A method of continuously manufacturing a template for a working electrode

Abstract

A method of continuously manufacturing a template (112) for a working electrode (114), a plurality of working electrodes (114), wherein each working electrode (114) is based on the template (112) for the working electrode (114) as produced by the method, and a continuous monitoring system comprising at least one working electrode (114) from the plurality of the working electrodes (114) are disclosed. The method comprises: • i. providing a continuous carbon-coated substrate (116); and • ii. forming a continuous line (120) of at least one enzyme-wired hydrogel compound (122) on the carbon-coated substrate (116) by using a continuous reel-to-reel coating process, whereby the continuous line (120) has a lateral width (132) of 0.2 mm to 3 mm and a mean thickness (134) of 2 μm to 40 μm.

Description

[0001] Roche Diabetes Care GmbH September 30, 2025

[0002] RD15672PC ST / GS / KV

[0003] A method of continuously manufacturing a template for a working electrode

[0004] Technical Field

[0005] The present invention refers to a method of continuously manufacturing a template for a working electrode, a plurality of working electrodes, wherein each working electrode is based on the template for the working electrode as produced by the method, and a continuous monitoring system comprising at least one working electrode from the plurality of the working electrodes. The method and the devices, as an example, may be used in the field of medical diagnostics for detecting one or more properties of a sample of a bodily fluid, e.g. a presence and / or a concentration of at least one analyte in the sample of the bodily fluid. Other fields of application of the present invention, however, are also feasible.

[0006] Background art

[0007] Analytical test elements addressed herein are wearable medical devices which comprise at least one electrochemical biosensor being configured for a continuous monitoring of at least one analyte in an interstitial fluid. For example, in the field of medical diagnostics, such in point of care applications and / or in laboratories, samples of a bodily fluid, particularly selected from saliva, blood, interstitial fluid, urine, salvia, sweat, or serum, have to be analyzed, e.g. in order to detect a presence and / or a concentration of an analyte in the sample of the bodily fluid. Examples of analytes to be detected are antigenic proteins of viruses, such as antigenic proteins of the SARS-CoV-2 coronavirus, and other types of analytes, such as glucose, triglycerides, lactate, cholesterol or other types of analytes typically present in these bodily fluids. For this purpose, the electrochemical biosensor comprises at least one working electrode, which has an analyte detection agent that is sensitive to a particular analyte provided on a substrate. Generally, a current that is generated by the working electrode for a particular analyte concentration scales with an effective area of the analyte detection agent provided on a surface of the working electrode being in contact with the analyte. As a consequence thereof, it is desirable to apply the analyte detection agent in a well-defined geometry of the effective area on the surface of the working electrode. In known prior art solutions, the well- defined geometry of the effective area is provided by using a particularly precise deposition of selected amounts of the analyte detection agent in order to confine the actual outlines of the effective area.

[0008] WO 2021 / 180977 Al discloses a method for the preparation of a working electrode on a sensor substrate. The method comprises: providing at least one sensor substrate comprising at least a first side, the first side comprising at least one conductive trace; applying at least one layer of at least one sensing material onto the first side of the sensor substrate, wherein the sensing material covers at least a portion of the at least one conductive trace; irradiating the layer of the sensing material with at least one laser beam, wherein at least a first portion of the layer of the sensing material is at least partially removed, and wherein at least a second portion of the sensing material covering the at least one conductive trace is preserved on the first side of the sensor substrate to obtain at least one working electrode on the sensor substrate; applying at least one membrane layer at least partially covering the working electrode, wherein the membrane layer comprises at least one cross-linker for cross-linking at least a part of the sensing material; and at least one diffusion step, wherein in the diffusion step the cross-linker comprised in the membrane layer at least partially diffuses into the sensing material.

[0009] It would be advantageous to apply a known slot-die coating process, however, such a process is, typically, only available for a coating width of above 3 mm, when additional shearthinning coating compounds are used. As the effective area of the analyte detection agent on the surface of the working electrode may have line widths of 3 mm or smaller, a sophisticated deposition method, particularly selected from micro dispensing or stationary screen printing, is, typically, used in prior art processes for manufacturing effective areas of the analyte detection agent on the surface of working electrodes. However, this approach requires sufficiently precise patterning and poses challenges, especially with regard to process times and / or material efficiency. Despite the advantages already achieved by known method and devices, several technical challenges remain. A typical analyte detection agent comprises a reactive mixture. As a consequence thereof, it is desirable to ensure that narrowly defined quantities of the analyte detection agent are handled in narrowly defined time windows to be deposited on narrowly defined locations. As a result, quantities, stand times, and positioning are, concurrently, crucial and need to be controlled simultaneously to ensure a sufficient product quality.

[0010] Problem to be solved

[0011] It is, therefore, desirable to provide a method of continuously manufacturing a template for a working electrode, a plurality of working electrodes, and a continuous monitoring system, which at least partially overcome the limitations of the prior art.

[0012] Specifically, it is desirable to provide a method that is configured to provide an analyte detection agent in a well-defined, highly homogeneous geometry on a surface of a template for a working electrode in a continuous manner, wherein desired extensions of the effective area of the analyte detection agent on the surface of the template of the working electrode are achieved.

[0013] Summary

[0014] This problem is addressed by a method of continuously manufacturing a template for a working electrode, a plurality of working electrodes, and a continuous monitoring system having the features of the independent claims. Advantageous embodiments that can be implemented in an isolated fashion or in any arbitrary combination are listed in the dependent claims as well as throughout the specification.

[0015] In a first aspect of the present invention, a method of continuously manufacturing a template for a working electrode is disclosed. In the following, the method may also be referred to as “manufacturing method”. The method comprises the following method steps: i. providing a continuous carbon-coated substrate; and ii. forming a continuous line of at least one enzyme-wired hydrogel compound on the carbon-coated substrate by using a continuous reel-to-reel coating process, whereby the continuous line has a lateral width of 0.2 mm to 3 mm and a mean thickness of 2 pm to 40 pm. The method steps may, as a preferred example, be performed in the given order. It shall be noted, however, that it is possible to perform one or more or even all of the method steps once or repeatedly. Further, it is possible to perform two or more of the method steps simultaneously or in a timely overlapping fashion. The method may comprise additional method steps, which are not listed.

[0016] The method is directed to a manufacturing process. The term “manufacturing” or any grammatical variation thereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of producing at least one product from one or more base products. Specifically, the manufacturing process may comprise processing and / or transforming one or more base products into the product. The product of the manufacturing method may comprise a template for a working electrode. The manufacturing of the template for the working electrode may comprise processing at least one element and / or component in such as manner as to retrieve the template for the working electrode.

[0017] The method is performed as a continuous manufacturing process. The term “continuous” or any grammatical derivation hereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. On one hand, the term specifically may refer, without limitation, to a characteristic of a process of potentially being uninterrupted and / or perpetual, which may, however, be interrupted by an intent of the user of the method or an unpredictable event. On the other hand, the term specifically may refer, without limitation, to a characteristic of an object of potentially having an unlimited extension, especially in one dimension, wherein the object may be provided in consecutive portions during subsequent time intervals by using a continuous process. As described below in more detail, the continuous manufacturing of the template comprises using a continuous reel-to-reel coating process, whereby consecutive portions of the continuous substrate are provided during subsequent time intervals for applying the analyte detection agent to the substrate.

[0018] The method is directed to manufacturing a template for a working electrode. The term “working electrode” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an electrode configured for performing at least one electrochemical detection reaction for detecting the at least one analyte. The working electrode may have an analyte detection agent being sensitive to the analyte to be detected. The term “analyte detection agent” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to at least one material adapted to change a detectable property in presence of an analyte. This property may, preferably, be an electrochemically detectable property. The analyte detection agent may be a selective analyte detection agent that only changes the detectable property if the analyte is present in the body fluid, whereas no change occurs if the analyte is not present. A degree of the change of the property is dependent on the concentration of the analyte in the body fluid to allow a quantitative detection of the analyte. As described below in more detail, the analyte detection agent may comprise an enzyme, such as glucose oxidase and / or glucose dehydrogenase; however, using a different kind of analyte detection agent may also be feasible. For potential analyte detection agents, reference can be made to WO 2007 / 071562 Al and the prior art documents cited therein. In addition to the working electrode which may be selected from a subcutaneous detection electrode or a minimally-invasive detection electrode, the electrochemical biosensor may comprise at least one further electrode, preferably selected from a counter electrode, a reference electrode, or a combined counter / reference electrode, which may be a subcutaneous electrode and / or an on-skin electrode.

[0019] As outlined above, the present method is directed to continuously manufacturing a template for a working electrode. The term “template” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an intermediate product being manufactured from simpler base products and intended for further processing of more complex products. Specifically, the template may be used for further processing to manufacture the plurality of the working electrodes. The intermediate product may at least partially form part of the manufactured plurality of the working electrodes. Alternatively, in other examples, the intermediate product may not be part of the manufactured plurality of the working electrodes but may be used in one or more processing steps to manufacture the plurality of the working electrodes.

[0020] The template for the working electrode as manufactured by using the present method is an intermediate product, which may, preferably, be configured for producing at least one working electrode in a continuous monitoring system. The term “continuous monitoring system” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a system configured for performing a process of continuously surveilling a person by consecutively acquiring data and deriving desired information therefrom without user interaction. For this purpose, a plurality of measurement signals are generated and evaluated, wherefrom the desired information is determined. Herein, the plurality of measurement signals may be recorded within fixed or variable time intervals or, alternatively or in addition, at an occurrence of at least one prespecified event. In particular, the continuous monitoring system may be configured for monitoring one or more analytes, in particular of glucose, such as for managing, monitoring, and controlling a diabetes state.

[0021] As outlined above, step i. of the present method comprises providing a continuous carbon- coated substrate. The term “providing” or any grammatical variation thereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of supplying and / or making available. Specifically, the providing of the substrate in step i. may comprise making the substrate available for further processing during the manufacturing process. The providing of the substrate may comprise supplying the substrate to a manufacturing device and / or producing the substrate from one or more base products.

[0022] The substrate as provided during step i. of the present method is a continuous substrate. As used herein, the term “substrate” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary element designed to carry one or more other elements disposed thereon or therein. Specifically, the substrate may be flexible and / or deformable. Preferably, the substrate may be a planar substrate. As generally used, the term “planar” refers to a body comprising extensions in two dimensions, typically denoted as “surface” of the planar body, which exceed the extension in a third dimension, usually denoted as “thickness” of the planar body, by a factor of 2, at least a factor of 5, at least a factor of 10, or even at least a factor of 20 or more. As an example, the substrate may have a thickness of 50 pm to 1 mm, specifically of 80 pm to 500 pm, such as 110 pm to 250 pm. Using a planar substrate may, particularly, facilitate providing a flat electrode. As generally used, the term “flat electrode” refers to a particular type of electrode which comprises a planar substrate that provides a carrier for the further elements, preferably the analyte detection agent, of the electrode to be provided, preferably, in form of one or more layers, directly or indirectly, deposited on the substrate. For the term “continuous”, reference can be made to the definition provided above. As outlined above, a continuous carbon-coated substrate is provided during step i. of the present method. The term “coating” or any grammatical variation thereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process which comprises depositing a material onto a surface. As described below in more detail, a portion of the surface of the substrate is coated with a selected kind of analyte detection agent. Further, the term “carbon” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a formation of the chemical element carbon from the period table of chemical elements.

[0023] The carbon-coated substrate may, preferably, comprise a polymer foil, wherein the polymer foil may be coated on at least one side, preferably on both sides, by a carbon ink, wherein the carbon ink may, in particular, comprise a binder material. The term “polymer” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. Further, the term “foil” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary film like material being designed as a carrier. Specifically, the foil may have a foil shape, wherein the foil in a first extension direction may be at least ten times smaller than an extension of the foil in another direction, extending orthogonally to the first direction. The foil specifically may be made of at least one flexible or deformable material, such as at least one flexible or deformable plastic foil. The foil, as an example, may have a thickness of 10 pm to 500 pm. The polymer foil, specifically, may comprise macromolecules having a plurality of repeated subunits in a manner that they constitute the foil.

[0024] The term “carbon ink” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a formation of carbon that comprises paracrystalline particles, also denoted as pigment “carbon black”, which can be obtained from incomplete combustion of a carbon-comprising material. In contrast to soot, carbon ink has a higher surface-area-to-volume ratio and a significantly lower, particularly a negligible and non-bioavailable, polycyclic aromatic hydrocarbon content. However, using, alternatively or in addition, a different kind of carbon, in particular graphite, may also be feasible. The carbon ink may, preferably, be a suspension having a solid content of 20 wt.% to 70 wt.%, more preferred of 30 wt.% to 60 wt.%, in particular of 40 wt.%, of the binder material. The term “binder material” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a first material which is configured to maintain at least one further material in a composition ‘as is’, preferably by using adhesion and / or cohesion. The solid content of the binder material as comprised by the carbon-coated substrate may, preferably, be selected for adjusting a contact angle between the surface of the carbon-coated substrate and the enzyme-wired hydrogel compound. In his manner, the deposition of the enzyme-wired hydrogel compound on the surface of the carbon-coated substrate can be controlled. The binder material may, preferably, be selected from an organic binder material, specifically from the group consisting of polyvinyl acetate (PVA), peroxyacetic acid (PAA), polyethylene glycol (PEG), polyvinylphenol (PVP), polyvinyl sulfonate, polyvinyl amine, and polyvinyl chloride (PVC). However, using a different kind of binder material may also be feasible.

[0025] As outlined above, step ii. of the present method comprises forming a continuous line of at least one enzyme-wired hydrogel compound on the carbon-coated substrate. The term “forming” or any grammatical variation thereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of generating at least one element, especially by using an initial composition that is designed for this purpose as described below in more detail. The term “surface” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an anterior area of an object or element. Specifically, the surface of the substrate may be an area having the selected kind of analyte detection agent disposed thereon. In other words, the surface of the substrate may be an area facing towards the selected kind of analyte detection agent as disposed onto the substrate.

[0026] The continuous line of the least one enzyme-wired hydrogel compound is formed on the carbon-coated substrate, especially on the surface of the carbon-coated substrate as a particular analyte detection agent that is configured for performing a detection reaction in the presence of the at least one analyte, wherein the detection reaction is sensitive to the analyte to be detected. The analyte detection agent as used herein comprises an hydrogel compound having a wired enzyme. The term “hydrogel compound” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a mixture comprising at least one permeable solid compound and an aqueous solution. The hydrogel may comprise a three-dimensional network of the permeable solid compound that is insoluble in the aqueous solution.

[0027] The continuous line of the least one enzyme-wired hydrogel compound may, preferably, be formed by applying to the carbon-coated substrate an initial composition, which may, in particular, comprise at least one enzyme, at least one polymer backbone, and at least one cross-linker in an aqueous solution, which are configured to collectively form the enzyme- wired hydrogel compound after a conditioning process. The term “applying” or any grammatical variation thereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of disposing or and / or placing at least one element on at least one further element. The applying may comprise forming a layer of one element on a surface of another element. Specifically, the applying in step ii. may comprise disposing a selected kind of analyte detection agent on a portion of the surface of the substrate. Further, the term “conditioning process” or any grammatical variation thereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of treating a substance under controlled conditions. The conditioning process may, preferably comprise at least one of drying or storing the initial composition at a controlled temperature and / or humidity for a period of time.

[0028] The initial composition may, particularly, be provided as an aqueous solution. In addition, the aqueous solution as comprised by the initial composition may, preferably, have a liquid content of 1 vol.% to 60 vol.%, more preferred of 10 vol.% to 30 vol.%, in particular of 20 vol.%, of at least one polar solvent. The term “polar solvent” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an organic solvent having a high dielectric constant suitable for being miscible with the aqueous solution as comprised by the initial composition. The liquid content of the at least one polar solvent may, preferably, be selected for adjusting a surface tension and an energy of the enzyme-wired hydrogel compound obtained from the initial composition on the carbon-coated substrate. The at least one polar solvent may, preferably, be selected from the group consisting of propanol, methanol, ethanol, acetonitrile, ethyl acetate, and acetone; however, using a different kind of polar solvent may also be feasible.

[0029] As outlined above, the initial composition, may, particularly, comprise at least one crosslinker. The term “cross-linker” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a substance configured to provide a temporary or a permanent connection between two different species. Preferably, the cross-linker may be selected from the group consisting of diglycidyl ethers and triglycidyl ethers, in particular polyethylene glycol diglycidyl ether (PEDGE), bisphenol A diglycidyl ether, butanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N-Diglycidyl-4-glycidyloxyaniline; cycloaliphatic epoxides, and epoxydized olefins.

[0030] As further outlined above, the enzyme-wired hydrogel compound as comprised by the analyte detection agent used herein has a wired enzyme. The term “enzyme” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a biological catalyst. The enzyme may be configured for increasing a reaction rate in the detection layer, specifically for speeding up a reaction process, such as the reaction process of the chemical compound. The enzyme may be or may comprise an analyte specific protein, such as a protein allowing for an analyte specific detection reaction. In particular, the enzyme may be configured for acting upon a specific analyte and / or a group of analytes only. The enzyme may configured for converting only specific analytes in the sample. By way of example, the enzyme may, preferably, be selected from glucose oxidase and / or glucose dehydrogenase, wherein the electrochemical biosensor may be configured to convert glucose into an electrically charged entity by using the enzyme.

[0031] The terms “wired enzyme” or “enzyme-wired” as used herein are broad terms and are to be given their ordinary and customary meaning to a person of ordinary skill in the art and are not to be limited to a special or customized meaning. The terms specifically may refer, without limitation, to a type of polymeric matrix that is immobilized in an electrode, particularly in a working electrode, wherein the matrix comprises at least one enzyme. The wired enzyme may be configured for providing a direct electron transfer mechanism which does not require the at least one mediator substance. As a preferred alternative, the wired enzyme may comprise at least one mediator substance. The term "mediator substance" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a substance configured for providing a mediator-based electron transfer mechanism, specifically by having binding redox-active centers. The mediator substance may, preferably, be selected from the group consisting of an osmium complex, a ruthenium complex, and a ferrocene; however, using a different kind of mediator substance may also be feasible.

[0032] The initial composition may, preferably, comprise a solid content of 5 wt.% to 30 wt.%, more preferred of 10 wt.% to 20 wt.%, in particular of 16 wt.%, of the polymer backbone which further comprises the at least one mediator substance. The term "polymer backbone" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a polymer species comprising at least one kind of polymer, wherein the at least one mediator substance is integrated and transformable into a hydrogel by reaction with a cross-linker. The solid content of the at least one mediator substance may, preferably, be selected for adjusting a viscosity of the enzyme- wired hydrogel compound to be generated by applying the initial composition to the carbon- coated substrate. The term "viscosity" as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a grade of resistance of a fluid, particularly of the enzyme-wired hydrogel compound, to a deformation at a particular rate, wherein the grade is indicated by a force applied to the fluid multiplied by a time and divided by an area application of the force to the fluid.

[0033] The continuous line of at the least one enzyme-wired hydrogel compound is formed on the carbon-coated substrate in a manner that the continuous line has a lateral width of 0.2 mm to 3 mm. The term “lateral width” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a lateral extension of an element, specifically the continuous line, in a direction that is perpendicular to a direction of a longitudinal extension of the element but parallel to the surface where the element is formed, wherein the longitudinal extension surpasses both the lateral width and the thickness of the element as defined below. The continuous line of at the least one enzyme-wired hydrogel compound is formed on the carbon-coated substrate in a further manner that the continuous line has a mean thickness of 2 pm to 40 pm. The term “thickness” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an elevational extension of an element, specifically the continuous line, in a direction which is perpendicular with respect to both the direction of the longitudinal extension of the element and the lateral width of the element, and which is further perpendicular with respect to the surface where the element is formed.

[0034] As further outlined above, step ii. of the present method is performed by using a reel-to-reel process. The term “reel-to-reel process” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process involving at least two turning objects and / or rotating objects, such as at least two rotating wheels and / or rolls. The reel-to-reel process may, specifically, comprise transferring at least one element stored on a first roll, such as an element having a sheet form and / or tape form, onto a second element, wherein at least one processing step is performed during the transfer. Thus, as an example, the reel-to-reel process may refer to a process starting with a first roll of material, wherein the first roll comprises a layer of the enzyme- wired hydrogel compound, and depositing the material as provided by the roll to a further roll as provided during step i., wherein the further roll comprises the carbon-coated substrate. The reel-to-reel-process may also be referred to as roll-to-roll-process.

[0035] In a preferred embodiment, the continuous reel-to-reel coating process may comprise using a cannula. The term “cannula” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device configured for guiding a liquid sample along a predetermined path. In particular, upon entry into the cannula, the liquid sample, especially the initial composition, may flow through the cannula, thus being transported by the cannula along the predetermined path, particularly to the surface of a substrate. The cannula may specifically be a tube, in particular a small tube, such as a tube having a limited height and / or a limited cross section or diameter. However, using a different type of cannula or performing the continuous reel-to-reel coating process without using a cannula may also be feasible. At least a surface of the cannula that is configured for being in contact with the enzyme- wired hydrogel compound may, preferably, be coated with a hydrophobic material. The term “hydrophobic material” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a substance which is configured to repel an aqueous solution from its surface. In particular, the hydrophobic material may be selected for adjusting an interaction between the cannula and the initial composition in a manner that a pinning on a dimension of the cannula and / or a creeping of the initial composition along the cannula may, preferably, be avoided. The hydrophobic material as used for the cannula may, preferably, be selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), and silicon; however, using a different kind of hydrophobic material may also be feasible.

[0036] The method may further comprise at least one further step: iii. applying at least one further continuous line of at least one additional substance to the carbon-coated substrate.

[0037] The at least one further continuous line of the at least one additional substance may, preferably, be applied laterally with respect to the continuous line of the at least one enzyme- wired hydrogel compound on the same surface of the carbon-coated substrate. The at least one further continuous line of the at least one additional substance may, preferably, be an insulating layer. The term “insulating layer” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a layer which comprises an electrically non-conductive material. The electrically non-conductive material may, preferably be selected from thermoplastic polyurethane, polytetrafluoroethylene, polyethylene, polyvinylidene difluoride, silicone, (meth)acrylate, polyurethane, polyimide, phenolic resins, polyolefines, resins, and waxes.

[0038] As an alternative, the at least one further continuous line of the at least one additional substance may, preferably, be selected from a reference electrode, or a combined counter / reference electrode. The term “reference electrode” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a further electrode of the electrochemical biosensor that is configured to provide an electrochemical reference potential which, at least widely, is independent of the presence or absence or concentration of the analyte. Further, the term “combined counter / reference electrode” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a further electrode of the electrochemical biosensor that is configured to provide an electrochemical reference potential and to balance the current flow from the working electrode.

[0039] The method may further comprise at least one further step: iv. patterning the continuous line of the at least one enzyme-wired hydrogel compound on the carbon-coated substrate.

[0040] The term “pattering” or any grammatical variation thereof as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of adjusting an area of a layer by using an additive process and / or a subtractive process, wherein the subtractive process is configured to remove already deposited material, while the additive process is configured to deposit further material to the already deposited material. The patterning of the continuous line of the at least one enzyme- wired hydrogel compound may, preferably, comprise using a subtractive process, which may, in particular, be selected from laser ablation and / or a lithographic process.

[0041] The method may further comprise at least one further step: v. cutting the carbon-coated substrate comprising the continuous line of the at least one enzyme-wired hydrogel compound into pieces in manner that each piece comprises a portion of the template for the working electrode.

[0042] The term “cutting” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of separating at least one element from at least one further element. The cutting may comprise using at least one cutting device configured for cutting the at least one element in the cutting process completely or using a device configured for introducing perforation lines into the at least one element. The cutting device may, preferably, be selected from a cutting blade or a laser, particularly depending on the dimensions involved in the cutting process; however using a different kind of cutting device may also be feasible.

[0043] The method may further comprise at least one further step: vi. applying at least one continuous diffusion-limiting membrane at least to the continuous line of the at least one enzyme-wired hydrogel compound.

[0044] The at least one continuous diffusion-limiting membrane may, preferably, be applied on a surface of the continuous line of the at least one enzyme-wired hydrogel compound by using at least one coating process, particularly selected from dip-coating or spray-coating; however, using at least one further type of coating process may also be feasible. The term “membrane” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a semipermeable layer which is placed on the surface of the enzyme-wired hydrogel compound forming the working electrode in a manner that the body fluid contacts the working electrode through the semipermeable layer which covers the surface of the working electrode, wherein the working electrode is embodied in a fashion that an electrochemical reaction, specifically oxidative processes and / or reductive processes, may occur at the surface of the working electrode. The membrane may, preferably, be a continuous membrane, thereby being adapted to the continuous working electrode. For the term “continuous”, reference can be made to definition provided above.

[0045] The membrane may, preferably, be a diffusion-limiting membrane. The term “diffusionlimiting” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a process of controlling access to a particular surface during a diffusion-based process. The diffusionlimiting membrane is configured for providing access to the analyte detection agent on the surface of the working electrode only to a particular amount of the analyte in order to control the reaction of the analyte with the analyte detection agent.

[0046] In principle, the optional steps iii. to vi. may be performed in any desired order, however, performing the optional steps iii. to vi. in the indicated order may be preferred, wherein any one of the optional steps iii. to vi. may be performed in a repeating manner.

[0047] In a further aspect of the present invention, plurality of working electrodes is disclosed, wherein each working electrode is based on the template for the working electrode which is produced by a method of continuously manufacturing a template for a working electrode according to the present invention, such as according to any one of the embodiments disclosed above and / or according to any one of the embodiments disclosed in further detail below. Each working electrode may, preferably, be configured for being inserted into a skin of a patient.

[0048] The plurality of working electrodes produced by the manufacturing method according to the present invention may be assembled in units of manufactured plurality of working electrodes, particularly in roll ware units or sheet ware units of 10, 20, 50, or even 100 working electrodes having perforation lines between adjacent working electrodes. Additionally or alternatively, the plurality of working electrodes produced by the manufacturing method according to the present invention may be identified at a cutting edge between two separations of the plurality of the working electrodes, e.g. at a plain cutting edge for a batch manufacturing method or at an angled cutting edged for a continuous manufacturing method.

[0049] In a further aspect of the present invention, a continuous monitoring system is disclosed, wherein the continuous monitoring system comprises at least one working electrode from the plurality of the working electrodes.

[0050] The manufacturing method, the template for a working electrode, and the plurality of the working electrodes according to the present invention may provide a larger number of advantages, specifically compared with known methods or devices. They work well in contrast to well-known continuous coating technologies, such as like reel-to-reel slot-die coating, which are, typically, applied for coatings having a width above 3 mm and shearthinning coating compounds. For water-based compounds, slot-die coating is, typically, not used since the coatings obtained therewith are suffering from a low homogeneity with regard to line width, thickness, or edge effects. Furthermore, working electrode used for continuous monitoring have areas which are small compared to a line width above 3 mm, thus resulting in a low material efficiency and long process times for patterning technologies used for generating a well-defined geometry for the working electrode form the continuous coating. Therefore, a use of laser ablation or lithographic methods for a purpose of generating a well- defined geometry for the working electrode is rare. Rather, a complex deposition technology, such as micro dispensing, or stationary screen printing, is, typically, applied for generating the well-defined geometry for the working electrode; however, these methods suffer from drawbacks regarding throughput, standing times and positioning tolerances. In contrast hereto, the manufacturing methods according to the present invention, specifically, require low efforts but they are, nevertheless, suitable for manufacturing the desired templates for the working electrodes at high quantities with high throughput and at low production costs. As used in the herein, the terms “have”, “comprise” or “include” or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situation in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions “A has B”, “A comprises B” and “A includes B” may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.

[0051] Further, it shall be noted that the terms “at least one”, “one or more” or similar expressions indicating that a feature or element may be present once or more than once typically will be used only once when introducing the respective feature or element. Herein, in most cases, when referring to the respective feature or element, the expressions “at least one” or “one or more” will not be repeated, non-withstanding the fact that the respective feature or element may be present once or more than once.

[0052] Further, as used herein, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative features. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features, without any restriction regarding alternative embodiments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.

[0053] Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged:

[0054] Embodiment 1. A method of continuously manufacturing a template for a working electrode, the method comprising: i. providing a continuous carbon-coated substrate; and ii. forming a continuous line of at least one enzyme- wired hydrogel compound on the carbon-coated substrate by using a continuous reel-to-reel coating process, whereby the continuous line has a lateral width of 0.2 mm to 3 mm and a mean thickness of 2 pm to 40 pm.

[0055] Embodiment 2. The method according to the preceding embodiment, wherein the continuous line of the enzyme-wired hydrogel compound is formed on a surface of the carbon-coated substrate.

[0056] Embodiment 3. The method according to any one of the preceding embodiments, wherein the continuous line of the least one enzyme-wired hydrogel compound is formed by applying to the carbon-coated substrate an initial composition, wherein the initial composition comprises at least one enzyme, at least one polymer backbone, and at least one cross-linker in an aqueous solution.

[0057] Embodiment 4. The method according to the preceding embodiment, wherein the at least one enzyme, the at least one polymer backbone and the at least one cross-linker as comprised by the initial composition are configured to collectively form the enzyme-wired hydrogel compound after a conditioning process.

[0058] Embodiment s. The method according to any one of the two preceding embodiments, wherein the aqueous solution has a liquid content of 1 vol.% to 60 vol.%, preferably of 10 vol.% to 30 vol.%, in particular of 20 vol.%, of at least one polar solvent.

[0059] Embodiment 6. The method according to the preceding embodiment, wherein the liquid content of the at least one polar solvent is selected for adjusting a surface tension and an energy of the enzyme-wired hydrogel compound on the carbon-coated substrate.

[0060] Embodiment 7. The method according to any one of the two preceding embodiments, wherein the at least one polar solvent is selected from the group consisting of propanol, methanol, ethanol, acetonitrile, ethyl acetate, and acetone.

[0061] Embodiment 8. The method according to any one of the five preceding embodiments, wherein the cross-linker is selected from the group consisting of diglycidyl ethers and triglycidyl ethers, in particular polyethylene glycol diglycidyl ether (PEDGE), bisphenol A diglycidyl ether, butanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N- Diglycidyl-4-glycidyloxyaniline; cycloaliphatic epoxides, and epoxydized olefins. Embodiment 9. The method according to any one of the preceding embodiments, wherein the enzyme-wired hydrogel compound is configured for providing a direct electron transfer mechanism or a mediator-based electron transfer mechanism.

[0062] Embodiment 10. The method according to the preceding embodiment, wherein the mediator-based electron transfer mechanism is provided by at least one mediator substance.

[0063] Embodiment 11. The method according to the preceding embodiment, wherein the at least one mediator substance is selected from the group consisting of an osmium complex, a ruthenium complex, and a ferrocene.

[0064] Embodiment 12. The method according to any one of the two preceding embodiments, wherein the initial composition comprises a solid content of 5 wt.% to 30 wt.%, preferably of 10 wt.% to 20 wt.%, in particular of 16 wt.%, of the polymer backbone further comprising the at least one mediator substance.

[0065] Embodiment 13. The method according to the preceding embodiment, wherein the solid content of the at least one mediator substance in the polymer backbone is selected for adjusting a viscosity of the enzyme-wired hydrogel compound.

[0066] Embodiment 14. The method according to any one of the preceding embodiments, wherein the continuous reel-to-reel coating process comprises using a cannula.

[0067] Embodiment 15. The method according to the preceding embodiment, wherein at least a surface of the cannula that is configured for being in contact with the enzyme-wired hydrogel compound is coated with a hydrophobic material.

[0068] Embodiment 16. The method according to the preceding embodiment, wherein the hydrophobic material is selected for adjusting an interaction between the cannula and the enzyme-wired hydrogel compound in a manner that at least one of a pinning on a dimension of the cannula or a creeping of the enzyme-wired hydrogel compound along the cannula is avoided.

[0069] Embodiment 17. The method according to any one of the two preceding embodiments, wherein the hydrophobic material is selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), and silicon. Embodiment 18. The method according to any one of the preceding embodiments, wherein the carbon-coated substrate comprises a polymer foil, wherein the polymer foil is coated on at least one side, preferably on both sides, by a carbon ink, wherein the carbon ink comprises a binder material.

[0070] Embodiment 19. The method according to the preceding embodiment, wherein the carbon ink is a suspension having a solid content of 20 wt.% to 70 wt.%, preferably of 30 wt.% to 60 wt.%, in particular of 40 wt.%, of the binder material.

[0071] Embodiment 20. The method according to the preceding embodiment, wherein the solid content of the binder material is selected for adjusting a contact angle between the surface of the carbon-coated substrate and the enzyme-wired hydrogel compound.

[0072] Embodiment 21. The method according to any one of the three preceding embodiments, wherein the binder material is selected from the group consisting of polyvinyl acetate (PVA), peroxyacetic acid (PAA), polyethylene glycol (PEG), polyvinylphenol (PVP), polyvinyl sulfonate, polyvinyl amine, and polyvinyl chloride (PVC).

[0073] Embodiment 22. The method according to any one of the preceding embodiments, the method further comprising iii. applying at least one further continuous line of at least one additional substance to the carbon-coated substrate.

[0074] Embodiment 23. The method according to the preceding embodiment, wherein the at least one further continuous line of the at least one additional substance is applied laterally with respect to the continuous line of the at least one enzyme-wired hydrogel compound on the same surface of the carbon-coated substrate.

[0075] Embodiment 24. The method according to any one of the two preceding embodiments, wherein the at least one further continuous line of the at least one additional substance is selected from at least one of an insulating layer or a reference electrode or a combined counter electrode and reference electrode.

[0076] Embodiment 25. The method according to any one of the preceding embodiments, the method further comprising iv. patterning the continuous line of the at least one enzyme-wired hydrogel compound on the carbon-coated substrate. Embodiment 26. The method according to the preceding embodiment, wherein the patterning of the continuous line of the at least one enzyme-wired hydrogel compound comprises using at least one of laser ablation or a lithographic process.

[0077] Embodiment 27. The method according to any one of the preceding embodiments, the method further comprising v. cutting the carbon-coated substrate comprising the continuous line of the at least one enzyme-wired hydrogel compound into pieces in manner that each piece comprises a portion of the template for the working electrode.

[0078] Embodiment 28. The method according to the preceding embodiment, wherein the cutting process is a continuous cutting process.

[0079] Embodiment 29. The method according to any one of the preceding embodiments, the method further comprising vi. applying at least one continuous diffusion-limiting membrane at least to the continuous line of the at least one enzyme-wired hydrogel compound.

[0080] Embodiment 30. The method according to the preceding embodiment, wherein the at least one continuous diffusion-limiting membrane is applied on a surface of the continuous line of the at least one enzyme-wired hydrogel compound by using at least one coating process.

[0081] Embodiment 31. The method according to any one of the preceding embodiments, wherein the template for the working electrode is an intermediate product configured for producing a working electrode in a continuous monitoring system.

[0082] Embodiment 32. A plurality of working electrodes, wherein each working electrode is based on the template for the working electrode which is produced by a method according to any one of the preceding embodiments.

[0083] Embodiment 33. The plurality of the working electrodes according to the preceding embodiment, wherein each working electrode is configured for being inserted into a skin of a patient. Embodiment 34. A continuous monitoring system, wherein the continuous monitoring system comprises at least one working electrode from the plurality of the working electrodes according to any one of the two preceding embodiments.

[0084] Short description of the Figures

[0085] Further optional features and embodiments are disclosed in more detail in the subsequent description of embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be implemented in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restricted by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally comparable elements. The dimensions as shown in the Figures are not to scale. In the Figures:

[0086] Figure 1 schematically illustrates an exemplary embodiment of an apparatus configured for performing a method of continuously manufacturing a template for a working electrode in a side view;

[0087] Figures 2 A to 2C schematically illustrate exemplary embodiments of templates for the working electrode in a top view after continuously manufactured by the method as illustrated in Figure 1 in a top view;

[0088] Figures 3 A to 3B schematically illustrate exemplary embodiments of working electrode sides of continuous monitoring sensors in a top view, the working electrode being based on the template for the working electrode as illustrated in Figures 2B or 2C; and

[0089] Figure 4 schematically illustrates an exemplary embodiment of a topography of a working electrode as illustrated in Figures 3 A or 3B in a side view.

[0090] Detailed description of the embodiments

[0091] Figure 1 schematically illustrates an exemplary embodiment of an apparatus 110, which is configured for performing a method of continuously manufacturing a template 112 for a working electrode 114 according to the present invention in a side view. As outlined above, the working electrode 114 is manufactured for a purpose of performing an electrochemical detection reaction for detecting a presence and / or a concentration of at one or more analytes in a sample of a bodily fluid. In the field of medical diagnostics, such in point of care applications and / or in laboratories, the sample of the bodily fluid may, particularly, be selected from saliva, blood, interstitial fluid, urine, salvia, sweat, or serum. Examples of analytes to be detected are antigenic proteins of viruses, such as antigenic proteins of the SARS-CoV-2 coronavirus, and other types of analytes, such as glucose, triglycerides, lactate, cholesterol or other types of analytes typically present in these bodily fluids. In the following, the analyte is represented by blood glucose as a particular example; however, the methods and apparatuses as described therein are also applicable to other kind of analytes and / or a further kind of samples comprising an analyte.

[0092] In accordance with step i. of the present method, a continuous carbon-coated substrate 116 is provided in a continuous manner by using a first roll 118 as illustrated in Figure 1. As outlined above, the carbon-coated substrate 116 may, preferably, comprise a polymer foil (not depicted here), wherein the polymer foil may be coated on at least one side, preferably on both sides, by carbon ink. Preferably, the carbon ink may be a suspension having a solid content of 20 wt.% to 70 wt.%, more preferred of 30 wt.% to 60 wt.%, in particular of 40 wt.%, of a binder material. The carbon ink may, preferably, be a formulation of at least one of carbon black, i.e. paracrystalline particles obtained from an incomplete combustion of a carbon-comprising material or graphite. The binder material is configured to maintain the carbon ink in a composition ‘as is’, preferably by using adhesion and / or cohesion. The binder material may, preferably, be selected from an organic binder material, specifically from the group consisting of polyvinyl acetate (PVA), peroxyacetic acid (PAA), polyethylene glycol (PEG), polyvinylphenol (PVP), polyvinyl sulfonate, polyvinyl amine, and polyvinyl chloride (PVC). However, using a different kind of binder material may also be feasible.

[0093] In accordance with step ii. of the present method, a continuous line 120 of at least one enzyme-wired hydrogel compound 122 is formed as analyte detection agent on the carbon- coated substrate 116 by using the continuous reel-to-reel coating process. As illustrated in Figure 1, the continuous reel-to-reel coating process involves the first roll 118, which is configured for providing the continuous carbon-coated substrate 116 in a continuous manner, and a second roll 124, which is configured for transporting the template 112 for the working electrode 114. The enzyme-wired hydrogel compound 122 is formed by applying an initial composition 123, which is a mixture comprising at least one enzyme, at least one polymer backbone, and at least one cross-linker in an aqueous solution, especially as a three- dimensional network of the permeable solid compound that is insoluble in the aqueous solution. As outlined above, the aqueous solution may, preferably, have a liquid content of 1 vol.% to 60 vol.%, more preferred of 10 vol.% to 30 vol.%, in particular of 20 vol.%, of at least one polar solvent. The polar solvent is an organic solvent having a high dielectric constant suitable for being miscible with the aqueous solution comprised by the hydrogel compound. The at least one polar solvent may, preferably, be selected from the group consisting of propanol, methanol, ethanol, acetonitrile, ethyl acetate, and acetone; however, using a different kind of polar solvent may also be feasible.

[0094] As further outlined above, the enzyme-wired hydrogel compound 122 comprises a wired enzyme as a type of polymeric matrix comprising at least one enzyme and configured for forming the working electrode 114. The wired enzyme may be configured for providing a direct electron transfer mechanism. As a preferred alternative, the wired enzyme may comprise at least one mediator substance configured for providing a mediator-based electron transfer mechanism. The mediator substance may, preferably, be selected from the group consisting of an osmium complex, a ruthenium complex, and a ferrocene; however, using a different kind of mediator substance may also be feasible. As outlined above, the enzyme- wired hydrogel compound 122 may, preferably, comprise a solid content of 5 wt.% to 30 wt.%, more preferred of 10 wt.% to 20 wt.%, in particular of 16 wt.%, of the polymer backbone further comprising the at least one mediator substance.

[0095] As further illustrated in Figure 1, the initial composition 123 can be applied to the carbon- coated substrate 116 by using a cannula 126, which is configured for guiding the initial composition 123 along a predetermined path towards a surface 130 of the carbon-coated substrate 116. The illustrated cannula 126 is a small tube having a limited cross section or diameter; however, using a different type of the cannula 126 or performing the continuous reel-to-reel coating process without using the cannula 126 may also be feasible. Further, the illustrated cannula 126 has a hydrophobic coating 128 configured to repel the initial composition 123 from a surface of the cannula 126, particularly for adjusting an interaction between the cannula 126 and the initial composition 123 in a manner that a pinning on a dimension of the cannula 126 and / or a creeping of the initial composition 123 along the cannula 126 may, preferably, be avoided. As outlined above, the hydrophobic coating 128 may, preferably, comprise polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), or silicon; however, using a different kind of hydrophobic material may also be feasible.

[0096] The application of the initial composition 123 to the carbon-coated substrate 116 is performed in a manner that the continuous line 120 of the enzyme-wired hydrogel compound 122 has a lateral width 132 of 0.2 mm to 3 mm and a mean thickness 134 of 2 pm to 40 pm. Herein, the lateral width 132 indicates a lateral extension of the continuous line 120 in a direction that is perpendicular to a direction 136 of transport of the carbon-coated substrate 116 by using the rolls 118, 124, while the mean thickness 134 indicates an elevational extension of the continuous line 120 in a direction that is perpendicular to both the direction 132 of transport of the carbon-coated substrate 116 and the lateral extension of the continuous line 120. Figure 4 schematically illustrates a manner of determining a value for the mean thickness 134 of the continuous line 120 on the carbon-coated substrate 116.

[0097] In accordance with optional step iii. of the present method, one or more further continuous lines 140, 140’ of at least one additional substance can be applied to the carbon-coated substrate. As schematically illustrated in Figures 2B and 2C, the further continuous lines 140, 140’ may, preferably, be applied laterally with respect to the continuous line 120 of the at least one enzyme-wired hydrogel compound 122 on the same surface 130 of the carbon- coated substrate 116. As shown there, the further continuous lines 140, 140’ may, preferably, be insulating layers comprising at least one electrically non-conductive material. As an alternative (not depicted here), the one or more further continuous lines 140, 140’ may, preferably, be selected from a reference electrode, or a combined counter / reference electrode.

[0098] In accordance with further optional step iv. of the present method, the continuous line 120 of the enzyme-wired hydrogel compound 122 on the carbon-coated substrate 116 may be patterned by adjusting an area of the enzyme-wired hydrogel compound 122, in particular, by using a subtractive process configured to remove already deposited material. As further illustrated in Figure 1, a laser 142 may be used for performing the subtractive process by using laser ablation via a laser light beam 144; however using a different kind of subtractive process, especially a lithographic process, may also be feasible.

[0099] In this manner, the area occupied by the enzyme-wired hydrogel compound 122 on the carbon-coated substrate 116 can be adjusted, thereby leaving an unoccupied space between an edge of the enzyme-wired hydrogel compound 122 and the edge of the carbon-coated substrate 116 and / or providing an unoccupied space between an edge of the enzyme-wired hydrogel compound 122 and the intended edge of the carbon-coated substrate 116 after cutting of the carbon-coated substrate comprising the continuous line 120 of the enzyme- wired hydrogel compound 122 into pieces according to further optional step v. of the present method, which is directed to cutting the carbon-coated substrate 116 comprising the continuous line 120 of the enzyme-wired hydrogel compound 122 into pieces 150 in manner that each piece 150 comprises a portion of the template 112 for the working electrode 114. As further illustrated in Figure 1, a continuous cutting process may comprise consecutively using at least one cutting device 152, which may be configured for cutting the template 112 into the desired pieces 150 during the cutting process. Herein, the cutting device may, preferably, be selected from a cutting blade or a laser, particularly depending on the dimensions involved in the cutting process. As an alternative (not depicted here), a device for introducing perforation lines can be used, wherein the desired pieces 150 can be obtained later by breaking the perforation lines.

[0100] In accordance with further optional step vi. of the present method, at least one continuous diffusion-limiting membrane may be applied (not depicted here) to the continuous line 120 of the enzyme-wired hydrogel compound 122. In this manner, a semipermeable layer may be placed on a surface 138 of the enzyme-wired hydrogel compound 122 used for forming the working electrode 114 in a manner that the body fluid can contact the working electrode 114 through the membrane, whereby an electrochemical reaction, specifically oxidative processes and / or reductive processes, may occur at the surface of the working electrode 114. As outlined above, diffusion-limiting membrane may, especially, be configured for providing access to the enzyme-wired hydrogel compound 122 on the surface 138 of the working electrode 114 only to a particular amount of the analyte in order to control the reaction of the analyte with the enzyme-wired hydrogel compound 122. As outlined above, the at least one continuous diffusion-limiting membrane may, preferably, be applied by using at least one coating process, particularly selected from dip-coating or spray-coating; however, using at least one further type of coating process may also be feasible.

[0101] Figures 2A to 2C schematically illustrate exemplary embodiments of the templates 112 for the working electrode 114 in a top view after continuously manufacturing the templates 112 by the method as illustrated in Figure 1 prior to an optional cutting process according to optional method step v.

[0102] The exemplary template 112 as shown in Figure 2A illustrates the templates 112 for the working electrode 114 after performing method step ii. as indicated above. As shown in Figure 2A, the enzyme-wired hydrogel compound 122 has already been formed on the carbon-coated substrate 116 in a manner that the continuous line 120 has a lateral width 132 of 0.2 mm to 3 mm and a mean thickness 134 of 2 pm to 40 pm.

[0103] The exemplary template 112 as further shown in Figure 2B illustrates the templates 112 for the working electrode 114 after performing optional method step iii. as indicated above. As shown in Figure 2B, the further continuous lines 140, 140’ of at least one insulating material have already been formed laterally with respect to the continuous line 120 of the at least one enzyme-wired hydrogel compound 122 on the same surface 130 of the carbon-coated substrate 116. The exemplary template 112 as further shown in Figure 2C illustrates the templates 112 for the working electrode 114 of Figure B after, additionally, performing optional method step iv. as indicated above. As shown in Figure 2C, the continuous line 120 of the enzyme-wired hydrogel compound 122 on the carbon-coated substrate 116 have already been patterned by using the laser light beam 144 provided by the laser 142 configured for performing laser ablation as the subtractive process.

[0104] Figures 3A to 3B schematically illustrate exemplary embodiments of working electrode sides of continuous monitoring sensors in a top view. The continuous monitoring sensor may, preferably, be configured for being inserted into a skin of a patient.

[0105] As shown in Figure 3 A, the working electrode 114 as illustrated here is based on the template 112 for the working electrode 114 as depicted in Figure 2B, still having the complete line 120 of the enzyme-wired hydrogel compound 122 over the piece 150 of the carbon-coated substrate 116.

[0106] As shown in Figure 3B, the working electrode 114 as illustrated here is based on the template 112 for the working electrode 112 as depicted in Figure 2C, comprising a pattern that has been formed from the line continuous 120 of the enzyme-wired hydrogel compound 122 by using the subtractive process, in particular the laser ablation and / or the lithographic process.

[0107] In this manner, a plurality of the electrodes 114 can, preferably, be produced by the manufacturing method according to the present invention, wherein the plurality of the working electrodes 114 may be assembled in units of manufactured plurality of the working electrodes 114, particularly in roll ware units or sheet ware units of 10, 20, 50, or even 100 working electrodes 114 already being cut into the pieces 150 or having perforation lines between adjacent working electrodes configured for generating the pieces 150 later.

[0108] Figure 4 schematically illustrates an exemplary embodiment of a topography 154 of the working electrode 114 as illustrated in Figures 3 A or 3B in a side view. As depicted therein, the mean thickness 134 of the continuous line 120 on the carbon-coated substrate 116 can be determined by measuring a mean height over a plateau region formed by the lateral width 132 of the continuous line 120. List of reference numbers apparatus template working electrode carbon-coated substrate first roll continuous line enzyme-wired hydrogel compound initial composition second roll cannula hydrophobic coating surface lateral width mean thickness direction of transport surface , 140’ further continuous line laser laser light beam piece cutting device topography

Claims

Roche Diabetes Care GmbH September 30, 2025RD15672PC ST / GS / KVClaims1. A method of continuously manufacturing a template (112) for a working electrode (114), the method comprising: i. providing a continuous carbon-coated substrate (116); and ii. forming a continuous line (120) of at least one enzyme-wired hydrogel compound (122) on the carbon-coated substrate (116) by using a continuous reel-to-reel coating process, whereby the continuous line (120) has a lateral width (132) of 0.2 mm to 3 mm and a mean thickness (134) of 2 pm to 40 pm.

2. The method according to the preceding claim, wherein the continuous line (120) of the enzyme-wired hydrogel compound (122) is formed by applying to the carbon-coated substrate (116) an initial composition (123), wherein the initial composition (123) comprises at least one enzyme, at least one polymer backbone, and at least one crosslinker in an aqueous solution.

3. The method according to any one of the preceding claims, wherein the aqueous solution has a liquid content of 1 vol.% to 60 vol.% of at least one polar solvent.

4. The method according to any one of the preceding claims, wherein the enzyme-wired hydrogel compound (122) is configured for providing a mediator-based electron transfer mechanism, wherein the mediator-based electron transfer mechanism is provided by at least one mediator substance, wherein the enzyme-wired hydrogel compound (122) comprises a solid content of 5 wt.% to 30 wt.% of the polymer backbone further comprising the at least one mediator substance.

5. The method according to any one of the preceding claims, wherein the continuous reel- to-reel coating process comprises using a cannula (126), wherein at least a surface of the cannula (126) that is configured for being in contact with the initial composition (123) is coated with a hydrophobic material.

6. The method according to any one of the preceding claims, wherein the carbon-coated substrate (116) comprises a polymer foil, wherein the polymer foil is coated on at leastone side by a carbon ink, wherein the carbon ink comprises a solid content of 20 wt.% to 70 wt.% of a binder material.

7. The method according to any one of the preceding claims, the method further comprising iii. applying at least one further continuous line (140, 140’) of at least one additional substance to the carbon-coated substrate (116).

8. The method according to the preceding claim, wherein the at least one further continuous line (140, 140’) of the at least one additional substance is applied laterally with respect to the continuous line (120) of the at least one enzyme-wired hydrogel compound (122) on the same surface (130) of the carbon-coated substrate (116), wherein the at least one further continuous line (140, 140’) of the at least one additional substance is selected from at least one of an insulating layer, a reference electrode, or a combined counter electrode and reference electrode.

9. The method according to any one of the preceding claims, the method further comprising iv. patterning the continuous line (120) of the at least one enzyme-wired hydrogel compound (122) on the carbon-coated substrate (116).

10. The method according to the preceding claim, wherein the patterning of the continuous line (120) of the at least one enzyme-wired hydrogel compound (122) comprises using at least one of laser ablation or a lithographic process.

11. The method according to any one of the preceding claims, the method further comprising v. cutting the carbon-coated substrate (116) comprising the continuous line (120) of the at least one enzyme-wired hydrogel compound (122) into pieces (150) in manner that each piece (150) comprises a portion of the template (112) for the working electrode (114).

12. The method according to any one of the preceding claims, the method further comprising vi. applying at least one continuous diffusion-limiting membrane at least to the continuous line (120) of the at least one enzyme-wired hydrogel compound (122).

13. The method according to the preceding claim, wherein the at least one continuous diffusion-limiting membrane is applied to a surface (138) of the continuous line (120) of the at least one enzyme-wired hydrogel compound (122) by using at least one coating process.

14. A plurality of working electrodes (114), wherein each working electrode (114) is based on the template (112) for the working electrode (114), which is produced by a method according to any one of the preceding claims.

15. A continuous monitoring system, wherein the continuous monitoring system comprises at least one working electrode (114) from the plurality of the working electrodes (114) according to the preceding claim.

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