Lateral flow test system and method

Abstract

The present disclosure relates to a device for lateral flow testing of a liquid sample, the device comprising: a test strip comprising: a membrane having a first capture reagent disposed on a first surface at a test location, the first capture reagent configured to capture an analyte in the liquid sample; a sample pad disposed on the first surface at a first end of the membrane spaced apart from the test location, the sample pad configured to receive a liquid sample; and a conjugate pad disposed on the first surface between the sample pad and the test location, the conjugate pad having deposited thereon a catalytic labeling reagent configured to chemically bind to an analyte; an activation layer disposed over the membrane, arranged to contact the first surface upon activation, the activation layer having deposited thereon at least one component of a catalyst substrate capable of chemically reacting with a catalytic labeling reagent upon activation; and a support structure configured to attach the test strip and the active layer when the device is in an inactive state such that the active layer is separated from the membrane.

Description

[0001] field This disclosure generally relates to equipment and methods for testing lateral flow.

[0002] background Immunosensors based on antibody-antigen immune complexes typically rely on the catalytic function of a labeled molecule (e.g., an enzyme) conjugated to the antibody. For example, assays such as enzyme-linked immunosorbent assays (ELISA) utilize an enzymatic reaction to catalyze the conversion of a substrate into a product measurable by absorbance due to the presence of the analyte in the liquid sample. In this context, substrate refers to the reactant consumed during the catalytic or enzymatic reaction. In assays such as ELISA, the enzyme can amplify the measurable signal while retaining specificity. However, assays require multiple steps (e.g., sampling, first wash, reaction with the labeled molecule, second wash, substrate introduction, and stop solution introduction) to complete because the enzyme substrate can only be introduced into the sample-labeled molecule mixture after the reaction has occurred.

[0003] One widely used and common immunosensor is the single-step lateral flow assay (LFT), in which the test is completed in a single step by the user depositing a sample or sample-buffer mixture onto the LFT. A lateral flow assay strip typically comprises a plastic backing card supporting a membrane (e.g., a porous hydrophilic membrane) in which analyte-specific capture antibodies or a set of analyte-specific capture antibodies are fixed along the test line. Upstream of the membrane is a conjugate pad, which is typically impregnated with a second set of analyte-specific detection antibodies, such as those conjugated to latex beads or gold nanoparticles (AuNPs). Upstream of the conjugate pad is a sample pad that receives the liquid sample applied by the user. The strip typically ends with an absorbent pad that facilitates the flow of the liquid sample by capillary action and acts as a waste reservoir while preventing backflow. As the user deposits the sample onto the sample pad, the sample travels toward the conjugate pad and dissolves the antibody-AuNP conjugate, which then travels downstream toward the test line. Upon reaching the test line, immune complex formation begins, and AuNP remains bound to the test line if analyte is present. Any remaining unbound conjugates are washed away and collected by the absorbent pad.

[0004] Most lateral flow tests require visual analysis (e.g., changes in test line color) to interpret the results. This can be erroneous because such interpretation is highly subjective. While the accuracy of interpretation can be improved if performed by trained professionals, this limits the use of LFT in environments without such personnel.

[0005] Digital LFTs have been proposed, in which the results of the test are interpreted by an electronic reader. One example is an optical pregnancy test, which utilizes the optical properties of common markers used in visual LFTs such as AuNP. Fluorescent LFT systems have also been proposed, in which fluorescent tags replace common marker molecules such as AuNP, and these systems require a light source to induce and read the resulting fluorescence. Furthermore, electrochemical LFT systems have been proposed, in which the presence of labeled immune complexes is read electrochemically by an electronic reader.

[0006] However, unlike enzyme / catalyst-based assays such as ELISA that use enzyme-catalyzed / catalytically labeled amplified signals, LFT cannot achieve the same level of sensitivity and specificity using non-catalytically labeled molecules such as gold nanoparticles or fluorescent tags. Therefore, LFT typically exhibits lower analytical performance compared to ELISA assays performed in a centralized laboratory setting. Performing ELISA-like assays on LFT requires a multi-step process, but this multi-step approach is undesirable for users and can introduce errors into the assay by untrained users.

[0007] The applicant has recognized that there are still opportunities to improve the analytical performance of the transverse flow test.

[0008] Overview In view of the foregoing, an aspect of the present invention provides an apparatus for performing lateral flow testing on liquid samples, the apparatus comprising: Test strips, the test strips comprising: — A membrane having a first trapping reagent disposed on a first surface at a test position, the first trapping reagent being configured to trap an analyte in a liquid sample; —A sample pad disposed on a first surface at a first end of the membrane spaced apart from the test position, the sample pad being configured to receive a liquid sample; and —A conjugate pad disposed on a first surface between the sample pad and the test site, wherein a catalytic labeling reagent is deposited on the conjugate pad, the catalytic labeling reagent being configured to chemically bind to the analyte; An electrode array disposed on the membrane and configured to apply a potential across the first surface upon activation, the electrode array having at least one component of a catalyst substrate deposited thereon, the catalyst substrate being capable of chemically reacting with a catalytically labeled reagent upon activation; and A support structure configured to attach the test strip and the electrode array when the device is in an inactive state, such that the electrode array is separated from the membrane.

[0009] According to embodiments of the invention, the conjugate pad is impregnated with a catalytic labeling reagent, which dissolves as the liquid sample or sample-buffer mixture travels along the membrane. The membrane can be, for example, a hydrophilic membrane, such as a nitrocellulose membrane. The catalytic labeling reagent reacts with the analyte in the solution (if present) to form an immune complex, which is captured by a capture reagent when the solution reaches the test site. Embodiments of the LFT device also include an electrode array on which at least one component of a catalyst substrate, for example in dry form, is deposited. Before the device is “activated,” the electrode array is separated from the membrane by a support structure. Thus, initial contact between the catalyst substrate and the liquid sample is prevented. By doing so, the reaction between the catalytic labeling reagent and the catalyst substrate is prevented, while the analyte in the liquid sample forms an immune complex with the catalytic labeling reagent and is captured by the capture reagent.

[0010] In some embodiments, the catalytic labeling reagent may include glucose oxidase, metal nanoparticles, enzymes, nanozymes, or ribozymes.

[0011] In some implementations, the catalytic labeling agent may include glucose oxidase, horseradish peroxidase, alkaline phosphatase, or any enzyme or catalyst that can convert the substrate into a product without being consumed itself.

[0012] In some implementations, at least one component of the catalyst substrate may include glucose, silver ions, or a reducing agent.

[0013] In some embodiments, at least one component of the catalyst substrate may include one or more of the following: glucose; 3,3',5,5'-tetramethylbenzidine (TMB); 2,2'-azido-di-[3-ethylbenzothiazoline-6-sulfonic acid] (ABTS); 1-naphthyl phosphate; L-ascorbic acid phosphate; p-nitrophenyl phosphate, phenolic phosphate; hydroquinone diphosphate; silver ions; reducing agents and the like.

[0014] In some embodiments, when a liquid sample is deposited on a sample pad, the support structure can be configured to facilitate contact between the electrode array and the membrane to activate the device, such that the contact between the electrode array and the membrane dissolves at least one component of the catalyst substrate in the liquid sample. When the electrode array contacts the membrane immersed in the liquid sample, the LFT device is "activated," causing the catalyst substrate or its components to contact the liquid sample and be dissolved by the water content of the liquid sample. In doing so, the catalyst substrate is introduced into the liquid sample, particularly into immune complexes formed by catalytically labeled reagents and analytes, in a simple step.

[0015] Many different methods and mechanisms exist for activating catalyst substrates, depending on factors such as the catalytic labeling reagent used, the catalyst substrate used, the analyte to be detected, and the desired detection sensitivity and / or specificity. In some embodiments, the electrode array can be configured such that operation of the electrode array oxidizes or reduces at least one component of the catalyst substrate to activate at least one component of the catalyst substrate, thereby making at least one component of the catalyst substrate water-soluble. In doing so, the catalyst substrate is activated only in the liquid sample (immersed in the membrane) while the electrode array is operating. Therefore, unintentional activation of the catalyst substrate can be reduced or completely prevented.

[0016] In some embodiments, at least one component of the catalyst substrate can form a catalyst substrate when dissolved in a liquid sample on the membrane, thereby enabling a catalytic reaction between the catalyst substrate and the catalytically labeled reagent.

[0017] In some implementations, the electrode array can be configured to detect the presence of an analyte in a liquid sample by detecting a catalytic reaction between a catalyst substrate and a catalytically labeled reagent. For example, any suitable electrochemical detection technique can be implemented to detect the catalytic reaction between the catalyst substrate and the catalytically labeled reagent via the electrode array, such as by monitoring, for example, the electrochemical reaction or the products of the catalytic reaction between the electrode and the catalyst substrate.

[0018] In some implementations, the electrode array can be configured to detect catalytic reactions, for example, by implementing one or more electrochemical detection techniques, by detecting the reaction substrate, product, or unreacted catalytically labeled reagent, or any combination thereof.

[0019] In some embodiments, the electrode array may also have catalytic portions deposited thereon. In this document, a portion refers to a distinct part or component that forms a larger molecule (in this case, a catalyst molecule).

[0020] Such portions can also facilitate electron transfer. These portions can act as electron mediators, such as potassium ferrocyanide and methylene blue and analogues. Electron mediators can reduce the electrode potential required to detect specific substances, such as catalyst substrates or products.

[0021] In some embodiments, at least one component of the catalyst substrate can form a catalyst substrate when dissolved in a liquid sample on the membrane, such that a catalytic reaction can occur between the catalyst substrate and the catalytic labeling reagent to form a secondary catalyst substrate.

[0022] In some implementations, the secondary catalyst substrate can undergo a catalytic reaction with the catalytic moiety to form secondary reaction products. Therefore, introducing a two-part catalytic reaction into the LFT device results in a series of electrochemically detectable and quantifiable products for finer-grained interpretation of results.

[0023] In some implementations, the electrode array can be configured to detect secondary reaction products.

[0024] In some implementations, the electrode array can be configured to detect secondary catalyst substrates.

[0025] In some implementations, the catalytic portion may comprise an enzyme, nanoparticles, nanozymes, or a combination thereof.

[0026] In some embodiments, the secondary catalyst substrate may comprise one or more substrates capable of undergoing redox reactions, optionally such as hydrogen peroxide, 4-aminophenyl phosphate, or o-aminophenol.

[0027] In some embodiments, the secondary reaction products may include one or more oxidation or reduction products that can be monitored using electrochemical techniques, optionally such as water or one or more oxidized sugars.

[0028] For the support structure, various suitable methods and mechanisms can exist to separate the membrane from the electrode array, as long as the electrode array is prevented from contacting the membrane. In some embodiments, the support structure can be configured to spatially separate the membrane from the electrode array.

[0029] In some embodiments, the device may include an insulating film disposed between the membrane and the electrode array to chemically separate the membrane from the electrode array. In such embodiments, spatial separation may or may not be present between the electrode array and the membrane.

[0030] In some embodiments, the insulating film may comprise one or more polymer-based films configured to degrade in an aqueous solution, the polymer-based films optionally being, for example, polysaccharides. One or more polymer-based films may be manufactured / constructed such that they degrade upon contact with a membrane immersed in a liquid sample, as a result of, for example, dissolution due to prolonged exposure to water, increased pressure due to compression of the electrode array on the membrane, or electrochemical stimulation due to the operation of the electrode array.

[0031] In some implementations, the insulating film can be arranged to be removable so that the electrode array contacts the film. For example, the support structure can be configured with a mechanism such as a slider mechanism to automatically remove the insulating film.

[0032] In some implementations, the insulating film can be configured to dissolve upon contact with a liquid.

[0033] In some embodiments, the support structure may include a compressible element configured to compress the insulating film upon activation. For example, the support structure may include an element that punctures the insulating film upon compression, or the compression of the insulating film may alter its physicochemical properties, leading to degradation or disintegration.

[0034] In some implementations, the electrode array may include at least a first pair of corresponding electrodes arranged to cover the test location on the membrane when activated, and optionally, the electrode array may include a second pair of corresponding electrodes arranged to cover the background area of ​​the membrane.

[0035] Another aspect of the present invention provides an electronic reader for reading results from a transverse flow testing device as described above, the electronic reader comprising: A receiving section, the receiving section being configured to receive a lateral flow testing device, the receiving section including an activation mechanism configured to activate the lateral flow testing device; and A readout port is configured to be electrically connected to the electrode array of a transverse flow testing device to generate electrical signals in the electrode array and receive the electrochemical signals obtained through the electrode array. The activation mechanism of the receiving section is configured to activate the transverse flow test device by bringing the electrode array into contact with the membrane.

[0036] According to embodiments of the present invention, an electronic reader can be provided to electronically read the results of the transverse flow testing device as described above. The electronic reader can be configured to read electrochemical signals generated by specific substances present in the test strips, such as products of a catalytic reaction between a catalyst substrate and a catalytically labeled reagent; or, in an alternative embodiment, the electronic reader can be configured to read optical signals (e.g., fluorescence) of substances present in the test strips. The electronic reader is also configured with an activation mechanism for activating the transverse flow testing device upon insertion into the electronic reader, such that the electrode array of the device contacts the membrane, allowing the catalyst substrate (or at least one component thereof) to be activated / dissolved by contact with a liquid sample on the membrane.

[0037] The activation mechanism can take different forms as needed. In some embodiments, the activation mechanism of the receiving section can bring the electrode array into contact with the membrane by compressing a portion of the transverse flow testing device. For example, the activation mechanism can take the form of a button or lever that, when compressed, physically pushes the electrode array onto the membrane (and vice versa), or it can take the form of a ramp that reduces the distance between the electrode array and the membrane as the device is pushed into the reader until they finally make contact.

[0038] In some implementations, compressing this part of the transverse flow testing apparatus can reduce the distance between the electrode array and the membrane.

[0039] In some implementations, the electrode array and the membrane may be separated by an insulating film, and this portion of the compression transverse flow testing device punctures the insulating film. For example, the activation mechanism may include sharp protrusions, such as pins, spikes, edges, etc., for puncturing the insulating film.

[0040] In some embodiments, the electrode array and the membrane may be separated by an insulating film, and the activation mechanism of the receiving portion brings the electrode array into contact with the membrane by peeling off or otherwise removing the insulating film. For example, the activation mechanism may be configured to grasp the edge or corner of the insulating film when the device is inserted into the reader, and the insertion action peels or pulls the insulating film off the membrane or electrode array. Alternatively, the insulating film may be made of a material that degrades upon compression or application of pressure or dissolves upon contact with water.

[0041] Another aspect of the present invention provides a method for performing lateral flow testing on a liquid sample using a lateral flow testing device, the device comprising: The test strip includes: — A membrane having a first trapping reagent disposed on a first surface at a test position, the first trapping reagent being configured to trap an analyte in a liquid sample; —A sample pad disposed on a first surface at a first end of the membrane spaced apart from the test position, the sample pad being configured to receive a liquid sample; —A conjugate pad disposed on a first surface between a sample pad and a test position, wherein a catalytic labeling reagent is deposited on the conjugate pad, the catalytic labeling reagent being configured to chemically bind to the analyte; An electrode array disposed on the membrane, the electrode array being configured to apply a potential across a first surface upon activation, the electrode array having at least one component of a catalyst substrate deposited thereon, the catalyst substrate being capable of chemically reacting with a catalytically labeled reagent upon activation; and A support structure configured to attach a test strip and an electrode array when the device is in an inactive state, such that the electrode array is separated from the membrane, and the method includes: The liquid sample is deposited onto the sample pad of the test strip; The electrode array is brought into contact with the membrane to activate the transverse flow testing device; Operate the electrode array to apply a potential across the first surface through the electrode array to drive electrochemical reactions in the test strip; and The presence of analytes in liquid samples is detected by measuring the electrochemical signals obtained from the test strips using an electrode array.

[0042] According to embodiments of the present invention, since the electrode array of the transverse flow testing device has a catalyst substrate or at least one component of the catalyst substrate deposited thereon, for example in dry form, the transverse flow testing device can be activated in a single step to initiate a catalytic reaction between the catalyst substrate and the catalytically labeled reagent on the membrane simply by bringing the electrode array into contact with the membrane after the liquid sample has been introduced onto the sample pad.

[0043] In some implementations, contacting the electrode array with the membrane can cause at least one component of the catalyst substrate to be dissolved by the liquid sample on the membrane.

[0044] In some embodiments, the operating electrode array can oxidize or reduce at least one component of the catalyst substrate to activate at least one component of the catalyst substrate, thereby making at least one component of the catalyst substrate water-soluble.

[0045] In some embodiments, at least one component of the catalyst substrate can form a catalyst substrate when dissolved in a liquid sample on the membrane, enabling a catalytic reaction between the catalyst substrate and the catalytically labeled reagent.

[0046] In some implementations, measuring the resulting electrochemical signal from the test strip via an electrode array can include measuring the catalytic reaction between the catalyst substrate and the catalytically labeled reagent. For example, any suitable electrochemical detection technique can be implemented for detecting the catalytic reaction between the catalyst substrate and the catalytically labeled reagent via an electrode array, such as by monitoring, for example, the electrochemical reaction or the products of the catalytic reaction between the electrode and the catalyst substrate.

[0047] In some implementations, measuring the catalytic reaction between the catalyst substrate and the catalytic labeling reagent may include, for example, measuring the amount of reaction product or the amount of unreacted catalytic labeling reagent, or both, by implementing one or more electrochemical detection techniques.

[0048] In some implementations, the electrode array may also have a catalytic portion deposited on it.

[0049] In some embodiments, at least one component of the catalyst substrate can form a catalyst substrate when dissolved in a liquid sample on the membrane, such that a catalytic reaction can occur between the catalyst substrate and the catalytic labeling reagent to form a secondary catalyst substrate.

[0050] In some implementations, the secondary catalyst substrate can undergo a catalytic reaction with the catalytic portion to form a secondary reaction product.

[0051] In some implementations, measuring the resulting electrochemical signal from the test strip via an electrode array may include measuring the amount of secondary reaction products.

[0052] In some implementations, measuring the resulting electrochemical signal from the test strip via an electrode array may include measuring the amount of secondary catalyst substrate.

[0053] In some implementations, measuring the electrochemical signal obtained from the test strip via an electrode array may include potentiometry, current measurement, voltammetry, one or more impedance-based measurements, one or more capacitance measurements, or a combination thereof.

[0054] Another aspect of the present invention provides an apparatus for performing lateral flow testing on liquid samples, the apparatus comprising: The test strip includes: — A membrane having a first trapping reagent disposed on a first surface at a test position, the first trapping reagent being configured to trap an analyte in a liquid sample; —A sample pad disposed on a first surface at a first end of the membrane spaced apart from the test position, the sample pad being configured to receive a liquid sample; and —A conjugate pad disposed on a first surface between a sample pad and a test position, wherein a catalytic labeling reagent is deposited on the conjugate pad, the catalytic labeling reagent being configured to chemically bind to the analyte; An activation layer disposed on the membrane, the activation layer being arranged to contact a first surface upon activation, the activation layer having at least one component of a catalyst substrate deposited thereon, the catalyst substrate being capable of chemically reacting with a catalytically labeled reagent upon activation; and A support structure configured to attach the test strip and the activation layer when the device is in an inactive state, such that the activation layer is separated from the membrane.

[0055] According to embodiments of the invention, when a liquid sample or sample-buffer mixture is introduced into the sample pad and travels along the membrane, a catalytically labeled reagent immobilized on the conjugate pad is dissolved. The catalytically labeled reagent reacts with an analyte in the solution (if present) to form an immune complex, which is captured by a capture reagent when the solution reaches the test site. Embodiments of the LFT device also include an activation layer on which at least one component of a catalyst substrate, for example in dry form, is deposited. Before the device is “activated,” the activation layer is separated from the membrane by a support structure. Thus, initial contact between the catalyst substrate and the liquid sample is prevented. By doing so, the reaction between the catalytically labeled reagent and the catalyst substrate is prevented, while the analyte in the liquid sample forms an immune complex with the catalytically labeled reagent and is captured by the capture reagent.

[0056] There can be many ways to implement the activation layer. In some embodiments, the activation layer may include an electrode array configured to apply a potential across a first surface upon activation, and the catalyst substrate producing an electrochemically detectable product upon reaction with a catalytically labeled reagent.

[0057] In some implementations, the activation layer may be a generally transparent foil, and the catalyst substrate produces a visually detectable product when it reacts with the catalytically labeled reagent.

[0058] Each embodiment of the present invention has at least one of the above-described objectives and / or aspects, but not necessarily all of them. It should be understood that some aspects of the present invention obtained by attempting to achieve the above objectives may not satisfy those objectives and / or may satisfy other objectives not specifically described herein.

[0059] Further and / or alternative features, aspects, and advantages of embodiments of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims. Brief description of the attached diagram The implementation scheme will now be described with reference to the accompanying drawings, in which: Figure 1A A chemical reaction cycle in an exemplary catalytic immune sensor is illustrated; Figure 1B The interruption was shown. Figure 1A The reaction cycle; Figure 2A A first embodiment of the transverse flow testing apparatus before activation is shown; Figure 2B Showing the activated Figure 2A Lateral flow testing equipment; Figure 3A A second embodiment of the transverse flow testing device before activation is shown; Figure 3B Showing the activated Figure 3A Lateral flow testing equipment; Figure 4A A third embodiment of the transverse flow testing apparatus before activation is shown; Figure 4B Showing the activated Figure 4A Lateral flow testing equipment; Figure 5A A fourth embodiment of the transverse flow testing apparatus before activation is shown; Figure 5B Showing the activated Figure 5A Lateral flow testing equipment; Figure 6A An embodiment of a transverse flow testing apparatus is shown; Figure 6B An embodiment of the electronic reader is shown; and Figure 7 A flowchart illustrating an exemplary method for operating a transverse flow test apparatus is shown; Figure 8 The components of the transverse flow test box are shown; Figure 9 The image shows the contents of the box, such as... Figure 8 The raw data output of the box shown; and Figure 10 The graph shows the effect of exposure to increased levels of human CRP from 35 sensors (such as...). Figure 8 The data output of the sensor shown in the figure.

[0061] Detailed Explanation In lateral flow tests using immunosensor analysis devices, the following interactions between the user and the analysis device are typically expected: 1. Open the kit containing the analytical device (lateral flow test device / kit) and connect it with the user manual or application that guides the user through the test; 2. Collect samples, such as blood, plasma, serum, saliva, urine, swabs, feces, and other non-biological samples, such as water or emulsion; 3. Open the sealed package containing the transverse flow test equipment (e.g., a sealed package to resist contamination) and introduce the sample into the sample pad of the LFT equipment; 4. Wait for a predetermined period of time (e.g., as described in the user manual) to allow the sample to flow through the membrane of the LFT device; 5. Read the test results; 6. Report the results (if applicable); and 7. Disposal test.

[0062] In the case of catalytic immunosensors, a cleaning step and a catalyst substrate introduction step are required between steps 3 and 4 above, which is a burden for users and increases the risk of introducing errors into the test.

[0063] This disclosure describes a sensor architecture that allows the introduction of a substrate during or as part of the results reading step (step 5), thereby simplifying user interaction with the analysis device and reducing the risk of errors.

[0064] The general principle of the transverse flow test according to the present invention is to interrupt the chemical reaction cycle occurring around the sample introduction step (step 3) and the sample flow step (step 4) before the result reading step (step 5). This principle is based on... Figure 1A and Figure 1B The image in the middle shows...

[0065] Figure 1A An exemplary cycle 100 is illustrated in a transverse flow test (LFT), for example on a membrane of a test strip in an LFT, between a catalyst and a corresponding catalyst substrate. Introducing the substrate into the LFT initiates a chemical reaction 101 between the substrate and the catalyst, resulting in the production of reaction products 102. In some embodiments, the substrate may need to be activated by oxidation or reduction 103, for example, facilitated by the operation of an electrode array. The reaction products generated by the catalytic reaction can be detected electrochemically, for example, via an electrode array 104.

[0066] Figure 1B The interruption was shown. Figure 1A The reaction cycle 100. The reaction cycle can be interrupted in any one or more of stages 101, 102, 103, and 104, and the cycle is subsequently resumed to completion during the results reading phase (step 5). For example, the substrate introduction stage 101 can be interrupted, for example, by physically separating the substrate from the catalyst; the product formation stage 102 can be interrupted, for example, by introducing an activation step of the catalyst or substrate or introducing a secondary reaction; and the substrate activation stage 103 or the product detection stage 104 can be interrupted, for example, by not operating the electrode array. In the initial phase of the test procedure (between steps 3 and 4), the reaction cannot proceed because the reaction components necessary to complete the reaction cycle are separated in one or more of stages 101 to 104, for example, by the physical separation of the substrate from the catalyst. At least one component required to complete the reaction cycle is separated from the other components, so the reaction cannot proceed. Once the reaction components are coupled and the reaction cycle is complete, the reaction between the substrate and the catalyst can continue to generate the reaction product.

[0067] In existing methods, such interruption of the reaction cycle is not necessary because a separate washing and substrate introduction step must be performed between steps 3 and 4 before the cycle can be completed.

[0068] This invention provides an apparatus for performing lateral flow testing on liquid samples. Due to its construction, the apparatus facilitates interruption of the reaction cycle 100 while keeping both the substrate and catalyst within the same LFT device / cassette, thereby eliminating the need to introduce the substrate into the LFT device. The LFT device according to this invention typically includes a test strip. The test strip includes a membrane having a capture reagent disposed on the membrane surface at a test position. The capture reagent is configured to capture an analyte in the liquid sample. A sample pad is disposed on the membrane surface at a position near one end of the membrane and spaced apart from the test position. The sample pad is configured to receive the liquid sample. A conjugate pad is disposed on the membrane surface between the sample pad and the test position. The conjugate pad has a catalytically labeled reagent deposited or impregnated thereon. The catalytically labeled reagent is configured to chemically bind to the analyte. The LFT device also includes an activation layer disposed on the membrane, which is arranged to contact the membrane surface when the LFT device is activated. The activation layer has at least one component of, for example, a catalyst substrate in its dry form, deposited thereon. When the LFT device is activated, the catalyst substrate reacts chemically with the catalytically labeled reagent. A support structure is provided to the LFT device, configured to attach the test strip and the activation layer in a manner that separates the activation layer from the membrane when the device is inactive. This separation can be, for example, through physical separation at a predetermined distance, such that the activation layer is spaced apart from the membrane; or through the separation of a barrier (e.g., a chemical barrier or a moisture barrier) between the activation layer and the membrane, such as by attaching an insulating film over the membrane or the activation layer; or both. Activation of the LFT device can be considered as bringing the activation layer into contact with the membrane, whether physically, chemically, or otherwise, such as by reducing the physical distance between the activation layer and the membrane until contact is made, or by removing the chemical barrier or moisture barrier.

[0069] According to embodiments of the invention, when a liquid sample or sample-buffer mixture is introduced onto the sample pad, the catalytic labeling reagent on the conjugate pad is dissolved by the aqueous contents of the liquid sample or sample-buffer mixture as the liquid sample or sample-buffer mixture travels along the membrane. A suitable membrane may be, for example, a hydrophilic membrane, such as a nitrocellulose membrane. The catalytic labeling reagent reacts with the analyte in the solution (if present) to form an immune complex, which is captured by a capturing reagent when the solution reaches the test site. Embodiments of the LFT device also include an activation layer that is separated from the membrane by a support structure before the device is “activated.” Such an activation layer may be, for example, a generally transparent foil or film impregnated with or deposited with a catalyst substrate, which produces a visually detectable product when reacting with the catalytic labeling reagent; or such an activation layer may be, for example, an electrode array configured to apply a potential across the membrane surface during operation, on which a catalyst substrate (e.g., in dry form) is deposited, which produces an electrochemically detectable product when reacting with the catalytic labeling reagent. Therefore, initial contact between the catalyst substrate and the liquid sample is prevented. This prevents the catalytic labeling reagent from reacting with the catalyst substrate, while simultaneously allowing the analyte in the liquid sample to form an immune complex with the catalytic labeling reagent and be captured by the trapping reagent.

[0070] According to embodiments of the present invention, an electronic reader can be provided to electronically read the results of the transverse flow testing device as described above. The electronic reader can be configured to read, for example, an electrochemical signal generated by a specific substance present in the test strip (e.g., the product of a catalytic reaction between a catalyst substrate and a catalytically labeled reagent) generated by applying a potential across the membrane via an electrode array. Alternatively, in some embodiments, the electronic reader can be configured to read an optical signal (e.g., fluorescence) of the substance present in the test strip. The electronic reader is also configured with an activation mechanism that, upon insertion into the electronic reader, activates the LFT device to bring the activation layer of the device (e.g., the electrode array) into contact with the membrane, such that the catalyst substrate (or at least one component thereof) can be dissolved or otherwise activated by contact with a liquid sample on the membrane.

[0071] According to embodiments of the invention, the catalyst substrate is deposited, for example, in dry form, on an activation layer (e.g., an electrode array) and separated from the catalytically labeled reagent (containing the catalyst that reacts with the catalyst substrate) deposited on the membrane of the test strip of the LFT device by a support structure. In doing so, the chemical reaction cycle between the catalyst and the substrate (e.g., reaction cycle 100) is interrupted. The LFT device is activated after a liquid sample is introduced into the membrane to bring the activation layer into contact with the membrane, and the reaction cycle is completed by bringing the catalyst into contact with the substrate in solution. The completion of the reaction cycle leads to the initiation of a catalytic reaction between the catalyst substrate and the catalytically labeled reagent on the membrane. Therefore, according to embodiments of the invention, the reaction cycle can be completed in a single step by simply bringing the activation layer (e.g., the electrode array) into contact with the membrane immersed in the liquid sample.

[0072] In one embodiment, an embodiment of the present invention provides a single-step electrochemical lateral flow assay device / kit in which a catalyst-mAb (monoclonal antibody) conjugate and a catalyst substrate are immobilized on two separate platforms: a test strip (membrane) and an electrode array (or electrodes of the electrode array). Materials can be selected to allow for flexible assembly of the test strip and electrode array. The dual-platform device facilitates the separation of reactant components during sample flow in lateral flow assays, but allows the chemical reaction between the catalyst and substrate to cycle through upon activation, thereby enabling electrochemical sample detection on the same platform.

[0073] An alternative implementation can achieve the same principle for visual result interpretation by replacing electrodes with transparent features (e.g., transparent foil), on which particles are fixed, which promote color development or the development of any other visual signal after a reaction cycle.

[0074] The substrate can be a single substrate, which may be immobilized on a conjugate pad, an electrode array, or present in a liquid sample (either in a buffer in which the sample is introduced or in the sample itself). In this case, the reaction is controlled solely by the presence of the substrate. In embodiments, if the substrate is an analyte being tested, the catalyst-substrate reaction can be used to determine the analyte concentration. In some embodiments, the reaction may require two or more substrates, and the reaction cycle may be interrupted before the results reading step (step 5) by the absence of one of the substrates. In some embodiments, the substrate may be in an inactive form, such as a dry form, which requires mixing it with a solution to convert it to its activated form; thereafter, the activated (e.g., dissolved) substrate can participate in the desired catalyst-substrate reaction. In other embodiments, an electrochemical oxidation or electrochemical reduction can be used to convert a non-reactive (inactive) substrate to a reactive (activated) substrate to complete the reaction cycle. In yet another embodiment, more than one substrate can be introduced by immobilizing more than one substrate on a single platform. For example, in the first (inactive) state, both silver ions and the reducing agent are inactive and co-immobilized on the working electrode (activation layer) using a low-pH solution, ensuring the preservation of the inactive state. Upon activation, both silver ions and the inactive reducing agent dissolve in the membrane. In embodiments of the invention, dissolution in a running buffer with a pH higher than that of the reducing agent leads to the activation of the reducing agent, allowing silver enhancement to occur on the AuNP (gold nanoparticle) catalyst. In embodiments of the invention, electrochemical measurements can be performed based on, for example, the detection of freely available silver ions near the electrode.

[0075] The catalyst used in embodiments of the present invention can be any suitable catalyst. For example, the catalyst can be a biocatalyst (e.g., an enzyme), a metal catalyst (e.g., metal nanoparticles), a nanozyme, a ribozyme, or any particle capable of converting a corresponding substrate into a product or capable of lowering the activation energy sufficiently for the reaction to proceed without being consumed itself. In another embodiment, the catalyst can be replaced by a liposome or any other encapsulating agent, which is destroyed upon completion of the reaction cycle and releases the catalyst or an electrochemically detectable molecule.

[0076] The reaction products can be electrochemically activated products that are detectable using electrochemical techniques, visually or optically detectable products, or mediators that enhance the detection of different products generated in buffer solutions, electrodes, or conjugate pads. The same product can serve as a substrate for secondary reactions, which can be detected, for example, by electrochemical means.

[0077] As described above, the separation of the reaction components can be spatial (physically spaced), requiring movement to connect the components; or it can be achieved by using barriers, such as insulating layers or films that prevent contact between the components. Such insulating layers can be pressure-sensitive, activated by the application of pressure / compression, or they can be physically removed or peeled off by a user or automated mechanism prior to test reading. In other embodiments, such insulating layers can be made of a soluble material that contacts the membrane during sample flow and slowly dissolves over time to facilitate time-dependent activation of the reaction. Other forms of reaction component separation that interrupt the reaction cycle prior to the result reading step, and subsequent reconnection of the reaction components during this period, have been considered.

[0078] Figure 2A A first embodiment of a transverse flow assay device before activation, according to an embodiment, is shown. The device of the first embodiment includes an electrode 201 having a substrate 202 (e.g., glucose-) deposited / immobilized thereon, a catalytically labeled molecule 203 immobilized on a membrane (e.g., glucose oxidase in a conjugate pad), conjugated to detect mAb 204, which forms an immune complex with analyte 205 and traps mAb 206. To ensure no contact occurs before measurement, the catalyst 203 is immobilized on the membrane, while the substrate 202 is immobilized in dry form on the electrode surface 201. When a sample is applied to the device (e.g., on a sample pad), capillary flow occurs, allowing resuspension of the catalyst-mAb conjugate and the formation of immune complexes (with catalytic labels) at the test line (if an antigen is present) and control line, terminating at the absorbent pad. When result reading and / or analysis is required, the device is activated, whereby the electrode 201 (e.g., as part of an array) comes into contact with one or more regions of the membrane (e.g., test lines, control lines, or background). Upon contact, the substrate 202 on electrode 201 dissolves on the membrane, where the reaction occurs only in the presence of an immune complex with a catalytically labeled molecule 203. Importantly, because the electrode is in contact with the membrane, the reaction can be monitored electrochemically, for example, by measuring the rate of substrate depletion or the rate of product formation.

[0079] Figure 2B Showing the activated Figure 2AA transverse flow testing device is used. Upon device activation, contact between electrode 201 and the membrane causes dissolution of substrate 202 near catalyst 203. Once the device transitions to the activated state and electrode 201 contacts the membrane, substrate 202 dissolves within the membrane, where it is consumed by the catalytically labeled molecule 203. The depletion of substrate 202 or the formation of reaction products can then be measured electrochemically as a result of the catalytic reaction. For example, reaction products formed during the catalytic reaction can subsequently be monitored in situ based on their local environment via electrochemical oxidation or electrochemical reduction. Various electrochemical methods can be used, including (but not limited to) potentiometry, amperometry, voltammetry, impedance-based measurements, and capacitance measurements.

[0080] In the embodiments, metal nanoparticles can be used as catalytic labels, such as gold nanoparticles, which are conjugated with antibodies. Embodiments of the present invention are compatible with a silver-enhanced mechanism, wherein silver ions (used as a substrate) are reduced on the surface of gold nanoparticles (AuNP, used as a catalyst) with the aid of a reducing agent (activator), such as... Figure 3A and Figure 3B As shown in the diagram.

[0081] Figure 3A A second embodiment of the transverse flow testing apparatus according to the implementation scheme is shown. Silver ions 307 may be present in the buffer solution or deposited on the conjugate pad or sample pad, while the reducing agent 308 may be immobilized on the electrode surface 301. In the inactive state, such as Figure 3A As shown, silver ions 307 are present in the running buffer and therefore do not react with AuNP 309 during sample flow or subsequent capture of AuNP 309 on the membrane, as demonstrated by detecting mAb 304, which forms an immune complex with analyte 305, and capturing mAb 306. In this embodiment of the invention, reducing agent 308 is immobilized on electrode 301 and physically separated from the membrane to prevent reaction between the catalyst and the substrate.

[0082] During the activation phase, such as Figure 3B As shown, the reaction between the catalyst and the substrate is activated by introducing reducing agent 308 into the membrane. When reducing agent 308 is introduced, silver ions (Ag)... + 307 is specifically reduced on the surface of AuNP 309 due to its catalytic properties. This reaction can be monitored electrochemically by measuring the available free silver ions near the electrode. In this embodiment of the invention, AuNP 309 reacts only when the reducing agent 308 is introduced into the membrane.

[0083] Another embodiment may involve an electrode coated with a combination of a catalytic moiety and a substrate, such as Figure 4A and Figure 4B As shown in the image.

[0084] Figure 4A A third embodiment of a transverse flow testing apparatus before activation, according to an embodiment, is shown. In the inactive state, the electrode array 401 is separated from the membrane. A catalytic portion 402 (e.g., an enzyme, nanoparticle, or nanozyme) and a substrate 403 co-immobilized on the electrode surface 401 together with the catalytic portion 402 are fixed thereon. In this embodiment, the substrate 403 can only be catalyzed by the catalyst 404 in the membrane, and not by the catalytic portion 402 on the electrode 401. The catalyst 404 on the membrane is conjugated with a detection mAb (labeled reagent) 405, which is capable of forming an immune complex with the analyte 406 and capturing the mAb (capture reagent) 407.

[0085] Figure 4B This shows the activated state when electrode 401 is in contact with the membrane. Figure 4A The device, upon activation, delivers substrate 403 and catalyst 402 to the membrane via contact with electrode 401. Substrate 403 is dissolved in the membrane by the aqueous contents of the liquid sample, and catalyst 404 consumes the dissolved substrate 403 in the catalytic reaction to form a first product 408. The first product 408 then acts as the substrate now present in the membrane for catalyst 402, allowing the formation of a second product 409. In embodiments of the invention, any one or more of substrate 403, first product 408, second product 409, catalyst 402, or catalyst 404 can be monitored electrochemically to determine the amount of immune complex, which, in the case of a test line, is directly related to the analyte concentration.

[0086] In another alternative implementation, the substrate can be transitioned from an inactive state to an active state, such as... Figure 5A and Figure 5B As shown in the image.

[0087] Figure 5A A fourth embodiment of a transverse flow testing apparatus in an inactive state according to an embodiment is shown, wherein electrode 501 is spatially separated from the membrane of the LFT apparatus. A substrate 502 in an inactive state is deposited on the working electrode 501. Upon sample introduction, an immune complex is formed in the membrane between the catalytic portion 503 and the conjugate of detection antibody (labeled reagent) 504, antigen 505, and capture antibody (capture reagent) 506.

[0088] exist Figure 5BIn this process, device activation brings electrode 501 into contact with the membrane to facilitate a subsequent catalytic reaction. In this embodiment of the invention, when electrode 501 is in operation, electrode 501 activates substrate 502 to an activated state 502* through oxidation or reduction. Substrate 502 is chosen because of its property that the substrate state is soluble only in its activated state 502*, for example, soluble in a liquid-immersed membrane. The activated substrate 502* can then be catalytically converted from a conjugate of catalytic moiety 503 and detection antibody 504 into a measurable product 507.

[0089] Figure 6A An embodiment of a transverse flow testing device 600 according to an implementation scheme is shown. The LFT device 600 includes a housing 601 formed of a material such as plastic capable of protecting a test strip (not shown) housed therein. The device is provided with an opening 602 for accessing the sample pad of the test strip to introduce a sample. The housing 601 may be configured with a mechanism such as a lever 603, which can be compressed to bring an electrode into contact with the test strip to activate the device 601. The test results can be read electronically via an electronic port 604. Furthermore, the device 600 may be provided with a unique identification code 605 for identifying the device 600, and a marking area 606 for marking the device 600 as needed.

[0090] Figure 6B An embodiment of an electronic reader 610 according to an implementation scheme is shown. The electronic reader 610 can be used to read results from an LFT device, such as device 600, via an electronic port, such as electronic port 604. The electronic reader 610 in this embodiment is provided with a compression mechanism 611 for compressing (applying pressure to) a corresponding compressible portion 603 of device 600. A button 612 or other activation mechanism may be provided to the electronic reader 610 to initiate result reading.

[0091] Figure 7A flowchart illustrating an exemplary method 700 for operating a transverse flow testing (LFT) apparatus is shown. The method 700 for performing a transverse flow test on a liquid sample can utilize a transverse flow testing apparatus, such as the apparatus 600 described with reference to Figures 2 through 5 and its embodiments. Such an LFT apparatus typically includes a test strip, an electrode array (activation layer), and a support structure. The test strip typically includes: a membrane having a trapping reagent disposed on a first surface at a test location, the trapping reagent being configured to trap an analyte in the liquid sample; a sample pad disposed on the membrane surface at an end of the membrane spaced apart from the test location, the sample pad being configured to receive the liquid sample; and a conjugate pad disposed on the membrane surface between the sample pad and the test location, the conjugate pad having a catalytically labeled reagent deposited thereon, the catalytically labeled reagent being configured to chemically bind to the analyte. The electrode array may be disposed on the membrane and is typically configured to apply a potential across the membrane surface upon activation, the electrode array having at least one component of a catalyst substrate deposited thereon, the catalyst substrate being capable of chemically reacting with the catalytically labeled reagent upon activation. The support structure is typically configured to attach the test strips and electrode array when the device is inactive, thus separating the electrode array from the membrane.

[0092] In this embodiment of the invention, method 700 begins at S701, where a liquid sample is deposited or otherwise introduced onto the sample pad of the test strip. Then, at S702, an electrode array is brought into contact with the membrane to activate the transverse flow testing device. Then, at S703, the electrode array is operated to apply a potential across the membrane surface via the electrode array to drive an electrochemical reaction in the test strip. At S704, the resulting electrochemical signal from the test strip is measured via the electrode array to detect the presence of an analyte in the liquid sample.

[0093] The following section elaborates on further details regarding some sensor manufacturing methods.

[0094] Methodology The transverse flow strips were manufactured using a typical manufacturing process. Specifically, according to one method, a mouse anti-human CRP antibody (1 mg / mL) was deposited onto a nitrocellulose membrane and dried at 37°C. The detection antibody was conjugated with alkaline phosphatase using an off-the-shelf conjugation kit and dried in a conjugated pad containing glass fibers. The sample pad and wicking pad were laminated onto a plastic backing card, which was then cut into strips to complete the strip fabrication.

[0095] The electrode is fabricated according to a typical electrode manufacturing process. In one embodiment, FR4 forms the base of the electrode, where traces are outlined in a conventional printed circuit board manufacturing process involving photolithography and metal plating. A working electrode can then be screen-printed using carbon paste to create the electrochemical surface of interest. Ag / AgCl ink can be used to create a reference electrode. The working electrode can be functionalized using a functionalization solution comprising water, ascorbic acid phosphate, 150 mM Tris-acetic acid buffer, and a binder such as sucrose or hydroxyethyl cellulose. This can be deposited onto the electrode using automated dispensing and then dried.

[0096] In one embodiment, the LFT cell may be injection molded and designed to carry and support the LFT strips and electrodes.

[0097] Figure 8 The components of the transverse flow test box are shown. Figure 8 a shows the lid or "top" part of the box. Figure 8 b shows the bottom or "base" part of the box. Figure 8 c shows an electrode array with a catalyst substrate. Figure 8 d shows the transverse flow test strips with catalytic labeling.

[0098] Figure 9 The image shows the contents of the box, such as... Figure 8 The raw data output of the cartridge shown is as follows. In one embodiment, the device is tested using a 150 mM Tris-acetate buffer supplemented with 1% Tween 20 and 0.05% Proclin, wherein the sample (CRP-depleted human serum, doped with recombinant CRP) is mixed with the run buffer at a ratio of 1:100, and then 70 μL is dropped onto the LFT and allowed to flow for 10 minutes. Current is measured after the cartridge is inserted into the reader, which allows the electrode array to touch the LFT. Electrochemical measurements are performed using chronoamperometry, set at 0.3 V relative to the reference electrode, for a duration of 10 seconds on each electrode. Data related to the current generated in front of the test line (background), on the test line, and on the control line are recorded. Figure 9 The raw data output shown relates to the system, such as Figure 8 The system shown is a (segmented) system. Figure 9 The current response from samples supplemented with 40 mg / L CRP is summarized. Figure 9 It can be seen that the electrode in front of the T line (background electrode) exhibits low current, the electrode covering the test line exhibits high current, and the electrode covering the control line exhibits current lower than that of the test line and higher than that of the background.

[0099] Figure 10 The graph shows the results of five repeated exposures to increasing levels of human CRP from 35 sensors (such as...). Figure 8 The data output of the sensor shown. Figure 10 In the embodiments shown, increased CRP levels covering a clinically relevant range of CRP concentrations were tested. Figure 10 The data outputs from 35 sensors exposed to increasing concentrations of human CRP in CRP-free serum are illustrated graphically. In the CRP-free sample (blank sample), the background current and test line current were low, but the control line current was significantly higher. This result indicates that the test was performed appropriately. As the CRP concentration increased, the T line current increased, while the background current and control line current remained stable. This result demonstrates that the sensor specifically responds to the CRP level in the sample.

[0100] The embodiments and conditional language described herein are intended to help the reader understand the principles of the invention and are not intended to limit its scope to such specific embodiments and conditions. It should be understood that those skilled in the art can design various arrangements, which, although not expressly described or shown herein, embody the principles of the invention and are included within the scope of the invention as defined by the appended claims.

[0101] Furthermore, to aid understanding, the above description represents a relatively simplified implementation of the invention. As those skilled in the art will understand, various implementations of the invention may involve greater complexity.

[0102] In some cases, embodiments that are considered useful examples of modifications to the technology of the present invention may also be described. This is done merely to aid understanding and again does not limit the scope of the technology of the present invention or set forth its boundaries. These modifications are not an exhaustive list, and those skilled in the art can make other modifications while still remaining within the scope of the technology of the present invention. Furthermore, the absence of embodiments with modifications described should not be construed as meaning that modifications are not possible and / or that the described content is the only way to implement that element of the technology of the present invention.

[0103] Furthermore, all statements regarding the principles, aspects, and implementation methods of the techniques described herein, as well as specific embodiments thereof, are intended to encompass both their structural and functional equivalents, whether they are currently known or will be developed in the future. Therefore, for example, those skilled in the art will understand that any block diagram herein represents a conceptual view of an illustrative circuit embodying the principles of the present invention. Similarly, it will be understood that any flowchart, flow diagram, state transition diagram, pseudocode, etc., represents various processes that can be substantially represented in a computer-readable medium and therefore executed by a computer or processor, whether or not such a computer or processor is explicitly shown.

[0104] Those skilled in the art will understand that many improvements and modifications can be made to the foregoing exemplary embodiments without departing from the scope of the present invention.

Claims

1. An apparatus for performing lateral flow testing on liquid samples, comprising: Test strips, the test strips comprising: — A membrane having a first trapping reagent disposed on a first surface at a test location, the first trapping reagent being configured to trap analytes in the liquid sample; —A sample pad disposed on the first surface at a first end of the membrane spaced apart from the test position, the sample pad being configured to receive the liquid sample; and —A conjugate pad disposed on the first surface between the sample pad and the test site, wherein a catalytic labeling reagent is deposited on the conjugate pad and the catalytic labeling reagent is configured to chemically bind to the analyte; An electrode array disposed on the membrane, the electrode array being configured to apply a potential across the first surface upon activation, the electrode array having at least one component of a catalyst substrate deposited thereon, the catalyst substrate being capable of chemically reacting with the catalytically labeled reagent upon activation; and A support structure configured to attach the test strip and the electrode array when the device is in an inactive state, such that the electrode array is separated from the membrane.

2. The device according to claim 1, wherein the catalytic labeling reagent comprises glucose oxidase, metal nanoparticles, enzymes, nanozymes, and ribozymes.

3. The apparatus according to claim 1 or 2, wherein the at least one component of the catalyst substrate comprises glucose, silver ions, and a reducing agent.

4. The device according to any of the preceding claims, wherein, When the liquid sample is deposited on the sample pad, the support structure is configured to facilitate contact between the electrode array and the membrane to activate the device, such that the contact between the electrode array and the membrane dissolves at least one component of the catalyst substrate in the liquid sample.

5. The apparatus of claim 4, wherein the electrode array is configured such that operation of the electrode array oxidizes or reduces the at least one component of the catalyst substrate to activate the at least one component of the catalyst substrate, thereby making the at least one component of the catalyst substrate water-soluble.

6. The apparatus of claim 4 or 5, wherein the at least one component of the catalyst substrate forms the catalyst substrate when dissolved by the liquid sample on the membrane, such that a catalytic reaction can occur between the catalyst substrate and the catalytic labeling reagent.

7. The apparatus of claim 6, wherein the electrode array is configured to detect the presence of the analyte in the liquid sample by detecting the catalytic reaction between the catalyst substrate and the catalytically labeled reagent.

8. The device of claim 7, wherein the electrode array is configured to detect the catalytic reaction by detecting the reaction substrate, product, or unreacted catalytic labeling reagent, or any combination thereof.

9. The device of claim 4, wherein the electrode array is further deposited thereon with a catalytic portion.

10. The apparatus of claim 9, wherein the at least one component of the catalyst substrate forms the catalyst substrate when dissolved by the liquid sample on the membrane, such that a catalytic reaction can occur between the catalyst substrate and the catalytic labeling reagent to form a secondary catalyst substrate.

11. The apparatus of claim 10, wherein the secondary catalyst substrate undergoes a catalytic reaction with the catalytic portion to form a secondary reaction product.

12. The apparatus of claim 11, wherein the electrode array is configured to detect the secondary reaction product.

13. The apparatus of claim 11 or 12, wherein the electrode array is configured to detect the secondary catalyst substrate.

14. The device according to any one of claims 9 to 13, wherein the catalytic portion comprises an enzyme, nanoparticles, nanozymes, or a combination thereof.

15. The apparatus according to any one of claims 10 to 14, wherein the secondary catalyst substrate comprises one or more substrates capable of undergoing redox reactions, optionally, for example, hydrogen peroxide, 4-aminophenyl phosphate, or o-aminophenol.

16. The apparatus according to any one of claims 10 to 14, wherein the secondary reaction product comprises one or more oxidation or reduction products that can be monitored using electrochemical techniques, optionally such as converting various substrates into water or one or more oxidized sugars.

17. The device according to any of the preceding claims, wherein the support structure is configured to spatially separate the membrane from the electrode array.

18. The device according to any of the preceding claims, wherein the device includes an insulating film disposed between the membrane and the electrode array to chemically separate the membrane from the electrode array.

19. The device of claim 18, wherein the insulating film comprises one or more polymer-based films configured to degrade in an water-based solution, the polymer-based films optionally being, for example, polysaccharides.

20. The device of claim 18 or 19, wherein the insulating film is arranged to be removable so that the electrode array contacts the film.

21. The device according to any one of claims 18 to 20, wherein the insulating film is configured to dissolve upon contact with a liquid.

22. The device according to any one of claims 18 to 21, wherein the support structure includes a compressible element configured to compress the insulating film upon activation, optionally such as to puncture the insulating film or alter its physicochemical properties.

23. The device according to any of the preceding claims, wherein the electrode array includes at least a first pair of corresponding electrodes arranged to cover the test location on the membrane when activated, and optionally, the electrode array includes a second pair of corresponding electrodes arranged to cover a background area of ​​the membrane.

24. An electronic reader for reading results from a transverse flow testing apparatus according to any of the preceding claims, the electronic reader comprising: A receiving section, the receiving section being configured to receive the transverse flow testing device, the receiving section including an activation mechanism configured to activate the transverse flow testing device; and A readout port is configured to be electrically connected to the electrode array of the transverse flow testing apparatus to generate an electrical signal in the electrode array and receive the electrochemical signal obtained through the electrode array. The activation mechanism of the receiving portion is configured to activate the transverse flow testing device by bringing the electrode array into contact with the membrane.

25. The electronic reader of claim 24, wherein the activation mechanism of the receiving portion brings the electrode array into contact with the membrane by compressing a portion of the transverse flow testing device.

26. The electronic reader of claim 25, wherein compressing the portion of the transverse flow testing apparatus reduces the distance between the electrode array and the membrane.

27. The electronic reader of claim 25, wherein the electrode array and the membrane are separated by an insulating film, and the portion of the transverse flow testing device is compressed to puncture the insulating film.

28. The electronic reader of claim 24, wherein the electrode array and the membrane are separated by an insulating film, and the activation mechanism of the receiving portion brings the electrode array into contact with the membrane by peeling off the insulating film.

29. A method for performing a lateral flow test on a liquid sample using a lateral flow testing device, the device comprising: Test strips, the test strips comprising: — A membrane having a first trapping reagent disposed on a first surface at a test location, the first trapping reagent being configured to trap analytes in the liquid sample; —A sample pad disposed on the first surface at a first end of the membrane spaced apart from the test position, the sample pad being configured to receive the liquid sample; —A conjugate pad disposed on the first surface between the sample pad and the test site, wherein a catalytic labeling reagent is deposited on the conjugate pad and the catalytic labeling reagent is configured to chemically bind to the analyte; An electrode array disposed on the membrane, the electrode array being configured to apply a potential across the first surface upon activation, the electrode array having at least one component of a catalyst substrate deposited thereon, the catalyst substrate being capable of chemically reacting with the catalytically labeled reagent upon activation; and A support structure configured to attach the test strip and the electrode array when the device is in an inactive state, such that the electrode array is separated from the membrane, and the method includes: The liquid sample is deposited onto the sample pad of the test strip; The electrode array is brought into contact with the membrane to activate the transverse flow testing device; Operate the electrode array to apply a potential across the first surface through the electrode array to drive electrochemical reactions in the test strip; and The presence of the analyte in the liquid sample is detected by measuring the electrochemical signal obtained from the test strip using the electrode array.

30. The method of claim 29, wherein contacting the electrode array with the membrane causes at least one component of the catalyst substrate to be dissolved by the liquid sample on the membrane.

31. The method of claim 30, wherein the electrode array is operated to oxidize or reduce the at least one component of the catalyst substrate to activate the at least one component of the catalyst substrate, thereby making the at least one component of the catalyst substrate water-soluble.

32. The method according to claim 30 or 31, wherein the at least one component of the catalyst substrate forms the catalyst substrate when dissolved by the liquid sample on the membrane, such that a catalytic reaction can occur between the catalyst substrate and the catalytic labeling reagent.

33. The method of claim 32, wherein measuring the obtained electrochemical signal from the test strip via the electrode array comprises measuring the catalytic reaction between the catalyst substrate and the catalytically labeled reagent.

34. The method of claim 33, wherein measuring the catalytic reaction between the catalyst substrate and the catalytic labeling reagent comprises measuring the amount of reaction product or the amount of unreacted catalytic labeling reagent or both.

35. The method of claim 30, wherein the electrode array is further deposited thereon with a catalytic portion.

36. The method of claim 35, wherein the at least one component of the catalyst substrate forms the catalyst substrate when dissolved by the liquid sample on the membrane, such that a catalytic reaction can occur between the catalyst substrate and the catalytic labeling reagent to form a secondary catalyst substrate.

37. The method of claim 36, wherein the secondary catalyst substrate undergoes a catalytic reaction with the catalytic portion to form a secondary reaction product.

38. The method of claim 37, wherein measuring the obtained electrochemical signal from the test strip via the electrode array includes measuring the amount of the secondary reaction product.

39. The method of claim 37 or 38, wherein measuring the obtained electrochemical signal from the test strip via the electrode array includes measuring the amount of the secondary catalyst substrate.

40. The method according to any one of claims 29 to 39, wherein measuring the obtained electrochemical signal from the test strip by the electrode array comprises potentiometry, current measurement, voltammetry, one or more impedance-based measurements, one or more capacitance measurements, or a combination thereof.

41. An apparatus for performing a transverse flow test on a liquid sample, comprising: Test strips, the test strips comprising: — A membrane having a first trapping reagent disposed on a first surface at a test location, the first trapping reagent being configured to trap analytes in the liquid sample; —A sample pad disposed on the first surface at a first end of the membrane spaced apart from the test position, the sample pad being configured to receive the liquid sample; and —A conjugate pad disposed on the first surface between the sample pad and the test site, wherein a catalytic labeling reagent is deposited on the conjugate pad and the catalytic labeling reagent is configured to chemically bind to the analyte; An activation layer disposed on the membrane, the activation layer being arranged to contact the first surface upon activation, the activation layer having at least one component of a catalyst substrate deposited thereon, the catalyst substrate being capable of chemically reacting with the catalytically labeled reagent upon activation; and A support structure configured to attach the test strip and the activation layer when the device is in an inactive state, such that the activation layer is separated from the membrane.

42. The device of claim 41, wherein the activation layer comprises an electrode array configured to apply a potential across the first surface upon activation, and the catalyst substrate generates an electrochemically detectable product upon reaction with the catalytically labeled reagent.

43. The device of claim 41, wherein the activation layer is a substantially transparent foil, and the catalyst substrate produces a visually detectable product when reacting with the catalytic labeling reagent.

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