Lateral flow device with BAW sensor

Abstract

Devices, systems, methods including a fluidic device with a BAW sensor and a wicking material for moving a fluidic sample are provided. The fluidic device may include a BAW sensor configured to detect an analyte in a fluid sample. The BAW sensor may have an active region including a functional material including a first member of a binding pair. The fluidic device may further include a fluidic channel positioned across the BAW sensor such that the fluidic channel is disposed over the active region. The fluidic channel may have an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the BAW sensor.

Description

LATERAL FLOW DEVICE WITH BAW SENSORInventors: Matthew RyderThayne EdwardsKevin McCarronKelsey CaplesCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is filed under the Patent Cooperation Treaty, and is based on and claims priority to U.S. Provisional Application Number 63 / 491,806, filed on March 23, 2023, which is hereby incorporated by reference in its entirety as if fully recited herein.TECHNICAL FIELD OF THE INVENTION

[0002] The present invention relates to lateral flow devices, and more particularly to devices, systems, and methods of making and using lateral flow devices including a bulk acoustic wave sensor for detecting an analyte in a sample.BACKGROUND AND SUMMARY OF THE INVENTION

[0003] A biosensor (or biological sensor) is an analytical device including a biological element that converts a biological response into an electrical signal. Certain biosensors involve a selective biochemical reaction between a specific binding material and a binding target (e.g., a molecule, protein, DNA, virus, bacteria, etc.), and the product of this specific binding reaction is converted into a measurable quantity by a transducer. Other sensors may utilize a nonspecific binding material capable of binding multiple types or classes of molecules or other moieties that may be present in a sample. Transduction methods used with biosensors may be based on various principles, such as electrochemical, optical, electrical, acoustic, and so on. Among these, acoustic transduction offers a number of potential advantages, such as being real time, label free, and low cost, as well as exhibiting high sensitivity.

[0004] An acoustic wave device, such as, for example, a bulk acoustic wave (BAW) device, employs an acoustic wave that propagates through or on the surface of the specific bindingmaterial, whereby any changes to the characteristics of the propagation path affect the velocity and / or amplitude of the wave. The presence of functionalization or functional material onor over an active region of an acoustic wave device permits an analyte to be bound to the functional material, thereby altering the mass being vibrated by the acoustic wave and altering the wave propagation characteristics (e.g., velocity, thereby altering resonance frequency). Changes in velocity can be monitored by measuring the frequency or phase characteristics of the sensor and can be correlated to a physical quantity being measured. Current diagnostic devices that incorporate BAW biosensors often lack robustness, are large in size, are expensive, and have special handling and storage requirements. BAW diagnostic devices also generally include pumps, fluidic wells, and other complex and / or active mechanisms. These mechanical components may be prone to failure, meaning they often require regular preventative maintenance and may have a shorter product life. Moreover, current BAW diagnostic devices require several different liquid reagents, which typically require special storage conditions and handling requirements. For example, these liquid components are stored in fluidic wells that are merged with the BAW diagnostic device, requiring the entire device to be temperature controlled to maintain the desired shelf life. Additionally, these devices include specific biological markers such as antibodies and other specific proteins that target specific biological analytes. Thus, each BAW diagnostic device includes a BAW sensor coating specific to a particular biological analyte rather than being able to detect a range of different biological analytes. For these reasons, current BAW diagnostic devices are not well- suited to being available over-the-counter (OTC) or at the point-of-need (PON).

[0005] Lateral flow devices (LFD) generally have no liquids stored in the device because the necessary reagents are stored up-stream from the sensing area and in a dried state, meaning they do not need to be, for example, temperature controlled. A wicking mechanism moves fluid across the sensing area, often using a porous material and a downstream absorbent pad. Generally, commercial LFDs use a functional material that reacts with the analyte to create a visual-colored pattern on the device, which is then measured by photodetectors or other optical sensors. This detection method is usually not particularly sensitive, limiting the range of potential tests that can be done on LFDs.

[0006] Thus, improved LFDs including BAW sensors are desired to effectively combine the highly sensitive BAW sensor with the less complex, less expensive, smaller, and more robust LFD. This may allow for diagnostic devices that can be provided OTC and used at PON, while being highly sensitive and effective.

[0007] Aspects of the invention relate to devices, systems, and methods of using fluidic devices, which may be LFDs, that include BAW sensors. In some cases, the fluidic devices may include a wicking material in the fluidic channel for improved movement of fluid with minimal mechanical elements and minimizing the effects on the sensitivity of the BAW sensor.

[0008] Some embodiments of the present disclosure include afluidic device. The fluidic device may include a BAW sensor configured to detect an analyte in a fluid sample. The BAW sensor may have an active region including a functional material including a first member of a binding pair. The fluidic device may further include a fluidic channel positioned across the BAW sensor such that the fluidic channel is disposed over the active region. The fluidic channel may have an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the BAW sensor.

[0009] In some embodiments, the analyte may include a second member of the binding pair such that the analyte is configured to bind to the functional material. In some embodiments, the functional material may include a universal capture reagent. In some embodiments, the wicking material may include at least one region including an analyte capture reagent located upstream of the active region. In some embodiments, the binding pair may be selected from the group consisting of: a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a peptide / aptamer binding pair, and a metal / metal-binding peptide pair. In some embodiments, the analyte may include a biological analyte. In some embodiments, the wicking material may be configured to move the sample from the inlet to the outlet. In some embodiments, the wicking material may include a fibrous material. In some embodiments, the wicking material may be semi-porous. In some embodiments, the wicking material may include one or more of cotton, cellulose, glass fiber, carbon fiber, nylon, polyether sulfone, polyvinylidene fluoride, carbon nanotubes, or copper nanotubes.

[0010] Some embodiments of the present disclosure may include a method of measuring an amount of an analyte in a sample. The method comprising the step of: providing a fluidic device. The fluidic device may include a BAW sensor, which may have an active region including a functional material including a first member of a first binding pair. The fluidic device may also include a fluidic channel positioned across the BAW sensor such that thefluidic channel is disposed over the active region. The fluidic channel may have an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the B A W sensor. The method may further include the steps of: inputting at least a portion of the sample into the inlet of the fluidic channel such that at least a portion of the sample contacts the wicking material; and measuring the amount of analyte coupled to the active region using the BAW sensor.

[0011] In some embodiments, the analyte may include a second member of the first binding pair such that the analyte is configured to bind the functional material.

[0012] In some embodiments, the method may also include the step of inputting, after inputting the at least a portion of the sample, an analyte capture reagent into the inlet of the fluidic channel. The analyte capture reagent may include a first member of a second binding pair and the analyte may include a second member of the second binding pair such that the analyte capture reagent is configured to bind the analyte. In some embodiments, an analyte capture reagent may be disposed within a portion of the wicking material upstream from the active region. In some embodiments, the analyte capture reagent may include a first member of a second binding pair and the analyte may include a second member of the second binding pair such that the analyte capture reagent is configured to bind the analyte.

[0013] In some embodiments, the method may also include the step of inputting, before inputting the at least a portion of the sample, an analyte capture reagent into the inlet of the fluidic channel, wherein the analyte capture reagent comprises a second member of the first binding pair such that the analyte capture reagent is configured to bind the functional material. In some embodiments, the analyte capture reagent may include a second member of the first binding pair such that the analyte capture reagent is configured to bind the functional material. In some embodiments, the analyte capture reagent may comprise a first member of a second binding pair and the analyte comprises a second member of the second binding pair such that the analyte is configured to bind the analyte capture reagent.

[0014] In some embodiments, the analyte capture reagent may include a first member of the first binding pair and the analyte may include a second member of the first binding pair such that the analyte is configured to bind the analyte capture reagent disposed in the wicking material and the functional material. The analyte capture reagent may prevent at least some of the analyte in the sample from contacting the functional material.

[0015] In some embodiments, at least one of the analyte or the analyte capture reagent may include a signal enhancing element. In some embodiments, the method may also include the step of: inputting a signal enhancing reagent into the inlet of the fluidic channel such that at least a portion of the signal enhancing reagent contacts the wicking material. The signal enhancing reagent may be configured to bind to the signal enhancing element. In some embodiments, the method may also include the step of: inputting, before inputting a signal enhancing reagent, a washing or rinsing reagent configured to remove unbound analyte and unbound analyte capture reagent. In some embodiments, signal enhancing reagent may be configured to cause a precipitation reaction when bound to the signal enhancing element.

[0016] In some embodiments, the binding pair may be selected from the group consisting of: a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a pep tide / aptamer binding pair, and a metal / metal-binding peptide pair.

[0017] Some embodiments of the present disclosure include a method of measuring an amount of analyte in a sample. The method may include the step of: providing a fluidic device. The fluidic device may include a BAW sensor having an active region including a functional material including a first member of a first binding pair. The fluidic device may also include a fluidic channel positioned across the BAW sensor such that the fluidic channel is disposed over the active region. The fluidic channel may include an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the BAW sensor. The method may further include the step of mixing at least a portion of the sample with an analyte capture reagent, where the analyte capture reagent may be configured to bind the analyte. The analyte capture reagent may include a second member of the first binding pair such that the analyte capture reagent is configured to bind the functional material. The method may also include the steps of: inputting the mixture into the inlet of the fluidic channel such that the mixture contacts the wicking material; and measuring the amount of analyte coupled to the active region using the BAW sensor.

[0018] In some embodiments, the analyte capture reagent may include a first member of a second binding pair and the analyte may include a second member of the second binding pair such that the analyte capture reagent is configured to bind the analyte.

[0019] In some embodiments, at least one of the analyte or the analyte capture reagent mayinclude a signal enhancing element. In some embodiments, the method may also include the step of: inputting a signal enhancing reagent into the inlet of the fluidic channel such that at least a portion of the signal enhancing reagent contacts the wicking material. The signal enhancing reagent may be configured to bind to the signal enhancing element. In some embodiments, the method may also include the step of: inputting, before inputting a signal enhancing reagent, a washing or rinsing reagent configured to remove unbound analyte and unbound analyte capture reagent. In some embodiments, the signal enhancing reagent may be configured to cause a precipitation reaction when bound to the signal enhancing element.

[0020] In some embodiments, at least one of the first binding pair or the second binding pair may be selected from a group consisting of: a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a peptide / aptamer binding pair, and a metal / metal-binding peptide pair.

[0021] Some embodiments of the present disclosure comprise a method of measuring an amount of an analyte in a sample. The method may include the step of: providing a fluidic device. The fluidic device may include a BAW sensor having an active region including a functional material. The functional material may include a first member of a first binding pair. The fluidic device may also include a fluidic channel positioned across the BAW sensor such that the fluidic channel is disposed over the active region. The fluidic channel may have an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the BAW sensor. The method may also include the step of: mixing at least a portion of the sample with an analyte capture reagent, where the analyte capture reagent is configured to bind the analyte. The analyte may include a second member of the first binding pair such that the analyte is configured to bind the functional material. The method may also include the steps of: inputting the mixture into the inlet of the fluidic channel such that the mixture contacts the wicking material; and measuring the amount of analyte coupled to the active region using the BAW sensor.

[0022] In some embodiments, the analyte capture reagent may include a first member of a second binding pair and the analyte may include a second member of the second binding pair such that the analyte capture reagent is configured to bind the analyte.

[0023] In some embodiments, at least one of the analyte or the analyte capture reagent mayinclude a signal enhancing element. In some embodiments, the method may include the step of: inputting a signal enhancing reagent into the inlet of the fluidic channel such that at least a portion of the signal enhancing reagent contacts the wicking material. The signal enhancing reagent may be configured to bind to the signal enhancing element. In some embodiments, the method may include the step of: inputting, before inputting a signal enhancing reagent, a washing or rinsing reagent configured to remove unbound analyte and unbound analyte capture reagent. In some embodiments, the signal enhancing reagent may be configured to cause a precipitation reaction when bound to the signal enhancing element.

[0024] In some embodiments, at least one of the first binding pair or the second binding pair may be selected from the group consisting of: a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a peptide / aptamer binding pair, and a metal / metal-binding peptide pair.

[0025] Some embodiments of the present disclosure include a method of determining an amount of an analyte in a sample. The method may include the step of providing a fluidic device. The fluidic device may include a bulk acoustic wave (B AW) sensor having an active region including a functional material including a first member of a first binding pair. The fluidic device may also include a fluidic channel positioned across the B AW sensor such that the channel is disposed over the active region. The fluidic channel may have an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the BAW sensor. The method may also include the steps of: mixing at least a portion of the sample with a first analyte capture reagent to form a mixture, where the first analyte capture reagent is configured to bind the analyte; inputting the mixture into the inlet of the fluidic channel such that the mixture contacts the wicking material; and measuring the amount of at least one of the analyte or the first analyte capture reagent coupled to the active region using the BAW sensor.

[0026] In some embodiments, the first analyte capture reagent may include a first member of the first binding pair and the analyte may include the second member of the second binding pair such that the first analyte capture reagent is configured to bind the analyte and the functional material.

[0027] In some embodiments, the step of mixing at least a portion of the sample with a firstanalyte capture reagent further includes mixing at least a portion of the sample with a plurality of analyte capture reagents. Each of the plurality of analyte capture reagents may be configured to bind the analyte and the first analyte capture reagent may include a second member of the first binding pair such that the first analyte capture reagent is configured to bind the functional material. In some embodiments, the plurality of analyte capture reagents may be mixed with the at least a portion of the sample sequentially. In some embodiments, the first analyte capture reagent may be 25 percent of the total analyte capture reagent in the mixture.

[0028] In some embodiments, the analyte may include the first member of the first binding pair such that the functional material and the analyte are the same. In some embodiments, the first analyte capture reagent may include a second member of the first binding pair such that the first analyte capture reagent is configured to bind both the analyte and the functional material. In some embodiments, the step of measuring the amount of at least one of analyte or first analyte capture reagent may include measuring the amount of first analyte capture reagent bound to the surface of the B AW sensor, where the amount of first analyte measured is inversely proportionalto an amount of analyte in the sample.

[0029] In some embodiments, at least one of the analyte or the first analyte capture reagent may include a signal enhancing element. In some embodiments, the method may also include the step of: inputting a signal enhancing reagent into the inlet of the fluidic channel such that at least a portion of the signal enhancing reagent contacts the wicking material, where the signal enhancing reagent is configured to bind to the signal enhancing element. In some embodiments, the method may also include the step of: inputting, before inputting a signal enhancing reagent, a washing or rinsing reagent configured to remove unbound analyte and unbound analyte capture reagent. In some embodiments, the signal enhancing reagent may be configured to cause a precipitation reaction when bound to the signal enhancing element.

[0030] In some embodiments, at least one of the first binding pair or the second binding pair may be selected from the group consisting of: a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / strepta vidin binding pair, an RNA hybridization pair, a DNA hybridization pair, a peptide / aptamer binding pair, and a metal / metal-binding peptide pair.

[0031] Some embodiments of the present disclosure include a system for determining an amount of an analyte in a sample. The system may include a fluidic device, an actuator, and adetector. The fluidic device may include a BAW sensor configured to detect an analyte in a fluid sample. The BAW sensor may have an active region comprising a functional material comprising a first member of a binding pair. The fluidic device may also include a fluidic channel positioned across the BAW sensor such that the fluidic channel is disposed over the active region. The fluidic channel may have an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the BAW sensor. The actuator may include electronic circuitry and may be configured to actuate the BAW sensor. The detector may be configured to deliver a signal to the BAW sensor and detect a modified signal output from the BAW sensor.

[0032] In some embodiments, the functional material may include a universal capture reagent. In some embodiments, the wicking material may include at least one region comprising an analyte capture reagent upstream of the active region. In some embodiments, the binding pair may be selected from the group consisting of: a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a peptide / aptamer binding pair, and a metal / metal-binding peptide pair. In some embodiments, the analyte may include a biological analyte. In some embodiments, the wicking material may be configured to move the sample from the inlet to the outlet. In some embodiments, the wicking material may include a fibrous material. In some embodiments, the wicking material may be semi -porous. In some embodiments, the wicking material may include one or more of cotton, cellulose, glass fiber, carbon fiber, nylon, polyether sulfone, polyvinylidene fluoride, carbon nanotubes, or copper nanotubes.

[0033] In some embodiments, the system may include processor configured to receive the modified signal from the detector and determine the amount of analyte in the sample. In some embodiments, the processor may be configured to compare the modified signal received from the detector to a calibration data set. In some embodiments, the system may also include a display coupled to the detector and the actuator. In some embodiments, the display may be configured to receive a user input. In some embodiments, the processor may be further configured to display the determination of the amount of analyte in the sample on the display.

[0034] Some embodiments of the present disclosure include a kit for measuring an amount of an analyte in a sample. The kit may include a fluidic device. The fluidic device may include aBAW sensor configured to detect an analyte in a fluid sample, where the BAW sensor may have an active region including a functional material including a first member of a first binding pair. The fluidic device may include a fluidic channel positioned across the BAW sensor such that the fluidic channel is disposed over the active region. The fluidic channel may have an inlet and an outlet. A wicking material may be disposed within the fluidic channel between the inlet and the outlet. The wicking material may be disposed in contact with the functional material coupled to the active region of the BAW sensor. The kit may also include a first analyte capture reagent, where the first analyte capture reagent may be configured to bind the analyte.

[0035] In some embodiments, the analyte may include a second member of the first binding pair such that the analyte is configured to bind the functional material. In some embodiments, the first analyte capture reagent may include a second member of the first binding pair such that the first analyte capture reagent may be configured to bind to the functional material. In some embodiments, the kit may also include a plurality of analyte capture reagents, where each of the plurality of analyte capture reagents is configured to bind the analyte. In some embodiments, the functional material may include a universal capture reagent.

[0036] In some embodiments, the kit may also include a signal enhancing reagent, where at least one of the analyte or the analyte capture reagent comprises a signal enhancing element and the signal enhancing reagent may be configured to bind the signal enhancing element. In some embodiments, the signal enhancing reagent may be configured to cause a precipitation reaction when bound to the signal enhancing element.

[0037] In some embodiments, the binding pair may be selected from the group consisting of: a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a pep tide / aptamer binding pair, and a metal / metal-binding peptide pair.

[0038] In some embodiments, the analyte may include a biological analyte. In some embodiments, the kit may also include a lysis buffer. In some embodiments, the sample may include whole blood, serum, plasma, urine, diluted human stool, saliva, mucus, tissue, or any combination thereof.

[0039] These and further aspects will be further explained in the rest of the disclosure, including the detailed description of the implementations, the claims, and the accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG. 1 is a schematic diagram of a fluidic device including a BAW sensor, according to some embodiments of the present disclosure.

[0041] FIG.2A is a bottom view of an example fluidic device, according to some embodiments of the present disclosure.

[0042] FIG. 2B is a top view of an example fluidic device, according to some embodiments of the present disclosure.

[0043] FIG. 2C is a cross sectional view of an example fluidic device, according to some embodiments of the present disclosure.

[0044] FIG. 2D is a table showing BAW sensor measurements for active pumping of a fluidic sample.

[0045] FIG. 2E is a graph showing BAW sensor measurements for active pumping of a fluidic sample.

[0046] FIG.2F is a table showing BAW sensor measurements for passive pumping of a fluidic sample.

[0047] FIG.2Gis a graph showing BAW sensor measurements for passive pumping of a fluidic sample.

[0048] FIG. 2H is a table showing BAW sensor measurements for fluidic samples with a signal enhancing reagent.

[0049] FIG. 21 is a graph showing BAW sensor measurements for fluidic samples with a signal enhancing reagent.

[0050] FIG. 3 A is a flow chart illustrating a method of performing a direct assay using a fluidic device, according to some embodiments of the present disclosure.

[0051] FIG. 3B is a diagram illustrating an exemplary method of performing a direct assay, according to some embodiments of the present disclosure.

[0052] FIG. 4 is a flow chart illustrating a method of performing an indirect assay using a fluidic device, according to some embodiments of the present disclosure.

[0053] FIG. 5 A is a flow chart illustrating a method of performing a sandwich assay using a fluidic device, according to some embodiments of the present disclosure.

[0054] FIG. 5B is a diagram illustrating an exemplary method of performing a sandwich assay, according to some embodiments of the present disclosure.

[0055] FIG. 5C is a diagram illustrating an exemplary method of performing a sandwich assay,according to some embodiments of the present disclosure.

[0056] FIG. 6A is a flow chart illustrating a method of performing a competitive assay using a fluidic device, according to some embodiments of the present disclosure.

[0057] FIG. 6B is a diagram illustrating an exemplary method of performing a competitive assay, according to some embodiments of the present disclosure.

[0058] FIG. 7 is a diagram illustrating an exemplary method of performing a combined competitive and indirect assay, according to some embodiments of the present disclosure.

[0059] FIG. 8 is a diagram illustrating a signal enhancing reaction, according to some embodiments of the present disclosure.DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0060] The practice of the present invention will employ, unless otherwise indicated, conventional techniques of silicon fabrication in the field of biosensors. Such techniques are explained fully in the literature, such as “Acoustic-Based Biosensors,” (Durmus et al., 2014); “Recent Advances in Acoustic Wave Biosensors for the Detection of Disease-related Biomarkers: A review,” (Zhang et al., 2021); and “Acoustic Biosensors and Microfluidic Devices in the Decennium: Principles and Applications,” (Nair, et al., 2021).

[0061] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

[0062] In the following description, numerous specific details are set forth to provide a more thorough understanding of the present invention. However, it will be apparent to one of skill in the art that the present invention may be practiced without one or more of these specific details. In other instances, well-known features and procedures well known to those skilled in the art have not been described in order to avoid obscuring theinvention.

[0063] All references cited throughout the disclosure, including patent applications and publications, are incorporated by reference herein in their entirety.I. Definitions

[0064] By “comprising,” it is meant that the recited elements are required in the device / system / method / kit, but other elements can be included to form the device / system / method / kit etc. within the scope of the claim.

[0065] By “consisting essentially of,” it is meant a limitation of the scope of composition or method described to the specified materials or steps that do not materially affect the basic and novel characteristic(s) of the subject invention.

[0066] By ‘ ‘consisting of,” it is meant the exclusion from the composition, method, or kit of any element, step, or ingredient not specified in the claim.

[0067] By “substantially” is meant the same meaning as “nearly completely,” and can be understood to modify the term that follows by at least about 90%, at least about 95%, or at least about 98%.

[0068] By “about” as used in conjunction with numeric values is meant to include normal variations in measurements as expected by persons skilled in the art, and is understood to have the same meaning as “approximately” and to cover a typical margin of error, such as ± 5% of the stated value.

[0069] By “analyte,” it is meant a substance that it is desired to detect. An analyte can be a biologic substance.

[0070] By ‘ ‘functional material” it is meant to generally relate to both specific and non-specific binding materials.

[0071] By “binding pair,” it is meant two substances that bind each other. The substances that make up the binding pair may specifically or non-specifically bind each other. For example, a binding pair may be a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a peptide / aptamer binding pair, or a metal / metal- binding peptide pair.

[0072] By “member of a binding pair,” it is meant one of two or more substances in a binding pair.

[0073] By ‘ ‘active region,” it is meant a region of a bulk acoustic wave (BAW) sensor where a reaction or binding occurs between the analyte and another substance and / or where the analyte is detected by the BAW sensor.

[0074] By “upstream,” it is meant moving or situated in the opposite direction from the fluidflow. In some cases, upstream in a fluidic device described herein may mean located before the active region in a fluidic channel. For example, upstream may include the region between the inlet of the fluidic channel and the active region.

[0075] By “downstream,” it is meant moving or situated in the direction of the fluid flow. In some cases, downstream in a fluidic device described herein may mean located after the active region in a fluidic channel. For example, downstream may include the region between the active region and the outlet of the fluidic channel.

[0076] By “wicking material,” it is meant a material that moves a fluid when the fluid contacts a part of the material. The wicking material may move the fluid using any suitable mechanism including, for example, capillary action.

[0077] By “fibrous material,” it is meant any material including one or more fibers.

[0078] By “semi-porous,” it is meant any material comprising one or more pores or voids. In some cases, semi-porous may mean a material that is permeable to some fluids and impermeable to other fluids.

[0079] By “universal capture reagent,” it is meant a reagent including a substance that binds to two or more different substances. A universal capture reagent may bind multiple different analytes. In some cases, a universal capture reagent may be a member of multiple binding pairs.

[0080] By “analyte capture reagent,” it is meant a substance that binds to an analyte.

[0081] By “signal enhancing reagent,” it is meant a substance configured to bind to and / or react with a substance bound to the surface of a BAW sensor (e.g., an analyte or an analyte capture reagent) to amplify the signal measured. In some cases, a signal enhancing reagent may improve detection of an analyte by the BAW sensor.

[0082] By ‘ ‘calibration data set,” it is meant a set of data that can be used to determine whether a measured signal indicates the presence and / or amount of an analyte in a sample. In some cases, the calibration data set may contain data corresponding to no analyte being present and data corresponding to the analyte being present.

[0083] All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the patent disclosure.

[0084] As used here, the singular forms “a,” “an,” and “the” encompass examples having plural referents, unless the content clearly dictates otherwise.

[0085] As used here, the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise. The term “and / or” means one or all of the listed elements or a combination of any two or more of the listed elements.

[0086] As used here, “have,” “having,” “include,” “including,” “comprise,” “comprising,” or the like are used in their open-ended sense, and generally mean “including, but not limited to.” It will be understood that “consisting essentially of,” “consisting of,” and the like are subsumed in “comprising” and the like. As used herein, “consisting essentially of,” as it relates to a composition, product, method or the like, means that the components of the composition, product, method or the like are limited to the enumerated components and any other components that do not materially affect the basic and novel characteristic(s) of the composition, product, method or the like.

[0087] The words “preferred” and “preferably” refer to examples of the invention that may afford certain benefits, under certain circumstances. However, other examples may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred examples does not imply that other examples are not useful, and is not intended to exclude other examples from the scope of the disclosure, including the claims.

[0088] The recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.8, 4, 5, etc. or 10 or less includes 10, 9.4, 7.6, 4.3, 2.9, 1.62, 0.3, etc.). Where a range of values is “up to” a particular value, that value is included within the range.

[0089] Any direction referred to here, such as “top,” “bottom,” “left,” “right,” “upper,” “lower,” and other directions and orientations are described herein for clarity in reference to the figures and are not to be limiting of an actual device or system or use of the device or system. Devices or systems as described herein may be used in a number of directions and orientations.II. Detailed Description

[0090] The present disclosure provides systems incorporating and methods of using fluidic devices that include a BAW sensor. As compared to other fluidic devices, various examples of the present disclosure include fluidic devices for detecting analytes with high sensitivity while incorporating benefits such as a smaller and less complex structure, fewer mechanical parts, less onerous storage and handling requirements, and the capability of detecting multiple analytes with a single fluidic device. Some embodiments of the present disclosure may include fluidic devices having a wicking material disposed within the fluidic channel. The wickingmaterial may move the fluidic sample through the fluidic channel without mechanical parts like pumps. Reagents may also be disposed within the wicking material such that the analyte or other substances in the fluidic sample can contact and bind the reagent, thereby limiting the number of additional reagents needed to use the fluidic device.

[0091] Fluidic devices described herein may use a variety of methods to detect one or more analytes. In some cases, the fluidic devices may be diagnostic devices that are configured to detect one or more biological analytes.LATERAL FLOW DEVICE WITH BULK ACOUSTIC SENSOR

[0092] FIG. 1 is a schematic cross-sectional view of a portion of a fluidic device 100 (e.g., a biochemical sensor device) including a fluidic channel 102 (which may be microfluidic in character) that is bounded from below by a bulk acoustic wave (B AW) resonator structure or sensor including an active region 104, bounded laterally by a wall structure 106, and bounded from above by a cover or cap layer 108 defining a fluidic inlet port 110 and a fluidic outlet port 112. The fluidic device 100 may be a lateral flow device (LFD).

[0093] The fluidic device 100 includes a substrate 114 overlaid with an acoustic reflector 116, and a bottom side electrode 118 arranged generally below a piezoelectric material 120. A top side electrode 122 extends over a portion of the piezoelectric material 120, wherein a portion of the piezoelectric material 120 arranged between the top side electrode 122 and the bottom side electrode 118 embodies the active region 104 of the BAW sensor 117. The bottom side electrode 118 is arranged along a portion of a lower surface 124 of the piezoelectric material 120. The top side electrode 122 and the piezoelectric material 120 are overlaid with a hermeticity layer 126, an interface layer 128, and a self-assembled monolayer (SAM) 130. Portions of the SAM 130 between the active region 104 and the wall structure 106 are overlaid with a chemical or biological blocking material 132 to prevent localized attachment of functional material and / or analyte. A portion of the SAM 130 that is registered with the active region 104 is overlaid with a layer of functional (e.g., specific binding) material 134 arranged to bind at least one analyte 136. Any combination of the layers 126, 128, 130 is contemplated. In some embodiments, the fluidic device 100 not include any layers 126, 128, 130 over the top side electrode 122 and piezoelectric material 120. In some embodiments, a combination of the hermeticity layer 126, interface layer 128, and SAM 130 may be used. In some embodiments, there may not be a layer of functional material over the active region 104 or, in some cases, the layer of functional material may cover surfacesaround the active region 104. In some cases, a layer of blocking material 132 may not be used. In some cases, the layer of blocking material 132 may be disposed over part or all of any suitable surfaces.

[0094] Walls of the wall structure 106 are laterally displaced from the active region 104 and extend upward from the SAM 130 to define lateral boundaries of the fluidic channel 102 containing the active region 104. The wall structure 106 may be formed of any suitable material, such as a laser-cut “stencil” layer of thin polymeric materials and / or laminate materials, optionally including one or more self-adhesive surfaces (e.g., adhesive tape). Optionally the wall structure 106 may be formed prior to deposition of the SAM 130, functional material 134, and blocking material 132 with an SU-8 negative epoxy resist or other photoresist material. The cover or cap layer 108 defining fluidic inlet and outlet ports 110, 112 is further provided to provide an upper boundary for the fluidic channel 102. The cover or cap layer 108 may be formed by defining fluidic inlet and outlet ports 110, 112 (e.g., via laser cutting or waterjet cutting) in a layer of an appropriate material (e.g., a substantially inert polymer, glass, silicon, ceramic, or the like), and adhering the cover or cap layer 108 to top surfaces of the wall structure 106.

[0095] A wicking material 138 may be disposed in the fluidic channel 102. The wi eking material 138 may extend from the inlet port 110 to the outlet port 112 and may extend into the ports 110, 112. The wicking material 138 may also contact or be pressed against the functional material 134 in the active region 104 of the fluidic device 100. The wicking material 138 may be capable of moving a fluid through the fluidic channel 102 from the inlet 110 to the outlet 112. The wicking material 138 may move the fluid using capillary action. The wicking material 138 may include any suitable material for moving a fluid and may be fibrous, porous, or semi -porous. For example, the wicking material 138 may include the cotton, cellulose, glass fiber, carbon fiber, nylon, polyether sulfone, poly vinylidene fluoride, carbon nanotubes, or copper nanotubes. In some cases, the wicking material 138 may be hydrophobic, hydrophilic, neutral or may have a polarity for driving fluid movement.

[0096] A fluid sample may be supplied through the fluidic inlet port 110 into the fluidic channel 102 over the active region 104 and then flow through the fluidic outlet port 112 to exit the fluidic channel 102. The fluid sample may or may not include an analyte 136 of interest. In some cases, the analyte 136 may tend to bind with functional material 134 arranged over the active region 104. In other embodiments, the analyte 136 may not beconfigured to bind the functional material 134 but may be configured to bind another material such as an analyte capture reagent 140, as described in more detail below.

[0097] An electric signal may be applied to the fluidic device 100 using an actuator to generate a bulk acoustic wave having a dominant shear component in the active region 104. The actuator may generate the bulk acoustic wave by supplying an electrical signal of a desired frequency to the bottom and top side electrodes 118,122. The actuator may include a battery or may be coupled to ground electrical power and an electrical signal may be applied may be in the form of an alternating current or direct current. A detector may be coupled to the BAW resonator structure such that the detector can deliver a signal to the BAW sensor and detect or measure a change in electroacoustic response (e.g., at least one of an amplitudemagnitude property, a frequency property, or a phase property, such as a shift in resonant frequency) or a modified signal of the BAW sensor 117 to indicate a presence and / or quantity of analyte bound to the functional material 134.

[0098] A processor may also be coupled to the fluidic device 100, the actuator, and / or the detector. The processor may be one or more central processing units, multi-core processors, microprocessors, microcontrollers, digital signal processors, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), graphics processing units (GPUs). The processor may control the actuator to control the fluidic device 100. Additionally, the processor may receive data detected by the detector and analyze or process the data to determine whether an analyte 136 is bound to the functional material 134 in the active region 104 and, thus, whether analyte 136 is present in the fluidic sample. The processor may also determine the amount of analyte 136 that is present in the fluidic sample based on the data from the detector. The processor may receive a calibration data set from memory. The processor may use the calibration data set to determine whether a measured signal indicates the presence and / or amount of an analyte 136 in the fluidic sample. In some cases, the calibration data set may contain data corresponding to no analyte 136 being present and data corresponding to the analyte 136 being present. Thus, in some cases, the processor may compare the data from the detector to the calibration data set and determine the presence and / or amount of analyte 136 in the fluidic sample.

[0099] A display may be coupled to the fluidic device 100, actuator, detector, and / or processor. The detector or processor may display the data detected by the detector. In some cases, the processor may display whether the analyte 136 is present in the fluidic sample and / or theamount of analyte 136 in the fluidic sample on the display. The display may include a user interface that allows a user to display selected data or control the actuator, detector, or processor. The user interface may be a touch screen, a joystick, buttons, or any other suitable mechanism. The display may include a monitor, such as an LED monitor.

[0100] The functional material 134 may include any substance configured to specifically or non- specifically bind to another substance. In some cases, the functional material 134 may comprise a member of a binding pair, where the functional material 134 comprises configured to bind the other member of the binding pair. The binding pair may include any two substances that bind each other. For example, a binding pair may be a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a peptide / aptamer binding pair, or a metal / metal-binding peptide pair. In some particular examples, the functional material 134 may comprise an antibody and may be configured to bind an antigen.

[0101] The functional material 134 may be a universal capture reagent, which may refer to a substance capable of binding two or more different substances. In some cases, the universal capture reagent may comprise members of multiple binding pairs. The universal capture reagent may bind multiple different analytes. Thus, when the functional material 134 comprises a universal capture reagent, the fluidic device 100 may be capable of detecting multiple different analytes 136. For example, a universal capture reagent may include, e.g., a murine anti-human antibody, which binds to any human antibody. Other non-limiting examples of universal capture reagents include ovine, bovine, and / or equine anti-human antibodies. Depending on the nature of the analyte, a universal capture reagent may include, for example, a member of a ligand / receptor binding pair, an antigen / antibody binding pair, a lectin / carbohydrate binding pair, an enzyme / substrate binding pair, a biotin / streptavidin binding pair, a nucleic acid hybridization pair, a peptide / aptamer binding pair, a metal / metal- binding peptide pair, and the like.

[0102] The functional material 134 may be configured to bind the analyte 136 as shown in FIG. 1 so that the fluidic device 100 can directly detect the analyte 136. However, the fluidic device 100 may also be capable of detecting an analyte 136 using any appropriate method. In some cases, the functional material 134 may bind another substance such as an analyte capture reagent 140. The methods of using fluidic devices 100 will be described in more detail below in reference to FIGS. 3-6.

[0103] A substance, such as an analyte capture reagent 140, may be disposed within the wicking material 138 upstream of the active region 104. Thus, the fluidic sample may move through the wicking material 138 and contact the analyte capture reagent 140 before moving through the active region 104 and contacting the functional material 134. The analyte capture reagent 140may bind the analyte 136 or another substance in the fluidic sample. In some cases, analyte capture reagent 140 may bind the analyte 136 and prevent it from moving further downstream in the fluidic channel 102. In these cases, the analyte capture reagent 140 may be bound or coupled to the wicking material 138. Thus, the analyte 136 bound to the analyte capture reagent 140 may not move into the active region 104 or out of the outlet port 112. In some cases, the analyte capture reagent 140 may not be bound or coupled to the wicking material 138 and may move through the wicking material 138 and contact the functional material 134 in the active region 104. The analyte capture reagent 140 may also move towards and out of the outlet port 112. In some cases, the analyte capture reagent 140 may be dried or otherwise disposed within the wicking material 138 without being bound or coupled to it. When the fluidic sample passes through the region of the fluidic channel 102 upstream from the active region 104, the fluidic sample may contact and wet the dried analyte capture reagent140. The analyte capture reagent 140 may dissolve into the fluidic sample. Thus, the analyte capture reagent 140 may mix with the fluidic sample and move with the fluidic sample across the active region 104 and out of the outlet port 112.

[0104] Although a particular fluidic device 100 including a BAW sensor 117 is described, any suitable structure for a fluidic device 100 including a BAW sensor 117 may be used. Experiment 1

[0105] FIGS. 2A-2C are images of an example fluidic device used in Experiment 1. FIG. 2 A is a bottom view of a modified cartridge 50. FIG. 2B is a top view of the modified cartridge 50. FIG. 2C is a cross-section of the fluidic channel of the modified cartridge 50, which was taken by sectioning the fluidic channel 1 12 after it was filled with an acrylic resin. A Qorvo Biotechnologies Cartridge 50 having BAW sensor 117 and compatible with a Qorvo Biotechnologies Omnia Platform was modified to create the fluidic device used in Experiment 1. The adhesive layer on the bottom of the cartridge 50 was removed and a fibrous wicking material 138 was placed into the fluidic channel 102, as shown in FIG. 2 A. TechniCloth TX609® was used as the wicking material 138, which comprises a blend of 55%cellulose and 45% polyester. The polyester fibers were approximately 10 (pm) in diameter. The fluidic channel 102 had a volume of approximately 3 cubic micrometers.

[0106] The platform was used with the mechanical components exposed allowing for addition of the sample directly into inlet port 110 of the modified cartridge 50 while the modified cartridge 40 was inserted into the platform. The sample was allowed to wick directly into the wicking material 138 through the inlet port 110 and through the wicking material 138 across the BAW sensor 117.

[0107] The wicking material 138 was pressed against the surface of the BAW sensor 117, as shown in FIG. 2C. The adhesive layer on the top of the cartridge 50 was partially removed to expose the inlet 110 and outlet 112 ports. The ports 110, 112 were then widened slightly and the channels next to the ports 110, 112 were blocked using a UV cure glue. The wicking material 138 was then extended through the inlet 110 and outlet 112 ports to promote wicking rather than a forced injection.

[0108] The BAW sensor 117 surface was coated with thyroxine bovine serum albumin (T4- BSA). A positive sample was prepared including anti-thyroxine conjugated with alkaline phosphatase (ALP) in bovine serum albumin (BSA) at a concentration of 20 micrograms per milliliter (pg / mL). A negative sample was prepared using only BSA. The functionalized surface of the BAW sensor 117 and the wicking material 138 saturated with the sample were allowed to bind for 15 minutes before a slope measurement was taken. This slope is representative of the amount of binding between the test analyte, anti-thyroxine ALP, and the functional material, T4-BSA, on the surface.

[0109] Different loading techniques were assessed including pushing the fluid into the inlet port via pipette, which can be referred to as active pumping, and allowing the sample to wick into the absorbent material passively, which can be referred to as passive pumping. A comparison between the BAW sensor readings for negative and positive samples loaded into the fluidic device using both active and passive pumping is shown in FIGS. 2D-2G. FIG. 2D is a table and FIG. 2E is a graph showing the results of actively pumping the positive and negative samples into the wicking material 138. FIG. 2F is a table and FIG. 2G is a graph showing the results of passively pumping the positive and negative samples into the wicking material 138. Both active and passive pumping show a difference between the negative and positive samples, with probability values of p=0.006 and p=0.07, respectively. Active pumping shows a statistically significantly difference of probability value p=0.006 between negative andpositive samples. These results indicate that robust B AW sensor measurements can be obtained using passive pumping with minimal inclusion of mechanical elements within the cartridge.

[0110] After the wicking material 138 was fully saturated, a signal enhancing reagent, 5- bromo- 4-chl oro-3 -indolyl phosphate nitro blue tetrazolium chloride (BCIP-NBT), was added to the wicking material 138 through the inlet port 110 and was allowed to move across the surface of the BAW sensor 117. When BCIP-NBT and ALP contact each other, an insoluble precipitate salt is formed. This enhances the signal to improve detection of bound ALP by the BAW sensor 117. FIG. 2H is a table and FIG. 21 is a graph showing the results of adding BCIP-NBT into the fluidic channel through the wicking material 138 after the initial loading of the positive and negative samples. The results show that the wicking material 138 allows for subsequent loading of fluids into the fluidic channel 102.

[0111] Thus, the wicking material 138 may provide effective fluid movement with minimal impact on the functioning or sensitivity of the BAW sensor 117.METHODS OF USE

[0112] Any one of the fluidic devices 100 described herein may be used to detect the presence or amount of analyte 136 in a fluidic sample. Various assay methods, such as, for example, enzyme-linked immunosorbent assay (ELISA) methods, may be applied to one or more fluidic devices 100 as described below.Direct Assay

[0113] In some embodiments, a fluidic device 100 described herein may be used to directly detect the presence or amount of analyte 136 in a fluidic sample. To this end, the functional material 134 on the surface of the BAW sensor 117 may be configured to orcapable of binding to the analyte 136.

[0114] FIG. 3A is a flowchart illustrating an example method 300 of performing a direct assay, such as, e.g., a direct ELISA, according to some embodiments of the present disclosure. Step 302 includes providing a fluidic device 100. The fluidic device 100 may be any fluidic device 100 described herein. For example, the fluidic device 100 may include a BAW sensor 117 with a functional material 134 disposed on the active region 104 of the surface of the BAW sensor 117. The fluidic channel 102 may have an inlet 110 and outlet 112 port and may be arranged across the active region 104. A wicking material 138 may be disposed within the fluidic channel 102 and may be pressed against the surface of the BAW sensor 117 and contact the functional material 134.

[0115] The functional material 134 may comprise a first member of a binding pair such that it can bind to a second member of the binding pair in the sample. For a direct assay, the analyte 136 may comprise the second member of the binding pair such that the analyte 136 in the sample directly binds to the functional material 134 of the surface of the BAW sensor 117.

[0116] Step 304 of the method 300 may include inputting a fluidic sample into the inlet port 110 of the fluidic channel 102 such that the fluidic sample contacts the wicking material 138 disposed therein. The fluidic sample may be added passively by allowing the sample to contact the wicking material 138 without applying additional pressure to the fluid fluidic sample, which may be referred to as passive pumping. In other embodiments, the fluid may be pushed into the inlet port 110 via a pipette or other pump, which may be referred to as active pumping. The wicking material 138 may wick or move the fluidic sample from the inlet port 110 to the outlet port 112 across the BAW sensor 117. Thus, the wicking material 138 may move the fluidic sample across and through the active region 104 such that the fluidic sample contacts the functional material 134. Some or all of the analyte 136 in the fluidic sample may contact and bind to the functional material 134. If there is no analyte 136 in the fluidic sample, the functional material 134 may not bind anything or may bind other substances in the fluidic sample.

[0117] Optionally, the method 300 may include step 306. Step 306 may include inputting a signal enhancing reagent into the inlet port 110 of the fluidic channel 112. In some cases, the mass, weight, and / or bulk of the analyte 136 may not be substantial enough for the BAW sensor 117 to detect the analyte 136 when it is bound to the functional material 134. Thus, a signal enhancing reagent may be wicked or moved through the fluidic channel 102 to enhance the signal of the analyte 136 when it is bound to the functional material 134 for more robust and easier detection by the BAW sensor 117. The analyte 136 may include a signal enhancing element that binds to the signal enhancing reagent as it moves through the active region 104. The signal enhancing reagent may add mass, weight, and / or bulk to the analyte 136 bound to the functional material 134. In some cases, the signal enhancing reagent may cause the signal enhancing reagent, analyte, and functional material complex to precipitate out of solution. Thus, when the BAW is activated, the complex will be easier to detect. In some embodiments, a washing or rinsing reagent may be input into the fluidic channel 102 before the signal enhancing reagent is input to remove or wash away any unbound analyte in the fluidic channel 102. This may prevent the signal enhancing reagent from binding to extraneous substances.

[0118] Step 308 of the method 300 may include measuring the amount of analyte 136 bound to the functional material 134 using the BAW sensor 117. In some cases, the modified signal received from the BAW sensor 117 may indicate a certain substance is bound to the functional material 134 on the surface. The modified signal may then be compared to a calibration data set to determine whether analyte 136 is bound to the functional material 134. The modified signal may also indicate the amount of analyte 136 that is bound, which may be used to calculate the concentration or amount of analyte 136 that is in the fluidic sample.

[0119] FIG. 3B illustrates an example of a process of implementing a method 300 of performing a direct assay. The first panel of FIG. 3B illustrates the fluidic sample passing through the wicking material 138 in the fluidic channel 102. In this example, the analyte 136 in the fluidic sample comprises an antigen and the functional material 134 comprises an antibody, where the antibody is configured to bind the antigen. In some cases, the antibody may specifically bind the antigen and, in other cases, the antibody may non-specifically bind the antigen. Some of the analyte 136 in the sample contacts and binds the functional material 134 on the surface of the BAW sensor 117. The right part of FIG. 3B illustrates the fluidic device after the fluidic sample has moved past the functional material 134. Here, the analyte 136 has bound to the functional material 134.

[0120] Although the illustrated example shows all binding sites on the antibodies bound to the antigen, not all of the binding sites need be bound to an antigen. In some cases, no antigen binds to the antibody. In some cases, the functional material 134 may comprise an antigen and the analyte 136 may comprise an antibody. In other cases, the analyte 136 and functional material 134 may comprise another type of binding pair.Indirect Assay

[0121] In some embodiments, a fluidic device 100 described herein may be used to indirectly detect the presence or amount of analyte 136 in a fluidic sample. To this end, the functional material 134 on the surface of the BAW sensor 1 17 may be configured to or capable of binding to an analyte capture reagent 140, which in turn binds to the analyte 136.

[0122] FIG. 4 is a flowchart illustrating an example method 400 of performing an indirect assay, according to some embodiments of the present disclosure. Step 402 includes providing a fluidic device 100. The fluidic device 100 may be any fluidic device 100 described herein. For example, the fluidic device 100 may include a BAW sensor 117 with a functional material 134 disposed on the active region 104 of the surface of the BAW sensor 117. The fluidicchannel 102 may have an inlet 110 and outlet 112 port and may be arranged across the active region 104. A wicking material 138 may be disposed within the fluidic channel 102 and may be pressed against the surface of the BAW sensor 117 and contact the functional material 134.

[0123] The functional material 134 may comprise a first member of a first bindingpair such that it can bind to a second member of the first binding pair. For an indirect assay, an analyte capture reagent 140 may comprise the second member of the first binding pair such that the analyte capture reagent 140 directly binds to the functional material 134 of the surface of the BAW sensor 117. The analyte capture reagent 140 may be configured to bind to the analyte 136 such that the analyte 136 is bound to the analyte capture reagent 140 that is bound to the functional material 134. The analyte 136 and the analyte capture reagent 140 may comprise the first and second members of a second binding pair that is different from the first binding pair.

[0124] Step 404 of the method 400 may include inputting an analyte capture reagent 140 into the inlet port 110 of the fluidic channel 102 such that the analyte capture reagent 140 contacts the wicking material 138 disposed therein. The analyte capture reagent 140 may be passively or actively pumped into the fluidic channel 102 via the inlet port 110. The wicking material 138 may wick or move the analyte capture reagent 140 from the inlet port 110 to the outlet port 1 12 across the BAW sensor 1 17. Thus, the wicking material 138 may move the analyte capture reagent 140 across and through the active region 104 such that the analyte capture reagent 140 contacts the functional material 134. Some or all of the analyte capture reagent 140 may contact and bind to the functional material 134.

[0125] Step 406 of the method 400 may include inputting a fluidic sample into the inlet port 110 of the fluidic channel 102 such that the fluidic sample contacts the wicking material 138 disposed therein. The fluidic sample may be passively or actively pumped into the fluidic channel 102 via the inlet port 110. The wicking material 138 may wick or move the fluidic sample from the inlet port 110 to the outlet port 112 across the BAW sensor 117. Thus, the wicking material 138 may move the fluidic sample across and through the active region 104 such that the fluidic sample contacts the analyte capture reagent 140 and / or the functional material 134. Some or all of the analyte 136 in the fluidic sample may contact and bind to the analyte capture reagent. If there is no analyte 136 in the fluidic sample, the analyte capture reagent may not bind anything or may bind other substances in the fluidic sample.

[0126] Optionally, the method 400 may include step 408. Step 408 may include inputting a signal enhancing reagent into the inlet port 110 of the fluidic channel 112. In some cases, themass, weight, and / or bulk of the analyte 136 and / or the analyte capture reagent 140 may not be substantial enough for the BAW sensor 117 to detect the analyte 136 and analyte capture reagent 140 when they are bound to the functional material 134. Thus, a signal enhancing reagent may be wicked or moved through the fluidic channel 102 to enhance the signal of the analyte 136 and analyte capture reagent 140 when they are bound to the functional material 134 for more robust and easier detection by the BAW sensor 117. The analyte 136 and / or the analyte capture reagent 140 may include a signal enhancing element that binds to the signal enhancing reagent as it moves through the active region 104. The signal enhancing reagent may add mass, weight, and / or bulk to the analyte 136 and / or analyte capture reagent 140 that are bound to the functional material 134. In some cases, the signal enhancing reagent may cause the signal enhancing reagent, analyte, analyte capture reagent, and functional material complex to precipitate out of solution. Thus, when the BAW is activated, the complex will be easier to detect. In some embodiments , a washing or rinsing reagent may be input into the fluidic channel 102 before the signal enhancing reagent is input to remove or wash away any unbound analyte or analyte capture reagent in the fluidic channel 102. This may prevent the signal enhancing reagent from binding to extraneous substances.

[0127] Step 410 of the method 400 may include measuring the amount of analyte 136 and analyte capture reagent 140 bound to the functional material 134 using the BAW sensor 117. In some cases, the modified signal received from the BAW sensor 117 may indicate a certain substance is bound to the functional material 134 on the surface. The modified signal may then be compared to a calibration data set to determine whether analyte 136 is bound to the functional material 134. The modified signal may also indicate the amount of analyte 136 that is bound, which may be used to calculate the concentration or amount of analyte 136 that is in the fluidic sample.

[0128] In other embodiments, instead of inputting the analyte capture reagent 140 into the fluidic channel 102 before inputting the fluidic sample, the analyte capture reagent 140 and fluidic sample are mixed, stirred, or otherwise contacted and combined before either are input into the fluidic channel 102. The analyte capture reagent 140 may be allowed to bind to the analyte 136 in the fluidic sample. The mixture may then be input into the inlet port 110 of the fluidic channel 102 such that it contacts the wicking material 138. The wicking material 138 may move the mixture across the active region 104 such that it contacts the functional material 134. The analyte, analyte capture reagent complex may then bind to the functional material 134such that the analyte capture reagent 140 portion of the complex binds to the functional material 134.

[0129] In yet other embodiments, instead of inputting analyte capture reagent 140 into the fluidic channel 102 before inputting the fluidic sample, the analyte capture reagent 140 may be disposed in the wicking material 138 in a portion of the fluidic channel 102 upstream from the active region 104. The analyte capture reagent 140 may be dried or otherwise disposed on the wicking material 138 such that it is not bound or coupled to the wicking material 138. Thus, when the fluidic sample is input into the inlet port 110 of the fluidic channel 102, the analyte capture reagent 140 may contact, dissolve into, or mix with the fluidic sample. The analyte capture reagent 140 may be allowed to bind to the analyte 136 in the fluidic sample. The wicking material 138 may move the fluidic sample including the dissolved analyte capture reagent 140 across the active region 104 such that it contacts the functional material 134.

[0130] In some cases, the analyte 136 and analyte capture reagent 140 may bind before contacting the functional material 134 and the analyte, analyte capture reagent complex may then bind to the functional material 134, where the analyte capture reagent 140 portion of the complex binds to the functional material 134. In some cases, the analyte 136 and analyte capture reagent 140 do not bind before contacting the functional material 134. Thus, the analyte capture reagent 140 contacts and binds to the functional material 134 and the analyte 136 binds to the analyte capture reagent 140 that is bound to the functional material 134.Sandwich Assay

[0131] In some embodiments, a fluidic device 100 described herein may be used to detect the presence or amount of analyte 136 in a fluidic sample using a sandwich method. To this end, the functional material 134 on the surface of the BAW sensor 117 may be configured to or capable of binding to an analyte 136, which in turn binds to an analyte capture reagent 140.

[0132] FIG. 5 is a flowchart illustrating an example method 500 of performing a sandwich assay, according to some embodiments of the present disclosure. Step 502 includes providing a fluidic device 100. The fluidic device 100 may be any fluidic device 100 described herein. For example, the fluidic device 100 may include a BAW sensor 117 with a functional material 134 disposed on the active region 104 of the surface of the BAW sensor 117. The fluidic channel 102 may have an inlet 110 and outlet 112 port and may be arranged across the active region 104. A wicking material 138 may be disposed within the fluidic channel 102 and may be pressed against the surface of the BAW sensor 117 and contact the functional material 134.

[0133] The functional material 134 may comprise a first member of a first binding pair such that it can bind to a second member of the first binding pair. For a sandwich assay, the analyte 136 may comprise the second member of the first binding pair such that the analyte 136 directly binds to the functional material 134 of the surface of the BAW sensor 117. The analyte 136 may also be configured to bind to analyte capture reagent 140 such that the analyte 136 is bound to both the analyte capture reagent 140 and the functional material 134 (where the analyte 136 is sandwiched between the analyte capture reagent 140 and the functional material 134). The analyte 136 and the analyte capture reagent 140 may comprise the first and second members of a second binding pair that is different from the first binding pair.

[0134] Step 504 of the method 500 may include inputting a fluidic sample into the inlet port 110 of the fluidic channel 102 such that the fluidic sample contacts the wicking material 138 disposed therein. The fluidic sample may be passively or actively pumped into the fluidic channel 102 via the inlet port 110. The wicking material 138 may wick or move the fluidic sample from the inlet port 110 to the outlet port 112 across the BAW sensor 117. Thus, the wicking material 138 may move the fluidic sample across and through the active region 104 such that the fluidic sample contacts the functional material 134. Some or all of the analyte 136 in the fluidic sample may contact and bind to the functional material 134. If there is no analyte 136 in the fluidic sample, the functional material 134 may not bind anything or may bind other substances in the fluidic sample.

[0135] Step 506 of the method 500 may include inputting an analyte capture reagent 140 into the inlet port 110 of the fluidic channel 102 such that the analyte capture reagent 140 contacts the wicking material 138 disposed therein. The analyte capture reagent 140 may be passively or actively pumped into the fluidic channel 102 via the inlet port 110. The wicking material 138 may wick or move the analyte capture reagent 140 from the inlet port 110 to the outlet port 112 across the BAW sensor 117. Thus, the wicking material 138 may move the analyte capture reagent 140 across and through the active region 104 such that the analyte capture reagent 140 contacts the analyte 136 and / or the functional material 134. Some or all of the analyte capture reagent 140 may contact and bind to the analyte 136 that is bound to the functional material 134.

[0136] Optionally, the method 500 may include step 508. Step 508 may include inputting a signal enhancing reagent into the inlet port 110 of the fluidic channel 112. In some cases, the mass, weight, and / or bulk of the analyte 136 and / or the analyte capture reagent 140 may not besubstantial enough for the BAW sensor 117 to detect the analyte 136 and analyte capture reagent 140 when they are bound to the functional material 134. Thus, a signal enhancing reagent may be wicked or moved through the fluidic channel 102 to enhance the signal of the analyte 136 and analyte capture reagent 140 when they are bound to the functional material 134 for more robust and easier detection by the BAW sensor 117. The analyte 136 and / or the analyte capture reagent 140 may include a signal enhancing element that binds to the signal enhancing reagent as it moves through the active region 104. The signal enhancing reagent may add mass, weight, and / or bulk to the analyte 136 and / or analyte capture reagent 140 that are bound to the functional material 134. In some cases, the signal enhancing reagent may cause the signal enhancing reagent, analyte capture reagent, analyte, and functional material complex to precipitate out of solution. Thus, when the BAW is activated, the complex will be easier to detect. In some embodiments , a washing or rinsing reagent may be input into the fluidic channel 102 before the signal enhancing reagent is input to remove or wash away any unbound analyte or analyte capture reagent in the fluidic channel 102. This may prevent the signal enhancing reagent from binding to extraneous substances.

[0137] Step 510 of the method 500 may include measuring the amount of analyte 136 and analyte capture reagent 140 bound to the functional material 134 using the BAW sensor 1 17. In some cases, the modified signal received from the BAW sensor 117 may indicate a certain substance is bound to the functional material 134 on the surface. The modified signal may then be compared to a calibration data set to determine whether analyte 136 is bound to the functional material 134. The modified signal may also indicate the amount of analyte 136 that is bound, which may be used to calculate the concentration or amount of analyte 136 that is in the fluidic sample.

[0138] In other embodiments, instead of inputting the analyte capture reagent 140 into the fluidic channel 102 after inputting the fluidic sample, the analyte capture reagent 140 and fluidic sample are mixed, stirred, or otherwise contacted and combined before either are input into the fluidic channel 102. The analyte capture reagent 140 may be allowed to bind to the analyte 136 in the fluidic sample. The mixture may then be input into the inlet port 110 of the fluidic channel 102 such that it contacts the wicking material 138. The wicking material 138 may move the mixture across the active region 104 such that it contacts the functional material 134. The analyte, analyte capture reagent complex may then bind to the functional material 134 such that the analyte 136 portion of the complex binds to the functional material 134.

[0139] In yet other embodiments, instead of inputting analyte capture reagent 140 into the fluidic channel 102 before inputting the fluidic sample, the analyte capture reagent 140 may be disposed in the wicking material 138 in a portion of the fluidic channel 102 upstream from the active region 104. The analyte capture reagent 140 may be dried or otherwise disposed on the wicking material 138 such that it is not bound or coupled to the wicking material 138. Thus, when the fluidic sample is input into the inlet port 110 of the fluidic channel 102, the analyte capture reagent 140 may contact, dissolve into, or mix with the fluidic sample. The analyte capture reagent 140 may be allowed to bind to the analyte 136 in the fluidic sample. The wicking material 138 may move the fluidic sample including the dissolved analyte capture reagent 140 across the active region 104 such that it contacts the functional material 134.

[0140] In some cases, the analyte 136 and analyte capture reagent 140 may bind before contacting the functional material 134 and the analyte, analyte capture reagent complex may then bind to the functional material 134, where the analyte 136 portion of the complex binds to the functional material 134. In some cases, the analyte 136 and analyte capture reagent 140 do not bind before contacting the functional material 134. Thus, the analyte 136 contacts and binds to the functional material 134 and the analyte capture reagent 140 binds to the analyte 136 that is bound to the functional material 134.

[0141] FIG. 5B illustrates an example of a process of implementing a method 500 of performing a sandwich assay. The first panel of FIG. 5B illustrates the fluidic sample passing through the wicking material 138 in the fluidic channel 102. In this example, the analyte 136 in the fluidic sample comprises an antigen and the functional material 134 comprises a first antibody, where the first antibody is configured to bind the antigen. In some cases, the first antibody may specifically bind the antigen and, in other cases, the first antibody may non- specifically bind the antigen. Some of the analyte 136 in the sample contacts and binds the functional material 134 on the surface of the BAW sensor 117. The second panel of FIG. 5B illustrates the analyte capture reagent 140 passing through the wicking material 138 in the fluidic channel 102. In this example, the analyte capture reagent 140 comprises a second antibody, where the second antibody is configured to bind the antigen. In some cases, the second antibody may specifically bind the antigen and, in other cases, the second antibody may non- specifically bind the antigen. Some of the analyte capture reagent 140 in the sample contacts and binds the analyte 136 that is bound to the functional material 134 on the surface of the BAW sensor 117. The third panel of FIG. 5B illustrates the fluidic device after theunbound analyte capture reagent 140 has moved past the functional material 134. Here, the analyte capture reagent 140 has bound to the analyte 136 that is bound to the functional material 134, thus forming a “sandwich” structure around the analyte 136.

[0142] FIG. 5C illustrates another example of a process of implementing a method 500 of performing a sandwich assay. The first panel of FIG. 5C illustrates the fluidic sample being mixed with the analyte capture reagent 140 before being input into the fluidic device. In this example, the analyte 136 in the fluidic sample comprises an antigen and the analyte capture reagent is a second antibody, where the second antibody is configured to bind the antigen. In some cases, the second antibody may specifically bind the antigen and, in other cases, the second antibody may non-specifically bind the antigen. At least some of the analyte 136 in the sample contacts and binds at least some of the analyte capture reagent 140 during mixing and forms analyte, analyte capture reagent complexes. The second panel of FIG. 5C illustrates the mixture including analyte, analyte capture reagent complexes passing through the wicking material 138 in the fluidic channel 102. In this example, the functional material 134 comprises a first antibody, where the first antibody is configured to bind the antigen. In some cases, the first antibody may specifically bind the antigen and, in other cases, the first antibody may non- specifically bind the antigen. Some of the analyte 136 bound to the analyte capture reagent 140 contact and binds the functional material 134 on the surface of the BAW sensor 117. The third panel of FIG. 5C illustrates the fluidic device after the mixture, which includes unbound analyte 136, unbound analyte capture reagent 140, and analyte, analyte capture reagent complexes that did not bind to functional material 134, has moved past the functional material 134. Here, the analyte 136 portion of an analyte, analyte capture reagent complex has bound to the functional material 134, thus forming a “sandwich” structure around the analyte 136.

[0143] Although the illustrated example shows all binding sites on the first antibodies bound to the antigen, not all of the binding sites need be bound to an antigen. In some cases, no antigen or antigen-antibody complexes bind to the first antibody. In some cases, the functional material 134 or the analyte capture reagent 140 may comprise an antigen and the analyte 136 may comprise an antibody. In other cases, the analyte 136, functional material 134, or analyte capture reagent 140 be other types of binding pairs.Competitive Assay

[0144] In some embodiments, a fluidic device 100 described herein may be used to detect the presence or amount of analyte 136 in a fluidic sample using a competitive method. To this end,the functional material 134 on the surface of the BAW sensor 117 may be configured to or capable of binding to an analyte 136 or to an analyte capture reagent 140, depending on the method used, as described below.

[0145] FIG. 6A is a flowchart illustrating an example method 600 of performing a competitive assay, according to some embodiments of the present disclosure. Step 602 includes providing a fluidic device 100. The fluidic device 100 may be any fluidic device 100 described herein. For example, the fluidic device 100 may include a BAW sensor 117 with a functional material 134 disposed on the active region 104 of the surface of the BAW sensor 117. The fluidic channel 102 may have an inlet 110 and outlet 112 port and may be arranged across the active region 104. A wicking material 138 may be disposed within the fluidic channel 102 and may be pressed against the surface of the BAW sensor 117 and contact the functional material 134.

[0146] The functional material 134 may comprise a first member of a first binding pair such that it can bind to a second member of the first binding pair. For a competitive assay, the analyte 136 may comprise the second member of the first binding pair such that the analyte 136 directly binds to the functional material 134 of the surface of the BAW sensor 117.

[0147] Step 604 of the method 600 may include mixing a fluidic sample with an analyte capture reagent 140. The analyte capture reagent 140 may be configured to bind the analyte 136. In some cases, the analyte capture reagent 140 may also be the first member of the first binding pair and may be the same substance as the functional material 140. In other cases, the analyte capture reagent 140 may comprise a first member of a different, second binding pair such that the analyte capture reagent 140 and the functional material 134 are not the same substance. In these cases, the analyte 136 may comprise the second member of the second binding pair. The analyte 136 may bind to the analyte capture reagent 140 before the mixture is input into the fluidic device.

[0148] Step 606 of the method 600 may include inputting the mixture into the inlet port 110 of the fluidic channel 102 such that the mixture contacts the wicking material 138 disposed therein. The mixture may be passively or actively pumped into the fluidic channel 102 via the inlet port 110. The wicking material 138 may wick or move the mixture from the inlet port 110 to the outlet port 112 across the BAW sensor 117.

[0149] The wicking material 138 may move the mixture across and through the active region 104 such that the fluidic sample contacts the functional material 134. The unbound analyte 136 remaining in the mixture that did not bind the analyte capture reagent 140 may contact andbind to the functional material 134. If there is no analyte 136 remaining in the fluidic sample, the functional material 134 may not bind anything or may bind other substances in the fluidic sample.

[0150] Optionally, the method 600 may include step 608. Step 608 may include inputting a signal enhancing reagent into the inlet port 110 of the fluidic channel 112. In some cases, the mass, weight, and / or bulk of the analyte 136 may not be substantial enough for the B AW sensor 117 to detect the analyte 136 when it is bound to the functional material 134. Thus, a signal enhancing reagent may be wicked or moved through the fluidic channel 102 to enhance the signal of the analyte 136 when it is bound to the functional material 134 for more robust and easier detection by the BAW sensor 117. The analyte 136 may include a signal enhancing element that binds to the signal enhancing reagent as it moves through the active region 104. The signal enhancing reagent may add mass, weight, and / or bulk to the analyte 136 that is bound to the functional material 134. In some cases, the signal enhancing reagent may cause the signal enhancing reagent, analyte, and functional material complex to precipitate out of solution. Thus, when the BAW is activated, the complex will be easier to detect. In some embodiments, a washing or rinsing reagent may be input into the fluidic channel 102 before the signal enhancing reagent is input to remove or wash away any unbound analyte in the fluidic channel 102. This may prevent the signal enhancing reagent from binding to extraneous substances.

[0151] Step 610 of the method 600 may include measuring the amount of analyte 136 bound to the functional material 134 using the BAW sensor 117. In some cases, the modified signal received from the BAW sensor 117 may indicate a certain substance is bound to the functional material 134 on the surface. The modified signal may then be compared to a calibration data set to determine whether analyte 136 is bound to the functional material 134. The modified signal may also indicate the amount of analyte 136 that is bound, which may be used to calculate the concentration or amount of analyte 136 that is in the fluidic sample. The amount of analyte capture reagent 140 mixed with the fluidic sample may be known and, thus, the approximate amount of analyte 136 bound to the analyte capture reagent 140 rather than to the surface of the BAW sensor 117 is known. Thus, the total amount of analyte 136 in the sample would be calculated as the amount of analyte 136 measured by the BAW sensor 117 andthe amount of analyte 136 bound to the analyte capture reagent 140. If there is no analyte 136 measured by the BAW sensor 117, then the amount of analyte 136 in the fluidic sample is lessthan the amount of analyte capture reagent 140 mixed with the fluidic sample. For example, there may be no analyte 136 in the fluidic sample or there may be a very small amount of analyte 136.

[0152] In other embodiments, instead of the analyte capture reagent 140 being mixed with the fluidic sample prior to being input into the fluidic device 100, the analyte capture reagent 140 may be disposed in the wicking material 138 in a portion of the fluidic channel 102 upstream from the active region 104. The analyte capture reagent 140 may be bound or coupled to the wicking material 138. In other embodiments, the analyte capture reagent 140 may be dried or otherwise disposed on the wicking material 138 such that it is not bound or coupled to the wicking material 138. Thus, when the fluidic sample is input into the inlet port 110 of the fluidic channel 102, the fluidic sample contacts the wicking material 138 and the wicking material 138 may move the fluidic sample through the portion of the wicking material 138 including the analyte capture reagent 140 and may contact or mix with the analyte capture reagent 140. Some or all of the analyte 136 in the fluidic sample may contact and bind or couple to the analyte capture reagent 140 in the wicking material 138. The analyte capture reagent 140 may prevent the bound analyte 136 from moving further downstream in the fluidic channel 102, thus preventing the bound analyte 136 from moving through the active region 104 and contacting the functional material 134.

[0153] In some embodiments, the fluidic sample is mixed, stirred, or otherwise contacted and combined with multiple analyte capture reagents. The analyte capture reagents may be mixed with the fluidic sample at the same time or may be mixed with the sample sequentially until all are mixed together. All of the analyte capture reagents may be configured to bind the analyte 136. However, only one of the analyte capture reagents, which may be referred to as the measured analyte capture reagent 140a, may be configured to bind the functional material 134. The measured analyte capture reagent 140a may comprise the second member of the first binding pair. The other analyte capture reagents in the mixture may be configured not to bind to the functional material 134. Thus, the percentage of measured analyte capture reagent 140a in the mixture may be the same the percentage of analyte that binds the measured analyte capture reagent 140a and is measured by the BAW sensor. In other words, the amount of measured analyte capture reagent 140a that binds to the functional material 134 may correspond to that percentage of the amount of analyte 136 in the sample.

[0154] For example, there may be four analyte capture reagents that are mixed with a sample: 140a, 140b, 140c, and 140d. Analyte capture reagent 140a may be configured to bind both the analyte 136 and the functional material 134. Analyte capture reagents 140b, 140c, and 140d may only be configured to bind the analyte 136 and not the functional material 136. The amount of each analyte capture reagent 140a, 140b, 140c, 140d added to the mixture may be the same. Thus, each analyte capture reagent 140a, 140b, 140c, 140d comprises 25% of the analyte capture reagent mixture. The analyte 136 may bind with each analyte capture reagent 140a, 140b, 140c, 140d at equal rates. Thus, there may be approximately the same number of analyte / analyte capture reagent complexes for each type of analyte capture reagent 140a, 140b, 140c, 140d. When the mixture is input into the inlet port 110 of the fluidic channel 102, the mixture is wicked by the wicking material 138 to the surface of the BAW sensor 117 and contacts the functional material 134. Only analyte capture reagent 140a binds to the functional material 134. Thus, only the amount of analyte 136 bound to the analyte capture reagent 140a is detected by the BAW sensor 117. Thus, the amount of analyte 136 detected is only 25% of the total analyte 136 in the fluidic sample. Therefore, the total amount of analyte 136 in the fluidic sample is approximately equal to 4 times the amount of analyte 136 detected. This approach can be implemented when an analyte concentration in a sample is above the dynamic range of the assay.

[0155] Although an example embodiment using four analyte capture reagents is described, any number of analyte capture reagents may be used. For example, 2, 3, 5, 6, 7, 8, 9, or 10 analyte capture reagents may be used. Moreover, equal amounts of analyte capture reagents may not be using in the mixture. Instead, more or less of one analyte capture reagent may be used. For example, a mixture of 20% of measure analyte capture reagent 140a may be used and 80% of analyte capture reagent 140b may be used.

[0156] In some embodiments, the functional material 134 on the surface of the BAW sensor 117 comprises the same substance as the analyte 136. In these cases, there may be an excess of analyte capture reagent 140 that did not bind to the analyte 136 when it was mixed with the fluidic sample in step 604. Thus, in step 606 of the method 600, the unbound analyte capture reagent 140 may bind to the functional material 134 on the surface of the BAW sensor 117. In this example, no analyte 136 would bind to the surface of the BAW sensor 117. Therefore, instead of measuring the amount of analyte 136 bound in step 610 of the method 600, the BAW sensor 117 would measure the amount of analyte capture reagent 140 bound to the functionalmaterial 134 on the surface. The amount of analyte capture reagent 140 mixed with the fluidic sample may be known. Therefore, the amount of analyte capture reagent 140 measured by the BAW sensor 117 may be inversely proportional to the amount of analyte 136 in the fluidic sample. The more analyte capture reagent 140 detected, the less analyte 136 in the fluidic sample and vice versa. The amount of analyte capture reagent 140 measured may be subtracted from the amount of analyte capture reagent 140 mixed with the fluidic sample to calculate the amount of analyte 136 in the fluidic sample.

[0157] In some embodiments, instead of analyte capture reagents being used, a competing analyte may be disposed within the wicking material 138 or may be mixed with the fluidic sample prior to inputting it into the fluidic channel 102. In this case, the competing analyte and sample analyte 136 may both be configured to bind the functional material 134 and may both be the second member of the first binding pair. Thus, the competing analyte and the sample analyte 136 may compete for binding with the functional material. Only the competing analyte bound to the functional material 134 may be detected by the BAW sensor 117 — the sample analyte 136 may not be able to be detected by the BAW sensor 117. The amount of competing analyte disposed within the wicking material 138 or mixed with the fluidic sample may be known. Thus, the amount of competing analyte detected by the BAW sensor 1 17 may be inversely related to the amount of analyte 136 in the sample. In some cases, the competing analyte may include a signal enhancing element and, thus, the signal enhancing reagent may only bind to the competing analyte and not the sample analyte. Thus, the signal measured by the competing analyte may be much higher than the signal measured from the sample analyte without a signal enhancing element. Therefore, the effect of the sample analyte would be negligible, and the BAW sensor may only be able to detect the effect of the competing analyte.

[0158] FIG. 6B illustrates another example of a process of implementing a method 600 of performing a competitive assay. The first panel of FIG. 6B illustrates the fluidic sample being mixed with the analyte capture reagent 140 before being input into the fluidic device. In this example, the analyte 136 in the fluidic sample comprises an antigen and the analyte capture reagent 140 comprises an antibody, where the antibody is configured to bind the antigen. In some cases, the antibody may specifically bind the antigen and, in other cases, the antibody may non-specifically bind the antigen. At least some of the analyte 136 in the sample contacts and binds at least some of the analyte capture reagent 140 during mixing and forms analyte, analyte capture reagent complexes. The second panel of FIG. 6B illustrates the mixtureincluding analyte, analyte capture reagent complexes passing through the wicking material 138 in the fluidic channel 102. In this example, the functional material 134 comprises the same substance as the analyte 136, which in this case is an antigen. Thus, the antigen on the surface of the B AW sensor (the functional material 134) is configured to bind the antibody (the analyte capture reagent 140). In some cases, the antibody may specifically bind the antigen and, in other cases, the antibody may non-specifically bind the antigen. At least some of the unbound analyte capture reagent 140 may contact and bind the functional material 134 on the surface of the BAW sensor 117. The analyte capture reagent 140 that is bound to the analyte 136 may not be able to bind to the functional material 134. The third panel of FIG. 6B illustrates the fluidic device after the mixture, which may include unbound analyte 136, analyte capture reagent complexes, and unbound analyte capture reagent 140 that did not bind to functional material 134, has moved past the functional material 134. Here, the analyte capture reagent 140 has bound to the functional material 134.

[0159] Although the illustrated example shows all binding sites of the antigen on the surface of the BAW sensor 117 are bound to the antibodies, not all of the binding sites need be bound to an antibody. In some cases, no antibody binds to the antigen on the surface of the BAW sensor 1 17. In some cases, the functional material 134 or the analyte 136 may comprise an antibody and the analyte capture reagent 140 may comprise an antigen. In other cases, the analyte 136, functional material 134, or analyte capture reagent 140 may comprise other types of binding pairs.

[0160] Although each assay method is described individually, different assay methods can be combined in any suitable way. For example, a competitive assay can be performed with any other format including a direct, sandwich, or indirect format.

[0161] FIG. 7 illustrates an example of a process of performing a competitive assay (as described in reference to FIG. 6 A) and an indirect assay (as described in reference to FIG. 4). The first panel of FIG. 7 illustrates the fluidic sample being mixed with the analyte capture reagent 140 before being input into the fluidic device. In this example, the analyte 136 in the fluidic sample comprises an antigen and the analyte capture reagent 140 comprises a primary antibody, where the primary antibody is configured to bind the antigen. In some cases, the primary antibody may specifically bind the antigen and, in other cases, the primary antibody may non-specifically bind the antigen. At least some of the analyte 136 in the sample contacts and binds at least some of the analyte capture reagent 140 during mixing and forms analyte,analyte capture reagent complexes. The second panel of FIG. 7 illustrates the mixture including analyte, analyte capture reagent complexes passing through the wicking material 138 in the fluidic channel 102. In this example, the functional material 134 comprises the same substance as the analyte 136, which in this case is an antigen. Thus, the antigen on the surface of the BAW sensor (the functional material 134) is configured to bind the primary antibody (the analyte capture reagent 140). In some cases, the primary antibody may specifically bind the antigen and, in other cases, the primary antibody may non-specifically bind the antigen. At least some of the unbound analyte capture reagent 140 may contact and bind the functional material 134 on the surface of the BAW sensor 117. The analyte capture reagent 140 that is bound to the analyte 136 may not be able to bind to the functional material 134. The third panel of FIG. 7 illustrates a secondary reagent 142 passing through the wicking material 138 in the fluidic channel 102 after the mixture, which may include unbound analyte 136, analyte capture reagent complexes, and unbound analyte capture reagent 140 that did not bind to functional material 134, has moved past the functional material 134. In this example, the secondary reagent 142 is a secondary antibody. The secondary antibody may be configured to bind to the primary antibody (the analyte capture reagent 140) that is bound to the antigen on the surface of the BAW sensor 1 17 (the functional material 134). At least some of the secondary reagent 142 may contact and bind the analyte capture reagent 140 bound to the functional material 134 on the surface of the BAW sensor 117. The fourth panel of FIG. 7 illustrates the fluidic device after the unbound secondary reagent 142 has moved past the functional material 134. Here, the secondary reagent 142 is bound to the analyte capture reagent 140, which in turn is bound to the functional material 134.

[0162] Although the illustrated example shows all binding sites of the antigen on the surface of the BAW sensor 117 are bound to the antibodies, not all of the binding sites need be bound to an antibody. In some cases, no antibody binds to the antigen on the surface of the BAW sensor 1 17. In some cases, the functional material 134 or the analyte 136 may comprise an antibody and the analyte capture reagent 140 may comprise an antigen. In other cases, the analyte 136, functional material 134, analyte capture reagent 140, or the secondary reagent 142 may comprise other types of binding pairs.

[0163] FIG. 8 illustrates an example of a process of performing a precipitation reaction using a signal enhancing reagent 144, according to some embodiments of the present disclosure. In the illustrated example, a sandwich assay has been performed according to any suitable methoddescribed or illustrated in FIGS. 5A-5C. However, it is contemplated that a signal enhancing reaction can be performed with any type of assay described herein. The first panel of FIG. 8 shows a functional material 134 disposed on the surface of the BAW sensor 117. In this case, the functional material 134 comprises a first antibody. An analyte 136, which in this case comprises an antigen, may be bound to the functional material 134. Moreover, an analyte capture reagent 140, which in this case comprises an antibody, may be bound to the analyte 136. Thus, the analyte 136 is disposed between the functional material 134 and the analyte capture reagent 140, forming a “sandwich” structure. The analyte capture reagent 140 may comprise one or more signal enhancing elements 146. The first panel illustrates a signal enhancing reagent 144 passing through the wicking material 138 in the fluidic channel 102. The signal enhancing reagent 144 may be configured to bind the signal enhancing element 146 on the analyte capture reagent 140. The signal enhancing reagent 144 may comprise any appropriate substance capable of reacting with the signal enhancing element 146. The signal enhancing element 146 may be a binding site, a substance bound to the analyte capture reagent 140, or any other suitable element. The signal enhancing reagent 144 may comprise, for example, an enzyme or any other suitable chemical. At least some of the signal enhancing reagent 144 contacts and binds or reacts with the signal enhancing element 146. The second panel of FIG. 8 shows the fluidic device after the unbound signal enhancing reagent 144 has moved past the functional material 134. Here, the signal enhancing reagent 144 contacts to the signal enhancing element 146 on the analyte capture reagent 140, which is bound to the analyte 136, which in turn is bound to the functional material 134. When the signal enhancing reagent 144 contacts the signal enhancing element 146, the signal enhancing reagent 144 may undergo a precipitation reaction. In some cases, the entire complex, including the functional material 134, analyte 136, analyte capture reagent 140, and signal enhancing reagent 144, may come out of solution and form a precipitate on the surface of the BAW sensor 117. In other cases, only part of the complex may form a precipitate. In some embodiments, the signal enhancing reagent 144 may not react when it contacts the signal enhancing element 146 and another substance may be input into and moved through the fluidic channel 102 to cause a precipitation reaction or other reaction to enhance the signal. For example, after the signal enhancing reagent 144 binds to the signal enhancing element 146, a substance may be input into the fluidic channel 102 to change the pH and cause a precipitation reaction. However, any suitable methodor substance for enhancing the signal of the analyte 136 and / or analyte capture reagent 140 may be used with any of the assays described herein.UTILITY

[0164] In some cases, a fluidic device described herein may be used to detect a biological analyte. The fluidic device may be included in a diagnostic device where the presence, absence, and / or amount of a biological analyte indicates that a patient may have a particular disease. In some cases, the biological analyte may be human chorionic gonadotrophin (hCG), where the presence of hCG indicates that the patient is pregnant. In other cases, the biological analyte is an antigen associated with SARS-CoV-2, where the presence of the antigen indicates that the patient is infected with COVID-19.

[0165] The fluidic sample may be collected from a patient’s body and may include whole blood, serum, plasma, urine, diluted human stool, saliva, mucus, tissue, or any other suitable sample. The fluidic sample may be processed in any suitable way including, for example, centrifugation, contact with one or more reagents, heating, cooling, extrusion, and / or filtering. For example, the fluidic sample may be mixed with a lysis buffer, which may rupture one or more cells in the fluidic sample. Moreover, the fluidic sample may be centrifuged to separate solid parts of the sample from the fluid.

[0166] In some cases, the functional material disposed on the fluidic device may include a universal capture reagent. The universal capture reagent may be able to detect a wide range of diseases using the same fluidic device or cartridge. In some cases, the universal capture reagent may include one or more analyte capture reagents that can be mixed with a sample before inputting the sample into the fluidic device. The analyte capture reagents may each be configured to specifically bind to a particular analyte. The functional material may non- specifically bind to all of the analyte capture reagents. Thus, the external analyte capture reagents could be chosen for the particular analyte that the user would like to detect and the same cartridge could be used for any of the availabletests.

[0167] The fluidic device or system may be provided as a kit, which includes the fluidic device, which may be coupled to an actuator, detector, processor, and / or display, one or more reagents for preparing the sample before inputting it into the device, and / or one or more reagents to be added to the fluidic device before or after the fluidic sample. Any of the fluidic devices, systems, or methods described herein may be used to detect a biological analyte in a fluidicsample. The reagents that may be included in the kit may be one or more of an analyte capture reagent, a signal enhancing reagent, or a washing or rinsing reagent.

[0168] The invention now being fully described, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made without departing from the spirit or scope of the invention.

[0169] While preferred examples of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such examples are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the examples of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

[0170] All references and publications cited herein are expressly incorporated herein by reference in their entirety into this disclosure, except to the extent they may directly contradict this disclosure. Although specific examples and embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific examples embodiments shown and described without departing from the scope of the present disclosure. It should be understood that this disclosure is not intended to be unduly limited by the illustrative examples and embodiments set forth herein and that such examples and embodiments are presented by way of example only with the scope of the disclosure to be limited only by the claims set forth here.

Claims

CLAIMS:

1. A fluidic device, comprising: a bulk acoustic wave (B AW) sensor configured to detect an analyte in a fluid sample, wherein the BAW sensor comprises an active region comprising a functional material comprising a first member of a binding pair; a fluidic channel positioned at the BAW sensor, wherein the fluidic channel comprises an inlet and an outlet; and a wicking material disposed at the fluidic channel.

2. The fluidic device of claim 1 , wherein the first member of the binding pair is capable of binding analyte having a second member of the binding pair.

3. The fluidic device of claim 1, wherein the functional material comprises a universal capture reagent.

4. The fluidic device of claim 1, wherein the wicking material comprises at least one region comprising an analyte capture reagent located upstream of the active region.

5. The fluidic device of claim 1, wherein the wicking material is configured to move the sample from the inlet to the outlet.

6. The fluidic device of claim 1, wherein the wicking material comprises a fibrous material.

7. The fluidic device of claim 1 , wherein the wicking material is semi- porous.

8. The fluidic device of claim 1 , wherein the wicking material comprises at least one selected from the group of cotton, cellulose, glass fiber, carbon fiber, nylon, polyether sulfone, poly vinylidene fluoride, carbon nanotubes, or copper nanotubes.

9. A method of measuring an amount of an analyte in a sample, the method comprising the steps of:providing a fluidic device comprising: a bulk acoustic wave (B AW) sensor comprising an active region comprising a functional material, wherein the functional material comprises a first member of a first binding pair; a fluidic channel positioned at the B AW sensor, wherein the fluidic channel comprises an inlet and an outlet; and a wicking material at the fluidic channel; and configuring the fluid channel to receive the sample at the inlet and cause the sample to contact the wicking material; and configuring the BAW sensor to measure the amount of analyte at the active region.

10. The method of claim 9, further comprising introducing analyte to the fluidic device, the analyte comprising a second member of the first binding pair such that the analyte is configured to bind to the functional material.

11. The method of claim 10, further comprising introducing an analyte capture reagent to the fluidic device, wherein the analyte capture reagent comprises a first member of a second binding pair and the analyte comprises a second member of the second binding pair such that the analyte capture reagent is configured to bind the analyte.

12. The method of claim 9, further comprising disposing an analyte capture reagent at the wicking material upstream from the active i in13. The method of claim 12, further comprising configuring the analyte capture reagent to prevent at least some of the analyte in the sample from contacting the functional material.

14. The method of claim 9, further comprising introducing a signal enhancing reagent capable of causing a precipitation reaction in the fluidic device.

15. A kit for measuring an amount of an analyte in a sample, comprising: a fluidic device, comprising: a bulk acoustic wave (BAW) sensor configured to detect an analyte in a fluid sample, wherein the BAW sensor comprises an active region comprising a functional material comprising a first member of a binding pair; a fluidic channel at the BAW sensor, wherein the fluidic channel comprises an inlet and an outlet; and a wicking material at the fluidic channel; and an analyte capture reagent, wherein the analyte capture reagent is configured to bind the analyte.

16. The kit of claim 15, wherein the analyte capture reagent comprises a second member of the binding pair such that the analyte capture reagent is configured to bind to the functional material.

17. The kit of claim 15, further comprising a plurality of analyte capture reagents, wherein each of the plurality of analyte capture reagents is configured to bind the analyte.

18. The kit of claim 15, wherein the functional material comprises a universal capture reagent.

19. The kit of claim 15, further comprising a signal enhancing reagent.

20. The kit of claim 15, further comprising a lysis buffer.

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