Devices, systems and methods for measuring solution properties of samples including microorganisms

Abstract

The present application relates to devices, systems, and methods for measuring solution characteristics of a sample comprising microorganisms. Various devices, systems, and methods for measuring solution characteristics of a sample including microorganisms are disclosed. In one embodiment, a sensor device is disclosed comprising: a sample container comprising a sample chamber configured to receive a sample; and a reference sensor component including a reference catheter having a reference catheter lumen defined therein. The reference catheter lumen may be at least partially filled with a reference buffer gel, buffer solution, or wicking component. A section of the reference conduit may extend into the sample chamber. The reference electrode material may be positioned at the proximal end of the wicking member or partially extend into the reference catheter lumen. The sensor device may also include an active sensor component having an active electrode in fluid contact with the sample. The sample in the sample chamber may be aerated through an aeration port defined along a surface of the sample container.

Description

[0001] This application is a divisional application of an application with an application date of June 19, 2019, application number 201980054622,3, and invention name “Device, system and method for measuring solution properties of samples including microorganisms”. CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 687,167, filed on June 19, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to diagnostic devices for measuring solution properties of a sample; more particularly, to devices, systems, and methods for measuring solution properties of a sample including microorganisms. background

[0004] Infections caused by infectious agents or microorganisms that are resistant to anti-infective drugs are a significant problem for medical professionals in hospitals, nursing homes, and other healthcare settings. For example, such infections can lead to a potentially life-threatening complication known as sepsis, in which chemicals released into the blood by the infectious agent can trigger a dangerous systemic inflammatory response and a vasoactive response that causes fever, hypotension, and possible death. When faced with such infections, the preferred course of action for clinicians is to use anti-infective compounds appropriately, preferably using only those measures necessary to alleviate the infection.

[0005] However, currently, it is most common to provide patients with broad-spectrum anti-infectives (often multiple drugs) to ensure the adequacy of treatment before the organism is identified and tested for drug susceptibility. This easily leads to multi-resistant infectious agents. Ideally, the susceptibility of infectious agents would be tested immediately after their presence is identified. In order to determine the susceptibility of such infectious agents to anti-infective drugs, samples containing such infectious agents must be quantified, which requires that such samples be assayed for microbial growth or absence of microorganisms.

[0006] Existing biosensors for determining infectious agents in biological or other types of samples typically include an active sensing component having an active electrode and a reference sensing component having a reference electrode immersed in a reference solution in ion exchange contact with the sample of interest. Traditionally, this is accomplished by using Ag / AgCl electrodes in an aqueous reference buffer solution (such as KCl). However, such conventional sensor designs are not ideal for a variety of reasons. First, silver or silver chloride diffuses into the sample and inhibits the growth of microorganisms in the sample, thereby complicating any measurement of the sample. In addition, conventional reference solutions are typically provided in disposable containers with thin glass walls, which are costly to manufacture, store, and transport. In addition, diffusion of microorganisms through salt bridges formed between the sample and the reference solution can contaminate the reference solution. In addition, conventional biosensors often require that the reference electrode be placed on the surface of the silicon die, which uses valuable wafer real estate and also increases the cost of such sensors.

[0007] Due to the above limitations and constraints, there is a need for improved devices, systems and methods to quickly and efficiently assay samples containing microorganisms for microbial growth or lack of microorganisms. Such solutions should be cost-effective and address the shortcomings of conventional biosensors. Overview

[0008] Disclosed are devices, systems, and methods for measuring solution properties (e.g., ORP or pH) of samples including microorganisms. In one embodiment, a sensor device for measuring solution properties of a sample is disclosed. The sensor device may include a sample container including a sample chamber configured to receive the sample and a reference sensor component. The reference sensor component may include a reference catheter, the reference catheter including a reference catheter cavity, a reference catheter first opening, and a reference catheter second opening. The reference sensor component may also include a wicking component extending through the reference catheter cavity, the wicking component having a wick distal end and a wick proximal end. At least a portion of the wicking component may be in fluid communication with the sample chamber so that the wicking component draws at least some of the sample in the direction of the wick proximal end. The reference sensor component may also include a reference electrode material disposed at the wick proximal end.

[0009] The sensor device may further comprise an active sensor component comprising an active electrode material. When the sample chamber is at least partially filled with the sample, at least a portion of the active electrode material may extend into the sample chamber and contact the sample fluid.

[0010] The reference sensor component and the active sensor component may be electrically coupled to a parameter analyzer via conductive connections.Solution properties of the sample may be determined based on a potential difference measured between the active electrode material and the reference electrode material.

[0011] The sensor device may include a container cover configured to be removably coupled to the sample container. The reference conduit may extend from the underside of the container cover. The container cover may be partially made of a non-conductive material. The container cover may be partially made of a transparent non-conductive material so that at least a portion of the wicking component can be visible through the container cover.

[0012] The sample container may be partially made of at least one of a ceramic material and a polymeric material. The reference electrode material may be a conductive ink applied or dispensed on the proximal end of the core. The conductive ink applied or dispensed on the proximal end of the core may be hardened by curing. In some embodiments, the conductive ink may be a silver-silver chloride ink.

[0013] The wicking member may be made in part of a porous polymeric material. In some embodiments, the wicking member may be made in part of high density polyethylene (HDPE). In other embodiments, the wicking member may be made in part of natural fibers. The wicking member may include pores having a size between about 15 μm and about 150 μm.

[0014] The wicking member may be treated with a surfactant such that at least a surface of the wicking member may be covered with the surfactant. The surfactant may be configured to increase the hydrophilicity of the wicking member.

[0015] The sensor device may further include an aeration port defined along at least one of the bottom side and the lateral side of the sample container. In some embodiments, the hydrophobic breathable membrane may cover the aeration port. The aeration port and the hydrophobic breathable membrane may be configured to allow air to enter the sample chamber through the aeration port and the hydrophobic breathable membrane to aerate the sample chamber.

[0016] When the reference sensor component is implemented as a container cover, the container cover can be configured to be removably coupled to the sample container via an attachment connector, and the additional hydrophobic breathable membrane can cover at least a portion of the underside of the container cover. In these embodiments, when the container cover is screwed onto the sample container via an attachment connector (e.g., a threaded connector), an air flow path can be formed. The air flow path can include an aeration port, a hydrophobic breathable membrane, a sample chamber, an additional hydrophobic breathable membrane, and an air gap defined between the container cover and the sample container along the attachment connector.

[0017] In some embodiments, the solution property measured by the sensor device is pH, and the active electrode material of the active sensor component can be made in part of a pH sensitive material. In some embodiments, the pH sensitive material includes at least one of silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, and zirconium dioxide.

[0018] In other embodiments, the measured solution property can be the redox potential (ORP) of the sample, and the active electrode material of the active sensor component can be made in part of a redox sensitive material. The redox sensitive material can include at least one of: platinum, gold, silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, and zirconium dioxide. In these and other embodiments, the parameter analyzer can be or include at least a portion of a voltmeter and a multimeter.

[0019] A reference sensor component is also disclosed. The reference sensor component can be configured to be removably coupled to a sample container configured to receive a sample. The reference sensor component can also include a reference conduit including a reference conduit cavity. In some embodiments, the reference sensor component can be implemented as a container cap. The reference conduit can extend from the underside of the container cap.

[0020] The reference sensor component may include a wicking component disposed in a portion of the reference catheter lumen, the wicking component having a core distal end and a core proximal end. At least a portion of the wicking component may be configured to contact the sample fluid when the container cap is coupled to the sample container so that the wicking component draws at least some of the sample in the direction of the core proximal end. The reference sensor component may also include a reference electrode material disposed at the core proximal end. The reference electrode material may be configured to exhibit a substantially stable electrode potential compared to an active electrode electrically connected to the reference electrode material.

[0021] The reference sensor component can be partially made of a non-conductive material. When the reference sensor component is implemented as a container lid, the container lid can be partially made of a non-conductive material. In a specific embodiment, the container lid can be partially made of a transparent non-conductive material so that at least a portion of the wicking component can be visible through the container lid.

[0022] In some embodiments, the reference electrode material may be a conductive ink applied or dispensed on the proximal end of the core. The conductive ink applied or dispensed on the proximal end of the core may be hardened by curing. In some embodiments, the conductive ink may be a silver-silver chloride ink.

[0023] The wicking member may be made in part from a porous polymeric material.In other embodiments, the wicking member may be made in part from natural fibers.The wicking member may include pores having a size between about 15 μm and about 150 μm.

[0024] The wicking member may be treated with a surfactant such that at least a surface of the wicking member is covered with the surfactant. The surfactant may be configured to increase the hydrophilicity of the wicking member.

[0025] A method of measuring a solution property of a sample is also disclosed. The method may include: filling a sample chamber of a sample container with a sample including an infectious agent; attaching a reference sensor component (e.g., implemented as a container cap) to the sample container; electrically coupling a reference electrode material of the reference sensor component to a parameter analyzer and electrically coupling the parameter analyzer to an active sensor component including an active electrode material, and determining the solution property of the sample based on a potential difference measured between the active electrode material and the reference electrode material.

[0026] At least a portion of the active electrode material may extend into the sample chamber and contact the sample fluid. The reference sensor component may include a reference catheter including a reference catheter lumen, a reference catheter first opening, and a reference catheter second opening. The reference catheter lumen may be partially filled by a wicking component extending through the reference catheter lumen, the wicking component having a wick distal end and a wick proximal end.

[0027] At least a portion of the wicking member can be in contact with the sample fluid within the sample chamber.The wicking member can draw at least some of the sample in the direction of the proximal end of the wick (eg, by capillary action).

[0028] The reference electrode material may be disposed at the proximal end of the core. The reference electrode material may be a conductive ink applied or dispensed on the proximal end of the core. The conductive ink may be hardened by curing. In some embodiments, the conductive ink may be a silver-silver chloride ink.

[0029] The method may also include pumping air into the sample chamber through an aeration port defined along at least one of a bottom side and a lateral side of the sample container and a hydrophobic, breathable membrane covering the aeration port, wherein the air pumped into the sample chamber aerates the sample. The air pumped into the sample chamber may exit the sample chamber through an additional breathable membrane covering at least a portion of an underside of the container cover and through an air gap defined between the container cover and the sample container along the attachment connector.

[0030] The step of determining the solution characteristics of the sample may include determining the pH of the sample. The active electrode material may be made in part of a pH sensitive material. In some embodiments, the pH sensitive material may include at least one of: silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, and zirconium dioxide.

[0031] In other embodiments, the step of determining the solution characteristic of the sample may include determining the redox potential (ORP) of the sample, and wherein the active electrode material is made in part of a redox sensitive material. The redox sensitive material may include at least one of platinum, gold, silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, and zirconium dioxide.

[0032] A method of manufacturing a reference sensor component is disclosed. The method may include providing a container cover configured to be removably coupled to a sample container configured to receive a sample. A reference conduit may extend from an underside of the container cover. The reference conduit may include a reference conduit cavity. The method may also include positioning a wicking component into the reference conduit cavity. The wicking component may include a wick distal end and a wick proximal end. The method may also include applying or dispensing a conductive ink on the wick proximal end and curing the conductive ink until the conductive ink hardens.

[0033] The method may further include applying or dispensing a volume of conductive ink between about 50 μL and 500 μL on the core proximal end. The conductive ink may be cured at a temperature above 100° C. The conductive ink may be cured for a period of about 60 minutes to about 180 minutes.

[0034] In some embodiments, the reference conduit can be tapered.The wicking member can be shaped such that the wicking member tapers from the wick proximal end to the wick distal end.

[0035] Another embodiment of a sensor device for measuring pH of a sample is disclosed herein. The sensor device may include: a sample container including a sample chamber configured to receive the sample; and a reference sensor component.

[0036] The reference sensor component may include a reference catheter including a reference catheter cavity, a reference catheter first opening, and a reference catheter second opening. In some embodiments, the reference catheter cavity may be at least partially filled with a reference buffer gel. A section of the reference catheter may extend into the sample chamber. The reference catheter second opening may be configured to allow the sample to contact the reference buffer gel fluid. The reference electrode may partially extend into the reference catheter cavity filled with the reference buffer gel.

[0037] The sensor device may further comprise an active sensor component comprising an active electrode housing extending into the sample chamber and an active electrode partially housed within the active electrode housing. The active electrode may comprise a sample contacting surface.

[0038] The active electrode may be disposed at a distal end of the active electrode housing.The active electrode housing may be configured to expose the sample contact surface such that the sample contact surface is in fluid communication with the sample.

[0039] The conductive contact layer can be coupled to the active electrode and positioned proximal to the active electrode within the active electrode housing. The conductive contact layer and the reference electrode can be electrically coupled to a voltmeter via a conductive connection. The pH of the sample can be measured based on the potential difference between the active electrode and the reference electrode.

[0040] The reference catheter may include a catheter wall. The catheter wall may be tapered from the reference catheter proximal end to the reference catheter distal end such that a first opening area of ​​the reference catheter first opening is greater than a second opening area of ​​the reference catheter second opening.

[0041] The reference electrode may include a reference electrode tip. When the reference electrode partially extends into the reference catheter lumen, the reference electrode tip may be positioned proximal to the reference catheter second opening such that a volume of reference buffer gel separates the reference electrode tip from the reference catheter second opening. The reference catheter lumen may be filled with about 100 μL to about 500 μL of reference buffer gel.

[0042] The reference electrode can be made in part of one or more metals. In some embodiments, the reference electrode can be made in part of platinum, stainless steel, or a combination thereof.

[0043] The active electrode can be made in part of a metal oxide. In some embodiments, the active electrode can be made in part of silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, zirconium dioxide, or a combination thereof.

[0044] The conductive contact layer may be partially made of one or more metals. The conductive contact layer may be partially made of aluminum, copper, platinum or a combination thereof.

[0045] In some embodiments, the reference buffer gel may be an agar gel formed from agar powder and a reference buffer solution. The concentration of agar powder in the agar gel may be about 1% (w / v%) to about 5% (w / v%).

[0046] The reference buffer solution may include potassium ferrocyanate (III), potassium ferrocyanate (II), potassium dihydrogen phosphate, disodium hydrogen phosphate, or a combination thereof. In other embodiments, the reference buffer solution may include potassium chloride.

[0047] The sensor device may include an aeration conduit. A section of the aeration conduit may extend into the sample chamber. The aeration conduit may be configured to aerate the sample in the sample container.

[0048] Another embodiment of a sensor device for measuring an oxidation reduction potential (ORP) of a sample is also disclosed.The sensor device may include a sample container including a sample chamber configured to receive the sample and a reference sensor component.

[0049] The reference sensor component may include a reference catheter including a reference catheter lumen, a reference catheter first opening, and a reference catheter second opening. The reference catheter lumen may be at least partially filled with a reference buffer gel. A section of the reference catheter may extend into the sample chamber.

[0050] The reference conduit second opening may be configured to allow the sample to contact the reference buffer gel fluid.The reference electrode may extend partially into the reference conduit lumen filled with the reference buffer gel.

[0051] The sensor device may also include an active sensor component. The active sensor component may include an active electrode housing extending into the sample chamber and an active electrode partially contained within the active electrode housing. The active electrode may include a sample contact surface. The active electrode may be disposed at a distal end of the active electrode housing and the active electrode housing may be configured to expose the sample contact surface so that the sample contact surface is in fluid communication with the sample. The active electrode and the reference electrode may be coupled to a voltmeter via a conductive connector. The ORP of the sample may be measured based on a potential difference between the active electrode and the reference electrode.

[0052] The reference catheter may include a catheter wall. The catheter wall may be tapered from the reference catheter proximal end to the reference catheter distal end such that a first opening area of ​​the reference catheter first opening is greater than a second opening area of ​​the reference catheter second opening. The reference catheter lumen may be filled with about 100 μL to about 500 μL of the reference buffer gel.

[0053] The reference electrode may include a reference electrode tip. When the reference electrode partially extends into the reference catheter lumen, the reference electrode tip may be positioned proximal to the reference catheter second opening such that a volume of reference buffer gel separates the reference electrode tip from the reference catheter second opening.

[0054] The reference electrode can be made in part of one or more metals. In some embodiments, the reference electrode can be made in part of platinum, stainless steel, or a combination thereof.

[0055] The active electrode can be made in part of one or more metals, one or more metal oxides, or a combination thereof. For example, the active electrode can be made in part of platinum, gold, silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, zirconium dioxide, or a combination thereof.

[0056] The reference buffer gel may be an agar gel formed of agar powder and a reference buffer solution. The concentration of agar powder in the agar gel may be about 1% (w / v%) to about 5% (w / v%).

[0057] The reference buffer solution may include potassium ferrocyanate (III), potassium ferrocyanate (II), potassium dihydrogen phosphate, disodium hydrogen phosphate, or a combination thereof. In other embodiments, the reference buffer solution may include potassium chloride.

[0058] The sensor device may further include an aeration conduit or an aeration port. A section of the aeration conduit may extend into the sample chamber. The aeration conduit may be configured to aerate the sample in the sample container.

[0059] Another embodiment of a sensor device for measuring pH of a sample is also disclosed. The sensor device includes: a sample container including a sample chamber configured to receive the sample; and a reference sensor component.

[0060] The reference sensor component may include a reference catheter including: a reference catheter proximal end defining a reference catheter first opening; a reference catheter distal end defining a reference catheter second opening; and a reference catheter lumen between the reference catheter proximal end and the reference catheter distal end.

[0061] The reference conduit lumen may be at least partially filled with a reference buffer solution. A section of the reference conduit may extend into the sample chamber. The reference electrode may partially extend into the reference conduit lumen filled with the reference buffer solution.

[0062] The ion exchange membrane may be coupled to the reference conduit distal end and configured to block the reference conduit second opening. The ion exchange membrane may be configured to prevent the sample from mixing with the reference buffer solution but allow ions to traverse the ion exchange membrane.

[0063] The sensor device may further include an active sensor component. The active sensor component may include an active electrode housing extending into the sample chamber and an active electrode partially housed within the active electrode housing.

[0064] The active electrode may include a sample contact surface. The active electrode may be disposed at a distal end of an active electrode housing and the active electrode housing may be configured to expose the sample contact surface such that the sample contact surface is in fluid communication with the sample.

[0065] The conductive contact layer can be coupled to the active electrode and positioned proximal to the active electrode within the active electrode housing. The conductive contact layer and the reference electrode can be electrically coupled to a voltmeter through a conductive connection, and wherein the pH of the sample is measured based on a potential difference between the active electrode and the reference electrode.

[0066] The reference catheter may include a catheter wall. The catheter wall may be tapered from the reference catheter proximal end to the reference catheter distal end such that a first opening area of ​​the reference catheter first opening is greater than a second opening area of ​​the reference catheter second opening. The reference catheter lumen may be filled with about 100 μL to about 500 μL of a reference buffer solution.

[0067] The reference electrode may include a reference electrode tip. When the reference electrode partially extends into the reference catheter lumen, the reference electrode tip may be positioned proximal to the ion exchange membrane such that a volume of reference buffer solution separates the reference electrode tip from the ion exchange membrane.

[0068] In some embodiments, the ion exchange membrane can be a perfluorosulfonated ionomer membrane. For example, the perfluorosulfonated ionomer membrane can be a Nafion® membrane. The ion exchange membrane can have a thickness of about 25 μm to about 180 μm.

[0069] The reference electrode may be partially made of one or more metals. For example, the reference electrode is partially made of platinum, stainless steel, or a combination thereof.

[0070] The active electrode can be made in part of a metal oxide. For example, the active electrode can be made in part of silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, zirconium dioxide, or a combination thereof.

[0071] The conductive contact layer may be partially made of one or more metals. In some embodiments, the conductive contact layer may be partially made of aluminum, copper, platinum, or a combination thereof.

[0072] The reference buffer solution may include potassium ferrocyanate (III), potassium ferrocyanate (II), potassium dihydrogen phosphate, disodium hydrogen phosphate, or a combination thereof. In other embodiments, the reference buffer solution may include potassium chloride.

[0073] The sensor device may further include an aeration conduit, a section of which extends into the sample chamber, and wherein the aeration conduit is configured to aerate the sample in the sample container.

[0074] The reference sensor component may be removably coupled to the sample container such that the reference sensor component is detachable from the sample container.

[0075] Another embodiment of a sensor device for measuring an oxidation-reduction potential (ORP) of a sample is disclosed herein. The sensor device includes a sample container including a sample chamber configured to receive the sample; and a reference sensor component.

[0076] The reference sensor component may include a reference catheter, the reference catheter including: a reference catheter proximal end defining a first opening of the reference catheter; a reference catheter distal end defining a second opening of the reference catheter; and a reference catheter lumen between the reference catheter proximal end and the reference catheter distal end. The reference catheter lumen may be at least partially filled with a reference buffer solution. A section of the reference catheter may extend into the sample chamber. The sensor device may also include a reference electrode, the reference electrode partially extending into the reference catheter lumen filled with the reference buffer solution.

[0077] The ion exchange membrane may be coupled to the reference conduit distal end and configured to block the reference conduit second opening. The ion exchange membrane may be configured to prevent the sample from mixing with the reference buffer solution but allow ions to traverse the ion exchange membrane.

[0078] Furthermore, the sensor device may include an active sensor component. The active sensor component may include an active electrode housing extending into the sample chamber and an active electrode partially accommodated within the active electrode housing.

[0079] The active electrode may include a sample contact surface. The active electrode may be disposed at a distal end of an active electrode housing, and the active electrode housing is configured to expose the sample contact surface such that the sample contact surface is in fluid communication with the sample.

[0080] The active electrode and the reference electrode may be electrically coupled to a voltmeter via a conductive connection.The ORP of the sample may be measured based on the potential difference between the active electrode and the reference electrode.

[0081] The reference catheter may include a catheter wall. In some embodiments, the catheter wall may be tapered from the reference catheter proximal end to the reference catheter distal end such that a first opening area of ​​the reference catheter first opening is greater than a second opening area of ​​the reference catheter second opening. The reference catheter lumen may be filled with about 100 μL to about 500 μL of a reference buffer solution.

[0082] The reference electrode may include a reference electrode tip. When the reference electrode partially extends into the reference catheter lumen, the reference electrode tip may be positioned proximal to the ion exchange membrane such that a volume of reference buffer solution separates the reference electrode tip from the ion exchange membrane.

[0083] The reference electrode can be made in part of one or more metals. For example, the reference electrode can be made in part of platinum, stainless steel, or a combination thereof.

[0084] The active electrode can be made in part of one or more metals, one or more metal oxides, or a combination thereof. For example, the active electrode can be made in part of platinum, gold, silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, zirconium dioxide, or a combination thereof.

[0085] In some embodiments, the reference buffer solution may include potassium ferrocyanate (III), potassium ferrocyanate (II), potassium dihydrogen phosphate, disodium hydrogen phosphate, or a combination thereof. In other embodiments, the reference buffer solution may include potassium chloride.

[0086] As previously discussed, the ion exchange membrane can be coupled to the distal end of the reference catheter and configured to block the second opening of the reference catheter. In some embodiments, the ion exchange membrane can be a perfluorosulfonated ionomer membrane. For example, the perfluorosulfonated ionomer membrane can be a Nafion® membrane. The thickness of the ion exchange membrane can be about 25 μm to about 180 μm.

[0087] The sensor device may further include an aeration conduit. A section of the aeration conduit may extend into the sample chamber. The aeration conduit may be configured to aerate the sample in the sample container.

[0088] The reference sensor component may be removably coupled to the sample container such that the reference sensor component is detachable from the sample container. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1A An embodiment of a sensor device for measuring the pH of a sample is shown.

[0090] Figure 1B An embodiment of a sensor device for measuring the ORP of a sample is shown.

[0091] Figure 1C Another embodiment of a sensor device for measuring the pH of a sample is shown.

[0092] Figure 1D Another embodiment of a sensor device for measuring the ORP of a sample is shown.

[0093] Figure 2 A top perspective view of an embodiment of a sensor device is shown.

[0094] Figure 3A A side cross-sectional view of an embodiment of a reference sensor component is shown.

[0095] Figure 3B A side cross-sectional view of another embodiment of a reference sensor component is shown.

[0096] Figure 4 Schematic diagram showing the active and reference electrodes of a sensor device connected to a high impedance voltmeter.

[0097] Figure 5A Shown are ORP measurements made using a traditional KCl reference solution and a stainless steel reference electrode in a reference buffer gel after adding a high potential ORP solution.

[0098] Figure 5B Shown are the results of pH measurements made using a conventional KCl reference solution and a platinum reference electrode in a reference buffer gel after exchanging a pH 7 solution with a pH 4 solution.

[0099] Figure 6 Shown are ORP measurements of E. coli bacteria grown in 1% agar gel buffer, 5% agar gel buffer, and traditional KCl reference solution using a reference electrode.

[0100] Fig. 7AShown are some ORP measurements taken when a conventional ORP buffer solution is replaced by a high potential ORP solution and then switched back to a conventional ORP buffer solution.

[0101] Figure 7B ORP measurement results for E. coli bacterial growth using a conventional ORP probe are shown, along with the potential difference between a reference sensor component with an ion exchange membrane and a KCl reference solution during the measurement.

[0102] Figure 8 Another embodiment of a sensor device for measuring a solution property of a sample is shown.

[0103] Fig.9A A side cross-sectional view of another embodiment of a sensor device is shown.

[0104] Fig. 9B An embodiment of a reference sensor component is shown.

[0105] Fig.10 Shown is the change in oxidation reduction potential (ORP) of three aliquots of a sample measured over time using three different sensor settings.

[0106] Fig.11 Shown are the results of cell counts performed on plated bacterial colonies of output samples including various E. coli strains.

[0107] Fig.12 The effect of aeration on the growth rate of two samples including Pseudomonas aeruginosa bacteria is shown.

[0108] Fig.13 Shown is the effect of aeration on the preparation time of two 0.5 McFarland bacteria samples using the sensor device. Detailed Description

[0109] Variations of the devices, systems, and methods described herein are best understood from the detailed description when read in conjunction with the accompanying drawings. It is emphasized that, in accordance with common practice, various features of the drawings may not be drawn to scale. The sizes of certain features have been exaggerated or reduced for clarity, and not all features may be visible or labeled in every figure. The drawings are for illustrative purposes only and are not intended to define or limit the scope of the claims to what is shown.

[0110] Figure 1A An embodiment of a sensor device 100 for measuring the pH of a sample 102 is shown. Figure 1A A side cross-sectional view of sensor device 100 is shown.

[0111] The sensor device 100 may include a sample container 104 having a sample chamber 106 configured to receive a sample 102. The sample 102 may include at least one of: a sample obtained from a patient or subject, a biological sample, an environmental sample, and a food sample. The sample 102 obtained from a patient or subject may include at least one of a bodily fluid of the patient or subject and a swab obtained from the patient or subject.

[0112] In some embodiments, the patient or subject can be a human patient or subject. In other embodiments, the patient or subject can be a non-human animal patient or subject.

[0113] In some embodiments, bodily fluids may include blood, urine, serum, plasma, saliva, sputum, semen, breast milk, joint fluid, spinal fluid (such as cerebrospinal fluid), wound material, mucus, fluid associated with stool, vaginal secretions, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, amniotic fluid, or combinations thereof.

[0114] In these and other embodiments, the swab obtained from the patient or subject can include a wound swab, a rectal swab, a vaginal swab, resuspended instances of the foregoing, or combinations thereof.

[0115] In all such embodiments, sample 102 may include a variety of microorganisms or infectious agents. The devices, systems, and methods disclosed herein may be used to assay sample 102 for microbial growth or lack thereof as part of a microbial quantification procedure or an antibiotic susceptibility testing (AST) procedure.

[0116] In certain embodiments, sample 102 may include or refer to a bacterial culture derived from at least one of: a sample obtained from a patient or subject, a biological sample, an environmental sample, and a food sample. For example, sample 102 may include or refer to a bacterial culture or a resuspended bacterial culture derived from a bodily fluid or swab obtained from a patient or subject. As a more specific example, sample 102 may include a bacterial culture or a resuspended bacterial culture derived from a bodily fluid or swab obtained from a patient or subject that tested positive for microbial growth.

[0117] More specifically, sample 102 may include a bacterial culture derived from blood obtained from a patient or subject that is positive for microbial growth. In some embodiments, sample 102 may be or refer to a positive blood culture. For the purposes of this disclosure, a positive blood culture may be a bacterial culture derived from blood drawn from a patient or subject that is positive for bacterial growth. For example, a patient may exhibit symptoms of sepsis (e.g., high fever, chills, etc.), and blood (e.g., 5 mL to 10 mL) may be drawn from the patient and then transferred to a commercial blood culture container or vessel containing a bacterial growth medium (e.g., 30 mL to 40 mL of growth medium). The blood culture container or vessel may then be incubated at 35°C ± 2°C to allow bacterial growth. If the patient's blood is contaminated with bacteria, the bacteria will replicate in the container or vessel. The blood culture system or device may then be used to monitor bacterial growth (such as by monitoring the CO2 production of bacteria in the container or vessel), and the system or device may determine the sample as "positive" for testing bacterial growth when a critical CO2 threshold is met. Depending on the pathogen type and growth rate, blood cultures can become positive between 7 hours and 3 days. Such "positive blood cultures" can then be used for additional downstream testing, such as using any of the devices, systems, and methods disclosed herein.

[0118] In additional embodiments, the sample 102 may include an environmental sample obtained from a stream, river, lake, ocean, contaminated site, quarantine area, emergency area, or a combination thereof. In other embodiments, the sample 102 may include a food sample obtained from a food preparation facility, dining facility, waste facility, or a combination thereof.

[0119] In some embodiments, the aqueous growth medium may be added to the sample 102 prior to introducing it into the sample container 104. In other embodiments, the aqueous growth medium may be added to the sample 102 once the sample 102 has been injected, delivered, or otherwise introduced into the sample container 104.

[0120] In one embodiment, the aqueous growth medium can be Miller-Hinton broth (MHG) supplemented with glucose. In other embodiments, the aqueous growth medium can be a solution comprising: bacterial tryptone, tryptic soy digest, yeast extract, beef extract, cation-adjusted Miller-Hinton broth (CAMHB), starch, casein acid hydrolysate, calcium chloride, magnesium chloride, sodium chloride, blood or lysed blood (including lysed horse blood (LHB)), CAMHB-LHB, glucose or other carbohydrates, or combinations thereof.

[0121] The microorganisms or infectious agents that can be assayed using the devices, methods, and systems disclosed herein can be any metabolic unicellular or multicellular organisms, including bacteria and fungi. In particular embodiments, the microorganisms or infectious agents can be bacteria selected from the following genera: Acinetobacter, Acetobacter, Actinomycetes, Aeromonas, Aeromonas, Agrobacterium, Atoplasma, Azorhizobium, Azotobacter, Bacillus, Bacteroides, Bartonella, Bordetella, Borrelia, Brucella, Burkholderia, Sheathbacter, Campylobacter, Chlamydia, Clostridium, Citrobacter, Clostridium, Corynebacterium, Coxiella, Ehrlichia, Enterobacter, Enterococcus, Escherichia coli, Francisella, Fusobacterium, Gardnerella, Haemophilus, Helicobacter pylori, Klebsiella, Lactobacillus, In some embodiments, the microorganism or infectious agent can be one or more fungi selected from the genus Candida, the genus Cryptococcus, the genus Cryptococcus, the genus Shewanella, the genus Shigella, the genus Spirillum, the genus Staphylococcus, the genus Stenotrophomonas, the genus Streptococcus, the genus Streptococcus, the genus Treponema, the genus Vibrio, the genus Wolbachia, the genus Yersinia or a combination thereof. In other embodiments, the microorganism or infectious agent can be one or more fungi selected from the genus Candida, the genus Cryptococcus or the genus Mycoplasma.

[0122] Other specific bacteria that can be assayed using the methods and systems disclosed herein can include: Staphylococcus aureus, Staphylococcus aeruginosa, coagulase-negative Staphylococci (including but not limited to Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus capitis, undifferentiated), Enterococcus faecalis, Enterococcus faecium (including but not limited to Enterococcus faecalis and other undifferentiated Enterococci, excluding Enterococcus faecalis), Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus spp. (including but not limited to Streptococcus mitis, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus spp.) Streptococcus, Streptococcus pneumoniae, undifferentiated), Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella (including but not limited to Klebsiella pneumoniae, Klebsiella oxytoca, undifferentiated), Escherichia coli, Enterobacter (including but not limited to Enterobacter cloacae, Enterobacter aerogenes, undifferentiated), Proteus (including but not limited to Proteus mirabilis, Proteus vulgaris, undifferentiated), Citrobacter (including but not limited to Citrobacter freundii, Citrobacter cohnii, undifferentiated), Serratia marcescens, Candida albicans, Candida glabrata, and Candida tropicalis.

[0123] Other more specific bacteria that can be assayed may include Acinetobacter baumannii, Actinomyces, Actinomyces, Actinomyces (including but not limited to Actinomyces israelii and Actinomyces naeslundii), Aeromonas (including but not limited to Aeromonas hydrophila, Aeromonas veronii biotype sobria (Aeromonas sobria) and Aeromonas caviae), Anaplasma phagocytophilum, Bacillus alcaligenes, Actinobacillus actinomycetemcomitans, Bacillus (including but not limited to Bacillus anthracis, Bacillus cereus, Bacillus subtilis, Bacillus thuringiensis and Bacillus stearothermophilus), Bacteroides (including but not limited to Bacteroides fragilis), Bartonella (including but not limited to Bartonella bacilliformis and Bartonella henselae), Bifidobacterium, Bordetella (including but not limited to Pertussis cough, Bordetella parapertussis and Bordetella bronchiseptica), spirochetes (including but not limited to recurrent spirochetes and Borrelia burgdorferi), Brucella (including but not limited to Brucella abortus, Brucella canis, Brucella meyeri and Brucella suis), Burkholderia (including but not limited to Burkholderia pseudomallei and Burkholderia cepacia), Campylobacter (including but not limited to Campylobacter jejuni, Campylobacter coli, Campylobacter larii and Campylobacter fetus), Capnocytophaga, Cardiomycobacterium, Chlamydia trachomatis, Chlamydia pneumoniae, Chlamydia psittaci, Citrobacter rodentium, Coxiella burnetii, Corynebacterium (including but not limited to Corynebacterium diphtheriae, Corynebacterium jejuni and Corynebacterium), Fusobacterium Bacillus (including but not limited to Clostridium perfringens, Clostridium difficile, Clostridium botulinum and Clostridium tetani), Eikenella, Enterobacter (including but not limited to Enterobacter aerogenes, Enterobacter agglomerans, Enterobacter cloacae and Escherichia coli, including opportunistic Escherichia coli, including but not limited to enterotoxigenic Escherichia coli, enteroinvasive Escherichia coli, enteropathogenic Escherichia coli, enteroaggregative Escherichia coli and uropathogenic Escherichia coli), Enterococcus (including but not limited to Enterococcus faecalis and Enterococcus faecium), Ehrlichia (including but not limited to Ehrlichia chaffeensis and Ehrlichia canis), Erysipelothrix rhusiopathiae, Eubacterium tularensis, Francisella tularensis, Fusobacterium nucleatum, Gardnerella vaginalis, Gemini coccus morbilli, Haemophilus species ( Including but not limited to Haemophilus influenzae, Haemophilus ducreyi, Haemophilus aegypti, Haemophilus parainfluenzae, Haemophilus haemolyticus and Haemophilus parahaemolyticus, Helicobacter pylori (including but not limited to Helicobacter pylori, Helicobacter homosexualus and Helicobacter fennarum), Kingella, Klebsiella (including but not limited to Klebsiella pneumoniae, Bacillus carnosus and Klebsiella oxytoca), Lactobacillus, Listeria monocytogenes, Leptospira interrogans, Legionella pneumophila, Leptospira interrogans, Peptostreptococcus, Moraxella catarrhalis, Morganella, Mobiluncus, Micrococcus, Mycobacterium (including but not limited to Mycobacterium leprae, Mycobacterium tuberculosis, Mycobacterium intracellulare, Mycobacterium avium, Mycobacterium bovis and Mycobacterium marinum),Mycoplasma (including but not limited to Mycoplasma pneumoniae, Mycoplasma hominis and Mycoplasma genitalium), Nocardia (including but not limited to Nocardia asteroides, Nocardia gelsenkii and Nocardia brasiliensis), Neisseria (including but not limited to Neisseria gonorrhoeae and Neisseria meningitidis), Pasteurella multocida, Shigella-like Pseudomonas, Prevotella, Porphyromonas, Prevotella melaninogenicus, Proteus (including but not limited to Proteus vulgaris and Proteus mirabilis), Providencia (including but not limited to Providencia alcaligenes, Providencia rettgeri and Providencia stuartii), Pseudomonas aeruginosa, Propionibacterium acnes, Rhodococcus equi, Rickettsia (including but not limited to Rickettsia rickettsii, Rickettsia erythrae, Rickettsia prowazekii, Orientia tsutsugamushi (formerly known as Rickettsia tsutsugamushi), Rickettsia typhi), Rhodococcus, Stenotrophomonas maltophilia, Salmonella (including but not limited to Salmonella enterica, Salmonella typhi, Salmonella paratyphi, Salmonella enteritidis, Salmonella choleraesuis and Salmonella typhimurium), Serratia (including but not limited to Serratia massiliense and Serratia liquidus), Shigella (including but not limited to Shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei), Staphylococcus (including but not limited to Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus saprophyticus), Streptococcus (including but not limited to Streptococcus pneumoniae (e.g., chloramphenicol-resistant serotype 4 pneumoniae, spectinomycin-resistant serotype 6B pneumoniae, streptomycin-resistant serotype 9V pneumoniae, erythromycin-resistant serotype 14 pneumoniae, optoxin-resistant serotype 14 pneumoniae, rifampicin-resistant serotype 18C pneumoniae, tetracycline-resistant serotype 19F pneumoniae, penicillin-resistant serotype 19F pneumoniae, and trimethoprim-resistant serotype 23F pneumoniae, chloramphenicol-resistant serotype 4 pneumoniae, spectinomycin-resistant serotype 6B pneumoniae, streptomycin-resistant serotype 9V pneumoniae, optoxin-resistant serotype 14 pneumoniae, rifampicin-resistant serotype 18C pneumoniae Streptococcus pneumoniae, penicillin-resistant serotype 19F Streptococcus pneumoniae, or trimethoprim-resistant serotype 23F Streptococcus pneumoniae), Streptococcus agalactiae, Streptococcus mutans, Streptococcus pyogenes, Group A Streptococcus, Streptococcus pyogenes, Group B Streptococcus, Streptococcus agalactiae, Group C Streptococcus, Streptococcus anginosus, Streptococcus equisimilis, Group D Streptococcus, Streptococcus bovis, Group F Streptococcus, Streptococcus anginosus, and Group G Streptococcus), Spirochete, Streptobacillus moniliformis, Treponema (including but not limited to Treponema pallidum, Treponema tenuissima, Treponema pallidum, and Treponema pallidum, systemic bacteria, Ureaplasma urealyticum, Veillonella, Vibrio (including but not limited to Vibrio cholerae, Vibrio parahemolyticus, Vibrio vulnificus, Vibrio parahaemolyticus),Vibrio vulnificus, Vibrio alginolyticus, Vibrio simulans, Vibrio hollis, Vibrio fluvii, Vibrio mechnikoffi, Vibrio marinum, and Vibrio freundii), Yersinia (including but not limited to Yersinia enterocolitica, Yersinia pestis, and Yersinia pseudotuberculosis), and Xanthomonas, etc.

[0124] In addition, other microorganisms or infectious agents that can be assayed using the methods and systems disclosed herein may include fungi or molds, including but not limited to Candida (including but not limited to Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis and Candida krusei), Aspergillus (including but not limited to Aspergillus fumigatus, Aspergillus flavus, Aspergillus clavatus), Cryptococcus (including but not limited to Cryptococcus neoformans, Cryptococcus gattii, Cryptococcus laurentii and Cryptococcus albicans), Fusarium (including but not limited to Fusarium oxysporum, Fusarium solani, Fusarium pseudoverticillium and Fusarium lamellifolium), Rhizopus oryzae, Penicillium marneffei, Coccidioides immitis and Blastomyces dermatitidis.

[0125] The sample container 104 may be made in part of an inert or non-conductive material. In some embodiments, the sample container 104 may include or be made in part of a polymeric material, a ceramic material, or glass, or a combination thereof. As a more specific example, the sample container 104 may include or be made in part of polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), or a combination thereof.

[0126] The sensor device 100 may also include a reference sensor component 108 and an active sensor component 122. The reference sensor component 108 may also include a reference catheter 110 including a reference catheter lumen 112, a reference catheter first opening 114, and a reference catheter second opening 116.

[0127] The reference catheter 110 may include a catheter wall 138, and the catheter wall 138 may be tapered from the reference catheter proximal end 140 to the reference catheter distal end 142. In one embodiment, the reference catheter 110 may be generally shaped as a cone or a frustoconical shape, and the reference catheter lumen 112 may also be generally shaped as a cone or a frustoconical shape. In other embodiments, the reference catheter 110 may be generally shaped as an elongated cone with a polygonal bottom. For example, the reference catheter 110 may be generally shaped as an elongated triangular pyramid, a quadrangular pyramid, or a pentagonal pyramid. In additional embodiments, the reference catheter 110 may be generally shaped as a cylinder with a generally cylindrical reference catheter lumen 112. In these embodiments, the reference catheter 110 may also have a tapered reference catheter distal end 142.

[0128] The reference conduit lumen 112 may be at least partially filled with a reference buffer gel 118. The reference conduit 110 may extend into the sample chamber 106 such that the reference conduit second opening 116 is configured to allow the sample 102 to be in fluid contact with the reference buffer gel 118 within the reference conduit lumen 112. For example, the reference conduit second opening 116 may allow the sample 102 to be in liquid-solid contact with the reference buffer gel 118. In this way, a salt bridge may be formed by a liquid-solid interface that acts as an interface of a salt bridge.

[0129] In one embodiment, the reference buffer gel 118 may be an agar gel formed by mixing agar powder with a reference buffer solution. In other embodiments, the reference buffer gel 118 may be a gel formed by mixing other types of polysaccharides with a reference buffer solution. As a more specific example, the agar powder used may be a commercially available agar powder, such as agar powder provided by Sigma-Aldrich, Inc. (e.g., Sigma-Aldrich TM Agar Powder05040) or agar powder provided by Thermo Fisher Scientific Inc. (e.g., Fisher Scientific™ Agar Powder, catalog number S14153).

[0130] The reference buffer solution may be an aqueous redox buffer solution. In one embodiment, the reference buffer solution may be an aqueous redox buffer solution comprising deionized water, potassium ferricyanide, monobasic phosphate, disodium hydrogen phosphate, or a combination thereof. For example, the reference buffer solution may be an aqueous redox buffer solution comprising deionized water (e.g., about 95% to 99%), potassium ferricyanide (III) (e.g., about 0.1% to 0.9%), potassium ferricyanide (II) (e.g., about 0.1% to 0.9%), monobasic potassium phosphate (e.g., less than about 0.5%), and disodium hydrogen phosphate (less than about 0.5%). As a more specific example, the reference buffer solution may be a 220 mV / pH 7 redox buffer solution (product code 51350060) provided by Mettler-Toledo AG.

[0131] In other embodiments, the reference buffer solution may be an aqueous redox buffer solution containing 3M KCl. As a more specific example, the reference buffer solution may be a 3M KCl redox buffer solution (material number 63056165) provided by Mettler-Toledo.

[0132] In one embodiment, the reference buffer gel 118 may include agar powder at a concentration of about 1% (w / v%, g / mL). In another embodiment, the reference buffer gel 118 may include agar powder at a concentration of about 5% (w / v%, g / mL). In some embodiments, the reference buffer gel 118 may include agar powder at a concentration of about 1% (w / v%, g / mL) to 5% (w / v%, g / mL). In other embodiments, the reference buffer gel 118 may include agar powder at a concentration of about 5% (w / v%, g / mL) to 10% (w / v%, g / mL).

[0133] The reference buffer gel 118 can be prepared by heating an aqueous reference buffer solution to above the boiling point of the aqueous reference buffer solution and stirring agar powder into the heated aqueous reference buffer solution. Once the agar powder is completely dissolved in the heated aqueous reference buffer solution, the hot gel slurry can be poured into the reference catheter lumen 112 and allowed to cool to room temperature. As the hot gel cools to room temperature within the reference catheter lumen 112, the reference buffer gel 118 can solidify.

[0134] In one embodiment, the reference catheter lumen 112 may be filled with about 100 μL of reference buffer gel 118. In another embodiment, the reference catheter lumen 112 may be filled with about 500 μL of reference buffer gel 118. In other embodiments, the reference catheter lumen 112 may be filled with about 100 μL to about 500 μL of reference buffer gel 118. In further embodiments, the reference catheter lumen 112 may be filled with about 500 μL to about 1 mL of reference buffer gel 118. The amount of reference buffer gel 118 may depend on the volume of the reference catheter lumen 112, the size of the reference catheter 110, the size of the sample container 104, or a combination thereof.

[0135] The reference sensor component 108 may also include a reference electrode 120 that extends into the reference catheter lumen 112 filled with the reference buffer gel 118. The reference electrode 120 may extend partially into the reference catheter lumen 112 filled with the reference buffer gel 118.

[0136] As a more specific example, the reference electrode 120 can include a reference electrode tip 144. When the reference electrode 120 partially extends into the reference catheter lumen 112 filled with the reference buffer gel 118, the reference electrode tip 144 can be positioned proximal to the reference catheter second opening 116. More specifically, a volume of the reference buffer gel 118 can separate the reference electrode tip 144 from the reference catheter second opening 116. The position of the reference electrode 120 within the reference catheter lumen 112 will be discussed in detail in the following sections.

[0137] The reference electrode 120 may be made in part of one or more metals. In one embodiment, the reference electrode 120 may be made in part of platinum (Pt), stainless steel, or a combination thereof. In other embodiments, the reference electrode 120 may be made in part of another type of conductive metal. For example, the reference electrode 120 may be a metal pin, a metal wire, or a rod inserted into the reference buffer gel 118 so that a section of the reference electrode 120 (e.g., the reference electrode tip 144 and a section of the reference electrode 120 proximal to the reference electrode tip 144) penetrates the reference buffer gel 118 and resides in the reference buffer gel 118.

[0138] An unexpected discovery made by the present application is that the reference buffer gel 118 slows diffusion across the solid-liquid interface created by the reference buffer gel 118 and the sample 102 and extends the amount of time that the reference sensor component 108 can serve as a viable reference cell for pH measurements.

[0139] The sensor device 100 may also include an active sensor component 122 including an active electrode housing 124 extending into a sample chamber 106 configured to receive the sample 102. The active sensor component 122 may also include an active electrode 126 at least partially housed in or surrounded by the active electrode housing 124.

[0140] The active electrode housing 124 may be made of an inert or non-conductive material. The active electrode housing 124 may include a polymeric material such as polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), ceramic, silicon dioxide (SiO2), or glass type, or a combination thereof.

[0141] The active electrode 126 may include a sample contact surface 128. The active electrode 126 may be disposed at an active component distal end 130. The active electrode housing 124 may be configured to expose the sample contact surface 128 so that the sample contact surface 128 is in fluid communication with the sample 102.

[0142] In some embodiments, the active electrode 126 may be partially made of a metal oxide. For example, the active electrode 126 may be partially made of silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), hafnium dioxide (HfO2), iridium dioxide (IrO2), ruthenium dioxide (RuO2), zirconium dioxide (ZrO2), or a combination thereof.

[0143] The active sensor component 122 may also include a conductive contact layer 132 coupled to and positioned proximal to the active electrode 126. The conductive contact layer 132 may also be housed within or encased by the active electrode housing 124.

[0144] The conductive contact layer 132 may be made in part of one or more metals. In some embodiments, the conductive contact layer 132 may be made in part of aluminum (Al), copper (Cu), platinum (Pt), or a combination thereof. The conductive contact layer 132 and the reference electrode 120 may be electrically coupled to the voltmeter 136 via a conductive connector 134 or a conductive trace. The conductive connector 134 may be made in part of a conductive material. In one embodiment, the conductive connector 134 may be a copper trace. For example, the conductive connector 134 may be electrodeposited copper, rolled annealed copper, high conductivity electrodeposited copper, or a combination thereof. In other embodiments, the conductive connector 134 may be made in part of silver or nickel.

[0145] In some embodiments, the voltmeter 136 can be a high impedance voltmeter. The conductive connection 134 can electrically couple the active electrode 126 (through the conductive contact layer 132) and the reference electrode 120 to the voltmeter 136. The pH of the sample 102 can be measured based on the potential difference between the active electrode 126 and the reference electrode 120.

[0146] The sensor device 100 may also include an aeration conduit 146. A section of the aeration conduit 146 may extend into the sample chamber 106 such that a lumen or cavity within the aeration conduit 146 is in fluid communication with the sample chamber 106. The aeration conduit 146 may be configured to aerate the sample 102 received within the sample container 104. Aerating the sample 102 may enhance the growth rate of the microorganisms within the sample 102 by increasing the oxygen supply to the microorganisms. In addition, aeration may also cause the microorganisms to detach from the inner wall of the sample container 104 so as to inhibit biofilm formation.

[0147] Figure 1B An embodiment of a sensor device 101 for measuring the oxidation-reduction potential (ORP) of a sample 102 is shown. Figure 1B A side cross-sectional view of sensor device 101 is shown.

[0148] The sensor device 101 may include a sample container 104 having a sample chamber 106 configured to receive a sample 102. The sample 102 may be a sample of a substance related to the sensor device 100 (e.g., Figure 1AThe same sample 102 discussed above (shown in FIG. 1 ) can include a variety of microorganisms or infectious agents. As part of a microbial quantification procedure or an antibiotic susceptibility testing (AST) procedure, the devices, systems, and methods disclosed herein can be used to assay the sample 102 for microbial growth or lack of microbial growth.

[0149] In some embodiments, the aqueous growth medium may be added to the sample 102 prior to introducing it into the sample container 104. In other embodiments, the aqueous growth medium may be added to the sample 102 once the sample 102 has been injected, delivered, or otherwise introduced into the sample container 104.

[0150] In one embodiment, the aqueous growth medium can be Miller-Hinton broth (MHG) supplemented with glucose. In other embodiments, the aqueous growth medium can be a solution comprising: bactotryptone, tryptic soy digest, yeast extract, beef extract, cation-adjusted Miller-Hinton broth (CAMHB), starch, acid hydrolysate of casein, calcium chloride, magnesium chloride, sodium chloride, blood or lysed blood (including lysed horse blood (LHB)), CAMHB-LHB, glucose or other carbohydrates, or combinations thereof.

[0151] The sample container 104 may be made in part of an inert or non-conductive material. In some embodiments, the sample container 104 may include or be made in part of a polymeric material, a ceramic material, or glass, or a combination thereof. As a more specific example, the sample container 104 may include or be made in part of a polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), or a combination thereof.

[0152] The sensor device 101 may further include a reference sensor component 108 and an active sensor component 122. The reference sensor component 108 may further include a reference catheter 110 including a reference catheter lumen 112, a reference catheter first opening 114, and a reference catheter second opening 116.

[0153] The reference catheter 110 may include a catheter wall 138. The catheter wall 138 may be tapered from the reference catheter proximal end 140 to the reference catheter distal end 142. In one embodiment, the reference catheter 110 may be generally shaped as a cone or a frustoconical shape, and the reference catheter lumen 112 may also be generally shaped as a cone or a frustoconical shape. In other embodiments, the reference catheter 110 may be generally shaped as an elongated cone with a polygonal bottom. For example, the reference catheter 110 may be generally shaped as an elongated triangular pyramid, a quadrangular pyramid, or a pentagonal pyramid. In additional embodiments, the reference catheter 110 may be generally shaped as a cylinder with a generally cylindrical reference catheter lumen 112. In these embodiments, the reference catheter 110 may also have a tapered reference catheter distal end 142.

[0154] The reference conduit lumen 112 may be at least partially filled with a reference buffer gel 118. The reference conduit 110 may extend into the sample chamber 106 such that the reference conduit second opening 116 is configured to allow the sample 102 to be in fluid contact with the reference buffer gel 118 within the reference conduit lumen 112. For example, the reference conduit second opening 116 may allow the sample 102 to be in liquid-solid contact with the reference buffer gel 118. In this way, a salt bridge may be formed by a liquid-solid interface that acts as an interface of a salt bridge.

[0155] In one embodiment, the reference buffer gel 118 may be an agar gel formed by mixing agar powder with a reference buffer solution. In other embodiments, the reference buffer gel 118 may be a gel formed by mixing other types of polysaccharides with a reference buffer solution. As a more specific example, the agar powder used may be a commercially available agar powder, such as agar powder provided by Sigma-Aldrich (e.g., Sigma-Aldrich™ Agar Powder 05040) or agar powder provided by Thermo Fisher Scientific (e.g., Fisher Fisher™ Agar Powder, catalog number S14153).

[0156] The reference buffer solution may be an aqueous redox buffer solution. In one embodiment, the reference buffer solution may be an aqueous redox buffer solution comprising deionized water, potassium ferricyanide, monobasic phosphate, disodium hydrogen phosphate, or a combination thereof. For example, the reference buffer solution may be an aqueous redox buffer solution comprising deionized water (e.g., about 95% to 99%), potassium ferricyanide (III) (e.g., about 0.1% to 0.9%), potassium ferricyanide (II) (e.g., about 0.1% to 0.9%), monobasic potassium phosphate (e.g., less than about 0.5%), and disodium hydrogen phosphate (less than about 0.5%). As a more specific example, the reference buffer solution may be a 220 mV / pH 7 redox buffer solution (product code 51350060) provided by Mettler-Toledo.

[0157] In other embodiments, the reference buffer solution may be an aqueous redox buffer solution including 3M KCl. As a more specific example, the reference buffer solution may be a 3M KCl redox buffer solution (material number 63056165) provided by Mettler-Toledo.

[0158] In one embodiment, the reference buffer gel 118 may include agar powder at a concentration of about 1% (w / v%, g / mL). In another embodiment, the reference buffer gel 118 may include agar powder at a concentration of about 5% (w / v%, g / mL). In some embodiments, the reference buffer gel 118 may include agar powder at a concentration of about 1% (w / v%, g / mL) to 5% (w / v%, g / mL). In other embodiments, the reference buffer gel 118 may include agar powder at a concentration of about 5% (w / v%, g / mL) to 10% (w / v%, g / mL).

[0159] The reference buffer gel 118 can be made by heating an aqueous reference buffer solution to above the boiling point of the aqueous reference buffer solution and stirring agar powder into the heated aqueous reference buffer solution. Once the agar powder is completely dissolved in the heated aqueous reference buffer solution, the hot gel slurry can be poured into the reference catheter lumen 112 and allowed to cool to room temperature. As the hot gel cools to room temperature within the reference catheter lumen 112, the reference buffer gel 118 can solidify.

[0160] In one embodiment, the reference catheter lumen 112 may be filled with about 100 μL of reference buffer gel 118. In another embodiment, the reference catheter lumen 112 may be filled with about 500 μL of reference buffer gel 118. In other embodiments, the reference catheter lumen 112 may be filled with about 100 μL to about 500 μL of reference buffer gel 118. In further embodiments, the reference catheter lumen 112 may be filled with about 500 μL to about 1 mL of reference buffer gel 118. The amount of reference buffer gel 118 may depend on the volume of the reference catheter lumen 112, the size of the reference catheter 110, the size of the sample container 104, or a combination thereof.

[0161] The reference sensor component 108 may also include a reference electrode 120 that extends into the reference catheter lumen 112 filled with the reference buffer gel 118. The reference electrode 120 may extend partially into the reference catheter lumen 112 filled with the reference buffer gel 118.

[0162] As a more specific example, the reference electrode 120 can include a reference electrode tip 144. When the reference electrode 120 partially extends into the reference catheter lumen 112 filled with the reference buffer gel 118, the reference electrode tip 144 can be positioned proximal to the reference catheter second opening 116. More specifically, a volume of the reference buffer gel 118 can separate the reference electrode tip 144 from the reference catheter second opening 116. The position of the reference electrode 120 within the reference catheter lumen 112 will be discussed in detail in the following sections.

[0163] The reference electrode 120 may be made in part of one or more metals. In one embodiment, the reference electrode 120 may be made in part of platinum (Pt), stainless steel, or a combination thereof. In other embodiments, the reference electrode 120 may be made in part of another type of conductive metal. For example, the reference electrode 120 may be a metal pin, a metal wire, or a rod inserted into the reference buffer gel 118 so that a section of the reference electrode 120 (e.g., the reference electrode tip 144 and a section of the reference electrode 120 proximal to the reference electrode tip 144) penetrates the reference buffer gel 118 and resides in the reference buffer gel 118.

[0164] An unexpected discovery made by the present application is that the reference buffer gel 118 slows diffusion across the solid-liquid interface created by the reference buffer gel 118 and the sample 102 and extends the amount of time that the reference sensor component 108 can serve as a viable reference cell for ORP measurements.

[0165] The sensor device 101 may also include an active sensor component 122 including an active electrode housing 124 extending into a sample chamber 106 configured to receive the sample 102. The active sensor component 122 may also include an active electrode 148 at least partially housed in or surrounded by the active electrode housing 124.

[0166] The active electrode housing 124 may be made of an inert or non-conductive material. The active electrode housing 124 may include a polymeric material such as polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), ceramic, silicon dioxide (SiO2) or glass types, or combinations thereof.

[0167] The active electrode 148 may include a sample contact surface 128. The active electrode 148 may be disposed at the active component distal end 130. The active electrode housing 124 may be configured to expose the sample contact surface 128 so that the sample contact surface 128 is in fluid communication with the sample 102.

[0168] In some embodiments, the active electrode 148 may be partially made of one or more metals, one or more metal oxides, or a combination thereof. For example, the active electrode 148 may be partially made of platinum (Pt), gold (Au), a redox-sensitive metal oxide, or a combination thereof. In some embodiments, the redox-sensitive metal oxide may include silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), hafnium dioxide (HfO2), iridium dioxide (IrO2), ruthenium dioxide (RuO2), zirconium dioxide (ZrO2), or a combination thereof.

[0169] The active electrode 148 and the reference electrode 120 can be electrically coupled to the voltmeter 136 via a conductive connector 134 or conductive trace. The conductive connector 134 can be made in part of a conductive material. In one embodiment, the conductive connector 134 can be a copper trace. For example, the conductive connector 134 can be electrodeposited copper, rolled annealed copper, high ductility electrodeposited copper, or a combination thereof. In other embodiments, the conductive connector 134 can be made in part of silver or nickel.

[0170] In some embodiments, the voltmeter 136 may be a high impedance voltmeter. The ORP of the sample 102 may be measured based on the potential difference between the active electrode 148 and the reference electrode 120 .

[0171] The sensor device 101 may also include an aeration conduit 146. A section of the aeration conduit 146 may extend into the sample chamber 106 such that a lumen or cavity within the aeration conduit 146 is in fluid communication with the sample chamber 106. The aeration conduit 146 may be configured to aerate the sample 102 received within the sample container 104. Aerating the sample 102 may enhance the growth rate of the microorganisms within the sample 102 by increasing the oxygen supply to the microorganisms. In addition, aeration may also cause the microorganisms to detach from the inner wall of the sample container 104 so as to inhibit biofilm formation.

[0172] Figure 1C Another embodiment of a sensor device 103 for measuring the pH of a sample 102 is shown. Figure 1C A side cross-sectional view of sensor device 103 is shown.

[0173] The sensor device 103 may include a sample container 104 having a sample chamber 106 configured to receive a sample 102. The sample 102 may be a sample of a sensor device 100 (e.g., Figure 1A ) and sensor device 101 (as shown Figure 1BThe same sample 102 discussed above (shown in FIG. 1 ) can be used to measure the sample 102 for microbial growth or lack thereof as part of a microbial quantification procedure or an antibiotic susceptibility testing (AST) procedure. The sample 102 can include a variety of microorganisms or infectious agents. The devices, systems, and methods disclosed herein can be used to measure the sample 102 for microbial growth or lack thereof as part of a microbial quantification procedure or an antibiotic susceptibility testing (AST) procedure.

[0174] In some embodiments, the aqueous growth medium may be added to the sample 102 prior to introducing it into the sample container 104. In other embodiments, the aqueous growth medium may be added to the sample 102 once the sample 102 has been injected, delivered, or otherwise introduced into the sample container 104.

[0175] In one embodiment, the aqueous growth medium can be Miller-Hinton broth (MHG) supplemented with glucose. In other embodiments, the aqueous growth medium can be a solution comprising: bacterial tryptone, tryptic soy digest, yeast extract, beef extract, cation-adjusted Miller-Hinton broth (CAMHB), starch, acid hydrolysate of casein, calcium chloride, magnesium chloride, sodium chloride, blood or lysed blood (including lysed horse blood (LHB)), CAMHB-LHB, glucose or other carbohydrates, or combinations thereof.

[0176] The sample container 104 may be made in part of an inert or non-conductive material. In some embodiments, the sample container 104 may include or be made in part of a polymeric material, a ceramic material, or glass, or a combination thereof. As a more specific example, the sample container 104 may include or be made in part of polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), or a combination thereof.

[0177] The sensor device 103 may also include a reference sensor component 108 and an active sensor component 122. The reference sensor component 108 may also include a reference catheter 110 including a reference catheter proximal end 140 defining a reference catheter first opening 114, a reference catheter distal end 142 defining a reference catheter second opening 116, and a reference catheter lumen 112 between the reference catheter proximal end 140 and the reference catheter distal end 142.

[0178] The reference catheter 110 may include a catheter wall 138, and the catheter wall 138 may be tapered from the reference catheter proximal end 140 to the reference catheter distal end 142. In one embodiment, the reference catheter 110 may be generally shaped as a cone or a frustoconical shape, and the reference catheter lumen 112 may also be generally shaped as a cone or a frustoconical shape. In other embodiments, the reference catheter 110 may be generally shaped as an elongated cone with a polygonal bottom. For example, the reference catheter 110 may be generally shaped as an elongated triangular pyramid, a quadrangular pyramid, or a pentagonal pyramid. In additional embodiments, the reference catheter 110 may be generally shaped as a cylinder with a generally cylindrical reference catheter lumen 112. In these embodiments, the reference catheter 110 may also have a tapered reference catheter distal end 142.

[0179] The reference conduit 110 may extend into the sample chamber 106 such that when the sample chamber 106 is filled with the sample 102, at least a portion of the reference conduit 110 is immersed in the sample 102. For example, the reference conduit distal end 142 may be immersed in the sample 102 within the sample chamber 106.

[0180] Reference sensor component 108 may include an ion exchange membrane 150 coupled to reference conduit distal end 142. Ion exchange membrane 150 may be configured to block reference conduit second opening 116 so that microorganisms within sample 102 do not enter reference conduit lumen 112. However, ion exchange membrane 150 may allow ions to traverse ion exchange membrane 150 to maintain charge balance.

[0181] In some embodiments, the ion exchange membrane 150 may be a perfluorosulfonated ionomer membrane. As a more specific example, the ion exchange membrane 150 may be a Nafion® membrane provided by EI du Pont de Nemours and Company. Likewise, for example, the ion exchange membrane 150 may be an Aciplex® membrane provided by Asahi Kasei Corporation or a Flemion® membrane provided by AGC Chemicals Americas.

[0182] In some embodiments, the thickness of ion exchange membrane 150 may be about 25 μm to about 180 μm. More specifically, the thickness of ion exchange membrane 150 may be about 25 μm to about 100 μm. The thickness of ion exchange membrane 150 may also be about 100 μm to about 180 μm.

[0183] In other embodiments, the thickness of the ion exchange membrane 150 may be about 180 μm to about 200 μm. For example, the ion exchange membrane 150 may have a thickness of about 183 μm.

[0184] The reference catheter lumen 112 can be at least partially filled with a reference buffer solution 152. The reference buffer solution 152 can be an aqueous redox buffer solution.

[0185] In one embodiment, the reference buffer solution 152 may include deionized water, potassium ferricyanide, dihydrogen phosphate, disodium hydrogen phosphate, or a combination thereof. For example, the reference buffer solution 152 may include about 95% to 99% (v / v%) deionized water, about 0.1% to 0.9% (w / v%) potassium hexacyanoferrate (III), about 0.1% to 0.9% (w / v%) potassium hexacyanoferrate (II), less than about 0.5% (w / v%) potassium dihydrogen phosphate, and less than about 0.5% (w / v%) disodium hydrogen phosphate. As a more specific example, the reference buffer solution may be a 220 mV / pH 7 redox buffer solution (product code 51350060) provided by Mettler-Toledo Corporation.

[0186] In other embodiments, the reference buffer solution 152 may be an aqueous redox buffer solution including 3M KCl. As a more specific example, the reference buffer solution may be a 3M KCl redox buffer solution (material number 63056165) provided by Mettler-Toledo.

[0187] In one embodiment, the reference catheter lumen 112 may be filled with about 100 μL of reference buffer solution 152. In another embodiment, the reference catheter lumen 112 may be filled with about 500 μL of reference buffer solution 152. In other embodiments, the reference catheter lumen 112 may be filled with about 100 μL to about 500 μL of reference buffer solution 152. In further embodiments, the reference catheter lumen 112 may be filled with about 500 μL to about 1 mL of reference buffer solution 152. The amount of reference buffer solution 152 may depend on the volume of the reference catheter lumen 112, the size of the reference catheter 110, the size of the sample container 104, or a combination thereof.

[0188] The reference sensor component 108 may also include a reference electrode 120 that extends into a reference catheter lumen 112 filled with a reference buffer solution 152. The reference electrode 120 may partially extend into the reference catheter lumen 112 filled with the reference buffer solution 152.

[0189] As a more specific example, the reference electrode 120 may include a reference electrode tip 144. When the reference electrode 120 partially extends into the reference catheter lumen 112 filled with a reference buffer solution 152, the reference electrode tip 144 may be positioned proximal to the ion exchange membrane 150. More specifically, a volume of the reference buffer solution 152 may separate the reference electrode tip 144 from the ion exchange membrane 150. The position of the reference electrode 120 within the reference catheter lumen 112 will be discussed in more detail in the following section.

[0190] The reference electrode 120 may be partially made of one or more metals. In one embodiment, the reference electrode 120 may be partially made of platinum (Pt), stainless steel, or a combination thereof. In other embodiments, the reference electrode 120 may be partially made of another type of conductive metal. For example, the reference electrode 120 may be a metal pin, a metal wire, or a rod inserted into the reference buffer solution 152 so that a section of the reference electrode 120 (e.g., the reference electrode tip 144 and a section of the reference electrode 120 proximal to the reference electrode tip 144) is immersed in the reference buffer solution 152.

[0191] The sample 102 can be in fluid contact with the ion exchange membrane 150, so that the ion exchange membrane 150 acts as an interface of a salt bridge. Ions can diffuse from one side of the ion exchange membrane 150 to the other side to maintain charge balance.

[0192] The sensor device 103 may also include an active sensor component 122 including an active electrode housing 124 extending into a sample chamber 106 configured to receive the sample 102. The active sensor component 122 may also include an active electrode 126 at least partially contained or surrounded by the active electrode housing 124.

[0193] The active electrode housing 124 may be made of an inert or non-conductive material. The active electrode housing 124 may include a polymeric material such as polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), ceramic, silicon dioxide (SiO2) or glass types, or combinations thereof.

[0194] The active electrode 126 may include a sample contact surface 128. The active electrode 126 may be disposed at an active component distal end 130. The active electrode housing 124 may be configured to expose the sample contact surface 128 so that the sample contact surface 128 is in fluid communication with the sample 102.

[0195] In some embodiments, the active electrode 126 may be partially made of a metal oxide. For example, the active electrode 126 may be partially made of silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), hafnium dioxide (HfO2), iridium dioxide (IrO2), ruthenium dioxide (RuO2), zirconium dioxide (ZrO2), or a combination thereof.

[0196] The active sensor component 122 may also include a conductive contact layer 132 coupled to and positioned proximal to the active electrode 126. The conductive contact layer 132 may also be housed within or encased by the active electrode housing 124.

[0197] The conductive contact layer 132 may be made in part of one or more metals. In some embodiments, the conductive contact layer 132 may be made in part of aluminum (Al), copper (Cu), platinum (Pt), or a combination thereof. The conductive contact layer 132 and the reference electrode 120 may be electrically coupled to the voltmeter 136 via a conductive connector 134 or a conductive trace. The conductive connector 134 may be made in part of a conductive material. In one embodiment, the conductive connector 134 may be a copper trace. For example, the conductive connector 134 may be electrodeposited copper, rolled annealed copper, high conductivity electrodeposited copper, or a combination thereof. In other embodiments, the conductive connector 134 may be made in part of silver or nickel.

[0198] In some embodiments, the voltmeter 136 can be a high impedance voltmeter. The conductive connection 134 can electrically couple the active electrode 126 (through the conductive contact layer 132) and the reference electrode 120 to the voltmeter 136. The pH of the sample 102 can be measured based on the potential difference between the active electrode 126 and the reference electrode 120.

[0199] The sensor device 103 may also include an aeration conduit 146. A section of the aeration conduit 146 may extend into the sample chamber 106 such that a lumen or cavity within the aeration conduit 146 is in fluid communication with the sample chamber 106. The aeration conduit 146 may be configured to aerate the sample 102 received within the sample container 104. Aerating the sample 102 may enhance the growth rate of the microorganisms within the sample 102 by increasing the oxygen supply to the microorganisms. In addition, aeration may also cause the microorganisms to detach from the inner wall of the sample container 104 so as to inhibit biofilm formation.

[0200] Figure 1D Another embodiment of a sensor device 105 for measuring the ORP of a sample 102 is shown. Figure 1D A side cross-sectional view of sensor device 105 is shown.

[0201] The sensor device 105 may include a sample container 104 having a sample chamber 106 configured to receive a sample 102. The sample 102 may be a sample of a sensor device 100 (e.g., Figure 1A As shown), sensor device 101 (as Figure 1B As shown) and sensor device 103 (as Figure 1C The same sample 102 discussed above (shown in FIG. 1 ) can include a variety of microorganisms or infectious agents. As part of a microbial quantification procedure or an antibiotic susceptibility testing (AST) procedure, the devices, systems, and methods disclosed herein can be used to assay the sample 102 for microbial growth or lack of microbial growth.

[0202] In some embodiments, the aqueous growth medium may be added to the sample 102 prior to introducing it into the sample container 104. In other embodiments, the aqueous growth medium may be added to the sample 102 once the sample 102 has been injected, delivered, or otherwise introduced into the sample container 104.

[0203] In one embodiment, the aqueous growth medium can be Miller-Hinton broth (MHG) supplemented with glucose. In other embodiments, the aqueous growth medium can be a solution comprising: bacterial tryptone, tryptic soy digest, yeast extract, beef extract, cation-adjusted Miller-Hinton broth (CAMHB), starch, acid hydrolysate of casein, calcium chloride, magnesium chloride, sodium chloride, blood or lysed blood (including lysed horse blood (LHB)), CAMHB-LHB, glucose or other carbohydrates, or combinations thereof.

[0204] The sensor device 105 may include a sample container 104 having a sample chamber 106 configured to receive a sample 102. The sample 102 may be a sample of a sensor device 100 (e.g., Figure 1A ) and sensor device 101 (as shown Figure 1B The same sample 102 discussed above (shown in FIG. 1 ) can be used to measure the sample 102 for microbial growth or lack thereof as part of a microbial quantification procedure or an antibiotic susceptibility testing (AST) procedure. The sample 102 can include a variety of microorganisms or infectious agents. The devices, systems, and methods disclosed herein can be used to measure the sample 102 for microbial growth or lack thereof as part of a microbial quantification procedure or an antibiotic susceptibility testing (AST) procedure.

[0205] The sample container 104 may be made in part of an inert or non-conductive material. In some embodiments, the sample container 104 may include or be made in part of a polymeric material, a ceramic material, or glass, or a combination thereof. As a more specific example, the sample container 104 may include or be made in part of polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), or a combination thereof.

[0206] The sensor device 105 may also include a reference sensor component 108 and an active sensor component 122. The reference sensor component 108 may also include a reference catheter 110 including a reference catheter proximal end 140 defining a reference catheter first opening 114, a reference catheter distal end 142 defining a reference catheter second opening 116, and a reference catheter lumen 112 between the reference catheter proximal end 140 and the reference catheter distal end 142.

[0207] The reference catheter 110 may include a catheter wall 138, and the catheter wall 138 may be tapered from the reference catheter proximal end 140 to the reference catheter distal end 142. In one embodiment, the reference catheter 110 may be generally shaped as a cone or a frustoconical shape, and the reference catheter lumen 112 may also be generally shaped as a cone or a frustoconical shape. In other embodiments, the reference catheter 110 may be generally shaped as an elongated cone with a polygonal bottom. For example, the reference catheter 110 may be generally shaped as an elongated triangular pyramid, a quadrangular pyramid, or a pentagonal pyramid. In additional embodiments, the reference catheter 110 may be generally shaped as a cylinder with a generally cylindrical reference catheter lumen 112. In these embodiments, the reference catheter 110 may also have a tapered reference catheter distal end 142.

[0208] The reference conduit 110 may extend into the sample chamber 106 such that when the sample chamber 106 is filled with the sample 102, at least a portion of the reference conduit 110 is immersed in the sample 102. For example, the reference conduit distal end 142 may be immersed in the sample 102 within the sample chamber 106.

[0209] Reference sensor component 108 may include an ion exchange membrane 150 coupled to reference conduit distal end 142. Ion exchange membrane 150 may be configured to block reference conduit second opening 116 so that microorganisms within sample 102 do not enter reference conduit lumen 112. However, ion exchange membrane 150 may allow ions to traverse ion exchange membrane 150 to maintain charge balance.

[0210] In some embodiments, the ion exchange membrane 150 may be a perfluorosulfonated ionomer membrane. As a more specific example, the ion exchange membrane 150 may be a Nafion® membrane provided by DuPont. For another example, the ion exchange membrane 150 may be an Aciplex® membrane provided by Asahi Kasei Corporation or a Flemion® membrane provided by AGC Chemicals Americas.

[0211] In some embodiments, the thickness of ion exchange membrane 150 may be about 25 μm to about 180 μm. More specifically, the thickness of ion exchange membrane 150 may be about 25 μm to about 100 μm. The thickness of ion exchange membrane 150 may also be about 100 μm to about 180 μm.

[0212] In other embodiments, the thickness of the ion exchange membrane 150 may be about 180 μm to about 200 μm. For example, the thickness of the ion exchange membrane 150 may be about 183 μm.

[0213] The reference catheter lumen 112 can be at least partially filled with a reference buffer solution 152. The reference buffer solution 152 can be an aqueous redox buffer solution.

[0214] In one embodiment, the reference buffer solution 152 may include deionized water, potassium ferricyanide, dihydrogen phosphate, disodium hydrogen phosphate, or a combination thereof. For example, the reference buffer solution 152 may include about 95% to 99% (v / v%) deionized water, about 0.1% to 0.9% (w / v%) potassium hexacyanoferrate (III), about 0.1% to 0.9% (w / v%) potassium hexacyanoferrate (II), less than about 0.5% (w / v%) potassium dihydrogen phosphate, and less than about 0.5% (w / v%) disodium hydrogen phosphate. As a more specific example, the reference buffer solution may be a 220 mV / pH 7 redox buffer solution (product code 51350060) provided by Mettler-Toledo Corporation.

[0215] In other embodiments, the reference buffer solution 152 may be an aqueous redox buffer solution including 3M KCl. As a more specific example, the reference buffer solution may be a 3M KCl redox buffer solution (material number 63056165) provided by Mettler-Toledo.

[0216] In one embodiment, the reference catheter lumen 112 may be filled with about 100 μL of reference buffer solution 152. In another embodiment, the reference catheter lumen 112 may be filled with about 500 μL of reference buffer solution 152. In other embodiments, the reference catheter lumen 112 may be filled with about 100 μL to about 500 μL of reference buffer solution 152. In further embodiments, the reference catheter lumen 112 may be filled with about 500 μL to about 1 mL of reference buffer solution 152. The amount of reference buffer solution 152 may depend on the volume of the reference catheter lumen 112, the size of the reference catheter 110, the size of the sample container 104, or a combination thereof.

[0217] The reference sensor component 108 may also include a reference electrode 120 that extends into a reference catheter lumen 112 filled with a reference buffer solution 152. The reference electrode 120 may partially extend into the reference catheter lumen 112 filled with the reference buffer solution 152.

[0218] As a more specific example, the reference electrode 120 may include a reference electrode tip 144. When the reference electrode 120 partially extends into the reference catheter lumen 112 filled with a reference buffer solution 152, the reference electrode tip 144 may be positioned proximal to the ion exchange membrane 150. More specifically, a volume of the reference buffer solution 152 may separate the reference electrode tip 144 from the ion exchange membrane 150. The position of the reference electrode 120 within the reference catheter lumen 112 will be discussed in more detail in the following section.

[0219] The reference electrode 120 may be partially made of one or more metals. In one embodiment, the reference electrode 120 may be partially made of platinum (Pt), stainless steel, or a combination thereof. In other embodiments, the reference electrode 120 may be partially made of another type of conductive metal. For example, the reference electrode 120 may be a metal pin, a metal wire, or a rod inserted into the reference buffer solution 152 so that a section of the reference electrode 120 (e.g., the reference electrode tip 144 and a section of the reference electrode 120 proximal to the reference electrode tip 144) is immersed in the reference buffer solution 152.

[0220] The sample 102 can be in fluid contact with the ion exchange membrane 150, so that the ion exchange membrane 150 acts as an interface of a salt bridge. Ions can diffuse from one side of the ion exchange membrane 150 to the other side to maintain charge balance.

[0221] The sensor device 105 may also include an active sensor component 122 including an active electrode housing 124 extending into a sample chamber 106 configured to receive the sample 102. The active sensor component 122 may also include an active electrode 148 at least partially housed in or surrounded by the active electrode housing 124.

[0222] The active electrode housing 124 may be made of an inert or non-conductive material. The active electrode housing 124 may include a polymeric material such as polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), ceramic, silicon dioxide (SiO2), or glass types or combinations thereof.

[0223] The active electrode 148 may include a sample contact surface 128. The active electrode 148 may be disposed at the active component distal end 130. The active electrode housing 124 may be configured to expose the sample contact surface 128 so that the sample contact surface 128 is in fluid communication with the sample 102.

[0224] In some embodiments, the active electrode 148 may be partially made of one or more metals, one or more metal oxides, or a combination thereof. For example, the active electrode 148 may be partially made of platinum (Pt), gold (Au), a redox-sensitive metal oxide, or a combination thereof. In some embodiments, the redox-sensitive metal oxide may include silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), hafnium dioxide (HfO2), iridium dioxide (IrO2), ruthenium dioxide (RuO2), zirconium dioxide (ZrO2), or a combination thereof.

[0225] The active electrode 148 and the reference electrode 120 can be electrically coupled to the voltmeter 136 via a conductive connector 134 or conductive trace. The conductive connector 134 can be made in part of a conductive material. In one embodiment, the conductive connector 134 can be a copper trace. For example, the conductive connector 134 can be electrodeposited copper, rolled annealed copper, high ductility electrodeposited copper, or a combination thereof. In other embodiments, the conductive connector 134 can be made in part of silver or nickel.

[0226] In some embodiments, the voltmeter 136 may be a high impedance voltmeter. The ORP of the sample 102 may be measured based on the potential difference between the active electrode 148 and the reference electrode 120 .

[0227] The sensor device 105 may also include an aeration conduit 146. A section of the aeration conduit 146 may extend into the sample chamber 106 such that a lumen or cavity within the aeration conduit 146 is in fluid communication with the sample chamber 106. The aeration conduit 146 may be configured to aerate the sample 102 received within the sample container 104. Aerating the sample 102 may enhance the growth rate of the microorganisms within the sample 102 by increasing the oxygen supply to the microorganisms. In addition, aeration may also cause the microorganisms to detach from the inner wall of the sample container 104 so as to inhibit biofilm formation.

[0228] Figure 2 2 shows a top perspective view of an embodiment of a sensor device 200. The sensor device 200 may be or refer to any of the sensors previously described, including Figure 1A The sensor device 100, Figure 1B Sensor device 101, Figure 1C The sensor device 103 and Figure 1D The sensor device 105.

[0229] like Figure 2 As shown, the sample container 104 can include a container cap 202 coupled to a container body 204. In one embodiment, the container body 204 can be a generally cylindrical container or vessel. In other embodiments, the container body 204 can be a generally cubic, pyramidal or conical container or vessel. The container cap 202 can have a shape configured to be coupled or attached to the container body 204.

[0230] In one embodiment, the container cap 202 can be coupled to the sample container 104 by a threaded connection. In other embodiments, the container cap 202 can be coupled to the sample container 104 by fasteners, latches, interference fits, or combinations thereof. The container cap 202 can be decoupled from or removed from the container body 204 to allow a user (e.g., a clinician or laboratory technician) to dispense the sample 102 into the sample chamber 106 of the sample container 104.

[0231] In one embodiment, the container cap 202 may have a reference port 206 defined along a surface of the container cap 202. The reference port 206 may be an opening or channel defined on a surface of the container cap 202.

[0232] In some embodiments, the reference conduit 110 can be integral with the container cap 202 such that separating the container cap 202 from the container body 204 also removes the reference conduit 110 from the sample chamber 106. In these and other embodiments, the reference port 206 can be an opening or passage that provides access to the reference conduit lumen 112. For example, the reference electrode 120 can be inserted into the reference conduit lumen 112 or otherwise extend into the reference conduit lumen 112 through the reference port 206 and the reference conduit first opening 114.

[0233] In other embodiments, the entire reference sensor component 108 (including the reference conduit 110) can be removably coupled to the sample container 104, such that the entire reference sensor component 108 is detachable from the sample container 104. For example, the reference conduit 110 can be removably coupled to the container cap 202. In these and other embodiments, the reference port 206 can provide access to the sample chamber 106. The reference conduit 110 (including the reference buffer gel 118 or the reference buffer solution 152) can be inserted into the reference port 206 or otherwise extended through the reference port 206. The reference conduit 110 can then be coupled to the sample container 104 (e.g., the container cap 202) via an interference fit, a threaded connection, a snap-on connection, or a combination thereof. The reference electrode 120 can then be inserted into the reference conduit lumen 112 or otherwise extended into the reference conduit lumen 112 through the reference port 206 and the reference conduit first opening 114.

[0234] Figure 2 The container cover 202 may also have an aeration port 208 defined along a surface of the container cover 202. The aeration port 208 may provide access to the aeration conduit 146 (see Figure 1A , Figure 1B , Figure 1C and Figure 1D For example, an aeration tube or hose may be inserted into the aeration conduit 146 through the aeration port 208 to aerate the sample 102 in the sample container 104.

[0235] The container cover 202 may also have an exhaust port 210 defined along a surface of the container cover 202. The exhaust port 210 may allow excess air or gaseous byproducts generated by microorganisms within the sample container 104 to be exhausted from the sample chamber 106.

[0236] The sample container 104 may also include a transverse port 212 defined along a transverse surface of the container body 204. The transverse port 212 may be an opening or passageway that provides access to the sample chamber 106. When coupled to the sample container 104, at least a portion of the active sensor component 122 may extend through the transverse port 212. In some embodiments, the active sensor component 122 may also be removably coupled to the sample container 104 such that a new instance of the active sensor component 122 may replace an old or used instance of the active sensor component 122.

[0237] Figure 3A A side cross-sectional view of an embodiment of a reference sensor component 108 is shown. Figure 3A The reference sensor component 108 shown may be used as Figure 1A The sensor device 100 or Figure 1B A portion of the sensor device 101.

[0238] The reference catheter 110 may include a catheter wall 138 that tapers from a reference catheter proximal end 140 to a reference catheter distal end 142. In addition, the reference catheter proximal end 140 may define a first opening area that is larger than a second opening area defined by the reference catheter distal end 142. For example, the first opening area may be approximately 19 mm 2 To about 80mm 2 , and the second opening area can be about 0.79mm 2 To about 3.14mm 2 .

[0239] exist Figure 3A In the illustrated example embodiment, the reference conduit 110 can be generally shaped as an elongated inverted frustoconical shape. In this embodiment, the reference conduit first opening 114 and the reference conduit second opening 116 can each be generally circular and defined by a first opening diameter 300 and a second opening diameter 302, respectively. In some cases, the first opening diameter 300 can be about 5.00 mm to about 10.0 mm. The second opening diameter 302 can be about 1.00 mm to about 5.00 mm.

[0240] Figure 3AIt is also shown that the reference buffer gel 118 can be filled with a gel height 304 of up to about 5.00 mm to about 20.0 mm. The gel height 304 can vary depending on the volume of the reference catheter lumen 112. As previously discussed, the reference catheter lumen 112 can be filled with about 100 μL of reference buffer gel 118. In another embodiment, the reference catheter lumen 112 can be filled with about 500 μL of reference buffer gel 118. In other embodiments, the reference catheter lumen 112 can be filled with about 100 μL to about 500 μL of reference buffer gel 118. In further embodiments, the reference catheter lumen 112 can be filled with about 500 μL to about 1 mL of reference buffer gel 118. The amount of the reference buffer gel 118 can be optimized to achieve a predetermined reference time. For example, in some cases, the amount of the reference buffer gel 118 can be optimized to achieve a reference time between 3.0 hours and 6.0 hours.

[0241] The reference electrode 120 may also be separated from the reference catheter second opening 116 by a separation distance 306. In one embodiment, the separation distance may be about 1.0 mm. In another embodiment, the separation distance 306 may be about 5.0 mm. In other embodiments, the separation distance 306 may be between about 1.0 mm and 5.0 mm.

[0242] Figure 3B A side cross-sectional view of another embodiment of a reference sensor component 108 is shown. Figure 3B The reference sensor component 108 shown may be used as Figure 1C The sensor device 103 or Figure 1D Part of the sensor device 105.

[0243] The reference catheter 110 may include a catheter wall 138 that tapers from a reference catheter proximal end 140 to a reference catheter distal end 142. In addition, the reference catheter proximal end 140 may define a first opening area that is larger than a second opening area defined by the reference catheter distal end 142. For example, the first opening area may be approximately 19 mm 2 To about 80mm 2 , and the second opening area can be about 0.79mm 2 To about 3.14mm 2 .

[0244] exist Figure 3BIn the illustrated example embodiment, the reference conduit 110 can be generally shaped as an elongated inverted frustoconical shape. In this embodiment, the reference conduit first opening 114 and the reference conduit second opening 116 can each be generally circular and defined by a first opening diameter 300 and a second opening diameter 302, respectively. In some cases, the first opening diameter 300 can be about 5.00 mm to about 10.0 mm. The second opening diameter 302 can be about 1.00 mm to about 5.00 mm. .

[0245] Figure 3B It is also shown that the reference buffer solution 152 can be filled with a solution height 308 of up to about 5.00 mm to about 20.0 mm. The solution height 308 can vary depending on the volume of the reference catheter lumen 112. As previously discussed, the reference catheter lumen 112 can be filled with about 100 μL of the reference buffer solution 152. In another embodiment, the reference catheter lumen 112 can be filled with about 500 μL of the reference buffer solution 152. In other embodiments, the reference catheter lumen 112 can be filled with about 100 μL to about 500 μL of the reference buffer solution 152. In further embodiments, the reference catheter lumen 112 can be filled with about 500 μL to about 1 mL of the reference buffer solution 152. The amount of the reference buffer solution 152 can be optimized to achieve a predetermined reference time. For example, in some cases, the amount of the reference buffer solution 152 can be optimized to achieve a reference time between 3.0 hours and 6.0 hours.

[0246] The reference electrode 120 may also be separated from the ion exchange membrane 150 by a separation distance 306. In one embodiment, the separation distance may be about 1.0 mm. In another embodiment, the separation distance 306 may be about 5.0 mm. In other embodiments, the separation distance 306 may be about 1.0 mm to 5.0 mm.

[0247] The ion exchange membrane 150 may have a membrane thickness 310 of about 25 μm to about 180 μm. More specifically, the ion exchange membrane 150 may have a membrane thickness 310 of about 25 μm to about 100 μm. The ion exchange membrane 150 may also have a membrane thickness 310 of about 100 μm to about 180 μm.

[0248] Figure 4A schematic diagram of an active electrode (e.g., active electrode 126 or active electrode 148) and a reference electrode (e.g., reference electrode 120) electrically coupled to a high impedance voltmeter (e.g., voltmeter 136) is shown. As previously described, the reference sensor component 108 can be configured such that the reference buffer gel 118 or the ion exchange membrane 150 is in fluid contact (or solid-liquid contact) with the sample 102 in the sample container 104. In addition, the active electrode (e.g., active electrode 126 or active electrode 148) can also be in fluid contact with the sample 102 in the sample container 104.

[0249] The reference electrode may be immersed or inserted into the reference buffer gel 118 or the reference buffer solution 152 and electrically coupled to a high impedance voltmeter (e.g., voltmeter 136). The active electrode may also be electrically coupled to the same high impedance voltmeter via the conductive connection 134. The reference electrode may serve as a stable half-cell potential compared to the active electrode, and the potential difference between the active electrode and the reference electrode may be used to determine the pH or ORP of the sample 102.

[0250] Figure 5A is a graph showing ORP measurements made using a conventional KCl reference solution and a stainless steel reference electrode in a reference buffer gel after adding a high potential ORP solution. Figure 1B ) and the effectiveness of known high potential ORP solutions (e.g., including Virkon TM The resulting change in potential difference is measured using a conventional ORP probe (e.g., a Mettler Toledo™ ORP probe provided by Mettler-Toledo Corporation) using a conventional KCl reference solution and a sensor device 101 including a stainless steel reference electrode 120 immersed in a reference buffer gel 118. Both the conventional ORP probe and the sensor device 101 use the same platinum (Pt) active electrode. Figure 5A As shown, both sensor settings behave similarly in response to the addition of a known high potential ORP solution. The reference sensor component 108 including the reference buffer gel 118 maintains a stable reference potential, similar to a conventional KCl reference in a conventional ORP probe.

[0251] Figure 5B is a graph showing the results of pH measurements using a conventional KCl reference solution and a platinum reference electrode in a reference buffer gel after exchanging a pH 7 solution for a pH 4 solution. Figure 1A), a pH change is induced by replacing a pH 7 solution with a pH 4 solution. The resulting change in potential difference is measured using a conventional pH probe (e.g., a Mettler Toledo™ pH probe provided by Mettler-Toledo Corporation) using a conventional KCl reference solution and a sensor device 100 comprising a platinum reference electrode 120 immersed in a reference buffer gel 118. Both the conventional pH probe and the sensor device 100 use the same iridium dioxide (IrO2) active electrode. Figure 5B As shown, both sensor configurations behave similarly in response to a step change in pH. The reference sensor component 108 including the reference buffer gel 118 shows similar sensitivity and step height to a conventional pH probe utilizing a KCl reference solution.

[0252] Figure 6 is a graph showing the results of ORP measurements of E. coli bacteria grown using a reference electrode in 1% agar gel buffer, 5% agar gel buffer, and a traditional KCl reference solution. Figure 6 As shown, the ORP of a solution including E. coli was monitored using a conventional ORP probe using a conventional KCl reference solution and also using two instances of the sensor device 101. In the first instance, the reference buffer gel 118 contained 1% (w / v%) agar powder. In the second instance, the reference buffer gel 118 contained 5% (w / v%) agar powder. All three sensor settings used the same platinum (Pt) active electrode. As shown Figure 6 As shown, all three sensor settings behaved similarly and produced similar growth curves. Any differences in the timing of the signals were within the variability of the three platinum (Pt) active electrodes.

[0253] Fig. 7A It is shown that when the conventional ORP buffer solution is replaced by a high potential ORP solution (e.g., Virkon TM FIG. 1 is a graph of some ORP measurements taken when a conventional ORP buffer solution is replaced by a high potential ORP solution and then switched back to a conventional ORP buffer solution. The dashed line indicates the ORP signal measured using a conventional ORP probe using a conventional KCl reference solution. As expected, the ORP signal measured by the ORP probe spikes when the conventional ORP buffer solution is replaced by a high potential ORP solution, and then drops again when the high potential ORP solution is switched back to the conventional ORP buffer solution.

[0254] The solid line indicates the measurement result of the potential difference between a conventional reference sensor component containing a conventional KCl reference solution and a reference sensor component including an ion exchange membrane 150 (e.g., a Nafion™ membrane). Fig. 7AAs shown, even when the ORP buffer solution is replaced by a high potential ORP solution, the potential difference between the conventional reference sensor component and the reference sensor component including the ion exchange membrane 150 remains unchanged.

[0255] Figure 7B is a graph showing ORP measurement results of E. coli bacterial growth using a conventional ORP probe and the potential difference between a reference sensor component using an ion exchange membrane and a conventional reference sensor component using a KCl reference solution. Figure 7B As indicated, the ORP of a solution including E. coli was monitored using a conventional ORP probe utilizing a conventional KCl reference solution. Figure 7B The dashed line in indicates the result of this measurement. Figure 7B The solid line in indicates the potential difference between the conventional KCl reference solution and the reference sensor component including the ion exchange membrane 150. Figure 7B As shown, the potential difference remained constant during the growth of E. coli (even for up to 15 h).

[0256] Figure 8 Another embodiment of a sensor device 800 for measuring a solution property (eg, pH or ORP) of a sample 102 is shown. The sensor device 800 may include a sensor having a sample chamber 908 defined therein (see, e.g., Fig.9A ) of a sample container 802. The sample chamber 908 can be configured to receive the sample 102. The sensor device 800 can also include a reference sensor component 804. In some embodiments, the reference sensor component 804 can be made as a part of a container cover 806 configured to cover the open end of the sample container 802.

[0257] In some embodiments, the sample container 802 may be a cuvette. In other embodiments, the sample container 802 may be a diagnostic tube, a portion of a test tube, a glass container, or another type of laboratory container or vessel.

[0258] In certain embodiments contemplated by the present disclosure, sample container 802 may refer to a sample well of a well plate. The well plate may be a custom well plate having deeper wells than a conventional well plate or microtiter plate.

[0259] Reference sensor component 804 may include reference catheter 900 including reference catheter lumen 902, reference catheter first opening 904, and reference catheter second opening 906 (see, e.g., Fig.9A and Fig. 9B ). The reference conduit 900 may be an elongated channel or passageway configured to extend into the sample chamber 908 of the sample container 802 .

[0260] The sensor device 800 may also include a wicking component 910 (see, e.g., Fig.9A and Fig. 9B ), wicking member 910 is positioned within reference catheter lumen 902 and extends through the length of reference catheter lumen 902. Wicking member 910 and reference catheter lumen 902 will be discussed in more detail in the following sections.

[0261] The sensor device 800 may also include a reference electrode material 808 disposed at the proximal end of the wicking component 910. When the reference sensor component 804 is made as a container lid 806, the reference electrode material 808 may protrude or extend through the lid top 810 of the container lid 806, so that the reference electrode material 808 is accessible and visible through the lid top 810 of the container lid 806. For example, an opening may be defined along the lid top 810 of the container lid 806, and the reference electrode material 808 may protrude or extend through the opening defined along the lid top 810 of the container lid 806. In other embodiments not shown in the figures but contemplated by the present disclosure, the reference electrode material 808 may protrude through a lateral side 812 or corner of the container lid 806.

[0262] When the reference sensor component 804 is made as a container cover 806, the container cover 806 can be removably attached or coupled to the sample container 802. For example, the container cover 806 can be removably attached or coupled to the sample container 802 via a threaded connection 944 (see Fig.9A and Fig. 9B ). In other embodiments, the container cap 806 can be removably attached or coupled to the sample container 802 by an interference fit, a press fit (e.g., a tapered press fit, an expansion press fit, etc.), a snap fit, a latch, or a combination thereof.

[0263] In these and other embodiments, the container cover 806 can fit over or cover a portion (e.g., a proximal portion) of the sample container 802. In these embodiments, the lateral sides 812 of the container cover 806 can extend radially beyond the container wall 814 of the sample container 802. In the case where the sample container 802 is generally cylindrical and the shape of the container cover 806 conforms to the shape of the sample container 802, the outer perimeter (or circular footprint) 806 of the container cover can be greater than the outer perimeter (or circular footprint) of the sample container 802.

[0264] The sensor device 800 may also include an active sensor component 816. The active sensor component 816 may be positioned or otherwise disposed along a container wall 814 of the sample container 802. The active sensor component 816 will be discussed in more detail in the following sections. The reference sensor component 804 and the active sensor component 816 may be electrically coupled to a parameter analyzer 916 (e.g., see FIG. 1 ) via conductive connections. Fig.9A). The active electrode material 918 in the active sensor component 816 (see, for example, Fig.9A ) and the reference electrode material 808 to determine the solution properties of the sample 102.

[0265] In some embodiments, the solution property measured or monitored using the sensor device 800 can be the pH of the sample 102, and at least a portion of the active sensor component 816 can be partially made of a pH-sensitive material. The pH-sensitive material can include at least one of the following: silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, and zirconium dioxide.

[0266] In these and other embodiments, the solution property measured or monitored using the sensor device 800 can be the redox potential (ORP) of the sample 102, and at least a portion of the active sensor component 816 can be fabricated in part from a redox sensitive material. The redox sensitive material can include at least one of platinum, gold, silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, and zirconium dioxide.

[0267] As previously described, sample 102 may include infectious agents or microorganisms (e.g., bacteria, fungi, etc.) Sensor device 800 may be used to assay sample 102 for growth or lack of growth of microorganisms or infectious agents as part of a microbial quantification procedure, a sample preparation procedure, or an antibiotic susceptibility testing (AST) procedure.

[0268] As previously discussed, sample 102 may include or refer to a bacterial culture derived from at least one of a sample obtained from a patient or subject, a biological sample, an environmental sample, and a food sample. For example, sample 102 may include or refer to a bacterial culture or a resuspended bacterial culture derived from a body fluid or swab obtained from a patient or subject. As a more specific example, sample 102 may include a bacterial culture or a resuspended bacterial culture derived from a body fluid or swab obtained from a patient or subject that tests positive for microbial growth.

[0269] More specifically, sample 102 may include a bacterial culture derived from blood drawn from a patient or subject that tested positive for microbial growth. In some embodiments, sample 102 may be or refer to a positive blood culture. For purposes of this disclosure, a positive blood culture may be a bacterial culture derived from blood drawn from a patient or subject that tested positive for bacterial growth.

[0270] In some embodiments, the aqueous growth medium may be added to the sample 102 to dilute the sample 102 prior to introducing it into the sample container 802. In other embodiments, the aqueous growth medium may be added to the sample 102 once the sample 102 is injected, delivered, or otherwise introduced into the sample container 802.

[0271] In one embodiment, the aqueous growth medium can be Miller-Hinton broth (MHG) supplemented with glucose. In other embodiments, the aqueous growth medium can be a solution comprising: bactotryptone, tryptic soy digest, yeast extract, beef extract, cation-adjusted Miller-Hinton broth (CAMHB), starch, acid hydrolysate of casein, calcium chloride, magnesium chloride, sodium chloride, blood or lysed blood (including lysed horse blood (LHB)), CAMHB-LHB, glucose or other carbohydrates, or combinations thereof.

[0272] The microorganisms or infectious agents that may be measured using the sensor device 800 may be any metabolic unicellular or multicellular organism, including any of the aforementioned species or genera of bacteria and fungi.

[0273] Sample container 802, container cover 806, or their combination can be partially made of non-conductive material or made. Sample container 802, container cover 806, or their combination can be partially made of non-leaching or sterilizable material or made. Sample container 802, container cover 806, or their combination can be partially made of polymeric material (e.g., thermoplastic, cured photopolymer, or their combination), ceramic material or glass, or their combination or made. For example, sample container 802, container cover 806, or their combination can be partially made of polycarbonate, polypropylene (PP), nylon, acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), poly (methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), or their combination or made. As a more specific example, sample container 802, container cover 806, or their combination can be partially made of molded polycarbonate or cured low viscosity liquid photopolymer (such as Somos® Watershed XC).

[0274] Fig.9A 8 shows a side cross-sectional view of sensor device 800. Fig.9A As shown, the sensor device 800 can include a reference sensor component 804 formed as a container cap 806 and a sample container 802. The container cap 806 can be removably or detachably coupled or fastened to the sample container 802.

[0275] Reference sensor component 804 may include reference conduit 900 including reference conduit lumen 902, reference conduit first opening 904, and reference conduit second opening 906. Reference conduit 900 may be an elongated channel or passage configured to extend into sample chamber 908 of sample container 802.

[0276] Sensor device 800 may also include wicking member 910 positioned within reference catheter lumen 902 and extending through the length of reference catheter lumen 902. In some embodiments, wicking member 910 may fill or occupy all of the space within reference catheter lumen 902. In other embodiments, wicking member 910 may partially fill or partially occupy the space within reference catheter lumen 902.

[0277] The wicking member 910 can have a wick distal end 912 and a wick proximal end 914. At least a portion of the wicking member 910 can be in fluid communication with the sample chamber 908 such that when the reference sensor member 804 (e.g., the container cap 806) is attached, fastened, or coupled to the sample container 802, at least some of the sample 102 in the sample chamber 908 is drawn, absorbed, or otherwise wicked by at least a portion of the wick distal end 912 in the direction of the wick proximal end 914.

[0278] In some embodiments, at least a portion of the core distal end 912 can extend beyond the reference conduit second opening 906 such that the core distal end 912 protrudes or extends into the sample chamber 908. In these embodiments, when the sample chamber 908 is filled with the sample 102, the core distal end 912 extends or protrudes into the fluid sample 102.

[0279] In other embodiments, the entire core distal end 912 is positioned proximal or above the reference conduit second opening 906 such that the core distal end 912 does not protrude or extend into the sample chamber 908. In these embodiments, the core distal end 912 can still be in fluid communication with the sample chamber 908, and the fluid sample 102 can still reach or contact the core distal end 912 by capillary action or by agitating / shaking the sample container 802 and being drawn into the reference conduit 900.

[0280] Fig.9A It is also shown that the reference catheter 900 can be tapered such that the volume of the reference catheter lumen 902 tapers or narrows from the reference catheter first opening 904 to the reference catheter second opening 906. The shape 910 of the wicking member can match or adapt to the shape of the reference catheter lumen 902. The wicking member 910 can be configured such that the shape of the wicking member 910 tapers or narrows from the core proximal end 914 to the core distal end 912.

[0281] The wicking component 910 can be fabricated in part from a porous material.The wicking component 910 can be fabricated in part from a material that includes pores having a size between 15 μm and about 150 μm (eg, about 50 μm).

[0282] In some embodiments, the wicking member 910 can be partially made of a polymeric material. As a more specific example, the wicking member 910 can be partially made of a porous polymeric material including pores having a size of 15 μm to about 150 μm. In one embodiment, the wicking member 910 can be partially made of high-density polyethylene (HDPE). For example, the wicking member 910 can be partially made of HDPE having pores having a size of about 50 μm.

[0283] In other embodiments, the wicking component 910 can be made in part from natural fibers. For example, the wicking component 910 can be made in part from cellulose fibers, pulp, paper, cotton, or a combination thereof.

[0284] The wicking member 910 may also be treated with a surfactant so that at least the surface of the wicking member 910 is covered with a surfactant. In some embodiments, the wicking member 910 may be saturated with a surfactant or immersed in a solution comprising a surfactant before being introduced into the reference catheter lumen 902. The surfactant may be configured to increase the hydrophilicity of the wicking member 910 (i.e., to make the substantially hydrophobic surface of the wicking member 910 more hydrophilic). In some embodiments, the surfactant may be a fluorosurfactant. In other embodiments, the surfactant may be a nonionic surfactant, such as one or more poloxamers. As a more specific example, the surfactant may include Pluronic® F-68.

[0285] The reference sensor component 804 may also include a reference electrode material 808 disposed at the core proximal end 914. The reference electrode material 808 may be a conductive material applied or dispensed on the core proximal end 914.

[0286] In some embodiments, the reference electrode material 808 may be a conductive ink applied or dispensed on the core proximal end 914. The conductive ink applied or dispensed on the core proximal end 914 may be hardened by curing. More specifically, the conductive ink may be silver-silver chloride (Ag-AgCl) ink.

[0287] At least a portion of the reference electrode material 808 can be in physical contact with the wicking member 910. In some embodiments, at least a portion of the reference electrode material 808 can protrude or extend beyond the container cap 806. The reference electrode material 808 can be a solidified and hardened mass positioned at the wick proximal end 914. In certain embodiments, the reference electrode material 808 can be positioned in the middle of the container cap 806.

[0288] One advantage of the wicking member 910 disclosed herein is that the wicking member 910 can draw away the liquid sample 102, and the sample 102 can proceed by capillary action through the pores of the wicking member 910 toward the reference electrode material 808. For example, the liquid sample 102 is wicked to the wick proximal end 914, where the liquid sample 102 is brought into fluid contact with the reference electrode material 808.

[0289] When the reference electrode material 808 is made of a material such as silver chloride-silver chloride (Ag-AgCl), the wicking component 910 can also act as a wick to the silver ions (Ag + ) of the barrier or obstacle, otherwise the silver ions (Ag + ) will freely diffuse into the sample 102. The silver ions may be harmful to or otherwise affect the growth of microorganisms or infectious agents in the sample 102. The wicking component 910 may act as a barrier or obstruction to harmful silver ions by slowing or preventing the diffusion of the ions into the sample 102. The wicking component 910 having the size and shape disclosed herein may effectively slow or prevent the diffusion of the harmful ions.

[0290] The reference sensor component 804 can be electrically coupled to a parameter analyzer 916 via the conductive connection 134. The parameter analyzer 916 can be a voltmeter or a multimeter. For example, the parameter analyzer 916 can be a high impedance voltmeter, such as the voltmeter 136 discussed previously.

[0291] The sensor device 800 may also include an active sensor component 816 that is attached to or otherwise positioned along a container wall 814 of the sample container 802. In other embodiments not shown in the figures, the active sensor component 816 may be attached to or otherwise positioned along the bottom of the sample container 802.

[0292] The active sensor component 816 can include an active electrode material 918, an active electrode housing 920, and a conductive contact layer 922. At least a portion of the active electrode material 918 can be in fluid communication with the sample chamber 908. For example, at least a portion of the active electrode material 918 can extend or protrude into the sample chamber 908. The active electrode material 918 can be positioned such that at least a layer or surface of the active electrode material 918 is in fluid contact with the sample 102 when the sample chamber 908 is at least partially filled with the sample 102.

[0293] The active electrode housing 920 may partially enclose or contain the active electrode material 918, the conductive contact layer 922, or a combination thereof. The active electrode housing 920 may be made of an inert non-conductive material. In some embodiments, the active electrode housing 920 is made of the same material as the container wall 814 and is a molded feature of the container wall 814. The active electrode housing 920 may be a conduit or channel defined along the container wall 814 of the sample container 802. In other embodiments, the active electrode housing 920 may be defined along the bottom of the sample container 802. The active electrode housing 920 may expose at least a portion of the active electrode material 918 at one end of the active electrode housing 920 and expose at least a portion of the conductive contact layer 922 at the other end of the active electrode housing 920. In certain embodiments, one or more conductive connectors 134 may be in physical contact with the conductive contact layer 922 or the active electrode material 918 through the active electrode housing 920.

[0294] The conductive contact layer 922 can be coupled to the active electrode material 918 and positioned or otherwise disposed proximal to or radially outward from the active electrode material 918 (e.g., closer to the outside of the sample container 802). The conductive contact layer 922 can be made in part of one or more metals. In some embodiments, the conductive contact layer 922 can be made in part of aluminum (Al), copper (Cu), platinum (Pt), or a combination thereof. The conductive contact layer 922 can be electrically coupled to the reference electrode material 808 via the parameter analyzer 916 through the conductive connector 134. The conductive connector 134 can be made in part of a conductive material. The conductive connector 134 can be a wire or a conductive trace. In one embodiment, the conductive connector 134 can be a copper wire or a copper trace. For example, the conductive connector 134 can be electrodeposited copper, rolled annealed copper, high conductivity electrodeposited copper, or a combination thereof. In other embodiments, the conductive connector 134 can be made in part of silver or nickel. Once the sample container 802 is at least partially filled with the sample 102 , the conductive connector 134 may contact the reference sensor component 804 and the active sensor component 816 .

[0295] Solution properties of the sample 102 may be determined based on the potential difference measured between the active electrode material 918 and the reference electrode material 808. The reference electrode material 808 may act as a reference electrode and provide a stable half-cell potential compared to the active electrode material 918, and the potential difference between the active electrode and the reference electrode may be used to determine the pH or ORP of the sample 102. For example, the reference electrode material 808 (e.g., Ag-AgCl ink) may be configured to exhibit a substantially stable electrode potential compared to the active electrode material 918 when the active electrode material 918 is in electrical communication with the reference electrode material 808.

[0296] In some embodiments, the solution property measured or monitored may be the pH of the sample 102. In other embodiments, the solution property measured or monitored may be the oxidation reduction potential (ORP) of the sample 102.

[0297] When the solution property measured or monitored is pH, the active electrode material 918 can be a pH sensitive material. The pH sensitive material can be silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), hafnium dioxide (HfO2), iridium dioxide (IrO2), ruthenium dioxide (RuO2), zirconium dioxide (ZrO2), or a combination thereof.

[0298] When the solution property measured or monitored is ORP, the active electrode material 918 can be a redox sensitive material. The redox sensitive material can be or include any one of platinum (Pt), gold (Au), a redox sensitive metal oxide, or a combination thereof. More specifically, the redox sensitive material can be or include any one of the following: silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), hafnium dioxide (HfO2), iridium dioxide (IrO2), ruthenium dioxide (RuO2), zirconium dioxide (ZrO2), or a combination thereof.

[0299] like Fig.9A As shown, when the reference sensor component 804 is implemented as a container cover 806, the container cover 806 can have a size defined by a cover width 924 (or diameter) and a cover height 926. In some embodiments, the cover width 924 can be between about 10.0 mm and about 20.0 mm. For example, the cover width 924 can be about 15.7 mm. In some embodiments, the cover height 926 can be between about 5.0 mm and 20.0 mm. For example, the cover height 926 can be about 10.5 mm. When the container cover 806 is fastened, attached or otherwise coupled to the sample container 802, the sensor device 800 can have a device height 928 measured from the bottom of the sample container 802 to the cover top 810 of the container cover 806.

[0300] In some embodiments, the device height 928 can be between about 20.0 mm and about 50.0 mm. In other embodiments, the device height 928 can be between about 25.0 mm and about 35.0 mm. For example, the device height 928 can be about 31.3 mm.

[0301] like Fig.9AAs shown, the wicking component 910 can have a core height 930 measured from the core proximal end 914 to the core distal end 912. In some embodiments, the core height 930 can be between about 10.0 mm and about 20.0 mm. More specifically, the core height 930 can be between about 14.0 mm and about 15.0 mm. For example, the core height 930 can be about 14.8 mm.

[0302] One advantage of a wicking member 910 having a wick height 930 disclosed herein is that the wicking member 910 can allow a sufficient amount of sample 102 to be drawn away in the direction of the reference electrode material 808 while still acting as a barrier or obstruction to certain harmful ions (e.g., silver ions) flowing from the reference electrode material 808 toward the microorganism-laden sample 102 in the sample chamber 908.

[0303] Fig.9A It is also shown that the reference electrode material 808 can have a reference material height 932 (or thickness) and a reference material width 934 (or diameter). When the reference electrode material is a solidified and hardened block of silver-silver chloride (Ag-AgCl), the reference material height 932 and the reference material width 934 can be the height and width of the silver-silver chloride hardened block, respectively.

[0304] In some embodiments, the reference material height 932 can be between about 0.2 mm and 1.0 mm. For example, the reference material height 932 can be about 0.4 mm. In some embodiments, the reference material width 934 can be between about 2.0 mm and about 5.0 mm. For example, the reference material width 934 can be about 3.0 mm. One advantage of the reference electrode material 808 disclosed herein is that the reference electrode material 808 can act as a stable reference electrode or provide a stable reference potential during testing or operation for up to 10 hours.

[0305] like Fig.9A As shown, the reference electrode material 808 can be at least partially positioned or disposed within the indentation, depression, or concave area created by the wicking member 910 and the reference conduit 900. When the reference electrode material 808 is a cured or hardened conductive ink or solution (e.g., Ag-AgCl ink), the indentation, depression, or concave area can serve as a receiving space for the liquid ink or solution to be cured.

[0306] Fig.9AIt is also shown that the sensor device 800 can include an aeration port 936 defined along the bottom side of the sample container 802, a container wall 814 of the sample container 802, or a combination thereof. The aeration port 936 can be covered by a first gas permeable membrane 938. The aeration port 936 and the first gas permeable membrane 938 can be configured to allow gas 940 to enter the sample chamber 908. In some embodiments, the gas 940 can be ambient air (e.g., the air in a laboratory, a clinical environment, or a testing facility). In other embodiments, the gas 940 can include a combination of pressurized oxygen, carbon dioxide, nitrogen, and argon. The aeration port 936 and the first gas permeable membrane 938 can allow air to enter the sample chamber 908 through the aeration port 936 and the first gas permeable membrane 938 to aerate the sample 102 in the sample chamber 908. Aeration of the sample 102 can benefit aerobic organisms such as Pseudomonas aeruginosa or Acinetobacter baumannii by providing an oxygen-rich environment in the sample chamber 908. Aerating the sample 102 may accelerate the growth of the microbial population within the sample 102 .

[0307] The aeration port 936 may be an opening or channel defined along the bottom side of the sample container 802, the container wall 814 of the sample container 802, or a combination thereof. For example, the aeration port 936 may be defined in the middle or center of the container bottom.

[0308] In additional embodiments, aeration ports 936 may be defined along lid top 810 of container lid 806 and gas 940 may be pumped from the top of sample container 802 into sample chamber 908 .

[0309] The gas 940 (e.g., ambient air) may be pumped into the sample chamber 908 by a micro pump or another pump-type device. The gas 940 (e.g., ambient air) may be pumped or otherwise directed into the sample chamber 908 through the aeration port 936 and the first gas permeable membrane 938 at a constant flow rate of about 1.0 to 10.0 mL / min. In other embodiments, the gas 940 (e.g., ambient air) may be pumped or otherwise directed into the sample chamber 908 through the aeration port 936 and the first gas permeable membrane 938 at specific operating cycles or intervals.

[0310] Fig.9A It is also shown that a second gas permeable membrane 942 can cover at least a portion of the underside of the container lid 806. The second gas permeable membrane 942 can allow any gas 940 pumped or otherwise introduced into the sample chamber 908 to exit the sample chamber 908 while also preventing any liquid within the sample chamber 908 from overflowing the sample container 802. The second gas permeable membrane 942 can also allow any gaseous byproducts generated or produced within the sample chamber 908 to exit the sample chamber 908.

[0311] In some embodiments, the first breathable membrane 938 and the second breathable membrane 942 are made of the same material. The first breathable membrane 938 and the second breathable membrane 942 can be made of a hydrophobic breathable membrane or a thin sheet. For example, the first breathable membrane 938 and the second breathable membrane 942 can both be made of polytetrafluoroethylene (PTFE) or include polytetrafluoroethylene (PTFE).

[0312] like Fig.9A As shown, the container cap 806 can be removably or detachably coupled or fastened to the sample container 802 by being screwed onto the proximal portion of the sample container 802 via a threaded connection 944. When the container cap 806 (serving as a part of the reference sensor component 804) is fixed or coupled to the sample container 802 via the threaded connection 944, an air flow path 946 can be created as follows: air enters the aeration port 936 through the first air permeable membrane 938, enters the sample chamber 908, and the air leaves the sample chamber 908 through the second air permeable membrane 942 and the air gap 948 defined between the threads of the container cap 806 and the sample container 802.

[0313] Fig. 9B An embodiment of a reference sensor component 804 of a sensor device 800 is shown. Fig. 9B As shown, the reference sensor component 804 can be implemented or made as a container cover 806, which includes a reference conduit 900 extending from the underside 950 of the container cover 806. The reference conduit 900 can be an elongated channel extending from the underside 950 of the container cover 806. The reference conduit 900 can be hollow and can be defined by a reference conduit lumen 902 extending from a reference conduit first opening 904 to a reference conduit second opening 906.

[0314] The reference catheter lumen 902 can extend through the entire length of the reference catheter 900. The reference catheter lumen 902 can be generally shaped as a cylinder, an elongated cone, an elongated frustoconical shape, an elongated cube, or a combination thereof. The shape of the wicking member 910 can adapt to and match the shape of the reference catheter lumen 902.

[0315] The container cover 806 can be partially made of a light-transmitting or transparent material, or a light-transmitting or transparent non-conductive material. In other embodiments, the container cover 806 can be partially made of a semi-light-transmitting or light-transmitting material. For example, Fig. 9B, at least a portion of the wicking member 910 may be visible through the lateral side 812 of the container cap 806. This may allow a user or operator of the sensor device 800 to observe the wicking of the fluid sample 102 from the wick distal end 912 to the wick proximal end 914 when the container cap 806 is secured to the sample container 802, and to ensure that at least some of the sample 102 is able to reach the reference electrode material 808 at the wick proximal end 914. In some embodiments, the container cap 806 may be made in part of a transparent or light transmissive polymeric material, glass, or a combination thereof.

[0316] The method of manufacturing the reference sensor component 804 may include providing a container cover 806 configured to be removably coupled to the sample container 802. The sample container 802 may be configured to receive the sample 102. As previously discussed, the reference conduit 900 may extend from the underside 950 of the container cover 806. The reference conduit 900 may include a reference conduit cavity 902. In these and other embodiments, the method may also include molding the reference sensor component 804 in the shape of the container cover 806, the container cover 806 having the reference conduit 900 defined in the center of the container cover 806. For example, the container cover 806 may be molded by injection molding or cast molding. In other embodiments, the method may include 3D printing the container cover 806, the container cover 806 having the reference conduit 900 defined in the center of the container cover 806, and having the reference conduit cavity 902 extending through the length of the reference conduit 900.

[0317] The method may also include placing or positioning a wicking member 910 into a reference catheter lumen 902 of the reference catheter 900. The wicking member 910 may include a core distal end 912 and a core proximal end 914. For example, the wicking member 910 may be made in part of a porous polymeric material (e.g., HDPE), a natural fiber, or a combination thereof. Prior to being introduced or placed into the reference catheter lumen 902, the wicking member 910 may also be treated, immersed, or otherwise saturated with a surfactant.

[0318] In some embodiments, grooves or trenches may be created on the surface of wicking member 910, reference electrode material 808 (e.g., cured conductive ink), or a combination thereof. Increasing the surface area of ​​wicking member 910, reference electrode material 808, or a combination thereof may improve the stability of the half-cell potential of the reference electrode.

[0319] The method may also include applying or dispensing a conductive ink (e.g., Ag-AgCl ink) onto the core proximal end 914. The conductive ink may be dispensed or otherwise applied to the core proximal end 914 via a syringe, dropper, drop dispenser, or pipette. The conductive ink may be dispensed or otherwise applied to a notch, groove, or depression defined by the core proximal end 914 and a section of the reference catheter 900 surrounding the core proximal end 914.

[0320] Dispensing the conductive ink may also include dispensing about 50 μL to about 500 μL of the conductive ink onto the core proximal end 914. More specifically, dispensing the conductive ink may also include dispensing about 80 μL to about 120 μL of the conductive ink onto the core proximal end 914. For example, the method may include dispensing about 100 μL of the conductive ink onto the core proximal end 914.

[0321] The conductive ink may then be cured until the conductive ink hardens to become the reference electrode material 808. In some embodiments, the method may involve curing the conductive ink at a temperature above 100°C. More specifically, the method may involve curing the conductive ink at a temperature of about 110°C to 120°C. For example, the method may involve curing the conductive ink at 115°C. The conductive ink may be cured for a time period between about 60 minutes and about 180 minutes to harden the conductive ink. For example, the conductive ink may be cured for a time period between about 110 minutes and about 130 minutes. For example, the conductive ink may be cured for about 120 minutes. More specifically, the conductive ink may be cured at 115°C for 120 minutes.

[0322] The method of measuring a solution property of a sample 102 may include filling a sample chamber 908 of a sample container 802 with the sample 102. The sample 102 may include an infectious agent or a microorganism. The method may also involve attaching a reference sensor component 804 configured as a container cap 806 to the sample container 802.

[0323] The container cap 806 can include a reference conduit 900 including a reference conduit lumen 902, a reference conduit first opening 904, and a reference conduit second opening 906. The reference conduit lumen 902 can be partially filled by a wicking member 910 extending through the reference conduit lumen 902, the wicking member 910 having a wick distal end 912 and a wick proximal end 914.

[0324] At least a portion of the wicking component 910 can be in fluid contact with the sample 102 in the sample chamber. At least some of the sample 102 can be drawn away by the wicking component 910 in the direction of the wick proximal end 914. A reference electrode material 808 (e.g., a cured and hardened conductive ink) can be disposed at the wick proximal end 914. The method can also include electrically coupling the reference electrode material 808 to a parameter analyzer 916 (e.g., a high impedance voltmeter), and electrically coupling the parameter analyzer 916 to an active sensor component 816 including an active electrode material 918. At least a portion of the active electrode material 918 can extend into the sample chamber 908 and be in fluid contact with the sample 102 in the sample chamber 908. When the wicking component 910 draws or wicks the sample 102, the sample 102 can reach the reference electrode material 808 and charge carriers within the sample 102 can establish an electrical connection between the reference electrode material 808 and the active electrode material 918. At this point, the circuit is formed, and then the circuit can be used to measure the change in the potential of the sample 102 .

[0325] The method may also include determining a solution property of the sample 102 based on the measured potential difference between the active electrode material 918 and the reference electrode material 808. As previously discussed, the measured solution property may be the pH of the sample 102, the ORP of the sample 102, or a combination thereof.

[0326] The method may further include pumping air into the sample chamber 908 through an aeration port 936 defined along at least one of a bottom side and a lateral side of the sample container 802. A hydrophobic, gas-permeable membrane (e.g., a first gas-permeable membrane 938) may cover the aeration port 936. The air pumped into the sample chamber 908 may aerate the sample 102 and accelerate the growth of infectious agents or microorganisms within the sample 102.

[0327] The air pumped into the sample chamber 908 may also pass through an additional gas permeable membrane (e.g., a second gas permeable membrane 942) covering at least a portion of the underside 950 of the container cover 806, and ultimately through an air gap 948 defined between the container cover 806 and the sample container 802 (see Fig.9A ) (eg, through an air gap 948 defined between the male threads of the sample container 802 and the female threads of the container cap 806 ) to exit the sample chamber 908 .

[0328] Fig.10The redox potential (ORP) of three aliquots of sample 102 measured using three different sensor settings is shown over time. All of these samples contain the bacterium Escherichia coli (E. coli or ECo). One such sensor setting involves an active sensor component 816 that includes a redox sensitive material (e.g., an ORP active sensor) as an active electrode material 918 and a commercially available, off-the-shelf silver-silver chloride reference electrode. This sensor setting is used as a control and the results obtained by these measurements are used as a standard or benchmark for other measurements of E. coli bacterial growth. The other two sensor settings involve the same active sensor component 816 that includes a redox sensitive material as an active electrode material, but use a container cap 806 disclosed herein as a reference sensor component 804. In these cases where the container cap 806 is used as the reference sensor component 804, the reference electrode material 808 is a cured and hardened deposit of silver-silver chloride (Ag-AgCl) ink. In one such sensor configuration, the Ag-AgCl ink used was Ag-AgCl 113-09 developed by Creative Materials Inc. In another sensor configuration, the Ag-AgCl ink used was Ag-AgCl 126-49 developed by Creative Materials Inc.

[0329] As shown in the three E. coli growth curves, the two sensor setups using the container cap 806 as the reference sensor component 804 performed similarly to the sensor setup using the conventional off-the-shelf silver-silver chloride reference electrode. Any variation in signal timing was within acceptable limits based on the active sensors used.

[0330] Fig.11 is a graph showing the results of cell counts (expressed in colony forming units (CFU) per milliliter) performed on plated bacterial colonies of output samples including various strains of E. coli. In some embodiments, the sensor device 800 disclosed herein can be used as part of a system for preparing an output sample of defined microbial concentration. For example, the sensor device 800 disclosed herein can be used as part of a system for preparing an output sample of defined microbial concentration, such as 0.5 McFarland (McF) to 0.6 McF (a microbial suspension exhibiting a turbidity equal to 0.5 McF to 0.6 McF), which is typically used as an input for antibiotic susceptibility testing.

[0331] Fig.11The dark bars in the figure represent quality control (QC) samples, which exhibit turbidity of 0.5 McF and 0.6 McF as measured by a standard turbidity (optical density) meter. The QC samples were prepared by resuspending colonies from 18-24 hour culture plates in saline to a final concentration between about 0.5 McF and 0.6 McF (concentrations of about 0.5 McF to 0.6 McF are acceptable input concentrations for antibiotic susceptibility testing). The QC samples included a quality control strain of E. coli designated ATCC 25922. Once the turbidity levels of the QC samples reached 0.5 McF and 0.6 McF, the samples were plated and viable cell counts were performed on these plated samples (the results of the counts are presented in CFU / mL in the figure).

[0332] Fig.11 The various white bars in represent cell counts for output samples of defined concentrations prepared using the sensor device 800 disclosed herein. The output samples were prepared from source samples including E. coli of various strains from positive blood cultures of sepsis patients. For all such output samples, the target was set to approximately 1.50*10 8 CFU / mL (expressed as turbidity 0.5McF).

[0333] A source sample including E. coli having various strains is introduced into the sample chamber 908 of the sample container 802 disclosed herein. Then, a reference sensor component 804 (e.g., container cap 806) is fastened to the sample container 802, and then the change of the solution property of the sample over time is measured or monitored by the parameter analyzer 916.

[0334] The system may also include one or more computing devices communicatively coupled to the parameter analyzer 916. The one or more computing devices may retrieve a specific lookup table associated with a specific infectious agent species (i.e., a species-specific lookup table) or an inter-species or universal lookup table to determine a real-time concentration of the infectious agent within the sample chamber 908 based on changes in solution properties of the sample within the sample chamber 908.

[0335] In some embodiments, the concentration data can be determined directly from one or more lookup tables based on real-time changes in solution properties monitored or measured by parameter analyzer 916, one or more computing devices, or a combination thereof. In these embodiments, real-time changes in solution properties of the sample in sample chamber 908 can be directly mapped to threshold solution property changes in the lookup table, which can be directly related to the estimated concentration of the infectious agent in sample chamber 908.

[0336] In other embodiments, one or more computing devices may perform additional calculations and data interpolation based on threshold data from one or more lookup tables and real-time solution property changes measured or monitored by the sensor device 800. For example, one method of preparing an output sample of defined concentration may include calculating a sample incubation or sample preparation time corresponding to the amount of time necessary for the infectious agent within the sample chamber 908 to reach a defined concentration based on a first threshold time, a second threshold time, concentration data from at least one lookup table, and a desired defined concentration. This method is further described in U.S. Patent Application No. 16 / 430,266, the contents of which are incorporated herein by reference in their entirety.

[0337] from Fig.11 As can be seen in the plate cell counts performed on the output sample (0.5McF) generated in part using the sensor device 800 disclosed herein, compared favorably with the 0.5McF and 0.6McF QC samples generated using the "gold standard" of resuspended colonies from 18 to 24 hour culture plates and using optical density measurement to determine the concentration of the suspension. Almost all of the output samples prepared using the sensor device 800 and methods disclosed herein produced samples with infectious agent concentrations within the acceptable range for the QC samples. Fig.11 It is shown that the sensor device 800 and methods disclosed herein can be used to effectively generate an output sample of a defined concentration (eg, a 0.5 McF bacterial sample).

[0338] Fig.12 The effect of aeration on the growth rate of two samples 102 comprising the aerobic bacterium Pseudomonas aeruginosa (PAe) is shown. The growth rate is measured based on the turbidity of the sample 102 over time (the turbidity is determined based on the McFarland (McF) reference standard for representing the turbidity of bacterial suspensions). The more turbid the sample solution, the higher the concentration of PAe within the sample 102.

[0339] like Fig.12As shown, aerating the sample 102 (as shown by the dashed curve) increases the growth rate of bacteria within the sample 102, so that the time required for the sample 102 to reach a turbidity level equivalent to 0.5 McFarland (McF) is significantly reduced (180 minutes vs. 460 minutes) compared to the unaerated or static sample 102 (as shown by the solid line graph). The sample 102 can be aerated by pumping a gas (e.g., ambient air, oxygen, etc.) into the sample chamber 908 through the aeration port 936 and the gas permeable membrane 938. In some embodiments, the aeration port 936 can be defined on the bottom side of the sample container 802. A micro pump can be used to pump gas 940 or ambient air into the sample chamber 908. In some embodiments, the gas 940 or ambient air can be pumped into the sample chamber 908 at a constant flow rate between about 1 mL / minute and about 10 mL / minute.

[0340] Fig.13 Shown is the effect of aeration on the preparation time of two 0.5 McFarland bacterial samples using the sensor device 800 disclosed herein. The 0.5 McFarland samples can be prepared for additional downstream testing, such as one of one or more antibiotic susceptibility tests.

[0341] like Fig.13 As shown, one sample container 802 filled with a sample including Pseudomonas aeruginosa (PAe) is aerated (e.g., with ambient air), while another sample container 802 filled with a similar sample including PAe is not aerated. A container cap 806 serving as a reference sensor component 804 is then secured to each of the sample containers 802, and each sensor device 800 is then electrically coupled to a parameter analyzer 916 for detecting changes in the ORP of the sample.

[0342] A computing device or another device coupled to the parameter analyzer 916 then records the changes in ORP of the samples within each of the sample containers 802 and compares these values ​​to data within one or more lookup tables retrieved from the computing device coupled to the parameter analyzer 916 or a database accessible to the computing device.

[0343] like Fig.13 As shown, the PAe concentration in the aerated sample container 802 reaches the defined concentration of 0.5 McFarland in about 160 minutes, while the PAe concentration in the static or unaerated sample container 802 reaches the same defined concentration of 0.5 McFarland in about 460 minutes. Therefore, it is shown that aerating the sample container 802 can significantly enhance the bacterial growth rate in the sample chamber 908.

[0344] Each of the various variations or embodiments described and illustrated herein has discrete components and features that can be readily separated or combined with the features of any of the other variations or embodiments. Modifications may be made to adapt a particular situation, material, composition of matter, process, one or more process actions, or one or more steps to one or more of the purposes, spirit, or scope of the present invention.

[0345] The methods described herein may be performed in any order of the described events that is logically possible, as well as in the described order of events. For example, the flowcharts or process flows depicted in the accompanying drawings do not require the particular order shown to achieve the desired results. Moreover, additional steps or operations may be provided, or steps or operations may be omitted to achieve the desired results.

[0346] Those of ordinary skill in the art will appreciate that all or part of the methods disclosed herein may be embodied in a non-transitory machine-readable or accessible medium including instructions that may be read or executed by a processor or processing unit of a computing device or other type of machine.

[0347] In addition, where a range of values ​​is provided, each intervening value between the upper and lower limits of that range and any other stated or intervening value in that stated range is included within the present invention. In addition, any optional features of the described inventive variations may be proposed and claimed independently or in combination with any one or more of the features described herein.

[0348] All prior subject matter (e.g., publications, patents, patent applications, and hardware) mentioned herein are incorporated herein by reference in their entirety, unless such subject matter may conflict with the subject matter of the present invention (in which case the content of this document controls). The referenced items are provided only for their disclosure as of the filing date of the present application. Nothing herein should be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior art.

[0349] References to singular items include the possibility of multiple identical items. More specifically, as used herein and in the appended claims, the singular forms "a," "an," "said," and "the" include plural objects unless the context clearly indicates otherwise. It should also be noted that the claims can be drafted to exclude any optional elements. In this way, this statement is intended to serve as a prior basis for using such exclusive terms such as "only," "only," etc., or using "negative" limitations in conjunction with the recitation of claim elements. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention belongs.

[0350] The present disclosure is not intended to be limited to the scope of the particular form set forth, but is intended to cover alternatives, modifications, and equivalents of the variations or embodiments described herein. In addition, the scope of the present disclosure fully encompasses other variations or embodiments that are obvious to those skilled in the art in view of the present disclosure. The scope of the present invention is limited only by the appended claims.

Claims

1. A reference sensor component, the reference sensor component comprising: a container cover configured to be removably coupled to a sample container configured to receive a sample; a reference conduit extending from an underside of the container cover, the reference conduit comprising a reference conduit lumen; a wicking member disposed within a portion of the reference catheter lumen, the wicking member having a wick distal end and a wick proximal end, wherein at least a portion of the wicking member is configured to contact the sample fluid when the container cap is coupled to the sample container such that at least some of the sample is drawn by the wicking member in the direction of the wick proximal end; and A reference electrode material is disposed at the core proximal end, wherein the reference electrode material is configured to exhibit a substantially stable electrode potential compared to an active electrode in electrical communication with the reference electrode material.

2. The reference sensor component according to claim 1, wherein: The container cover is partially made of a non-conductive material.

3. The reference sensor component according to claim 2, wherein: The container cover is fabricated in part from a transparent non-conductive material such that at least a portion of the wicking component is visible through the container cover.

4. The reference sensor component according to claim 1, wherein: The reference electrode material is a conductive ink applied or dispensed on the proximal end of the core.

5. The reference sensor component according to claim 4, wherein: The conductive ink applied or dispensed on the proximal end of the core is hardened by curing.

6. The reference sensor component according to claim 4, wherein: The conductive ink is silver-silver chloride ink.

7. The reference sensor component according to claim 1, wherein: The wicking member is fabricated in part from a porous polymeric material.

8. The reference sensor component according to claim 1, wherein: The wicking component is made in part from natural fibers.

9. The reference sensor component according to claim 1, wherein: The wicking component comprises pores having a size between 15 μm and 150 μm.

10. The reference sensor component according to claim 1, wherein: The wicking member is treated with a surfactant such that at least a surface of the wicking member is covered with the surfactant, wherein the surfactant is configured to increase the hydrophilicity of the wicking member.

11. A method for measuring a solution property of a sample, the method comprising: filling a specimen chamber of a specimen container with a specimen including an infectious agent; attaching a container cap to the sample container, wherein the container cover comprises a reference conduit, the reference conduit comprising a reference conduit cavity, a reference conduit first opening and a reference conduit second opening, wherein the reference catheter lumen is partially filled by a wicking member extending through the reference catheter lumen, the wicking member having a wick distal end and a wick proximal end, wherein at least a portion of the wicking member is in contact with the sample fluid within the sample chamber, and wherein at least some of the sample is drawn by the wicking member in the direction of the wick proximal end, wherein a reference electrode material is disposed at the proximal end of the core; electrically coupling the reference electrode material to a parameter analyzer and electrically coupling the parameter analyzer to an active sensor component including an active electrode material, wherein at least a portion of the active electrode material extends into the sample chamber and contacts the sample fluid; and Based on the potential difference measured between the active electrode material and the reference electrode material, a solution property of the sample is determined.

12. The method according to claim 11, wherein: The reference electrode material is a conductive ink applied or dispensed on the proximal end of the core.

13. The method according to claim 12, wherein: The conductive ink applied or dispensed on the proximal end of the core is hardened by curing.

14. The method according to claim 12, wherein: The conductive ink is silver-silver chloride ink.

15. The method of claim 11, wherein air is pumped into the sample chamber through an aeration port defined along at least one of a bottom side and a lateral side of the sample container and a hydrophobic, breathable membrane covering the aeration port, wherein: The air pumped into the sample chamber aerates the sample.

16. The method according to claim 15, wherein: The air pumped into the sample chamber passes through an additional air permeable membrane covering at least a portion of an underside of the container cover and exits the sample chamber through an air gap defined between the container cover and the sample container along an attachment connection.

17. The method according to claim 11, wherein: Determining a solution property of the sample includes determining a pH of the sample, and wherein the active electrode material is fabricated in part from a pH sensitive material.

18. The method according to claim 17, wherein: The pH sensitive material includes at least one of silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide and zirconium dioxide.

19. The method according to claim 11, wherein: Determining a solution property of the sample includes determining an oxidation-reduction potential (ORP) of the sample, and wherein the active electrode material is fabricated in part from a redox-sensitive material.

20. The method according to claim 19, wherein: The redox sensitive material includes at least one of the following: platinum, gold, silicon dioxide, aluminum oxide, titanium dioxide, tantalum pentoxide, hafnium dioxide, iridium dioxide, ruthenium dioxide, and zirconium dioxide.

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