamide acrylates and C3F7-based sulfonamide acrylates.

[0054] Fluorinated oligomers suitable for use in the hydrophobic ink compositions described herein include FLUORAD, commercially available from 3M Company, St. Paul, MN. TMFC-4430 and FC-4432. Suitable fluorinated polymers include perfluoropolyether polymers having poly(epoxide) repeating units, such as those described in PCT application No. WO2009 / 076389 (Yang et al.). Suitable silicone monomers include, but are not limited to, silicone acrylate monomers. Exemplary silicone acrylates applicable herein include BYK-371 reactive silicone surface additive, BYK-373 reactive silicone surface additive, BYK-377 reactive silicone surface additive, BYK-UV 3500 surface additive for radiation-curable systems, BYK-UV3530 surface additive for radiation-curable systems, BYK-UV3570 surface additive for radiation-curable systems, and BYK SILCLEAN 3710 surface additive for radiation-curable systems to improve surface cleanability. Other suitable silicone monomers include TEGORAD from Evonik Goldschmidt Corporation (Hopewell, VA). TM 2100, TEGORAD TM 2200N, TEGORAD 2250 and TEGORAD2300 silicone acrylate monomers.

[0055] Hydrocarbon monomers can be used to reduce the surface energy of the coating. These hydrocarbon monomers are characterized by long side chains that can form crystalline structures on the surface. Suitable hydrocarbon monomers include, but are not limited to, octadecyl acrylate.

[0056] In one embodiment, the low surface energy monomer, oligomer, or polymer is used at a level sufficient to generate a wetting tension of about 20 mJ / m. 2 Approximately 40 mJ / m 2 The concentration of the cured coating is added to the coating formulation. In some embodiments, the wetting tension of the cured coating is approximately 30 mJ / m. 2 Approximately 36 mJ / m 2 .

[0057] In some embodiments, the radiation-curable material contains one or more of the aforementioned oligomers, one or more monomers, and / or one or more polymers, along with an optional amount of particles or nanoparticles, in one or more solvents, for example, to impart increased hardness and durability to the writing component. In some cases, dilution of the hydrophobic ink in the solvent can promote faster wicking into porous or fibrous substrates (by reducing the viscosity of the ink) and can leave more interconnecting spaces between the fibers.

[0058] Nanoparticles can be surface-modified, meaning they have modified surfaces that enable them to provide a stable dispersion. A "stable dispersion" is one in which colloidal nanoparticles do not aggregate after being left to stand for a period of time, for example, about 24 hours, under ambient conditions, such as at room temperature (about 20°C to about 22°C), atmospheric pressure, and without extreme electromagnetic forces.

[0059] Surface-modified colloidal nanoparticles may optionally be present in polymer coatings used in the coatable compositions described herein, wherein the amount of nanoparticles can effectively improve the durability of the finished product or optical element. The surface-modified colloidal nanoparticles described herein may possess a variety of desired properties, including, for example: compatibility of the nanoparticles with the coatable composition to form a stable dispersion within the coatable composition; reactivity of the nanoparticles with the coatable composition, thereby making the composite more durable; and low impact on the viscosity of the uncured composition. Combinations of surface modifications can be used to control the uncured and cured properties of the composition. Surface-modified nanoparticles can improve the optical and physical properties of the coatable composition, for example, increasing the mechanical strength of the resin, minimizing viscosity changes while increasing the solids volume loading in the coatable composition, and maintaining optical clarity while increasing the solids volume loading in the coatable composition.

[0060] In some embodiments, the nanoparticles are surface-modified nanoparticles. Suitable surface-modified colloidal nanoparticles may include oxide microparticles. For a given material, the nanoparticles may have a range of particle sizes in a known particle size distribution. In some embodiments, the average particle size may be in the range of about 1 nm to about 100 nm. The particle size and particle size distribution may be determined in a known manner, including, for example, by transmission electron microscopy (“TEM”). Suitable nanoparticles may include any of a variety of materials, such as metal oxides selected from alumina, tin oxide, antimony oxide, silicon dioxide, zirconium oxide, titanium dioxide, and combinations of both or more of the foregoing. Surface-modified colloidal nanoparticles may be substantially completely agglomerated.

[0061] In some embodiments, the silica nanoparticles may have a particle size of about 5 nm to about 100 nm. In some embodiments, the silica nanoparticles may have a particle size of about 10 nm to about 30 nm. The silica nanoparticles may be present in the coatable composition in an amount of about 10 to about 100 phr. In some embodiments, the silica nanoparticles may be present in the coatable composition in an amount of about 30 to about 90 phr. The silica nanoparticles suitable for use in the coatable compositions of this disclosure are commercially available under the product name NALCO COLLOIDAL SILICAS from Nalco Chemical Co., Naperville, IL. Suitable silica products include NALCO products 1040, 1042, 1050, 1060, 2327, and 2329. Suitable pyrolytic silica products include, for example, the AEROSIL series OX-50, -130, -150, and -200, available from DeGussa AG, Hanau, Germany, and CAB-O-SPERSE2095, CAB-O-SPERSE A105, and CAB-O-SIL MS, available from Cabot Corp., Tuscola, IL, Illinois. Surface treatment of nanoparticles can provide a stable dispersion in coatable compositions, such as polymeric resins. Preferably, the surface treatment stabilizes the nanoparticles so that they are well dispersed in the coatable composition and result in a substantially homogeneous composition.

[0062] Furthermore, at least a portion of the nanoparticle surface can be modified with a surface treatment agent to allow the stabilized particles to copolymerize or react with the coatable composition during the curing process. Silica nanoparticles can be treated with a surface treatment agent. Suitable surface treatment agents for particles to be included in the coatable composition include compounds such as isooctyltrimethoxysilane, N-(3-triethoxysilylpropyl)carbamate methoxyethoxyethoxyethyl ester (PEG3TES), and SILQUEST. A1230, N-(3-triethoxysilylpropyl)carbamate methoxyethoxyethoxyethyl ester (PEG2TES), 3-(methacryloyloxy)propyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-(methacryloyloxy)propyltriethoxysilane, 3-(methacryloyloxy)propylmethyldimethoxysilane, 3-(acryloyloxypropyl)methyldimethoxysilane, 3-(methacryloyloxy)propyldimethylethoxysilane, 3-(methacryloyloxy)propyldimethylethoxysilane, vinyldimethylethoxysilane, phenyltrimethoxysilane, n-octyltrimethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, vinylmethyldimethoxysilane Acetoxysilane, vinylmethyldiethoxysilane, vinyltriacetoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriphenoxysilane, vinyltritert-butoxysilane, vinyltriisobutoxysilane, vinyltriisopropoxysilane, vinyltri(2-methoxyethoxy)silane, styrylethyltrimethoxysilane, mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, acrylic acid, methacrylic acid, oleic acid, stearic acid, dodecanoic acid, 2-[2-(2-methoxyethoxy)ethoxy]acetic acid (MEEAA), β-carboxyethyl acrylate, 2-(2-methoxyethoxy)acetic acid, methoxyphenylacetic acid, and mixtures of two or more of the foregoing compounds.

[0063] In some embodiments, the average particle size (e.g., particle diameter) can be in the range of about 1 nm to about 1000 nm. In addition to the aforementioned particle sizes, smaller and larger average particle sizes are also conceivable. In embodiments of this disclosure, at least a portion of the aforementioned particles can be surface modified in the manner described above. In other embodiments, all particles are surface modified. In other embodiments, none of the particles are surface modified.

[0064] As will be understood, the coating compositions used to prepare the hydrophobic regions of this disclosure may contain optional additives to enhance or control properties as needed, such as rheology modifiers like JAYLINK rheology modifiers, colorants (e.g., dyes and / or pigments), flame retardants, antioxidants, stabilizers, anti-ozone agents, plasticizers, UV absorbers, amine light stabilizers (HALS), etc.

[0065] Hydrophobic ink compositions suitable for forming hydrophobic regions 24, 28 may include any commercially available ink that provides desired resistance to capillary flow or wicking of selected liquids, such as the sample fluid. Suitable examples include, but are not limited to, NAZDAR 9400 series UV flexographic inks or OP series inks (available from NAZDAR Ink Technologies, Shawnee, KS, United States), such as 9418 or OP1028. In some embodiments, the ink composition may be cured or cured by radiation such as ultraviolet (UV) light.

[0066] In some embodiments, the hydrophobic ink composition may contain a solvent selected to provide optimal wicking properties, for example, along fibers of substrate 12. Suitable solvents include, but are not limited to, water, alcohols, ethers, ketones, esters, and mixtures and combinations thereof.

[0067] The hydrophobic regions 24 and 28 can be patterned with a curable hydrophobic ink using any suitable technique, including but not limited to coating, screening, embossing, printing, photolithography, and combinations thereof. In some embodiments, the patterning technique may include heating the ink composition to a suitable temperature, causing the ink to be drawn and flow along the fiber core of the substrate without occupying the gap regions between the fibers. The gap regions in the hydrophobic regions 24 and 28 are sufficiently open and interconnected to allow some fluid to flow between the main surfaces 17 and 19 and 21 and 23 of the substrate 12, but the fluid flow rate between the main surfaces of the substrate 12 in the hydrophobic regions 24 and 28 is significantly lower than that in the hydrophilic regions 26 and 30, such that fluid placed in the hydrophilic regions 26 and 30 avoids the hydrophobic regions 24 and 28 and remains in the hydrophilic regions 26 and 30 to advance along the sample flow path 32.

[0068] In various embodiments, the optional bonding regions 34, 36 can vary widely and may include any type of adhesive, such as pressure-sensitive adhesives, hot melt adhesives, cohesive adhesives, and mixtures and combinations thereof. In this application, the term cohesive adhesive refers to an adhesive material that adheres to itself but has low or no adhesion to other non-adhesive surfaces.

[0069] A suitable pressure-sensitive adhesive (“PSA”) is defined herein as an adhesive that exhibits durable tack at room temperature. This property allows the PSA to adhere firmly with only light finger pressure. A PSA possesses a balance of the following properties: adhesion, cohesion, tensile strength, and elasticity. Adhesion refers both to the instantaneous adhesion to a surface and to the bond strength (typically measured as “peel strength”) developed after pressure is applied. Cohesion refers to the “shear strength” under shear force, or the resistance of the applied PSA to failure. Tensile strength refers to the ability to elongate under low stress. Elasticity refers to the property of a material to exhibit retraction force when stretched and to retract when that force is released. A general description of pressure-sensitive adhesives can be found in the Encyclopedia of Polymer Sciences and Engineering, Volume 13, Wiley-Interscience Publishers (New York, 1988).

[0070] In one exemplary embodiment, suitable cohesive adhesives as used herein include fast-drying adhesives that, once dry, produce a substantially non-tacky surface and, when placed under pressure, will only adhere to other surfaces coated with the same adhesive. The cohesive adhesive self-bonds at ambient temperature and pressure but is substantially non-tacky to the touch, thereby allowing the coated substrate to fold or roll itself and be stored without adhering to the opposite surface of the substrate backing.

[0071] In various embodiments, suitable cohesive adhesives include latex or water-based adhesive compositions that are substantially non-sticky to the touch after drying, but adhere to themselves at ambient temperature and pressure of 100 psi, and preferably at about 60 psi or less. The bond strength of the self-sealing component can vary depending on the weight of the coating used, the pressure, and the residence time. However, the minimum removal force is at least about 10 g / linear inch, typically at least about 20 g / linear inch, preferably at least 50 g / linear inch, and most preferably at least about 100 g / linear inch. Being substantially non-sticky to the touch means that the dried composition is non-adhesive.

[0072] Cohesive adhesives can be applied to hydrophilic substrate materials at relatively high production rates and dry relatively quickly. Therefore, cohesive adhesives enable the manufacture of relatively low-cost diagnostic devices at a much faster production rate than conventional adhesive materials used in the prior art.

[0073] This type of adhesive has been used in a variety of packaging applications, including food (i.e., flexible packaging for candy packaging materials, flakes, etc.); pharmaceutical packaging; self-sealing and tamper-evident seals; bundling for banknotes, napkins and clothing; and protective packaging, such as folded “blister” packages for hardware and small parts.

[0074] In some embodiments, for example, a high-speed printing method can be used to apply the cohesive binder to reduce the film thickness, further enabling the manufacture of diagnostic devices at a much faster production rate than conventional binder materials used in the art. In some embodiments provided by way of example and not intended to be limiting, suitable cohesive binders comprise emulsions of natural and / or synthetic latex rubber in an aqueous solution of ammoniated water, having a solids content between 15% and 65% by weight.

[0075] In some exemplary embodiments provided by way of example and not intended to be limiting, the viscosity of a suitable cohesive adhesive can be between 10 centipoise (cP) and 450 cP at 20 rpm and 23°C, according to ASTM D1084 Test Method B. In some embodiments, the density of the cohesive adhesive can be between 8.0 lb / gal and 9.0 lb / gal at 25°C, and the alkalinity or pH can be between 9.5 and 12.

[0076] In various embodiments, the cohesive adhesive may optionally contain dispersants, surfactants, tackifiers, isocyanates, antioxidants, and defoamers, as known in the art, without departing from the scope of this disclosure.

[0077] In at least one embodiment of this disclosure, which is not intended to be limiting, the cohesive adhesive has the following properties: a solids content of 57.5% by weight, a viscosity of 75 cP at 25°C, a density of 8.3 lb / gal, and a pH of 10.0. In at least one embodiment of this disclosure, the adhesive has a solids content between 45% and 58% by weight, a viscosity between 75 cP and 200 cP at 23°C, a density between 8.3 lb / gal and 8.7 lb / gal at 23°C, and a pH of 10 to 11.

[0078] In some embodiments, mechanical fasteners may be used alone or in combination with any of the aforementioned adhesive layers to maintain the alignment of one or more hydrophilic areas in the stacked layers or panels of the diagnostic device. Suitable mechanical fasteners include, but are not limited to, plastic or metal clamps, nails, elastic bands such as plastic or rubber bands, plastic cable ties, and combinations thereof.

[0079] Typically, multiple reagents 40 may be disposed in or in fluid communication with the test region 42 within the hydrophilic regions 26, 30 of the diagnostic device 10 to detect one or more analytes in the sample fluid. These reagents include, but are not limited to, antibodies, nucleic acids, aptamers, molecularly imprinted polymers, chemical receptors, proteins, peptides, inorganic compounds, and small organic molecules. In a given device, one or more reagents may be adsorbed (non-covalently via non-specific interactions) or covalently (as esters, amides, imines, ethers, or via carbon-carbon, carbon-nitrogen, carbon-oxygen, or oxygen-nitrogen bonds) onto one or more hydrophilic regions 26, 30.

[0080] Any reagents 40 required for the assay may be disposed within or therein a separate adsorbent layer in fluid communication with the test area 42 within the hydrophilic regions 26, 30 and the sample flow path 32. Exemplary assay reagents include protein assay reagents, immunoassay reagents (e.g., ELISA reagents), glucose assay reagents, sodium acetoacetate assay reagents, sodium nitrite assay reagents, or combinations thereof. In various embodiments not intended to be limiting, the diagnostic device 10 may include blocking agents, enzyme substrates, specific binding reagents such as antibodies or sFv reagents, labeled binding agents such as labeled antibodies, which may be disposed within or in fluid communication with one or more hydrophilic regions 26, 30 in the device, or disposed in a specific region therein configured as the test area 42.

[0081] In some implementations, the binder, such as an antibody, can be labeled with an enzyme or colored particles to allow for colorimetric assessment of the presence or concentration of an analyte in the sample fluid. For example, the binder can be labeled using colloidal gold particles or similar chromogenic markers. In cases involving enzymes as markers, such as alkaline phosphatase, horseradish peroxidase, luciferase, or β-galactosidase, the enzyme substrate can be located within or in fluid communication with one of the hydrophilic regions 26, 30 in the device. Exemplary substrates for these enzymes include BCIP / NBT, 3,3',5,5'-tetramethylbenzidine (TMB), 3,3'-diaminobenzidine (DAB), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 4-methylumbelliferyl phosphate, 3-(4-hydroxyphenyl)-propionic acid, or 4-methylumbelliferyl-β-D-galactosidase, etc. In various embodiments, reagent 40 develops color (including a gradient from white to black) in one or more test areas 42 along the sample path 32 as an indication of the presence, absence, or concentration of the analyte in the sample.

[0082] In some embodiments, the apparatus may include a plurality of reagents 40 disposed along a sample flow path, each reagent being capable of reacting with a different analyte to produce a detectable effect. Alternatively, the reagents 40 may be sensitive to a predetermined concentration of a single analyte.

[0083] In some embodiments, reagent 40 may include a washing reagent or a combination of washing reagents, such as buffer solutions or surfactant solutions, within or in fluid communication with the hydrophilic regions 26, 30 or the sample flow path 32. The washing reagent is used to wash the analyte by removing unbound material within the hydrophilic regions 26, 30. For example, a suitable washing buffer may contain PBS, detergent, surfactant, water, and salt. The composition of the washing reagent will vary depending on the requirements of the specific assay, such as specific capture and indicator reagents used to determine the presence of the target analyte in the test sample, and the properties of the analyte itself.

[0084] Alternatively, the reaction steps using the apparatus disclosed herein can be washed as follows. In some embodiments, the defined hydrophilic regions 26, 30 do not contain reagent 40. In this case, water or a buffer solution is then added to the hydrophilic regions 26, 30 of the apparatus 10, and fluid flows through the apparatus along the sample flow path 32 to provide a washing step for the analyte in the fluid sample. Such a washing step can be used to remove unbound analytes or other components added to detect the presence of the analyte.

[0085] Hydrophilic regions 26, 30 may include one or more test regions 42, which can be used to perform one or more assays for detecting multiple analytes in a sample fluid. One or more hydrophilic regions 26, 30 may be treated with reagent 40, which responds to the presence of an analyte in the sample fluid and provides an indicator of the analyte's presence in the sample fluid. In some embodiments, the detection of the analyte in the sample fluid is visible to the naked eye and may provide a color indicator of the analyte's presence. In various embodiments, the indicator may include molecules that become colored in the presence of an analyte, change color in the presence of an analyte, or emit fluorescence, phosphorescence, or cold light in the presence of an analyte. In other embodiments, radiometric, magnetic, optical, and / or electrical measurements may be used to determine the presence of proteins, antibodies, or other analytes in the sample flow path 32.

[0086] In some implementations, the analyte can be detected by direct or indirect detection methods that apply the principle of immunoassay (e.g., sandwich or competitive immunoassay or ELISA).

[0087] In some embodiments, to detect a specific protein, one or more regions of the hydrophilic regions 26, 30 can be derivatized with a reagent 40 (such as an antibody, ligand, receptor, or a small molecule that selectively binds to or interacts with a protein in the sample fluid). For example, to detect a specific antigen in the sample, the test region 42 of the hydrophilic regions 26, 30 can be derivatized with a reagent (such as an antibody that selectively binds to or interacts with that antigen). Alternatively, to detect the presence of a specific antibody in the sample fluid, the test region 42 of the hydrophilic regions 26, 30 can be derivatized with an antigen that binds to or interacts with that antibody. For example, the reagent 40 (such as a small molecule and / or protein) can use chemicals similar to those used to immobilize molecules on beads or slides, or chemicals used to link molecules to carbohydrates, covalently linked to the hydrophilic regions 26, 30. In alternative embodiments, the reagent 40 can be applied and / or immobilized in the hydrophilic regions 26, 30 by applying a solution containing the reagent and allowing the solvent to evaporate (e.g., depositing the reagent into the hydrophilic region). The reagent can be immobilized on the porous substrate by physical adsorption, which is achieved through other non-covalent interactions.

[0088] Some analytes may not exhibit visible color changes due to interactions with certain reagents unless the analyte is previously labeled. The apparatus disclosed herein can be further processed to add staining agents or labeled proteins, antibodies, nucleic acids, or other reagents that bind to the target analyte after binding to reagent 40 disposed in the sample flow path 32, resulting in a visible color change. For example, apparatus 10 may include a separation region already containing the staining agent or labeled reagent, and includes a mechanism by which the staining agent or labeled reagent can be readily introduced into the sample flow path to bind to the target analyte after its binding to reagent 40. Alternatively, apparatus 10 may be provided with a separate channel for allowing the staining agent or labeled reagent to flow from different regions of hydrophilic regions 26, 30 along the sample flow path 32 to the target analyte into the test region 42 after the target analyte has bound to the reagent in the sample flow path. In one embodiment, this flow begins with a drop of water or some other fluid. In another embodiment, the reagent and the labeled reagent are applied at the same location in the device, for example in the test area 42 of one of the hydrophilic regions 26, 30 along the sample flow path 32.

[0089] In one exemplary implementation, ELISA can be used to detect and analyze a wide range of analytes and disease biomarkers with high specificity, and the results of ELISA can be quantified colorimetrically by appropriately selecting enzymes and substrates.

[0090] Detecting analytes in a sample fluid may include the following additional steps: generating an image of the test area 42 indicating development and digital data of the measurement results, and remotely transmitting the data for further analysis to obtain diagnostic information or storing the measurement results in an appropriate database. Some embodiments also include devices that can be used to image the device after liquid deposition to obtain information about the amount of analyte based on the intensity of the device's colorimetric response. In some embodiments, the device establishes a communication link with a field operator, for example, via a cellular telephone communication channel, who performs analysis based on the images acquired by the device.

[0091] In some exemplary embodiments, which are not intended to be limiting, the entire assay can be completed in less than 30 minutes, 20 minutes, 15 minutes, 10 minutes, or 5 minutes. In some exemplary embodiments, device 10 may have a detection limit of about 500 pM, 250 pM, 100 pM, 1 pM, 500 fM, 250 fM, or 100 fM.

[0092] The diagnostic device 10 of the present invention can be used to measure small volumes of fluid samples. In various embodiments, the fluid samples that can be measured include, but are not limited to, biological samples such as urine, whole blood, plasma, serum, sputum, cerebrospinal fluid, ascites, tears, sweat, saliva, feces, gingival crevicular fluid, or tissue extracts. In some embodiments, the volume of the fluid sample to be measured may be, for example, a drop of blood from a finger prick, or, for example, a small urine sample from a newborn or small animal. In some embodiments, the sample fluid is an environmental sample, such as a water sample obtained from a river, lake, ocean, etc., or a sample of an industrial fluid. The device 10 can also be adapted to measure non-aqueous fluid samples to detect environmental pollution.

[0093] In some embodiments, a single drop of liquid (e.g., a drop of blood from a pricked finger) is sufficient to perform a simple yes / no assay to determine the presence of an analyte in the sample fluid, or to perform a semi-quantitative measurement of the amount of analyte present in the sample, for example, by performing a visual or numerical comparison of the assay intensity with a calibrated colorimetric chart. However, to obtain a quantitative measurement of the analyte in the liquid, a defined volume of fluid is typically deposited in the device. Therefore, in some embodiments, a defined volume of fluid (or a volume sufficiently close to the defined volume to provide a reasonably accurate reading) can be obtained by patterning the hydrophilic substrate 12 to include a sample well that receives the defined volume of fluid. For example, in the case of a whole blood sample, the subject's finger can be pricked and then pressed against the sample well until the well is filled, thus providing a satisfactory approximation of the defined volume.

[0094] The assay reagents included in device 10 are selected to provide a visible indication of the presence of one or more analytes in the sample fluid. The source or nature of the analytes that can be detected using the disclosed device is not limiting. Exemplary analytes include, but are not limited to, toxins, organic compounds, proteins, peptides, microorganisms, bacteria, viruses, amino acids, nucleic acids, carbohydrates, hormones, steroids, vitamins, drugs, contaminants, pesticides, and metabolites or antibodies of any of the foregoing. Analytes may also include any antigenic substance, hapten, antibody, macromolecule, and combinations thereof. For example, an immunoassay using the disclosed device can be applied to antigens having known antibodies that specifically bind to the antigen.

[0095] In exemplary embodiments, the disclosed apparatus can be used to detect the presence or absence of one or more viral antigens, bacterial antigens, fungal antigens, or parasitic antigens or cancer antigens.

[0096] Exemplary viral antigens may include those derived from, for example, hepatitis A virus, hepatitis B virus, hepatitis C virus or hepatitis E virus, human immunodeficiency virus (HIV), herpes simplex virus, Ebola virus, varicella-zoster virus (the virus that causes chickenpox and shingles), avian influenza virus, SARS virus, MERS virus, Epstein virus, rhinovirus, coronavirus (e.g., COVID-19 coronavirus), and Coxsackie virus.

[0097] Exemplary bacterial antigens may include those derived from, for example, Staphylococcus aureus, Staphylococcus epidermidis, Helicobacter pylori, Streptococcus bovis, Streptococcus pyogenes, Streptococcus pneumoniae, Listeria monocytogenes, Mycobacterium tuberculosis, Mycobacterium leprae, Corynebacterium diphtheriae, Borrelia burgdorferi, Bacillus anthracis, Bacillus cereus, Clostridium botulinum, Clostridium difficile, Salmonella typhi, Vibrio cholerae, Haemophilus influenzae, Bordetella pertussis, Yersinia pestis, Neisseria gonorrhoeae, Treponema pallidum, Legionella pneumophila, Rickettsia typhi, Chlamydia trachomatis, Shigella dysenteriae, and Vibrio cholerae.

[0098] Exemplary fungal antigens may include those derived from fungi such as tinea pedis, tinea corporis, tinea cruris, onychomycosis, Cladosporium carionii, Coccidioides immitis, Candida spp., Aspergillus fumigatus, and Pneumocystis carinii.

[0099] Exemplary parasite antigens include those derived from, for example, Giardia lamblia, Leishmania sp., Trypanosoma sp., Trichomonas sp., and Plasmodium sp.

[0100] Exemplary cancer antigens may include antigens expressed in, for example, colon cancer, stomach cancer, pancreatic cancer, lung cancer, ovarian cancer, prostate cancer, breast cancer, liver cancer, brain cancer, skin cancer (e.g., melanoma), leukemia, lymphoma, or myeloma.

[0101] In other embodiments, the assay reagent may react with one or more metabolic compounds. Exemplary metabolic compounds include, for example, proteins, nucleic acids, polysaccharides, lipids, fatty acids, amino acids, nucleotides, nucleosides, monosaccharides, and disaccharides. For example, the assay reagent is selected to react with the presence of at least one of glucose, protein, fat, vascular endothelial growth factor, insulin-like growth factor 1, antibody, and cytokines.

[0102] Now for reference Figures 2A to 2B Another embodiment of the diagnostic device 110 includes a substantially flat, elongated hydrophilic substrate 112 having a first end 113, a second end 115, and at least one folded region 114 between the first end 113 and the second end 115. The folded region 114 divides the hydrophilic substrate 112 into a first sheet-like portion 116 and a second sheet-like portion 118, each sheet-like portion occupying a substantially parallel plane relative to the folded region 114. The first substrate portion 116 includes a first main surface 117 and a second main surface 119, while the second substrate portion 118 includes a first main surface 121 and a second main surface 123. Figure 2A In one embodiment, the first portion of substrate 116 and the second portion of substrate 118 cover each other, such that the respective main surfaces 119 and 121 are adjacent to each other.

[0103] The first substrate portion 116 includes a first hydrophobic region 124 and a first hydrophilic region 126, while the second substrate portion 118 includes a second hydrophobic region 128 and a second hydrophilic region 130. The hydrophobic regions 124 and 128 each resist fluid flow in the direction of arrow A, which is aligned along the thickness of the substrate portions 116 and 118 or along the z-axis of the three-dimensional diagnostic device 110. The hydrophilic regions 126 and 130 are registered and aligned with each other, such that the first hydrophilic region 126 (in...) Figure 2A A fluid sample (not shown) can be flowed along a sample flow path 132 using, for example, wicking or capillary action, to provide fluid communication between a first substrate portion 116 and a second substrate portion 118, such that the fluid sample is wicked into a second hydrophilic region 130.

[0104] All or a portion of one or both of the hydrophilic regions 126 and 130 may include a test area 142, in which analytical results or outputs of the diagnostic device 110 may be displayed to a user, and one or more reagents 140 in or in fluid communication with the test area 142. One or more reagents 140 disposed in the sample flow path 132 are selected to provide an indication of at least one of the presence, absence, or concentration of an analyte in the sample fluid. In various embodiments, reagents 140 may be applied to all or a portion of one or both of the hydrophilic regions 126 and 130, either in another part of the device 110 and in fluid communication with the flow path 132, or may be applied to the sample flow path 132 before or after the fluid sample is applied to the sample flow path 132.

[0105] The diagnostic device 110 includes a regular or irregular grid or mesh-like first connection area 154 on the second main surface 119 of the first substrate portion 116. (As in...) Figure 2C As illustrated in an exemplary embodiment, the first connection area 154 includes grid lines 153, 155 that are substantially perpendicular to each other.

[0106] In some embodiments, the diagnostic device 110 also includes an optional grid or mesh-like second connection area 156 on the first main surface 121 of the second substrate portion 118.

[0107] The mesh-like connection regions 154 and 156 are configured to include sufficient open areas 160 between mesh lines 153 and 155 to allow sample fluid to be wicked along the sample flow path 132 and flow from the first hydrophilic region 126 to the second hydrophilic region 130, while adhering the first substrate portion 116 to the second substrate portion 118 and maintaining the registration of the hydrophilic regions 126 and 130 to preserve the alignment of the sample flow path 132. Figure 2B The grid lines 153 and 155 in the connecting regions 154 and 156, together with the hydrophobic regions 124 and 128, prevent the sample fluid from flowing along direction B, which is perpendicular to the sample flow path 132.

[0108] In various embodiments, the connection areas 154, 156 may comprise any of the adhesives described above, such as pressure-sensitive adhesives, hot-melt adhesives, cohesive adhesives, etc. In some embodiments, the adhesive may be applied by spraying, printing, or using a transfer adhesive, which provides a sufficiently open structure to allow sample fluid to wick between the layers or panels of the device.

[0109] Now for reference Figure 3AA portion of the elongated web 200 includes a hydrophilic substrate 212, which includes a first end 213 and a second end 215. The web 200 includes a plurality of web regions 270A-270E, which are separated by separating regions 272A-272D. Figure 3A In one embodiment, each web region 270A-270E includes hydrophobic regions 224A-224E and hydrophilic regions 226A-226E. In some embodiments, the separation region 272 does not have hydrophobic regions, but such an arrangement is not necessary. Figure 3A In some implementations, the hydrophobic regions 224A-224E and the hydrophilic regions 226A-226E have the same shape, but in some implementations, the hydrophobic and hydrophilic regions may have different shapes, depending on the specific diagnostic requirements.

[0110] exist Figure 3A In the implementation scheme, the web areas 270A and 270B also include connecting areas 234A and 234B surrounding the hydrophilic areas 226A and 226B. Furthermore, in Figure 3A In one embodiment, the web area 270D includes, for example, a patterned bonding area 254 of a pressure-sensitive adhesive (PSA).

[0111] like Figure 3B As shown, Figure 3A The web 200 can be folded along the separation regions 272A-272D ​​in the direction of arrow C to form a diagnostic device 300 including stacked and substantially parallel panels 270A-270E. When folded in this way, connecting regions 234A and 234B are joined together to adhere and maintain the registration of panels 270A-270B, and patterned connecting regions 254 maintain the registration of panels 270C-270D. The registration of panels 270A-270E maintains the alignment of hydrophilic regions 226A-226E, which allows sample fluid to flow along sample flow path 232 through hydrophilic regions 226A-226E. Although in Figures 3A to 3B Not shown, but additional connection areas of any suitable shape or configuration can be used to maintain alignment of the hydrophilic areas in panels 270B-270C and 270D-270E. In some embodiments, mechanical fasteners (in...) Figures 3A to 3B (Not shown) It can also be used alone or in combination with adhesive bonding areas to maintain the alignment of any or all of the panels 270A-270E.

[0112] As described above, one or more reagents (in) Figure 3B (not shown) may be included in the hydrophilic areas 226A-226E ( Figure 3A Any or all of the following, and one or more of the panels 270A-270E may include a test area to indicate at least one of the presence, absence or concentration of the analyte in the sample fluid.

[0113] In some implementation schemes (in) Figures 3A to 3B (Not shown in the image), each web section 270A-270E can be printed on a separate web or web area. After further processing of the web, the individual web sections 270-270E can then be aligned, placed on top of each other in the desired order, and stacked to form a suitable diagnostic device. However, in some cases, with Figures 3A to 3B Compared to the folding process described in the text, the alignment and stacking steps in this process may increase the total manufacturing cost of the diagnostic device.

[0114] In another aspect, this disclosure relates to a measurement method for any embodiment of the diagnostic device described above. Reference Figures 1A to 1B The diagnostic device 10 shown illustrates an exemplary measurement method that includes adding a fluid sample containing the analyte to the hydrophilic regions 26, 30, such that the sample fluid enters and is wicked along the sample flow path 32 via capillary action. In some embodiments, water or a buffer solution may also be added to the hydrophilic regions 26, 32 to assist the movement of the sample fluid along the sample flow path 32.

[0115] Visual or machine inspection of the test area 42 within the hydrophilic zones 26, 30, or the entire hydrophilic zones 26, 30, allows for the determination of at least one of the presence, absence, or concentration of an analyte in the fluid sample. For example, in some embodiments, the assay protocol produces a color reaction, which includes grayscale development from black to white, and examining the development or intensity of the color in the test area 42 within the hydrophilic zones 26, 30, or the entire hydrophilic zones 26, 30, to determine the presence, absence, or concentration of the analyte.

[0116] In one embodiment, the disclosed apparatus can be used to perform an ELISA test. The method may include the following steps: (1) adding a sample to the apparatus, wherein the sample is directly wicked through hydrophilic regions 26, 30 along the sample flow path 32; (2) binding an analyte with a labeled antibody along the flow path 32 and into a test region 42; and binding the analyte to an antigen in the test region 42; and optionally washing the hydrophilic regions 26, 30 with a buffer such as PBS to observe the results in the test region 42.

[0117] In another aspect, this disclosure relates to a kit comprising a diagnostic device 10 and other devices for performing assays on selected analytes. For example, the kit may optionally include one or more vials of purified water and / or buffer (e.g., PBS), one or more vials of suitable reagents, a device for obtaining blood samples (e.g., a device for performing acupuncture), a device for collecting urine or saliva samples or other bodily fluids, or a pipette for transferring water and / or buffer to the device. Furthermore, the kit may include instructions or colorimetric charts for quantifying colorimetric reactions.

[0118] The devices and methods of this disclosure will now be further described in the following non-limiting embodiments.

[0119] Example

[0120] Example 1

[0121] Using a FLEXIPROOF 100 printing system (obtained from RK Industries, Herts, United Kingdom), flexographic ink (9418, obtained from NAZDAR Ink Technologies, Shawnee, KANS) was printed onto a WHATMAN Class 1 filter paper substrate (obtained from GE Healthcare Life Sciences, Piscataway, NJ). Printing was completed using an anilox roller with a diameter of 38.75 microns (25 billion cubic microns (BCM)) and 35.4 lines / cm (90 lines / inch) to form a circle with a diameter of 5.08 cm (2 inches). After printing, the printed paper samples were heated at 177°C (350°F) for eight minutes, and the ink was cured by exposure to UV radiation from a FUSION high-intensity UV curing system (from FUSION UV Systems Inc., Hampshire, United Kingdom), equipped with an H-bulb and conveyed at 1.5 m (5 ft) / min, to create hydrophobic zones on the paper samples. After curing, the properties of the printed paper samples were tested by depositing dyed deionized water into non-printed areas and visually inspecting the diffusion of the dyed water. Dye was added to the water to aid in observation.

[0122] Figures 4A to 4BThe image shows printed paper after being tested with dyeing water. The dyeing water saturates most of the unprinted areas but does not wick into the printed areas or areas near the boundaries of the printed areas. The ink contains pigment particles (which appear blue) that do not wick along the fibers, while the polymer components of the ink wick along the fibers, thus creating hydrophobic areas around the printed pattern. Gray water remains at the resulting hydrophobic boundaries.

[0123] Tests were conducted to demonstrate that the volumetric hydrophobic regions of the paper maintain sufficient fluid permeability. A 5.08 cm (2 inch) diameter disc was cut from the printed paper. The paper sample was inserted into a standard filter housing, and a water line with a pressure of one meter head was connected to the filter housing. The outflow was measured. See Table 1 below for the test results. Figure 5 .

[0124] Table 1

[0125] <![CDATA[ sample ]]> <![CDATA[ Average flow rate (ml / s) ]]> Comparison 4.56 100% easy to peel 2.36 80% easy to peel 2.24 60% easy to peel 2.08 NAZDAR 9418 1.70 NAZDAR 1028 1.90 wax 0.23

[0126] Example 2

[0127] Samples were produced as described in Example 1 using OP 1028 ink (obtained from NAZDAR Ink Technologies, Shawnee, KANS) instead of 9418 ink. Tests were performed to demonstrate that the volumetric hydrophobic regions of the printed paper maintained sufficient fluid permeability. A 5.08 cm (2 inch) diameter disc was cut from the printed paper. The paper sample was inserted into a standard filter housing, and a water line with a pressure of one meter head was connected to the filter housing, and the outflow was measured. See Table 1 for the test results. Figure 5 .

[0128] Examples 3-5

[0129] Three samples were produced as described in Example 1 using UVF03408 (UV Easy Release) peel ink (obtained from Flint Group, Rogers, MN, Minnesota) instead of 9418 ink. The first sample was undiluted. The second sample was diluted with 20% isopropyl alcohol (IPA) solvent before ink application. The third sample was diluted with 40% IPA solvent before ink application. Samples with solvent-containing inks were dried at room temperature for 15 minutes. Tests were performed to demonstrate that the volumetric hydrophobic regions of the printed paper maintained sufficient fluid permeability. A 5.08 cm (2 inch) diameter disc was cut from the printed paper. The paper sample was inserted into a standard filter housing, and a water line with a 1-meter head pressure was connected to the filter housing, and the outflow was measured. See Table 1 for test results. Figure 5 .

[0130] Comparative Example 1

[0131] Wax-saturated paper was prepared by melting Batik wax (available from Jacquard Products, Healdsburg, CA) at 65.6°C (150°F) and dropping it onto WHATMAN Grade 1 paper preheated to the same temperature until saturation in less than about 5 minutes. Tests were conducted to demonstrate that the volumetric hydrophobic regions of the printed paper maintained sufficient fluid permeability. A 5.08 cm (2 inch) diameter disc was cut from the printed paper. The paper sample was inserted into a standard filter housing, and a water line with a pressure of one meter head was connected to the filter housing, and the outflow was measured. See Table 1 for test results. Figure 5 .

[0132] Example 6

[0133] CH 265 self-adhesive (obtained from Valpac Industries, Federalsburg, MD, USA) was manually applied to the printed areas on both sides of the sample produced in Example 1 using a cotton swab. After drying at room temperature for one hour, the sample was folded and gently pressed together. Stained water was placed on one side of the sample, and wicking to the other side was observed after 25 seconds, indicating successful fluid transport through the layer.

[0134] Example 7

[0135] The adhesive is printed in an open mesh pattern onto a specific area of ​​the hydrophobic printing area of ​​the configuration as described in Example 1.

[0136] Table 1 and Figure 5 The relevant section shows that the flow rate was highest for unprinted paper, followed by printed paper. This indicates that the printed paper retains its water permeability. The flow rate through the wax saturation pan was very low and is due to the stratification of wax under one meter of water pressure.

[0137] Example 8

[0138] On a custom flexographic printing line, using a 24bcm (billion cubic micrometers) anilox roller at 100 lines per inch and a linear speed of 10 fpm, Flint Group peelable coating (available from FlintGroup, Rogers, MN) was flexographically printed onto a 12-width roll of Great Lakes filter paper (equivalent to #1 Whatman, Grade 601, available from Great Lakes Filters, Bloomfield Hills, MI) to represent a pattern representing a 5-fold array of biodiagnostic devices.

[0139] The ink is UV-cured online on both sides during two passes. Individual 5-fold units are cut from the paper roll and folded along the unprinted spaces between the printed areas. 3M Spray 77 (available from 3M) is lightly sprayed by hand onto the hydrophobic and hydrophilic areas on both sides of the unit.

[0140] After drying for 2 minutes, fold the device. Place the dyed water onto the top hydrophilic ring (covered with sprayed adhesive) and allow it to wick. Observe wicking to the other side within about 50 seconds, indicating that fluid delivery through the layer is successful.

[0141] Various embodiments of the present invention have been described. These and other embodiments are within the scope of the following claims.

Claims

1. A diagnostic device, comprising: A substantially flat, elongated porous substrate having a first end and a second end, wherein the substrate includes at least one folded region between the first end and the second end, the substrate being bent in the folded region such that a first portion and a second portion of the substrate overlap each other, and wherein: A first portion of the substrate lies in a first plane relative to the folded region, wherein the first portion of the substrate includes a first hydrophobic region and a first hydrophilic region, wherein the first hydrophobic region includes a first low surface energy polymer material extending from a first primary surface of the first portion of the substrate to a second primary surface of the first portion of the substrate, and wherein the first hydrophobic region includes an arrangement of interconnecting openings providing at least one uninterrupted path extending from the first primary surface of the first portion of the substrate to the second primary surface of the first portion of the substrate; and The second portion of the substrate is located in a second plane relative to the folded region, wherein the second plane is substantially parallel to the first plane, the second portion of the substrate includes a second hydrophilic region and a second hydrophobic region comprising a second low surface energy polymer material, the second low surface energy polymer material may be the same as or different from the first low surface energy polymer material, extending from a first main surface of the second portion of the substrate to a second main surface of the second portion of the substrate, and wherein the second hydrophobic region includes an arrangement of interconnecting openings that provide at least one uninterrupted path extending from the first main surface of the second portion of the substrate to the second main surface of the second portion of the substrate; At least one connection region is located between the first portion and the second portion of the substrate, wherein the at least one connection region is configured to adhere the first portion of the substrate to the second portion of the substrate and maintain alignment of the first hydrophilic region and the second hydrophilic region, the alignment being sufficient to provide a sample flow path between the first portion and the second portion of the substrate in a direction perpendicular to the first plane and the second plane; and A reagent along the sample flow path, wherein the reagent is selected to detect at least one of the presence, absence, or concentration of an analyte present in a sample applied to the diagnostic device.

2. The diagnostic device of claim 1, wherein the connection area comprises an adhesive layer, the adhesive being selected from pressure-sensitive adhesives, hot melt adhesives, cohesive adhesives, and mixtures and combinations thereof.

3. The diagnostic device of claim 2, wherein the connection region comprises a first layer of cohesive adhesive on the first portion of the substrate and a second layer of cohesive adhesive on the second portion of the substrate.

4. The diagnostic device of claim 2, wherein the connection region comprises a patterned adhesive on at least one of the first portion and the second portion of the substrate, wherein the patterned adhesive comprises an arrangement of open regions configured to allow fluid to flow between a first hydrophilic region of the first portion of the substrate and a second hydrophilic region of the second portion of the substrate.

5. The diagnostic device of claim 1, wherein the elongated porous substrate is selected from paper, nonwoven materials, polymer films, and combinations thereof.

6. The diagnostic device of claim 1, wherein the first low surface energy polymer material and the second low surface energy polymer material each comprise a radiation-curable polymer ink.

7. The diagnostic device according to claim 1, wherein the first low surface energy polymer material and the second low surface energy polymer material comprise monomers or polymers selected from fluorocarbons, organosilicones, or hydrocarbons.

8. The diagnostic device according to claim 7, wherein the fluorocarbon compound is selected from perfluoro(meth)acrylates, perfluoropolyethers, and mixtures and combinations thereof.

9. The diagnostic device according to claim 7, wherein the organosilicon is selected from organosilicon (meth)acrylates.

10. The diagnostic device according to claim 7, wherein the hydrocarbon comprises octadecyl acrylate.

11. The diagnostic device of claim 1, wherein the first low surface energy polymer material and the second low surface energy polymer material comprise a hydrophobic ink with a surface energy of less than 35 dynes / cm.

12. The diagnostic device of claim 1, wherein the first low surface energy polymer material and the second low surface energy polymer material comprise oligomers selected from fluorocarbons, organosilicones, or hydrocarbons.

13. A diagnostic device, comprising: A substantially flat, elongated porous fiber substrate having a first end and a second end, wherein the substrate comprises: A plurality of folded regions between the first end and the second end, the plurality of folded regions dividing the porous fiber substrate into a stack of stacked, substantially flat panels, wherein each of the panels in the stack occupies a different substantially parallel plane, and wherein each of the panels comprises: Hydrophobic and hydrophilic regions, the hydrophobic regions comprising fibers coated with a hydrophobic low surface energy polymer ink, such that open regions are maintained between the fibers, the open regions between the fibers providing at least one uninterrupted open path between a first main surface of the panel and a second main surface of the panel; and At least some of the panels mentioned above include: The reagents selected for detecting the analytes present in the sample, and The connection area is configured to attach adjacent panels to each other; and The hydrophobic and hydrophilic regions in the stacked adjacent panels are aligned with each other to provide a sample flow path between the hydrophilic regions in a direction perpendicular to the first and second main surfaces, such that the sample contacts the reagent disposed in the flow path to provide an indication of at least one of the presence, absence, or concentration of the analyte in the sample.

14. The diagnostic device of claim 13, wherein the connection area comprises an adhesive selected from pressure-sensitive adhesives, hot melt adhesives, cohesive adhesives, and mixtures and combinations thereof.

15. The diagnostic device of claim 13, wherein adjacent stacked panels include registration regions of a cohesive adhesive, the registration regions being configured to allow fluid to flow between the hydrophilic regions in the adjacent panels.

16. The diagnostic device of claim 13, wherein the connection area includes a patterned adhesive, the patterned adhesive including an arrangement of open areas configured to allow fluid to flow between adjacent panels.

17. The diagnostic device of claim 13, wherein the connection area occupies the periphery of the panel and surrounds the hydrophobic layer.

18. The diagnostic device of claim 13, wherein the hydrophobic region surrounds the hydrophilic region.

19. The diagnostic device of claim 13, wherein the porous fiber substrate is selected from paper, nonwoven materials, polymer films, and combinations thereof.

20. The diagnostic device of claim 19, wherein the porous fiber substrate comprises paper.

21. The diagnostic device of claim 13, wherein the ink is radiation-curable.

22. A detection method, the method comprising: A diagnostic device is provided, the diagnostic device comprising an elongated, substantially flat, porous fiber substrate having a first end and a second end, wherein the substrate includes a plurality of folded regions between the first end and the second end, the plurality of folded regions dividing the porous fiber substrate into a stack of stacked flat panels, each flat panel occupying a different substantially parallel plane, and wherein each of the panels comprises: Hydrophobic and hydrophilic regions are arranged such that the hydrophilic regions in the panel are registered with each other to provide a sample flow path therebetween. The hydrophobic region includes fibers coated with a low surface energy polymer material such that open regions are maintained between the fibers, and the open regions between the fibers provide at least one uninterrupted open path between the first main surface of the panel and the second main surface of the panel; The reagents placed in the sample flow path, and A connector between at least some of the panels in the panel, the connector maintaining the alignment of the hydrophilic area along the sample flow path; Apply the sample to the sample flow path; and The sample is flowed along the sample flow path by capillary action, such that the reagent provides an indication of at least one of the presence, absence, or concentration of the analyte in the sample.

23. The method of claim 22, wherein the sample is selected from blood, urine, sputum, water, and combinations thereof.

24. A method of manufacturing a diagnostic device, the method comprising: A hydrophobic curable polymer ink composition is applied to an elongated web of fibrous material, wherein the hydrophobic curable polymer ink composition is applied to a plurality of adjacent web regions extending from a first edge of the web to a second edge of the web, wherein each web region is separated from adjacent web regions by a boundary region; And each of these areas includes: The hydrophobic region comprises the hydrophobic region of the hydrophobic curable polymer ink composition. It substantially lacks the hydrophilic regions of the hydrophobic curable polymer ink composition, and The hydrophobic curable polymer ink composition is at least partially cured in the hydrophobic region of each web area to provide hydrophobic ink on the fibers of the fibrous material and the open regions between the fibers, the open regions between the fibers providing at least one uninterrupted open ink-free path between the first main surface of the web and the second main surface of the web; as well as The web of porous material is folded along the boundary region to form a stack of stacked, substantially flat panels, each of which occupies a different substantially parallel plane, and each of which includes a registered hydrophilic region thereby forming a sample flow path therebetween.

25. The method of claim 24, wherein the boundary region is substantially free of the ink.

26. The method of claim 24, wherein the ink composition is applied to the elongated web by at least one of printing, coating, physical vapor deposition, and combinations thereof.

27. The method of claim 26, wherein the ink is applied by a printing technique selected from inkjet, flexographic, screen printing, gravure, offset printing, and combinations thereof.

28. The method of claim 24, wherein at least a portion of the web region includes a bonding region selected from pressure-sensitive adhesives, hot melt adhesives, cohesive adhesives, and mixtures and combinations thereof.

29. The method of claim 28, wherein the adhesive in the bonding region is applied by at least one of spraying, printing, transferring adhesive, and combinations thereof.

30. The method of claim 28, wherein the bonding region comprises a cohesive adhesive applied to the periphery of at least some of the web regions in the web region, wherein the bonding region at least partially surrounds the hydrophobic region and the hydrophilic region in the web region.

31. The method of claim 28, wherein the connecting region includes a patterned adhesive that at least partially covers each web region, wherein the patterned adhesive includes an open region covering the hydrophilic region.

32. The method of claim 31, wherein the patterned adhesive comprises a grid pattern.

33. The method of claim 28, wherein the connecting region is applied at at least one of the first edge and the second edge of the elongated web.

34. The method of claim 24, wherein the curable polymer ink composition is UV-curable.

35. The method of claim 28, further comprising: The web is folded such that the connecting areas in at least some adjacent panels at least partially cover each other.

36. The method of claim 24, further comprising: A reagent is disposed along the flow path in at least one of the hydrophilic regions, wherein the reagent is selected to provide an indication of at least one of the presence, absence, and concentration of an analyte in the sample.

37. A kit comprising the diagnostic apparatus of claim 1 and a sample collection device configured to collect a sample containing the analyte.

38. The kit of claim 37, wherein the sample collection device includes means for collecting bodily fluid samples selected from blood, urine and saliva.

39. The kit of claim 37, further comprising instructions for using the diagnostic device.

40. The kit of claim 37 further includes a vial containing a reagent selected to provide an indication of at least one of the presence, absence, or concentration of the analyte in the sample.

41. The kit of claim 37 further includes a vial containing a fluid selected from water, buffer solutions, and combinations thereof.

42. A system comprising: Diagnostic device, the diagnostic device comprising: An elongated, substantially flat, porous substrate having a first end and a second end, wherein the substrate includes at least one folded region between the first end and the second end, and wherein: A first portion of the substrate lies in a first plane relative to the folded region, wherein the first portion of the substrate includes a first hydrophobic region and a first hydrophilic region, wherein the first hydrophobic region comprises a hydrophobic polymeric low surface energy material extending from a first primary surface of the first portion of the substrate to a second primary surface of the first portion of the substrate, and wherein the first hydrophobic region includes an arrangement of interconnecting openings providing at least one uninterrupted path extending from the first primary surface of the first portion of the substrate to the second primary surface of the first portion of the substrate; and The second portion of the substrate is different from the first portion of the substrate, wherein the second portion of the substrate is located in a second plane relative to the folded region, wherein the second plane is substantially parallel to the first plane, the second portion of the substrate includes a second hydrophilic region and a second hydrophobic region, the second hydrophobic region comprising a hydrophobic polymer low surface energy material and extending from a first main surface of the second portion of the substrate to a second main surface of the second portion of the substrate, and wherein the second hydrophobic region includes an arrangement of interconnecting openings that provide at least one uninterrupted path extending from the first main surface of the second portion of the substrate to the second main surface of the second portion of the substrate; At least one connection region is located between the first portion and the second portion of the substrate, wherein the at least one connection region is configured to maintain registration of the first hydrophilic region and the second hydrophilic region, the registration being sufficient to provide a passive sample flow path between the first portion and the second portion of the substrate in a direction perpendicular to the first plane and the second plane; and The reagent is selected for detecting at least one of the presence, absence, or concentration of an analyte in a sample fluid applied to the flow path of the diagnostic device.

43. The system of claim 42, wherein the connection region comprises an adhesive selected from pressure-sensitive adhesives, hot melt adhesives, cohesive adhesives, and mixtures and combinations thereof.

44. The system of claim 42, wherein the connection area includes a mechanical fastener.

45. The system of claim 43, wherein the connection area includes a mechanical fastener.

46. ​​The system of claim 44, wherein the mechanical fastener is selected from nails, clamps, elastic bands, cable ties, and combinations thereof.

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