Magnetic bead ELISA detector device and use method thereof

Abstract

Systems, cartridges, devices, and methods for detecting a target analyte in a test sample are provided. The system employs multiple magnetic sources to sequentially move magnetic beads through various portions, such as cartridges or strips, such as from one or more hybridization portions, through one or more wash portions, and to a redox portion. The system employs a set of electrodes and a potentiostat to perform galvanic analysis to obtain electrochemical measurements based on conversion of redox active molecules. Also provided are methods of detecting a target analyte using the system, as well as cartridges and strips for use in the system or devices of the system.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of U.S. Patent Application Serial No. 63 / 393,677, filed on July 29, 2022, the entire content of which is incorporated herein by reference. Technical field

[0003] The present disclosure generally relates to systems, devices, cartridges, strips, and methods for detecting a target analyte in a test sample, and in particular, to a system or device that employs multiple magnetic sources for moving magnetic beads in sequential movement and an potentiostat for performing current analysis to obtain electrochemical measurements. Background art

[0004] Enzyme - linked immunosorbent assay (ELISA) is used in many different fields of analytical chemistry and medicine and can test for and provide semi - quantitative measurements of a wide variety of target analytes or compounds of interest (such as antigens, toxins, hormones, proteins, or specific biomarkers in blood or plasma) in a given test sample.

[0005] However, currently available ELISA tests and devices are not ideal for detecting the presence or precise quantity of certain analytes, for example due to their low concentration and / or insufficient detection efficiency. In addition, ELISA tests are generally too complex for point - of - care (POC) tests and home tests. Currently available lateral flow tests also lack the sensitivity to detect the presence of certain analytes at low concentrations and the ability to perform quantitative measurements. Accordingly, there is a need for devices and methods with improved performance, sensitivity, and other characteristics.

[0006] The object of the present disclosure is to provide systems, their components, and methods for detecting a target analyte in a test sample. Summary of the invention

[0007] The present disclosure relates to systems, devices, cartridges, strips, and methods for detecting an analyte in a test sample.

[0008] According to one aspect of the present disclosure, there is provided a system for detecting a target analyte in a test sample, the system comprising: a test sample receiving portion; one or more hybridization portions interconnected with the test sample receiving portion, the one or more hybridization portions including or capable of being loaded with: a first antibody conjugated to magnetic beads and a second antibody conjugated to an enzyme, the first antibody being capable of specifically binding to the target analyte, the second antibody being capable of specifically binding to the target analyte and the enzyme being capable of converting a redox-active molecule; a redox portion interconnected with the one or more hybridization chambers, the redox portion including or capable of being loaded with a developing solution having a redox-active molecule; an electrode set; a potentiostat for performing a current analysis to obtain an electrochemical measurement based on the conversion of the redox-active molecule; and a plurality of magnetic sources positioned to sequentially move the magnetic beads from the hybridization portion to the redox portion and optionally beyond the redox portion, different magnetic sources among the plurality of magnetic sources being capable of being turned on and off in a desired order to effect the sequential movement of the magnetic beads.

[0009] In an embodiment, the system includes a cartridge or strip that can be inserted into and removed from the device, the cartridge or strip including a test sample receiving portion, one or more hybridization portions, a redox portion, and an electrode set; and a device including a potentiostat and a plurality of magnetic sources.

[0010] In an embodiment, the device further includes a slot or opening for receiving the cartridge or strip. In an embodiment, the device includes one or more piercing members.

[0011] In an embodiment, the cartridge includes: a port or receptacle as the test sample receiving portion; one or more hybridization chambers as the one or more hybridization portions and interconnected with the port or receptacle through a first passage; a redox chamber as the redox portion and interconnected with the one or more hybridization chambers through a second passage; and an electrode set.

[0012] In an embodiment, the cartridge further includes one or more valves that can be opened and closed, the one or more valves being located in the first passage, the second passage, or both.

[0013] In an embodiment, the first passage, the second passage, or both are tubes or microchannels.

[0014] In an embodiment, the strip includes an absorbent pad as the test sample receiving portion.

[0015] In an embodiment, the strip is a disposable strip.

[0016] In an embodiment, the first antibody and / or the second antibody is in a hybridization solution, and the hybridization solution is contained in a hybridization bag or blister that can be pierced to release the hybridization solution into or onto one or more hybridization portions.

[0017] In an embodiment, the one or more hybridization portions include: a first hybridization portion that is interconnected with a test sample receiving portion and includes or is capable of being loaded with a first antibody; and a second hybridization portion that is interconnected downstream of the first hybridization portion and includes or is capable of being loaded with a second antibody.

[0018] In an embodiment, the system further includes a washing portion that is located between the one or more hybridization portions and the redox portion, and the washing portion includes or is capable of being loaded with a washing solution.

[0019] In an embodiment, the system further includes a washing portion that is located between the one or more hybridization portions and the redox portion along a second path, and the washing portion includes or is capable of being loaded with a washing solution.

[0020] In an embodiment, the washing portion is a washing chamber.

[0021] In an embodiment, the washing solution is contained in a washing bag or blister that can be pierced to release the washing solution into or onto the washing portion.

[0022] In an embodiment, the washing solution is an oil or an organic gel.

[0023] In an embodiment, the developing solution is contained in a developing bag or blister that can be pierced to release the developing solution into or onto the redox portion.

[0024] In an embodiment, the system further includes one or more piercing members for piercing the bag or blister.

[0025] In an embodiment, the test sample receiving portion includes a size-selective grid for capturing cells or molecules larger than a defined size.

[0026] In an embodiment, the defined size of the size-selective grid is between about 0.5 μm and about 10 μm, and more specifically about 4.5 μm.

[0027] In an embodiment, the test sample receiving portion or one or more of the hybridization portions includes an absorbent pad for absorbing fluid and transferring it to one or more of the hybridization portions.

[0028] In an embodiment, the electrode set includes a three-electrode cell.

[0029] In an embodiment, the three-electrode cell includes a reference electrode, a counter electrode, and a working electrode.

[0030] In an embodiment, the working electrode and the counter electrode comprise carbon ink, the reference electrode comprises Ag, AgCl or carbon ink, and optionally, the working electrode is further coated with an acid. In a specific embodiment, both the working electrode and the counter electrode comprise carbon ink, and the reference electrode comprises Ag, AgCl ink.

[0031] In an embodiment, the magnetic source is an electromagnet.

[0032] In an embodiment, the magnetic source is positioned in a zigzag pattern along a path of sequential movement.

[0033] In an embodiment, the system further comprises a Faraday cage that separates the electrode assembly and / or potentiostat from the plurality of magnetic sources.

[0034] In an embodiment, the potentiostat comprises a potentiostat circuit that is electrically coupled to the electrode assembly for performing a current analysis to obtain an electrochemical measurement.

[0035] According to another aspect of the present disclosure, a force method for detecting a target analyte in a test sample is provided, the force method comprising: providing a system as described herein; contacting the test sample with a test sample receiving portion to receive the test sample; allowing the test sample to migrate from the test sample receiving portion to one or more hybridization portions; contacting the test sample in the one or more hybridization portions with a first antibody and a second antibody; sequentially activating different ones of the plurality of magnetic sources to move magnetic beads coupled to the first antibody from the one or more hybridization portions to a redox portion; contacting the magnetic beads in the redox portion with a developing solution having a redox-active molecule; performing a current analysis using a potentiostat to obtain an electrochemical measurement from the electrode assembly based on the conversion of the redox-active molecule through a redox reaction; and determining or evaluating the presence, absence, and / or quantity of the target analyte based on the electrochemical measurement.

[0036] In an embodiment, the step of allowing the test sample to migrate from the test sample receiving portion to one or more hybridization portions comprises: passing the test sample through a size-selective grid.

[0037] In an embodiment, the method comprises the step of piercing one or more hybridization bags or blisters to release the first antibody and / or the second antibody into or onto the one or more hybridization portions.

[0038] In an embodiment, the method further comprises one or more steps of washing the magnetic beads, the one or more washing steps being performed in a washing portion located between the one or more hybridization portions and the redox portion.

[0039] In an embodiment, the washing solution comprises an oil or an organic gel.

[0040] In an embodiment, the one or more washing steps include: piercing a wash bag or blister to release a wash solution into or onto a wash section.

[0041] In an embodiment, the method further includes the step of piercing a development bag or blister to release a development solution into a redox section.

[0042] In an embodiment, the step of sequentially activating different magnetic sources among a plurality of magnetic sources includes: sequentially activating different magnetic sources in a zigzag pattern along a sequentially moving path.

[0043] In an embodiment, the method further includes the step of opening and / or closing one or more valves to assist the sequential movement of magnetic beads.

[0044] In an embodiment, the step of performing a current analysis includes the step of introducing a termination solution into a redox section.

[0045] In an embodiment, the termination solution includes an acid solution.

[0046] In an embodiment, the acid solution includes sulfuric acid.

[0047] In an embodiment, the step of performing a current analysis includes: flowing the contents of the redox section into an electrode chamber, passageway, or section that includes a working electrode of an electrode group or is operatively associated with the working electrode of the electrode group.

[0048] In an embodiment, the working electrode includes an acid solution for terminating or quenching a redox reaction. In an embodiment, the working electrode contains or is coated with an acid solution for terminating or quenching a redox reaction.

[0049] In an embodiment, the step of performing a current analysis is performed for 30 seconds.

[0050] According to another aspect of the present disclosure, a disposable cartridge is provided, including: a port or container for receiving a test sample; one or more hybridization chambers interconnected with the port or container through a first passageway, wherein the one or more hybridization chambers include or are capable of being loaded with: a first antibody conjugated to magnetic beads and a second antibody conjugated to an enzyme, the first antibody being capable of specifically binding to a target analyte, the second antibody being capable of specifically binding to the target analyte, and the enzyme being capable of converting a redox-active molecule; wherein the first antibody and the second antibody are from an antibody source located on the cartridge; a redox chamber interconnected with the one or more hybridization chambers through a second passageway, wherein the redox chamber includes or is capable of being loaded with a development solution having a redox-active molecule; and an electrode group; wherein the cartridge is configured to sequentially move magnetic beads from the hybridization chamber to the redox chamber and optionally beyond the redox chamber by a plurality of magnetic sources present in a device capable of accommodating the cartridge.

[0051] According to another aspect of the present disclosure, a disposable strip is provided, comprising: a test sample receiving portion; one or more hybridization portions located downstream of the test sample receiving portion, the one or more hybridization portions comprising or being capable of being loaded with: a first antibody conjugated to magnetic beads and a second antibody conjugated to an enzyme, the first antibody being capable of specifically binding to a target analyte, the second antibody being capable of specifically binding to the target analyte, and the enzyme being capable of converting a redox-active molecule; the first antibody and the second antibody being from an antibody source located on the strip; a redox portion located downstream of the hybridization portion, the redox portion comprising or being capable of being loaded with a developing solution having a redox-active molecule; and an electrode set; wherein the strip is configured to sequentially move the magnetic beads from a hybridization chamber to a redox chamber and optionally beyond the redox chamber by a plurality of magnetic sources present in a device capable of accommodating the strip.

[0052] According to another aspect of the present disclosure, a kit for detecting a target analyte in a test sample is provided, the kit comprising: a device as disclosed herein and instructions for using the device having a cartridge or strip as disclosed herein. In an embodiment, the kit further comprises one or more cartridges or strips as disclosed herein. In an embodiment, the kit further comprises one or more buffers or solutions, including for example a solution for dissolving or suspending the test sample, a solution comprising the first and / or second antibody, a wash buffer or solution, a redox buffer or solution, a solution comprising an acid, or any combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In the following detailed description with reference to the accompanying drawings, these and other features of the present disclosure will become more apparent. The drawings illustrate by way of example only one or more embodiments of the present disclosure and should not be construed as limiting the scope of the present disclosure.

[0054] Figure 1 is a perspective view of a cartridge having a linear design for detecting a target analyte in a test sample according to an embodiment of the present disclosure;

[0055] Figure 2 is a cross-sectional view of a cartridge having a pouch or blister that can be pierced to release the contents inside the pouch or blister;

[0056] Figure 3 is a perspective view of a cartridge having a circular design for detecting a target analyte in a test sample according to another embodiment of the present disclosure;

[0057] Figure 4 is a cross-sectional view of a strip for detecting a target analyte in a test sample according to another embodiment of the present disclosure;

[0058] Figure 5 is a perspective view of a system for detecting a target analyte in a test sample according to an embodiment of the present disclosure, which shows the Figure 1 cartridge shown in and the means having a slot for receiving the cartridge;

[0059] Figure 6 is Figure 4 a cross-sectional view of the means shown in; and

[0060] Figure 7 is a flow chart showing the steps of a process for detecting a target analyte in a test sample according to an embodiment of the present disclosure. Detailed Description

[0061] The present disclosure relates to systems, devices, cartridges, strips, and methods for detecting a target analyte in a test sample. The systems, devices, cartridges, strips, and methods include improved designs and features.

[0062] Advantageously, the systems and devices disclosed herein include a plurality of magnetic sources disposed throughout (e.g., on the devices of the system) for moving magnetic beads in a sequential movement and, in selected embodiments, generating a wobbling and / or mixing movement. Different magnetic sources among the plurality of magnetic sources can be turned on and off in a desired sequence to effect the sequential movement. During the sequential movement, and in certain embodiments, in relation to the wobbling and / or mixing movement of the magnetic beads and the increased travel distance, improved hybridization can be achieved, for example, by rapid and efficient mixing, and improved washing can also be achieved by removing the fluid containing materials of no interest from the test sample, since only the magnetic beads conjugated to the first antibody binding the target analyte will move through the system (e.g., on the cartridge or strip). This can also result in an improved redox reaction by the rapid and efficient mixing of the magnetic beads conjugated to the first antibody and the enzyme conjugated to the second antibody with redox-active molecules in a redox solution. The directional path of such sequential movement can be designed and achieved by turning the magnetic sources on and off, for example, in a zigzag pattern. In selected embodiments, the zigzag pattern provides an improved and efficient system for detecting the target analyte.

[0063] Systems, Devices, Cartridges, Strips, and Kits

[0064] In an embodiment, the present disclosure relates to a system for detecting a target analyte in a test sample, the system comprising: a test sample receiving portion; one or more hybridization portions interconnected with the test sample receiving portion, the one or more hybridization portions including or capable of being loaded with: a first antibody conjugated to magnetic beads and a second antibody conjugated to an enzyme, the first antibody being capable of specifically binding to the target analyte, the second antibody being capable of specifically binding to the target analyte, wherein the enzyme is capable of transforming a redox-active molecule; a redox portion interconnected with the one or more hybridization chambers, the redox portion including or capable of being loaded with a developing solution having a redox-active molecule; an electrode set; a potentiostat for performing a current analysis to obtain an electrochemical measurement based on the transformation of the redox-active molecule; and a plurality of magnetic sources positioned for sequentially moving the magnetic beads from the hybridization portion to the redox portion and optionally beyond the redox portion, wherein different magnetic sources among the plurality of magnetic sources can be turned on and off in a desired order to effect the sequential movement of the magnetic beads.

[0065] In an embodiment, the system is a device that includes all of the above components in a fixed unit, i.e., it includes each of the following in the fixed unit: a test sample receiving portion, one or more hybridization portions, a redox portion, an electrode set; a potentiostat; and a plurality of magnetic sources. "Fixed unit" means that the system operates as a single unit without a removable cartridge or strip. In such an embodiment, the entire system can be a single-use design and can be disposable.

[0066] In an embodiment, the system includes a cartridge or strip that can be inserted into and removed from the device, the cartridge or strip including a test sample receiving portion, one or more hybridization portions, a redox portion, and an electrode set; and a device including a potentiostat and a plurality of magnetic sources.

[0067] In an embodiment, the device includes a slot or opening for receiving the cartridge or strip. The slot or opening can have any design or configuration suitable for receiving the cartridge or strip. In an embodiment, the cartridge or strip is inserted in a manner that positions it inside the device. In an embodiment, the cartridge or strip is inserted in a manner that positions it on the outer surface of the device. In an embodiment, the cartridge or strip is inserted in a manner that is partially positioned inside the device and partially positioned on the outer surface of the device. In an embodiment, the device is capable of confirming that the strip or cartridge is correctly inserted into the slot or opening of the device and, if the strip or cartridge is inserted incorrectly, is capable of providing an alert and / or error message to the user. In another embodiment, the device further includes a timer, which is configured, for example, to start when a test sample is added to the sample receiving portion and then continuously time the progress as the test sample moves through the device and the various parts and / or chambers.

[0068] As used herein, the term "target analyte" refers to any compound, molecule, or substance that is desired to be detected in a test sample. Examples of target analytes include, but are not limited to, antigens, proteins, peptides, toxins, drugs, metabolites, antibodies, hormones, vitamins, cytokines, microorganisms (such as bacteria, viruses, or protozoa), etc. For example, the test sample can be any body fluid, such as blood, serum, plasma, or urine.

[0069] As used herein, the "test sample receiving portion" refers to the portion where the test sample is deposited or the portion that comes into contact with the system (such as on a cartridge or strip). The test sample receiving portion can be of any size or shape. The test sample receiving portion can be made of any suitable material to receive the test sample and allow fluid to flow, for example, by capillary action. In an embodiment where the system includes a cartridge, the test sample receiving portion can be a port or a container. In another embodiment where the system includes a strip, the test sample receiving portion can be an absorbent pad.

[0070] In embodiments where the system includes an insertable and / or removable cartridge or strip, the test sample can be loaded onto the cartridge or strip before or after inserting the cartridge or strip into the device of the system. In an embodiment, the test sample is loaded onto the cartridge or strip before inserting the cartridge or strip into the device of the system.

[0071] In an embodiment, the test sample receiving portion includes a size-selective grid for prohibiting the passage of materials including cells or molecules larger than a defined size. In an embodiment, the size-selective grid has a defined size between about 0.5 μm and about 10.0 μm. In an embodiment, the defined size of the size-selective grid is about 0.5 μm, about 1.0 μm, about 1.5 μm, about 2.0 μm, about 2.5 μm, about 3.0 μm, about 3.5 μm, about 4.0 μm, about 4.5 μm, about 5.0 μm, about 5.5 μm, about 6.0 μm, about 6.5 μm, about 7.0 μm, about 7.5 μm, about 8.0 μm, about 8.5 μm, about 9.0 μm, about 9.5 μm, or about 10.0 μm. In an embodiment, the size-selective grid has a defined size of about 4.5 μm.

[0072] Different grid materials can be used to capture or prohibit the passage of unwanted materials or test sample components. For example, the size-selective grid can have a defined size that absorbs and does not allow certain or any large complexes or biomolecules (such as megadalton-sized) to pass through, but does not capture the specific target analyte. Those skilled in the art will recognize that various alternative materials or grid sizes are readily available.

[0073] The system of the present disclosure includes one or more hybridization portions. As used herein, "hybridization portion" is intended to refer to a portion where a test sample can contact one or more antibodies as described herein. As described herein, in an embodiment, the hybridization portion can be one or more hybridization chambers. In another embodiment, the hybridization portion can be one or more regions on a strip. In an embodiment, there is a single hybridization portion where the test sample contacts the first antibody and the second antibody as described herein. In an embodiment, there are multiple hybridization portions where the test sample contacts the first antibody and the second antibody in different hybridization portions.

[0074] In an embodiment, one or more hybridization portions include: a first hybridization portion that is interconnected with the test sample receiving portion and internally includes or is capable of being loaded with a first antibody; and a second hybridization portion that is interconnected downstream with the first hybridization chamber and internally includes or is capable of being loaded with a second antibody.

[0075] As described elsewhere herein, the first antibody is conjugated to magnetic beads and is capable of specifically binding to a target analyte, and the second antibody is conjugated to an enzyme and is also capable of specifically binding to the target analyte. The enzyme is capable of transforming a redox-active molecule. Specifically, the enzyme can transform the redox molecule into a form that changes its "energy property", and then the redox molecule is detected with a potentiostat.

[0076] In an embodiment where the system includes a cartridge, one or more hybridization portions can be one or more chambers, and the test sample receiving portion can be a port or a container. The one or more hybridization chambers can be interconnected with the port or the container by any suitable means. In an embodiment, the one or more hybridization chambers can be interconnected with the port or the container through a first passageway (such as a pipe or a conduit) to allow the test sample to move from the port or the container to the one or more hybridization chambers.

[0077] As used herein, the term "passageway" is intended to refer to any conduit, channel, or other structure that allows materials to pass through and connects various parts and chambers of the device. In an embodiment, the passageway is a pipe or a microchannel.

[0078] In an embodiment where the system includes a strip, one or more hybridization portions can be regions on the strip that are downstream of the flow path from the test sample receiving portion. In such an embodiment, "interconnected" means that the test sample can flow from one part or region of the strip to another part or region. The first antibody and the second antibody described herein can be located within the same region of the strip such that the test sample contacts both simultaneously, or one of the antibodies can be downstream of the other in the flow path such that the test sample contacts the two antibodies sequentially.

[0079] In an embodiment, when a test sample reaches one or more hybridization portions, the first antibody and the second antibody may already be located in these portions. In an embodiment, the first antibody and the second antibody may be in a hybridization solution or a hybridization buffer. In an embodiment, the first antibody and the second antibody may be in a lyophilized state. In an embodiment where the first antibody and the second antibody are in a lyophilized state, the hybridization solution or the hybridization buffer may be added to one or more hybridization portions before, during, or after introducing the test sample into the one or more hybridization portions. In an embodiment, the hybridization solution or the hybridization buffer is contained in a bag or a blister that can be opened or pierced to release the hybridization solution or the hybridization buffer onto or into the one or more hybridization portions.

[0080] In other embodiments, the first antibody and the second antibody may be contained within a hybridization bag or blister that is opened or pierced to release the first antibody and the second antibody into (e.g., for a chamber) or onto (e.g., for a strip) one or more hybridization portions. In an embodiment where one or more hybridization portions are chambers, the bag or blister may be located inside or outside the chamber, provided that the first antibody and the second antibody can be released into the chamber. Inside the bag or blister, the first antibody and the second antibody may already be in the hybridization solution or buffer, or upon opening or piercing, the hybridization solution or buffer is released to dissolve or suspend the first antibody and the second antibody.

[0081] As used herein, the terms "bag" or "blister" are intended to refer to any enclosed structure that can be opened or pierced to release its contents. Those skilled in the art will recognize that various materials for bags or blisters are readily available. In an embodiment, the system (e.g., the device) further includes a piercing component for opening or piercing a bag or blister as described herein to release the contents.

[0082] In an embodiment, the test sample receiving portion or one or more hybridization portions further includes: an absorption pad for absorbing fluid and transferring it to the one or more hybridization portions. The absorption pad may include a size-selective grid as described elsewhere herein. The absorption pad may also absorb or capture components of the test sample that are not suitable for movement through the system. In effect, this can provide an efficient washing effect even without a washing portion component (as described elsewhere herein).

[0083] The system of the present disclosure includes a redox portion. As used herein, "redox portion" is intended to refer to a part of the system where a magnetic bead complex contacts a developing solution having a redox-active molecule. "Magnetic bead complex" refers to a complex formed in one or more hybridization portions. In the absence of a target analyte in the test sample, the magnetic bead complex should only include a first antibody conjugated to a magnetic bead. In the presence of a target analyte in the test sample, the magnetic bead complex should include a first antibody conjugated to a magnetic bead, the target analyte, and a second antibody conjugated to an enzyme. The redox portion includes or is capable of being loaded with a developing solution having a redox-active molecule.

[0084] In embodiments where the system includes a cartridge, the redox portion can be a redox chamber. The redox chamber can be interconnected with one or more hybridization chambers in any suitable manner. In an embodiment, the redox chamber can be interconnected with one or more hybridization chambers through a second passageway (such as a tube or conduit) to allow any magnetic bead complex to move from one or more hybridization chambers to the redox chamber.

[0085] In embodiments where the system includes a strip, the redox portion can be an area on the strip that is downstream of the flow path from one or more hybridization portions. In such an embodiment, "interconnected" means that the magnetic bead complex can flow from one part or area of the strip to another part or area.

[0086] In an embodiment, when the magnetic bead complex reaches the redox portion, the redox-active molecule may already be in that portion. In an embodiment, the redox-active molecule can be in a redox developing solution or a developing buffer. In an embodiment, the redox-active molecule can be in a lyophilized state. In embodiments where the redox-active molecule is in a lyophilized state, the redox developing solution or the developing buffer can be added to the redox portion before, during, or after introducing the magnetic bead complex into the redox portion. In an embodiment, the redox developing solution or the developing buffer is contained in a bag or blister that can be opened or pierced to release the redox developing solution or the developing buffer into or onto the redox portion.

[0087] In other embodiments, the redox-active molecule can be contained within a redox bag or blister that is opened or pierced to release the redox-active molecule into the redox portion (such as for a chamber) or onto the redox portion (such as for a strip). In embodiments where the redox portion is a chamber, the bag or blister can be inside or outside the chamber as long as the redox-active molecule can be released into the chamber. Inside the bag or blister, the redox-active molecule may already be in the developing solution or buffer, or a developing solution or buffer is released upon opening or piercing to dissolve or suspend the redox-active molecule.

[0088] In an embodiment, the system of the present disclosure further includes one or more washing portions located between one or more hybridization portions and the redox portion. As used herein, "washing portion" is intended to refer to a portion where the magnetic bead complex can come into contact with a washing solution. The washing portion includes or is capable of being loaded with a washing solution.

[0089] In embodiments where the system includes a cartridge, the one or more washing portions can be one or more chambers located along the second passageway or can be within the second passageway itself.

[0090] In embodiments where the system includes a strip, the one or more washing portions can be one or more regions on the strip downstream of the flow path from the one or more hybridization portions and upstream of the redox portion. In such embodiments, "interconnect" means that the magnetic bead complex can flow from one part or region of the strip to another part or region.

[0091] In an embodiment, when the magnetic bead complex reaches the washing portion, the washing solution may already be in that portion. In other embodiments, the washing solution can be contained within a washing bag or blister that is opened or pierced to inject the washing solution into the washing portion (e.g., for a chamber or passageway) or onto the washing portion (e.g., for a strip). In embodiments where the washing portion is a chamber or the washing portion is carried out within the second passageway, the bag or blister can be inside or outside the chamber or passageway, as long as the washing solution can be released into the chamber or passageway.

[0092] As used herein, the term "washing solution" is intended to refer to any solution suitable for washing the magnetic bead complex to remove any unwanted residual components (e.g., unbound antibodies) from the test sample itself or from one or more hybridization chambers. In an embodiment, the washing solution is an oil or an organic gel. The hydrophobic and elastic properties of the organic gel can make it a good and suitable choice for high-performance liquid displacement. Additionally, the organic gel can help prevent the magnetic bead complex from flowing back to a previous portion. Those skilled in the art will recognize that various alternative options for the washing solution are readily available.

[0093] The system of the present disclosure includes a plurality of magnetic sources. As used herein, "a plurality of magnetic sources" is intended to refer to magnetic sources capable of providing a controlled magnetic field to direct the sequential movement of magnetic beads (and thereby magnetic bead complexes). The plurality of magnetic sources are positioned throughout the system (e.g., device components) for moving magnetic bead complexes in sequential movement from one or more hybridization sections to a redox section and optionally beyond to another section, chamber, or passageway. Different magnetic sources among the plurality of magnetic sources can be turned on and off in a desired sequence to effect the sequential movement of the magnetic bead complexes. In this regard, in an embodiment, the system or device includes a processor and / or circuitry for controlling the timed sequential activation and deactivation of the different magnetic sources.

[0094] A magnetic source can be any suitable component that provides or is capable of conducting magnetic charge. In an embodiment, the magnetic source is an electromagnet, a magnetic wire, a magnet, or any combination thereof. In an embodiment, the magnetic sources are placed in a zigzag pattern throughout the system or device of the system.

[0095] Advantageously, the sequential movement and / or movement in different portions or routes of the magnetic beads in three-dimensional space (e.g., in a hybridization chamber), specifically, for example, movement in a zigzag pattern to increase the travel distance, can produce a wobbling and / or mixing movement. During the sequential and / or spatial movement (including the wobbling / mixing movement of the magnetic beads), improved hybridization can be achieved by rapid and efficient mixing (e.g., with a hybridization solution), improved washing can be achieved, and improved redox reactions can be achieved, all of which increase the efficiency and accuracy of detecting a target analyte in a test sample. The directed path of such sequential and / or spatial movement can be designed and achieved by turning magnetic sources on and off. In an embodiment, the magnetic beads move in batches and travel together. Specifically, batch movement and travel while mixing or wobbling is advantageous for hybridization and washing. In another embodiment, the magnetic beads can travel via alternative routes or at different speeds, e.g., based on the properties of the magnetic beads and / or the binding material. For example, in some embodiments, the systems and methods herein can involve using magnetic beads made of different materials (e.g., having different magnetic properties that allow for weaker or stronger interaction with a magnetic field) and / or magnetic beads of different sizes. In some embodiments, the magnetic beads can move at different rates based on other properties, such as based on the specific target analyte (or non-bound target analyte) to which they are bound.

[0096] In an embodiment, the system further includes one or more valves that can be opened and closed. This feature is particularly relevant to embodiments of the systems and cartridges having passageways and chambers disclosed herein. As used herein, "valve" is intended to refer to any structure that can be opened and closed to control fluid flow. The one or more valves can be located within a first passageway, a second passageway, or both. Advantageously, when closed, the valve prevents material or fluid from passing through (e.g., preventing backflow into a previous chamber or passageway).

[0097] In an embodiment, the system further includes a Faraday cage that separates the electrode assembly and / or the potentiostat from a plurality of magnetic sources to prevent interference. A Faraday cage is an enclosed structure for blocking electromagnetic fields. Advantageously, this can help prevent any interference between the magnetic sources and the potentiostat. Those skilled in the art will recognize that various alternative structures or materials can be readily obtained to achieve the same goal.

[0098] The system of the present disclosure includes an electrode assembly. As used herein, "electrode assembly" is intended to refer to a plurality of electrodes for measuring the energy properties of a test sample received therein. In operation, and without being bound by theory, the electrode assembly can be connected and / or electrically engaged with a potentiostat to perform a current analysis to obtain an electrochemical measurement based on reducing the oxidized form of a substrate back to its original form (after the enzyme oxidizes the substrate in the redox section / compartment), and applying a potential to the working electrode, and then recording the current at the working electrode.

[0099] In an embodiment, the electrode assembly includes a three - electrode cell. In an embodiment, the three - electrode cell includes a reference electrode, a counter electrode, and a working electrode. In an embodiment, the working electrode and the counter electrode include carbon ink, and the reference electrode includes Ag, AgCl, or carbon ink. In a specific embodiment, both the working electrode and the counter electrode include carbon ink, and the reference electrode includes Ag, AgCl ink. Specifically, a reference electrode containing Ag, AgCl can provide a more stable and reliable reference potential. In an embodiment, all three electrodes are made of the same material. In an embodiment, all three electrodes are printed carbon ink. In an embodiment, the electrodes can contain or be coated with an acid or acid solution. In a specific embodiment, the working electrode can be coated with an acid, for example, to terminate or quench the redox reaction. By coating the working electrode with an acid (such as sulfuric acid), when the reactant solution from the redox section contacts the working electrode, the acid dissolves and the redox reaction is substantially terminated or quenched, and more specifically, completely terminated or quenched (before performing the current analysis). Specifically, without being bound by theory, the acid denatures the enzyme and terminates the enzyme activity and conversion. In addition, the acid also converts the redox molecules into different forms. After terminating or quenching the redox reaction associated with the enzyme, the current analysis is the reverse redox reaction, which measures how much has been converted, thereby allowing for a quantitative measurement of the concentration of the target analyte in the test sample.

[0100] As used herein, "reactant solution" refers to the developing solution in the redox portion after reaction with the magnetic bead complex. In an embodiment, the mixture is reacted for between 5 seconds and 5 minutes and then terminated. In an embodiment, the mixture is reacted for a period of about 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55 seconds, 1 minute, 1.5 minutes, 2 minutes, 2.5 minutes, 5.0 minutes, 7.5 minutes or 10 minutes. In an embodiment, the mixture is reacted for a period of about 30 seconds.

[0101] The system of the present disclosure includes a potentiostat. As used herein, "potentiostat" is intended to refer to a potentiostat that is connected, connectable or electrically engageable with an electrode set to perform amperometric analysis to obtain an electrochemical measurement based on the conversion of redox active molecules by an enzyme on a second antibody. In an embodiment, the potentiostat includes a potentiostat circuit that electrically engages the electrode set for performing amperometric analysis to obtain an electrochemical measurement.

[0102] The potentiostat is connected or electrically engaged to an electrode set for analyzing the presence, absence, amount and / or concentration of a target analyte in a test sample. Generally, the potentiostat is designed to control the potential of a working electrode in a three-electrode cell. The potentiostat can include a number of internal circuits that enable it to operate with this capability. The circuit generates and measures potential and current. Exemplary potentiostats that can be used as part of an electrochemical sensor system are disclosed in International Patent Application Serial Number PCT / CA 2019 / 051567 and U.S. Patent Publication Number US2021 / 0270766A1, and the electrochemical sensor system can be modified to accommodate the system disclosed in the present disclosure. Specifically, similar to the electrochemical sensor system disclosed therein, the potentiostat of the present disclosure can include a potentiostat circuit that is electronically engaged with the electrode set for measuring the energy properties of the magnetic bead complex or the reactant solution. Specifically, in one embodiment, the potentiostat circuit is in the form of a direct current (DC) potentiostat circuit for controlling the voltage between a working electrode (WE) and a reference electrode (RE).

[0103] In an embodiment of the present disclosure, amperometric analysis can be performed on the remaining reactant solution in the redox chamber. In such an embodiment, a termination solution including an acid can be added to the redox chamber to terminate the reaction. Additionally, in such an embodiment, the working electrode of the three-electrode set can be in contact with or operationally exposed to the redox chamber. In an embodiment, the working electrode can be coated with an acid to terminate the redox reaction.

[0104] In another embodiment, the current analysis can be performed by moving the reactant solution from the redox chamber to another component of the system, cartridge, or strip. In an embodiment, the system, cartridge, or strip of the present disclosure further includes an electrode chamber, passageway, or section that includes the working electrode of the electrode group or is operatively associated with the working electrode of the electrode group. In such an embodiment, a termination solution including an acid can be added to the redox chamber before moving the reactant solution forward. In other embodiments, the termination solution including an acid can be located within or added to the electrode chamber, passageway, or section. In other embodiments, the working electrode can be coated with an acid to terminate the redox reaction.

[0105] As described herein, the system of the present disclosure can be a fixed unit or can include a cartridge or strip and a device. It will be understood that any description herein related to the structure or embodiment of the cartridge (e.g., chamber, passageway, etc.) can equally apply to the system as a fixed unit herein. Similarly, the fixed unit can include a permanently embedded strip, and thus any description herein related to the structure or embodiment of the strip can equally apply to the system as a fixed unit herein.

[0106] In another aspect, the present disclosure relates to a disposable cartridge including: a port or container for receiving a test sample; one or more hybridization chambers interconnected with the port or container through a first passageway, wherein the one or more hybridization chambers include or are capable of being loaded with: a first antibody conjugated to magnetic beads, the first antibody being capable of specifically binding to a target analyte, and a second antibody conjugated to an enzyme, the second antibody being capable of specifically binding to the target analyte, and the enzyme being capable of converting a redox-active molecule; wherein the first antibody and the second antibody are from an antibody source located on the cartridge; a redox chamber interconnected with the one or more hybridization chambers through a second passageway, the redox chamber including or being capable of being loaded with a developing solution having a redox-active molecule; and an electrode group; wherein the cartridge is configured to sequentially move the magnetic beads from the hybridization chamber to the redox chamber and optionally beyond the redox chamber by a plurality of magnetic sources present in a device capable of accommodating the cartridge.

[0107] "Disposable" means that the cartridge can be used for a single use. The cartridge can be of any shape or configuration suitable for use in a device. In an embodiment, the cartridge has a generally linear flow path. In an embodiment, the cartridge has a non-linear (e.g., circular) flow path. The terms and components used in the above description of the cartridge have meanings similar to those used elsewhere herein when describing the system of the present disclosure.

[0108] In another embodiment, the present disclosure relates to a disposable strip comprising: a test sample receiving portion; one or more hybridization portions located downstream of the test sample receiving portion, wherein the one or more hybridization portions comprise or are capable of being loaded with: a first antibody conjugated to magnetic beads, the first antibody being capable of specifically binding to a target analyte, and a second antibody conjugated to an enzyme, the second antibody being capable of specifically binding to the target analyte, and the enzyme being capable of transforming a redox-active molecule; wherein the first antibody and the second antibody are from an antibody source located on the strip; a redox portion located downstream of the hybridization portion, the redox portion comprising or being capable of being loaded with a developing solution having a redox-active molecule; and an electrode set; wherein the strip is configured to sequentially move the magnetic beads from a hybridization chamber to a redox chamber and optionally beyond the redox chamber by a plurality of magnetic sources present in a device capable of accommodating the strip.

[0109] "Disposable" means that the strip can be used for a single use. The strip can be of any width, length or design suitable for use in a device. In an embodiment, the strip has a generally straight linear flow path. The terms and components used in the above description of the strip have meanings similar to those used elsewhere in this document to describe the systems of the present disclosure.

[0110] Non-limiting embodiments of the systems, cartridges and strips of the present disclosure are described below with reference to the drawings herein.

[0111] Now turning to Figure 1 , the cartridge is generally identified by reference numeral 100. In this embodiment, the cartridge 100 has a linear design and includes, from upstream to downstream in the flow direction (indicated by arrow 122), a test sample receiving portion 104 for receiving a test sample, a hybridization portion 106, a washing portion 108, a redox portion 110, and an electrode set 114 having a three-electrode cell.

[0112] The various portions of the cartridge 100 (such as the test sample receiving portion 104, the hybridization portion 106, the washing portion 108, the redox portion 110 and the electrode set 114) are interconnected by passages 112A, 112B, 112C and 112D. The passages can be tubes or microchannels. Additionally, in this particular embodiment, the portions 104, 106, 108 and 110 are chambers.

[0113] In an embodiment, the cartridge 100 further includes: one or more valves (not shown) located within the passages that can be opened and closed. The valves can prevent materials or fluids from passing through when closed (e.g., prevent backflow into a previous chamber or passage). The valves can also be opened when needed to direct or allow the fluid to continue through the cartridge 100.

[0114] The test sample receiving portion 104 may optionally include a size - selective grid (not shown) that can be used to capture unwanted molecules or components or test samples so that they do not pass through the cartridge 100. In an embodiment, the test sample receiving portion 104 includes a size - selective grid for prohibiting cells or molecules larger than a defined size from passing through. In an embodiment, the size - selective grid has a defined size of 4.5 μm. Additionally, different grid materials can be used to attempt to capture or trap different unwanted materials. For example, the size - selective grid can have a defined size that absorbs and does not allow large complexes or biomolecules (e.g., of megadalton size) to pass through, but allows the target analyte to pass through. The test sample receiving portion 104 can also be made of any suitable material to receive the test sample and allow fluid flow, such as by capillary action. Those skilled in the art will recognize that various alternative materials or grid sizes are readily available.

[0115] The hybridization portion 106 is the part of the cartridge 100 where the test sample can contact a first antibody and a second antibody. The first antibody is conjugated to magnetic beads and can specifically bind to the target analyte, and the second antibody is conjugated to an enzyme and can specifically bind to the target analyte. The enzyme is an enzyme capable of converting a redox - active molecule. Specifically, the enzyme can convert the redox molecule into a form that changes its "energy properties", and then the redox molecule is detected with a potentiostat. In an embodiment, the hybridization portion 106 is a chamber.

[0116] The hybridization portion 106 is interconnected with the test sample receiving portion 104 through a first passageway 112A to allow the test sample to move into the hybridization chamber 106. The first passageway 112A allows materials to pass through and connects the various parts and chambers of the device together. In an embodiment, the passageway is a tube or a microchannel.

[0117] In an embodiment, the first antibody and the second antibody are in a hybridization solution, and the hybridization solution is contained in a hybridization bag or blister that can be pierced to release the hybridization solution into the hybridization portion 106. The bag or blister is any structure that can be opened or pierced to release its contents. Those skilled in the art will recognize that various materials for the bag or blister are readily available. In an embodiment, the system of the present disclosure can include a piercing component for piercing the bag or blister to release the hybridization solution.

[0118] In an embodiment, the first passageway 112A or the hybridization section 106 further includes an absorbent pad (not shown) for absorbing fluid and transferring it into the hybridization chamber 106. Although the magnetic beads conjugated to the first antibody can continue to move in a sequential movement and travel via a directed path achieved by turning the magnetic source on and off, the non-composite materials will be left behind and / or captured on the absorbent pad. This provides efficient washing even without a washing section and a washing solution.

[0119] The washing section 108 is part of the cartridge 100 where the magnetic bead complex can contact the washing solution. In an embodiment, the washing section 108 is positioned along a second passageway (112B / 112C) between the hybridization section 106 and the redox section 110. Thus, the washing function can be provided by the washing chamber 108 and / or within the second passageway (112B / 112C).

[0120] The washing solution can be any solution suitable for washing the magnetic bead complex as described herein. In an embodiment, the washing solution is an oil or an organic gel.

[0121] In an embodiment, the washing solution is contained in a washing bag or blister that can be pierced to release the washing solution (see Figure 2 ). The bag or blister is any structure that can be opened or pierced to release its contents. Those skilled in the art will recognize that various materials for the bag or blister are readily available. In an embodiment, the system further includes a piercing member for piercing the bag or blister to release the washing solution.

[0122] The redox section 110 is part of the device where the magnetic bead complex contacts a developing solution having a redox-active molecule. The redox section 110 is interconnected with the hybridization chamber 106 via a second passageway (112B / 112C). The redox section 110 includes or is capable of being loaded with a developing solution having a redox-active molecule. In an embodiment, the developing solution is contained in a developing bag or blister that can be pierced to release the developing solution into the redox section (see Figure 2 ). In an embodiment, the redox section 110 is a chamber. The bag or blister is any structure that can be opened or pierced to release its contents. Those skilled in the art will recognize that various materials for the bag or blister are readily available. In an embodiment, the system includes a piercing member for piercing the bag or blister to release the developing solution.

[0123] The electrode set 114 is a set of electrodes located downstream of or extending into the redox section for measuring the energy properties of the magnetic bead complex or the reactant solution, and is connected to a potentiostat to perform current analysis, thereby obtaining electrochemical measurements based on the conversion of redox-active molecules. In this embodiment, the electrode set 114 includes a three-electrode cell having a working electrode 118, a reference electrode 116, and a counter electrode 120. The reference electrode 116 may include Ag, AgCl, or carbon ink. The working electrode 118 and the counter electrode 120 include carbon ink. The electrode, particularly the working electrode 118, may be coated with an acid (such as sulfuric acid) to terminate the redox reaction. Specifically, in the case where the working electrode 118 is coated with an acid, once the reactant solution reaches the electrode, the acid dissolves and the redox reaction terminates (before performing current analysis).

[0124] Now turning to Figure 2 , the cartridge is typically identified using the reference numeral 130. The cartridge in this embodiment is generally similar to the cartridge 100. The cartridge 130 includes a plurality of bags or blisters that can be pierced to release the contents inside the bag or blister.

[0125] The wash section / compartment 108 is connected via a passage 112E similar to the passages 112A to 112D shown in Figure 1 to three bags or blisters 132A, 132B, and 132C. The bags or blisters 132A, 132B, and 132C contain a wash solution or wash buffer. The bags or blisters 132A, 132B, and 132C may contain the same or different wash buffers. The wash section / compartment 108 is also connected to the waste section / compartment 136 for containing any waste generated by the wash. Once the bags or blisters 132A, 132B, and 132C are pierced, their contents will be released into the wash section 108.

[0126] The redox section / compartment 110 is connected via a passage 112F similar to the passages 112A to 112D shown in Figure 1 to two bags or blisters 134A and 134B. One of the bags or blisters 134A and 134B contains a developing solution or developing buffer having redox-active molecules / substrates, while the other bag or blister contains a termination solution (e.g., a solution containing an acid (such as sulfuric acid)) to terminate or quench the redox reaction. Once the bags or blisters 134A and 134B are pierced, their contents will be released into the redox section 110.

[0127] Now turning to Figure 3, the cartridge is typically identified using reference numeral 200. The cartridge 200 in this embodiment is generally similar to the cartridge 100, but is of a circular design. The cartridge 200 includes a port or container 204 for receiving a test sample, a hybridization chamber 206, a wash chamber 208, a redox chamber 210, and an electrode assembly 214 having a three - electrode cell.

[0128] The electrode assembly 214 includes a three - electrode cell having a working electrode 218, a reference electrode 216, and a counter electrode 220. As above, the reference electrode 116 may include Ag, AgCl, or carbon ink. The working electrode 118 and the counter electrode 120 include carbon ink. The electrode, particularly the working electrode 218, may be coated with an acid. In particular, when the working electrode 218 is coated with an acid, once the test sample solution reaches the working electrode 218, the acid dissolves and the redox reaction terminates (before performing the current analysis).

[0129] Now turning to Figure 4 , the strip is typically identified using reference numeral 300. The strip 300 in this embodiment is generally similar to the cartridge 100, but is of a strip design. From upstream to downstream according to the flow direction (indicated by arrow 326), the strip 300 includes: a test sample receiving portion 304 for receiving a test sample 301, a hybridization portion 306, a wash portion 308, a redox portion 310, and an electrode assembly 314 having a three - electrode cell. The test sample receiving portion 304 includes a size - selective grid 303 as described herein, which terminates and captures any unwanted particles. As disclosed herein and in a specific embodiment, the device into which the strip 300 can be inserted includes a plurality of magnetic sources 312 (not located on the strip 300) located throughout the system or device. In an embodiment, the strip 300 includes an absorbent pad as the test sample receiving portion 304.

[0130] The plurality of magnetic sources 312 are magnetic sources capable of providing a controlled magnetic field to direct the sequential movement of magnetic beads. The plurality of magnetic sources 312 are located throughout the system or device (e.g., see Figure 5 and Figure 6 , device 406) for sequentially moving the magnetic bead complex from the hybridization portion 106 / 206 / 306 to the redox portion 110 / 210 / 310 and optionally to a further location, wherein different magnetic sources among the plurality of magnetic sources 312 can be turned on and off in a desired sequence to effect the sequential movement of the magnetic bead complex. In an embodiment, the magnetic source is an electromagnet.

[0131] In this embodiment, the magnetic source 312 is placed in a zigzag pattern throughout the system or device. The sequential movement of the magnetic bead complex in a zigzag pattern is shown by arrow 322. Advantageously, the zigzag pattern allows the magnetic bead complex to move in a zigzag sequence throughout the device, providing greater swaying and / or mixing movement and further travel distance, resulting in improved hybridization, washing, and / or redox reactions.

[0132] The electrode set 314 includes a three - electrode cell having a working electrode 318, a reference electrode 316, and a counter electrode 320. As above, the reference electrode 116 can include Ag, AgCl, or carbon ink. The working electrode 118 and the counter electrode 120 include carbon ink. The electrode, particularly the working electrode 318, can be coated with an acid to terminate the redox reaction. Specifically, in the case where the working electrode 318 is coated with an acid, once the reactant solution reaches the electrode, the acid dissolves and the redox reaction terminates (before performing current analysis).

[0133] Now turning to Figure 5 , system 400 is shown, which includes cartridge 100 and a device 406 capable of accommodating cartridge 100. In an embodiment, the cartridge can be cartridge 200 (circular design) or strip 300. Additionally, the cartridge or strip can be removed from device 406 or be disposable.

[0134] Now turning to Figure 6 , a cross - sectional view of device 406 is shown. Device 406 contains a plurality of magnetic sources 410 (see Figure 6 ), a potentiostat 408, and a slot or opening 404 for receiving cartridge 100. The magnetic sources are the same as or similar to the magnetic sources described herein and Figure 4 shown in

[0135] According to another aspect of the present disclosure, a kit for detecting a target analyte in a test sample is provided, the kit including: a device as disclosed herein and instructions for using the device having a cartridge or strip as disclosed herein. In an embodiment, the kit further includes one or more cartridges or strips as disclosed herein. In an embodiment, the kit further includes one or more buffers or solutions, including for example a solution for dissolving or suspending the test sample, a solution including a first and / or second antibody, a wash buffer or solution, a redox buffer or solution, a solution containing an acid, or any combination thereof.

[0136] Method

[0137] In an embodiment, the present disclosure relates to a method for detecting a target analyte in a test sample, the method comprising: providing a system as described herein; contacting the test sample with a test sample receiving portion to receive the test sample; allowing the test sample to migrate from the test sample receiving portion to one or more hybridization portions; contacting the test sample within the one or more hybridization portions with a first antibody and a second antibody; sequentially activating different magnetic sources among a plurality of magnetic sources to move magnetic beads conjugated to the first antibody from the one or more hybridization portions to a redox portion; contacting the magnetic beads in the redox portion with a developing solution having a redox-active molecule; performing a current analysis using a potentiostat to obtain an electrochemical measurement from an electrode set based on the conversion of the redox-active molecule through a redox reaction; and determining or evaluating the presence, absence, and / or quantity of the target analyte based on the electrochemical measurement.

[0138] Figure 7 is a flow chart showing the steps of a method 600 for detecting a target analyte in a test sample according to an embodiment of the present disclosure. Method 600 starts with providing a cartridge and a device (step 602). At step 604, the test sample is contacted with the cartridge (specifically, the test sample receiving portion of the cartridge). For example, one or more drops of a fluid test sample are dropped onto the test sample receiving portion 104 of the cartridge 100 or the test sample receiving portion 304 of the strip 300. The cartridge can be of a circular design, a linear design, or a strip (see, for example Figures 1 to 4 ).

[0139] At step 606, the test sample is allowed to migrate through the cartridge or strip towards the hybridization portion 106 or 306 (e.g., by capillary movement from the test receiving portion to the hybridization portion). In an embodiment, at step 606, when the test sample migrates from the test sample receiving portion to one or more hybridization portions, the test sample also passes through a size-selective grid at the test sample receiving portion. For example, Figure 4 the grid 303 in

[0140] At step 608 (hybridization step or stage), if the target analyte is present in the test sample, magnetic beads conjugated to the first antibody will specifically bind to the target analyte. In addition, a second antibody conjugated to an enzyme capable of converting a redox-active molecule will also specifically bind to the target analyte. In a preferred embodiment, both the first antibody and the second antibody are capable of specifically binding to the target analyte at different regions of the target analyte.

[0141] In an embodiment, the first antibody and / or the second antibody are in a hybridization solution, and the hybridization solution is contained in a hybridization bag or blister that can be pierced to release the hybridization solution into one or more hybridization sections. Thus, at step 608, there may be an additional step of piercing one or more hybridization bags or blisters to release the first antibody and / or the second antibody into the hybridization section. This piercing step can be achieved by a piercing component within the device.

[0142] In another embodiment, the first antibody and the second antibody are lyophilized and they are contained in the hybridization section. In such an embodiment, a supportive buffer mixture is added to the hybridization section to dissolve the antibody.

[0143] During and after step 608, the magnetic bead complex moves on a directed path from sequential movement achieved by turning the magnetic source on and off.

[0144] At step 610 (optional washing step or stage), the magnetic bead complex is washed with a washing solution. In an embodiment, the washing step 610 is performed within the washing section 108 or 306.

[0145] In another embodiment, the washing step 610 is performed within a second passageway (112B and / or 112C) connecting the hybridization section to the redox section, and no washing chamber is required because the magnetic bead complex is washed as it moves through the second passageway (112B and / or 112C). The movement is also in a directed path activated in sequence by turning the magnetic source on and off. In an embodiment, the washing solution is oil or an organic gel.

[0146] In an embodiment, the washing solution is contained in a washing bag or blister that can be opened or pierced to release the washing solution (see, for example, Figure 2 ). Thus, at step 610, there may be an additional step of piercing the washing bag or blister to release the washing solution into the second passageway or the washing section. This piercing step can be achieved by a piercing component within the device.

[0147] The washing step 610 is optional because during and after step 608, the magnetic beads travel in a directed path with a swinging and / or mixing movement (such as a zigzag pattern), which effectively achieves washing as well. Again, only the magnetic bead complex will move through the device from sequential movement achieved by turning the magnetic source on and off. Thus, in some embodiments, efficient washing can be achieved by allowing the magnetic beads to travel through the cartridge or strip even without a washing solution.

[0148] At step 612 (the redox step or stage), the magnetic bead complex travels to the redox section 110 or 310, which contains or is capable of being loaded with a developing solution having a redox-active molecule. The enzyme conjugated to the second antibody (which binds the target analyte) converts the redox-active molecule into a form that changes its "energy properties" to be detected later.

[0149] In an embodiment, the developing solution is contained in a developing pouch or blister that can be opened or pierced to release the developing solution into the redox section (see, for example, Figure 2 ). Thus, at step 612, there may be an additional step of piercing the developing pouch or blister to release the developing solution into the redox section. This piercing step can be achieved by a piercing component on the device.

[0150] At step 616 (the current analysis and measurement step or stage), the reactant solution is exposed to the electrode set 114 or 314, which is connected or electronically coupled to the potentiostat 408. In an embodiment, the electrode set 114 or 314 is a three-electrode cell having a reference electrode, a counter electrode, and a working electrode.

[0151] Before or during step 616, it is necessary to terminate the redox reaction at step 612. To terminate the redox reaction, in an embodiment, the working electrode is exposed to the redox section or chamber, where a termination solution (such as a solution containing an acid (such as sulfuric acid)) is added therein before performing the current analysis to terminate the redox reaction.

[0152] In another embodiment, the working electrode is exposed to a channel or passageway leading away from the redox section or chamber, where the contents of the redox section can be released into the passageway on the working electrode, and the working electrode is coated with a termination solution material (such as an acid) to terminate the redox reaction, and then the current analysis can be performed.

[0153] In another embodiment, the termination solution is first added to the redox section or chamber, and the redox reaction is terminated. Then, the contents are released from the redox section or chamber into a passageway or channel connected to the electrode set.

[0154] After the redox reaction is terminated and the electrode set is in contact with the reactant solution from the redox section, the current analysis is performed. In an embodiment, the current analysis is performed for about 30 seconds. The electrode set is connected or electronically coupled to the potentiostat for performing the current analysis to obtain an electrochemical measurement based on the conversion of the redox-active molecule. In an embodiment, the potentiostat further includes a potentiostat circuit electronically coupled to the electrode set for performing the current analysis to obtain an electrochemical measurement.

[0155] In an embodiment, step 616 of performing current analysis further includes: flowing the contents of the redox section into an electrode chamber, passage, or portion that includes or is operatively associated with the working electrode of the electrode set.

[0156] After performing the current analysis, a measurement value is obtained and a result is determined based on the measurement value, and an assessment can be provided as to whether a target analyte is present in the test sample, the concentration of the target analyte, or both.

[0157] From step 608 to step 614, different ones of the plurality of magnetic sources are sequentially activated to move the magnetic bead complexes from the hybridization section to the redox section. In an embodiment, the plurality of magnetic sources includes sequentially activating different magnetic sources in a zigzag pattern along a path of sequential movement. As described herein, this increases the travel distance and provides a wobbling and / or mixing movement that improves the hybridization, washing, and redox stages.

[0158] In another embodiment, from step 606 to step 614, one or more valves (located within passages 112A to 112D) are closed to prevent fluid from flowing back into a previous section, chamber, or passage. A valve is any valve that can be opened and closed and is used to control the forward and / or backward flow of fluid.

[0159] In the present disclosure, all terms recited in the singular are intended to cover their plural forms. Similarly, all terms recited in the plural are intended to cover their singular forms. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0160] It should be understood that compositions and methods are described as "comprising", "containing", or "including" various components or steps, and such compositions and methods can also "consist essentially of various components and steps". Further, as used in the claims, the indefinite articles "a" or "an" are defined herein as meaning one or more of the elements introduced thereby.

[0161] For the sake of brevity, only certain ranges are explicitly disclosed in this document. However, any lower range limit can be combined with any upper range limit to enumerate ranges not explicitly recited, and any lower range limit can be combined with any other lower range limit to enumerate ranges not explicitly recited; similarly, in this way, any upper range limit can be combined with any other upper range limit to enumerate ranges not explicitly recited. Additionally, whenever a numerical range with a lower and an upper limit is disclosed, any numerical value and any included range falling within that range are specifically disclosed. Specifically, each range value disclosed herein (in the form of "from about a to about b", or equivalently "from about a to b", or equivalently "from about a - b") should be understood to list every numerical value and range included within the broader range even if not explicitly recited. Thus, each point or single value can be combined with any other point or single value or any other lower or upper limit as its own lower or upper limit to enumerate ranges not explicitly recited.

[0162] Accordingly, the present disclosure is well-suited to achieve the recited objects and advantages as well as those inherent therein. The specific embodiments disclosed above are merely illustrative, as the present disclosure can be modified and practiced in different but equivalent manners, which will be apparent to those skilled in the art benefiting from the teachings herein. Although individual embodiments are discussed, the present disclosure encompasses all combinations of all such embodiments. Moreover, the details of the construction or design shown herein are not intended to be limited other than as described in the following claims. Additionally, unless the patentee otherwise clearly and explicitly defines them, the terms in the claims have their plain and ordinary meaning. Thus, it is evident that the specific illustrative embodiments disclosed above can be varied or modified, and all such variations are considered to be within the scope and spirit of the present disclosure. If there is any conflict in the use of words or terms in this specification and their use in one or more patents or other documents that may be incorporated herein by reference, the definition consistent with this specification shall be adopted.

[0163] Many obvious variations of the embodiments set forth herein will occur to those skilled in the art in light of the present disclosure. These obvious variations are within the full scope of the appended claims.

Claims

1. A system for detecting a target analyte in a test sample, the system comprising: a test sample receiving portion; one or more hybridization portions interconnected with the test sample receiving portion, wherein the one or more hybridization portions include or are capable of being loaded with: a first antibody conjugated to magnetic beads, the first antibody being capable of specifically binding to the target analyte, and a second antibody conjugated to an enzyme, the second antibody being capable of specifically binding to the target analyte, wherein the enzyme is capable of converting a redox-active molecule; a redox portion interconnected with the one or more hybridization chambers, wherein the redox portion includes or is capable of being loaded with a developing solution having a redox-active molecule; an electrode set; a potentiostat for performing a current analysis to obtain an electrochemical measurement based on the conversion of the redox-active molecule; and a plurality of magnetic sources positioned to sequentially move the magnetic beads from the hybridization portion to the redox portion and optionally beyond the redox portion, wherein different magnetic sources among the plurality of magnetic sources can be turned on and off in a desired sequence to effect the sequential movement of the magnetic beads.

2. The system according to claim 1, comprising: - a cartridge or strip that can be inserted into and removed from the device, the cartridge or strip including the test sample receiving portion, the one or more hybridization portions, the redox portion, and the electrode set; and - a device including the potentiostat and the plurality of magnetic sources.

3. The system according to claim 2, wherein, the device further includes a slot or opening for receiving the cartridge or strip.

4. The system according to claim 2 or 3, including a cartridge, wherein, the cartridge includes: - a port or container as the test sample receiving portion; - one or more hybridization chambers as the one or more hybridization portions and interconnected with the port or container through a first passage; - a redox chamber as the redox portion and interconnected with the one or more hybridization chambers through a second passage; and - the electrode set.

5. The system according to claim 4, wherein, the cartridge further includes one or more valves that can be opened and closed, the one or more valves being located in the first passage, the second passage, or both.

6. The system according to claim 4 or 5, wherein, the first passage, the second passage, or both are pipes or microchannels.

7. The system according to claim 2 or 3, including the strip, wherein, the strip includes an absorbent pad as the test sample receiving portion.

8. The system according to claim 2, 3, or 7, wherein, the strip is a disposable strip.

9. The system according to any one of claims 1 to 8, wherein, the first antibody and / or the second antibody are in a hybridization solution, and the hybridization solution is contained in a hybridization bag or blister that can be pierced to release the hybridization solution into or onto the one or more hybridization portions.

10. The system according to any one of claims 1 to 9, wherein, the one or more hybridization portions include: A first hybridization section, interconnected with the test sample receiving section and comprising or capable of being loaded with the first antibody; and A second hybridization section, interconnected downstream of the first hybridization section and comprising or capable of being loaded with the second antibody.

11. The system according to any one of claims 1 to 10, further comprising: A washing section located between the one or more hybridization sections and the redox section, the washing section comprising or capable of being loaded with a washing solution.

12. The system according to any one of claims 4 to 6, further comprising: A washing section located between the one or more hybridization sections and the redox section along the second path, the washing section comprising or capable of being loaded with a washing solution.

13. The system according to claim 12, wherein, The washing section is a washing chamber.

14. The system according to any one of claims 11 to 13, wherein, The washing solution is contained in a washing bag or blister that can be pierced to release the washing solution into or onto the washing section.

15. The system according to any one of claims 11 to 14, wherein, The washing solution is an oil or an organic gel.

16. The system according to any one of claims 1 to 15, wherein, The developing solution is contained in a developing bag or blister that can be pierced to release the developing solution into or onto the redox section.

17. The system according to claim 9, 14 or 16, further comprising: One or more piercing members for piercing the bag or the blister.

18. The system according to claim 2, wherein, The device includes one or more piercing members.

19. The system according to any one of claims 1 to 18, wherein, The test sample receiving section includes a size-selective grid for capturing cells or molecules larger than a defined size.

20. The system according to claim 19, wherein, The defined size of the size-selective grid is about 4.5 μm.

21. The system according to any one of claims 1 to 20, wherein, The test sample receiving section or the one or more hybridization sections includes an absorption pad for absorbing fluid and transferring the fluid to the one or more hybridization sections.

22. The system according to any one of claims 1 to 21, wherein, The electrode set includes a three-electrode cell.

23. The system according to claim 22, wherein, The three-electrode cell includes a reference electrode, a counter electrode and a working electrode.

24. The system according to claim 23, wherein, The working electrode and the counter electrode include carbon ink, the reference electrode includes Ag, AgCl or carbon ink, and optionally, the working electrode is also coated with an acid.

25. The system according to any one of claims 1 to 24, wherein, The magnetic source is an electromagnet.

26. The system according to any one of claims 1 to 25, wherein, The magnetic source is positioned in a zigzag pattern along the path of sequential movement.

27. The system according to any one of claims 1 to 26 further includes a Faraday cage that separates the electrode assembly and / or the potentiostat from the plurality of magnetic sources.

28. The system according to any one of claims 1 to 27, wherein, the potentiostat includes a potentiostat circuit that is electrically coupled to the electrode assembly to perform current analysis to obtain electrochemical measurement values.

29. A method for detecting a target analyte in a test sample, the method comprises: - providing a system according to any one of claims 1 to 28; - contacting the test sample with a test sample receiving portion to receive the test sample; - allowing the test sample to migrate from the test sample receiving portion to one or more hybridization portions; - contacting the test sample with a first antibody and a second antibody within the one or more hybridization portions; - sequentially activating different ones of the plurality of magnetic sources to move magnetic beads coupled to the first antibody from the one or more hybridization portions to a redox portion; - contacting the magnetic beads in the redox portion with a developing solution having a redox-active molecule; - performing current analysis using the potentiostat to obtain electrochemical measurement values from the electrode assembly based on the conversion of the redox-active molecule through a redox reaction; and - determining or evaluating the presence, absence, and / or quantity of the target analyte based on the electrochemical measurement values.

30. The method according to claim 29, wherein, the step of allowing the test sample to migrate from the test sample receiving portion to one or more hybridization portions includes passing the test sample through a size-selective grid.

31. The method according to claim 29 or 30, comprises: the step of piercing one or more hybridization bags or blisters to release the first antibody and / or the second antibody into or onto the one or more hybridization portions.

32. The method according to any one of claims 29 to 31 further comprises: one or more steps of washing the magnetic beads, performing the one or more washing steps within a washing portion located between the one or more hybridization portions and the redox portion.

33. The method according to claim 32, wherein, the washing solution includes oil or an organic gel.

34. The method according to claim 32 or 33, wherein, the one or more washing steps include piercing a washing bag or blister to release the washing solution into or onto the washing portion.

35. The method according to any one of claims 29 to 34 further comprises: the step of piercing a developing bag or blister to release the developing solution into the redox portion.

36. The method according to any one of claims 29 to 35, wherein, the step of sequentially activating different ones of the plurality of magnetic sources includes sequentially activating the different magnetic sources in a zigzag pattern along a path of sequential movement.

37. The method according to any one of claims 29 to 36 further comprises: the step of opening and / or closing one or more valves to assist the sequential movement of the magnetic beads.

38. The method according to any one of claims 29 to 37, wherein, the step of performing current analysis includes: introducing a termination solution into the redox section.

39. The method according to claim 38, wherein, the termination solution includes an acid solution.

40. The method according to claim 39, wherein, the acid solution includes sulfuric acid.

41. The method according to any one of claims 29 to 40, wherein, the step of performing current analysis includes: flowing the contents of the redox section into an electrode chamber, passageway, or portion that includes the working electrode of the electrode group or is operatively associated with the working electrode of the electrode group.

42. The method according to claim 41, wherein, the working electrode contains or is coated with an acid solution for terminating the redox reaction.

43. The method according to any one of claims 29 to 42, wherein, the step of performing current analysis is performed for 30 seconds.

44. A disposable cartridge, comprising: a port or container for receiving a test sample; one or more hybridization chambers interconnected with the port or container through a first passageway, wherein the one or more hybridization chambers include or are capable of being loaded with: a first antibody conjugated to magnetic beads, the first antibody being capable of specifically binding to a target analyte, and a second antibody conjugated to an enzyme, the second antibody being capable of specifically binding to the target analyte, and the enzyme being capable of converting a redox-active molecule; wherein the first antibody and the second antibody are from an antibody source located on the cartridge; a redox chamber interconnected with the one or more hybridization chambers through a second passageway, the redox chamber including or being capable of being loaded with a developing solution having the redox-active molecule; and an electrode group; wherein the cartridge is configured to sequentially move the magnetic beads from the hybridization chamber to the redox chamber and optionally beyond the redox chamber by a plurality of magnetic sources present in a device capable of accommodating the cartridge.

45. A disposable strip, comprising: a test sample receiving portion; one or more hybridization portions located downstream of the test sample receiving portion, wherein the one or more hybridization portions include or are capable of being loaded with: a first antibody conjugated to magnetic beads, the first antibody being capable of specifically binding to a target analyte, and a second antibody conjugated to an enzyme, the second antibody being capable of specifically binding to the target analyte, and the enzyme being capable of converting a redox-active molecule; wherein the first antibody and the second antibody are from an antibody source located on the strip; a redox portion located downstream of the hybridization portion, the redox portion including or being capable of being loaded with a developing solution having the redox-active molecule; and an electrode group; wherein the strip is configured to sequentially move the magnetic beads from the hybridization chamber to the redox chamber and optionally beyond the redox chamber by a plurality of magnetic sources present in a device capable of accommodating the strip.

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