Flux-limiting polymer membrane

Abstract

The present invention relates generally to flux-limiting polymer membranes for analyte sensors and analyte sensors including flux-limiting polymer membranes.

Description

[Technical field]

[0001] The present invention relates generally to flux-limiting polymer membranes for analyte sensors and analyte sensors including flux-limiting polymer membranes. [Background technology]

[0002] Monitoring of certain bodily functions, and more specifically, the concentration of one or more specific analytes, plays an important role in the prevention and treatment of various diseases.

[0003] Along with so-called point measurements, where a sample of a body fluid is specifically taken from a user and investigated for the analyte concentration, continuous measurements are increasingly becoming available. Thus, there is an increasing demand for accurate analyte sensors that allow reliable and cost-effective detection of analytes from body fluids or other samples. An analyte sensor for determining the concentration of an analyte under in vivo conditions is known from WO 2010 / 028708 A1. Another example of such a sensor is disclosed in WO 2012 / 130841 A1. Furthermore, WO 2007 / 147475 A1 discloses an amperometric sensor that is implanted in a living body and measures the concentration of an analyte in a body fluid. An alternative sensor element is disclosed in WO 2014 / 001382 A1.

[0004] WO 03 / 085372 relates to biosensor membranes composed of polymers containing heterocyclic nitrogen. Although these polymers have been found to be useful as flux (or diffusion) limiting membranes for analyte sensors, they often exhibit undesirably long run-in times and / or strong changes in sensitivity throughout their lifetime. This is particularly difficult when storing the sensors for long periods of time before use.

[0005] The problem that the present invention aims to solve is to provide an analyte sensor comprising a working electrode and a flux-limiting polymer membrane disposed on the working electrode, which avoids the above-mentioned drawbacks. In particular, the present invention aims to provide a sensor with improved stability over its lifetime and / or short run-in time.

[0006] It would therefore be desirable to provide a sensor that addresses the above-mentioned technical challenges. Summary of the Invention

[0007] The above problems are addressed by an analyte sensor comprising a working electrode and a flux-limiting polymer membrane arranged on the working electrode, with the features of the independent claims. Advantageous embodiments, which may be realised alone or in any combination, are recited in the dependent claims and throughout the specification.

[0008] Analyte sensors according to the present invention are advantageous because they have improved stability over their lifetime and / or short run-in times while maintaining sufficient sensitivity.

[0009] According to a first aspect of the present invention, there is provided an analyte sensor comprising at least one working electrode and a flux limiting polymer membrane disposed on the at least one working electrode, the flux limiting polymer membrane having a moiety of formula (I): TIFF2024500627000001.tif4560 (wherein x is about 2 to about 8 mol %) y is about 72 to about 98 mol %, z is 0 to about 20 mol %. The poly(vinylpyridine) based polymer comprises a poly(vinylpyridine) based polymer having the formula:

[0010] A further aspect of the invention relates to a polymer membrane for use in an analyte sensor, in particular for use as a flux limiting polymer membrane in an analyte sensor, the polymer membrane comprising a polymer having formula (I) above.

[0011] A still further aspect of the present invention relates to a polymer having the above formula (I) A cross-linking agent; A solvent; The present invention relates to a liquid composition comprising:

[0012] Yet another aspect of the present invention is a method for manufacturing an analyte sensor, comprising the steps of: a) providing a substrate having a first side and a second side, and at least one working electrode disposed on the first side of the substrate; b) forming a layer of a flux-limiting polymer membrane on at least one working electrode, the flux-limiting polymer membrane comprising a polymer having formula (I) above; The present invention relates to a method comprising the steps of:

[0013] In certain embodiments, x is about 5 mol %, y is about 85 mol %, and z is about 10 mol %.

[0014] definition As used below, the terms "have", "comprise" or "include" or any grammatical variants thereof are used non-exclusively. These terms may therefore refer both to the situation where no further features are present in the entity described in this context, in addition to the features introduced by these terms, and to the situation where one or more additional features are present. As an example, the expressions "A has B", "A comprises B" and "A includes B" may refer both to the situation where, apart from B, no other elements are present in A (i.e., A consists solely and exclusively of B) and to the situation where, apart from B, one or more further elements are present in the entity A, such as element C, elements C and D, as well as further elements.

[0015] Furthermore, it should be noted that the terms "at least one," "one or more," or similar expressions indicating that a feature or element may be present one or more times are typically used only once when introducing each feature or element. In the following, in most cases, when referring to each feature or element, the expressions "at least one" or "one or more" will not be repeated, despite the fact that each feature or element may be present one or more times.

[0016] Furthermore, when used hereinafter, the terms "preferably", "more preferably", "particularly", "more particularly", "particularly", "more particularly" or similar terms are used in conjunction with any feature without limiting the possibility of substitution. Thus, features introduced by these terms are optional features and are not intended to limit the scope of the claims in any way. The invention may be implemented by using alternative features, as recognized by those skilled in the art. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features without any limitation regarding alternative embodiments of the invention, without any limitation regarding the scope of the invention, and without any limitation regarding the possibility of combining the feature introduced in such a way with other optional or non-optional features of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention relates to an analyte sensor comprising at least one working electrode and a flux limiting polymer membrane disposed on the at least one working electrode, a polymer membrane for use in the analyte sensor, a liquid composition comprising a polymer, a crosslinker and a solvent, and a method for manufacturing the analyte sensor.

[0018] The term "analyte sensor" as used herein is a broad term and should be given its ordinary and customary meaning to one of ordinary skill in the art and should not be limited to any special or customized meaning. The term may specifically refer to, but is not limited to, any element or device configured to detect or measure the concentration of at least one analyte. The analyte sensor may specifically be an analyte sensor suitable for at least partial implantation in a body tissue of a user, and more specifically, an analyte sensor for continuous monitoring of an analyte.

[0019] In a particular embodiment, the analyte sensor of the invention is an electrochemical sensor comprising a working electrode and at least one further electrode and respective circuitry. More particularly, the sensor is an amperometric electrochemical sensor comprising at least one working electrode. Typically, the analyte sensor comprises at least one further electrode, in particular a counter electrode and / or a reference electrode or a combined counter / reference electrode.

[0020] In certain embodiments, the analyte sensor is a two-electrode sensor that specifically includes one working electrode and one combination counter / reference electrode.

[0021] As used herein, the term "working electrode" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. The term may specifically, but not limited to, refer to an electrode of an analyte sensor that is sensitive to an analyte. The working electrode may be disposed on at least one first side of at least one substrate. In particular, the working electrode includes at least one conductive material and at least one sensing material, which is applied to a coating area on the conductive material on the first side of the sensor substrate. The working electrode is sensitive to the analyte, which is measured at a polarization voltage that may be applied between the working electrode and the reference electrode and may be adjusted by a potentiostat. The measurement signal may be provided as a current between the counter electrode and the working electrode. There may be no separate counter electrode, and there may be a pseudo reference electrode, which may also function as a counter electrode. Thus, an analyte sensor may typically include a set of at least two electrodes, and in one embodiment, a set of three electrodes. In particular, the sensing material is present only in the working electrode.

[0022] The layer of sensing material may be present only on the working electrode and typically not on any further electrodes, for example the counter electrode and / or reference electrode may not include a layer of sensing material.

[0023] In particular, the analyte sensor according to the invention may be fully or partially implanted and thus adapted to perform detection of an analyte in body fluids, particularly interstitial fluid, in subcutaneous tissue. Other parts or components may remain outside the body tissue. For example, as used herein, the terms "implantable" or "subcutaneous" refer to being fully or at least partially disposed within the body tissue of a user. To this end, the analyte sensor may comprise an insertable portion, and the term "insertable portion" may generally refer to a part or component of an element configured to be insertable into any body tissue. The insertable portion may include a working electrode and typically at least one further electrode, e.g., a counter electrode, a reference electrode and / or a combined counter / reference electrode. In certain embodiments, the working electrode is disposed on a first side of the substrate, the at least one further electrode is disposed on a second side of the substrate, and all electrodes are disposed in the insertable portion. The portion of the sensor that is not inserted is a top portion of the sensor and may comprise contacts for connecting the sensor to an electronics unit.

[0024] Furthermore, as used herein, the term "analyte" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically refer to, but is not limited to, any element, component or compound that may be present in a bodily fluid and whose concentration may be of interest to a user. Specifically, an analyte may be or include any chemical or chemical compound that may be involved in a user's metabolism, such as at least one metabolic product. By way of example, the at least one metabolic product may be selected from the group consisting of glucose, cholesterol, triglycerides, lactate, and more specifically, the analyte may be glucose. However, additionally or alternatively, other types of analytes and / or any combination of analytes may be determined.

[0025] The analyte sensor may be configured for at least partial implantation into a user's body tissue, particularly for percutaneous insertion, more particularly, the analyte sensor may be configured for continuous monitoring of the analyte, and even more particularly, the analyte sensor may be configured for continuous glucose monitoring.

[0026] The analyte sensor of the present invention includes at least one flux-limiting polymer membrane, which is disposed on the working electrode, meaning that the at least one flux-limiting polymer membrane at least partially covers the working electrode. In one embodiment of the present invention, the flux-limiting membrane completely covers the working electrode. The flux-limiting polymer membrane may generally allow one or more molecules and / or compounds to selectively pass through, while other molecules and / or compounds are stopped by the membrane. In particular, the flux-limiting polymer membrane is permeable to at least one analyte to be detected. Thus, by way of example, the membrane may be permeable to one or more of glucose, lactate, cholesterol or other types of analytes. Thus, the at least one flux-limiting polymer membrane may function as a diffusion barrier that controls the diffusion of the analyte from the outside, e.g., the bodily fluid surrounding the analyte sensor, to the sensing material, i.e., the enzyme molecules in the sensing material.

[0027] In certain embodiments, the flux-limiting polymer membrane is glucose permeable. For example, the flux-limiting polymer membrane has a glucose permeability of at least about 1×10 -6 cm 2 / s, preferably about 1 × 10 -6 cm 2 / s~approx. 1×10 -10 cm 2 The diffusion coefficient of glucose may be determined by diffusion cells fabricated by the doctor blade method on polypropylene and flux-limiting membrane foils.

[0028] The flux limiting polymer membrane of the present invention has the following formula (I): TIFF2024500627000002.tif4560 (wherein x is about 2 to about 8 mol %) y is about 72 to about 98 mol %, z is 0 to about 20 mol %. The poly(vinylpyridine) based polymer comprises a poly(vinylpyridine) based polymer having the formula:

[0029] The polymer of formula (I) comprises two or three different monomer units, 4-sulfonatopropyl-vinylpyridinium units, 4-vinylpyridine units, and optionally styrene units. In certain embodiments, the polymer consists of the above two or three different monomer units. The parameters x, y, and z in formula (I) indicate the relative molar amounts (i.e., mole %) of each monomer unit in the polymer.

[0030] In the present invention, the parameter x corresponds to the relative molar amount of 4-sulfonatopropyl-vinylpyridinium units and is in the range of about 2 to about 8 mol %, about 3 to about 7 mol %, about 4 to about 6 mol %, in particular about 5 mol %.

[0031] The parameter y corresponds to the relative molar amount of 4-vinylpyridine units and is in the range of about 72 to about 98 mol %, 82 to about 88 mol %, about 83 to about 87 mol %, about 84 to about 86 mol %, and in particular about 85 mol %.

[0032] The parameter z corresponds to the relative amount of styrene units and is in the range of from 0 to about 20 mol %, from about 7 to about 13 mol %, from about 8 to about 12 mol %, from about 9 to about 11 mol %, and in particular about 10 mol %.

[0033] The sum of the mole % of parameters x, y, and z typically equals 100 mole %.

[0034] In certain embodiments, the polymer of formula (I) is a statistical copolymer, i.e., the individual monomer units are incorporated randomly into the polymer chain.

[0035] In certain embodiments, the polymer has a weight average molecular weight of about 60 kDa to about 200 kDa, about 80 kDa to about 160 kDa, about 100 kDa to about 140 kDa, and particularly about 120 kDa. In certain embodiments, the polymer has a number average molecular weight of about 40 kDa to about 90 kDa, about 50 kDa to about 70 kDa, and particularly about 60 kDa. In certain embodiments, the polymer has a polydispersity index of about 1.4 to about 3, and particularly about 2.

[0036] In certain embodiments, the polymer has the weight average molecular weight, number average molecular weight, and optionally, polydispersity index described above.

[0037] The above molecular weights refer to the polymer of formula (I) in the non-crosslinked state. The weight average molecular weight and the number average molecular weight are measured by GPC using PMMA (polymethyl methacrylate) as the standard. The polydispersity is the ratio of the weight average molecular weight to the number average molecular weight.

[0038] The polymers of formula (I) may be prepared by known methods, for example as described in WO 03 / 085372, for example by reacting a poly(4-vinylpyridine-co-styrene) copolymer, in particular a statistical poly(4-vinylpyridine-co-styrene) copolymer, comprising a relative amount of x+y mol % of 4-vinylpyridine units and a relative amount of z mol % of styrene units, where x, y and z are defined as above, with 1,3-propane sultone under conditions in which 4-sulfonatopropyl-vinylpyridinium units are formed in a relative amount of x mol %.

[0039] In certain embodiments, the polymer of formula (I) in the flux-limiting polymer membrane is crosslinked by a crosslinking agent. A crosslinking agent is a molecule that contains at least two functional groups that can link at least two molecules together or at least two parts of the same molecule together. The linking of at least two molecules is called intermolecular crosslinking, and the linking of at least two parts of the same molecule is called intramolecular crosslinking. A crosslinking agent with three or more functional groups may simultaneously perform both intermolecular and intramolecular crosslinking.

[0040] The crosslinking agent can react with functional groups on the polymer, particularly alkyl-sulfonate groups and / or pyridine groups. The polymer of the flux-limiting polymer membrane of the present invention is crosslinked by an amount of crosslinking agent to provide sufficient crosslinking of the polymer. For example, the weight ratio of polymer to crosslinking agent in the flux-limiting polymer membrane is about 8:1 (w / w) to about 16:1 (w / w), about 10:1 (w / w) to about 14:1 (w / w), particularly about 12:1 (w / w).

[0041] Specifically, the flux limiting polymer film may include at least one crosslinker selected from a UV curable crosslinker and a chemical crosslinker. More specifically, the sensing material includes a chemical crosslinker.

[0042] As used herein, the term "chemical crosslinker" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically, but not limited to, refer to a crosslinker that can initiate a chemical reaction to produce a crosslinked molecular network and / or crosslinked polymer when exposed to heat. "Exposed to heat" may refer to exposure to a temperature greater than 15°C, specifically greater than 20°C, more specifically, a temperature in the range of 20°C to 50°C, and even more specifically, a temperature in the range of 20°C to 25°C. More specifically, the chemical crosslinker may initiate crosslinking of a layer of sensing material when exposed to heat.

[0043] Suitable chemical crosslinkers according to the present invention include epoxide based crosslinkers, e.g. diglycidyl ethers such as poly(ethylene glycol) diglycidyl ether (PEG-DGE) and poly(propylene glycol) diglycidyl ether; trifunctional short chain epoxides; anhydrides; resorcinol diglycidyl ether, bisphenols such as bisphenol A diglycidyl ether, diglycidyl 1,2-cyclohexanedicarboxylate, poly(ethylene glycol) diglycidyl ether, glycerol diglycidyl ether, 1,4-butanediol diglycidyl ether, poly(propylene glycol) diglycidyl ether, and the like. diglycidyl ethers such as diglycidyl ether, poly(dimethylsiloxane), diglycidyl ether, neopentyl glycol diglycidyl ether, 1,2,7,8-diepoxyoctane, 1,3-glycidoxypropyl-1,1,3,3-tetramethyldisiloxane; triglycidyl ethers such as N,N-diglycidyl-4-glycidyloxyaniline, trimethylolpropane triglycidyl ether; and tetraglycidyl ethers such as tetrakisepoxycyclosiloxane, pentaerythritol tetraglycidyl ether, and tetraglycidyl-4,4'-methylenebisbenzeneamine.

[0044] In certain embodiments, the chemical crosslinker is PEG-DGE having a number average molecular weight of about 200 Da or more, for example, a number average molecular weight of about 200 Da. In further embodiments, the crosslinker is N,N-diglycidyl-4-glycidyloxyaniline. For example, the crosslinker may be selected from the group consisting of PEG-DGE and N,N-diglycidyl-4-glycidyloxyaniline having a number average molecular weight of 200 Da.

[0045] The term "UV curable" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically, but not exclusively, refer to the ability of a chemical, e.g., a crosslinking agent, to initiate a photochemical reaction that produces a crosslinked molecular network and / or crosslinked polymer when irradiated by light in the UV spectral range. More specifically, a UV curable crosslinking agent may initiate crosslinking of a layer of sensing material when irradiated with UV light. Crosslinking may be initiated, among other things, as shown herein below.

[0046] Suitable UV curable crosslinkers according to the present invention include benzophenones, diazirines and azides. Particularly suitable UV curable crosslinkers are selected from the group consisting of, for example, benzophenone containing crosslinkers, poly(di(2-hydroxy-3-aminobenzophenone propylene) glycol), dibenzophenone 1,2-cyclohexane dicarboxylate, bis[2-(4-azidosalicylamido)ethyl] disulfide, reaction products of 4-aminobenzophenone with any one of the above mentioned diglycidyl crosslinkers, triglycidyl crosslinkers and tetraglycidyl crosslinkers, examples of such reaction products are 2,4,6,8-tetramethyl-2,4,6,8-tetrakis(2-hydroxy-3-aminopropylbenzophenone)-cyclotetrasiloxane, reaction products of 4-benzoylbenzoic acid N-succinimidyl ester with diamines or Jeffamine.

[0047] In certain embodiments, the crosslinker comprises two, three or more functional groups. A particular example of a functional group is an epoxide group. Preferably, the crosslinker comprises at least two functional epoxide groups, more preferably three functional epoxide groups. More preferably, the crosslinker is a triglycidyl ether. A particularly preferred example of a crosslinker is N,N-diglycidyl-4-glycidyloxyaniline.

[0048] The flux-limiting polymer membrane may have a thickness sufficient to provide mechanical stability, specifically, a thickness of about 1 μm to about 150 μm.

[0049] In addition to the polymers and crosslinkers described above, the flux limiting polymer membranes may contain further components, such as polymeric and / or non-polymeric components, which may be dispersed and / or dissolved in the polymer. Non-polymeric components include plasticizers, particularly biocompatible plasticizers, such as tri-(2-ethylhexyl) trimellitate and / or glycerol.

[0050] Further components optionally present in the polymer membrane are medicinal drugs, corticoids, heparin and salts, e.g. Na + , Cl - and / or Br - It is a salt containing ions such as:

[0051] In certain embodiments, the membrane comprises a poly(vinylpyridine)-based polymer of formula (I) as the only polymeric component.

[0052] The flux limiting polymer membrane of the present invention may be applied to the analyte sensor as a liquid composition by a coating process, particularly a wet coating process.

[0053] As used herein, the term "coating process" may refer to any process for applying at least one layer to at least one surface of any object. The applied layer may completely cover the object, e.g., the working electrode, or may cover only a portion of the object. The layer may be applied by a coating process in which the material is provided, e.g., in liquid form, illustratively as a suspension or solution, and distributed onto the surface. In particular, the coating process may include a wet coating process selected from the group consisting of: spin coating; spray coating; doctor blading; printing; dispensing; slot coating; dip coating. A preferred wet coating process is dip coating or spray coating.

[0054] After application, the liquid composition may be subjected to at least one curing step, in which at least a portion of the polymer is crosslinked. The terms "crosslinking" and "curing" are used interchangeably herein. Suitable methods for initiating crosslinking depend on the type of crosslinking agent and are known to those skilled in the art. Since the preferred crosslinking agents are chemical crosslinkers, curing is preferably carried out essentially at ambient temperature or up to about 90°C, without UV light. As used herein, the term "ambient temperature" is specifically understood as a temperature between 15°C and 30°C, more specifically between 20°C and 25°C. Curing with UV-curable crosslinkers is generally induced by irradiation with UV light. As used herein, the term "UV light" generally refers to electromagnetic radiation in the ultraviolet spectrum range. The term "ultraviolet spectrum range" generally refers to electromagnetic radiation in the range of 1 nm to 380 nm, preferably light in the range of 100 nm to 380 nm. Curing may generally be carried out at room temperature.

[0055] Furthermore, after application, the liquid composition may be subjected to at least one drying step. Specifically, the curing step and drying may be performed simultaneously, especially when a chemical crosslinker is used. Alternatively, the curing step may be followed by a drying step. Specifically, the composition may be dried at ambient temperature or up to about 50° C. for about 10 minutes or less, or about 5 minutes or less, for example, about 0.5 to about 10 minutes.

[0056] The analyte sensors of the present invention include at least one working electrode. In certain embodiments, the analyte sensor comprises: (i) a substrate, A first aspect and a second aspect; at least one conductive material disposed on a first side of the substrate; (ii) a working electrode comprising a sensing material at least partially covering a first side of the substrate, the sensing material comprising at least one enzyme; and (iii) a polymer membrane comprising a polyvinylpyridine-based polymer of formula (I), the membrane at least partially covering the working electrode; and Includes.

[0057] The term "substrate" as used herein is a broad term and should be given its ordinary and customary meaning to one of ordinary skill in the art and should not be limited to any special or customized meaning. The term "substrate" is used synonymously with the term "sensor substrate" and may specifically refer, without limitation, to any type of material or combination of materials suitable for forming a polymer layer covering a working electrode as described herein. In particular, as understood herein, a "sensor substrate" may include an electrically insulating material.

[0058] As used herein, the term "layer" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. The term may refer to, but is not limited to, an element of a layer configuration of an analyte sensor. Specifically, the term "layer" may refer to any coating of any substrate, particularly a flat substrate. A layer may specifically have an outer extension that exceeds a thickness of at least 2 times, at least 5 times, at least 10 times, or even at least 20 times or more. Specifically, an analyte sensor may have a layer configuration. An analyte sensor may include multiple layers, such as at least one conductive material, at least one layer of at least one sensing material, and optionally at least one membrane layer. One or more layers of an analyte sensor may include sublayers. For example, a layer including a conductive material may include at least one additional layer.

[0059] As used herein, the term "electrically insulating material" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. "Electrically insulating material" may also refer to a dielectric material. The term may specifically, but not limited to, refer to a material or combination of materials that prevents the transfer of electric charge and does not sustain a significant current. Specifically, without limiting other possibilities, the at least one electrically insulating material may be or include at least one insulating resin, such as an insulating epoxy resin used in the manufacture of electronic printed circuit boards. In particular, the electrically insulating material may include or be a thermoplastic material, polycarbonate, polyester such as polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyurethane, polyether, polyamide, polyimide or copolymers thereof, such as glycol-modified polyethylene terephthalate, polyethylene naphthalate, polytetrafluoroethylene (PTFE) or alumina.

[0060] In methods and analyte sensors according to the present invention, the sensor substrate may include two opposing sides, at least a first side and at least a second side opposing the first side.

[0061] Specifically, the analyte sensor, more specifically the sensor substrate, may further include at least one additional electrode, which may include at least one of a reference electrode and a counter electrode. In one embodiment, the at least one additional electrode includes a combined counter / reference electrode. In particular, the reference electrode may include at least one reference electrode conductive material and / or the counter electrode may include at least one counter electrode conductive material. More specifically, the at least one additional electrode may be disposed on at least one of a first side and a second side opposite the first side of the sensor substrate.

[0062] As used herein, the term "conductive material" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically refer to, but is not limited to, a conductive strip, layer, wire, or other type of elongated conductor. More specifically, the term "conductive material" may refer to, but is not limited to, a material that is conductive and thus capable of sustaining an electric current, for example, the conductive material may include at least one material selected from the group consisting of carbon; carbon paste; gold; copper; silver; nickel; platinum; palladium. Specifically, the conductive material may be or include at least one metal, such as one or more of gold, copper, silver, nickel, palladium, or platinum. Additionally or alternatively, the at least one conductive material may be or include at least one conductive compound, such as at least one conductive organic or inorganic compound. Additionally or alternatively, the at least one conductive material may be or may include at least one non-metallic conductive material, such as polyaniline, poly-3,4-ethylenedioxythiophene (PEDOT), carbon or carbon paste. Carbon paste may specifically refer to a material comprising carbon, a solvent such as diethylene glycol butyl ether, and at least a binder such as vinyl chloride copolymers and terpolymers. Preferably, the conductive material according to the invention may comprise gold and / or carbon, more preferably the conductive material may consist of gold and / or carbon and / or carbon paste. Specifically, the conductive material may comprise gold and a further material, such as carbon.

[0063] Furthermore, the conductive material may include at least one further layer of at least one further material, in particular the further layer may include a further conductive material. More particularly the further layer of conductive material may include or consist of carbon. The further material may be disposed on the first side. The use of the further layer, in particular carbon, may contribute to efficient electron transfer by the conductive material.

[0064] The conductive material may have a thickness of at least about 0.1 μm, preferably at least about 0.5 μm, more preferably at least about 5 μm, specifically at least about 7 μm, or at least about 10 μm. When the conductive material includes or is carbon, the conductive material may have a thickness of at least about 7 μm, more specifically at least about 10 μm, for example, about 10 μm to 15 μm. Specifically, when the conductive material is gold, the conductive material may have a thickness of at least about 100 nm, more specifically at least about 500 nm.

[0065] Such minimum thicknesses may be advantageous to ensure adequate electron transport. Thicknesses below the specified values ​​are usually not sufficient for reliable electron transport. More specifically, they should not exceed about 30 μm for carbon and about 5 μm for gold. Too large a thickness may increase the overall thickness and therefore the size of the analyte sensor. Larger analyte sensor sizes are generally undesirable as they may cause difficulties during implantation. Furthermore, they may be less flexible, especially in the case of carbon, and / or more expensive, especially in the case of gold.

[0066] The conductive material may be hydrophobic, for example the contact angle between the conductive material and water may be in the range of 60° to 140°, in particular about 100°, for a drop volume of e.g. 5 μl, as determined by microscopy using a Keyence VHX-100.

[0067] The conductive material may further comprise a rough surface. A rough surface usually increases the efficiency of electron transfer. Furthermore, it is more hydrophobic. By rough surface, it is meant that the surface may include irregularities. The depth of the irregularities may be, for example, in the range of 1 μm to 6 μm, for example about 3 μm, as determined by optical scanning microscope, in particular laser scanning microscope. The distance between two ridges on the rough surface may be, for example, in the range of 20 μm to 80 μm, for example about 40 μm, as determined by optical scanning microscope, in particular laser scanning microscope.

[0068] As used herein, the terms "reference electrode conductive material" and "counter electrode conductive material" are broad terms and are given their ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. These terms may specifically refer to, but are not limited to, a conductive strip, layer, wire or other type of elongated electrical conductor present on the reference electrode or counter electrode, respectively. More specifically, these terms may refer to, but are not limited to, a material that is conductive and thus capable of sustaining an electric current, for example, the reference electrode conductive material and / or the counter electrode conductive material may include at least one material described herein above with respect to conductive materials. In addition to the above materials, the reference electrode conductive material and / or the counter electrode conductive material may specifically include Ag / AgCl.

[0069] As used herein, the term "sensing material" is a broad term and should be given its ordinary and accustomed meaning to those of ordinary skill in the art and should not be limited to any special or customized meaning.

[0070] The sensing material comprises at least one enzyme, specifically the enzyme can catalyze a chemical reaction that consumes at least the analyte. Specifically, the enzyme can be an H2O2 producing and / or consuming enzyme; even more specifically, glucose oxidase (EC 1.1.3.4), hexose oxidase (EC 1.1.3.5), (S)-2-hydroxyacid oxidase (EC 1.1.3.15), cholesterol oxidase (EC 1.1.3.6), glucose dehydrogenase (EC 1.1.1.47), galactose oxidase (EC 1.1.3.9), alcohol oxidase (EC 1.1.3.13), L-glutamate oxidase (EC 1.4.3.11) or L-aspartate oxidase (EC 1.4.3.16); even more specifically, glucose oxidase (GOx) including any modifications thereof.

[0071] Additionally, the sensing material may include a cross-linking agent, such as a chemical cross-linking agent or a UV cross-linking agent, such as those cross-linking agents described above.

[0072] Furthermore, the sensing material may include at least one polymeric transition metal complex. The term "polymeric transition metal complex" may specifically refer to a material that may be or may include at least one polymeric material, but is not limited to this, specifically it may be or may include at least one polymeric material and at least one metal-containing complex. The metal-containing complex may be selected from the group of transition metal element complexes, specifically the metal-containing complex may be selected from osmium complexes, ruthenium complexes, vanadium complexes, cobalt complexes, and iron complexes, such as ferrocene, such as 2-aminoethylferrocene. Even more specifically, the sensing material may include a polymeric transition metal complex, such as those described in WO 01 / 36660 A2, the contents of which are incorporated by reference. In particular, the sensing material may include a modified poly(vinylpyridine) backbone carrying a poly(biimidyl)Os complex covalently bonded via a bidentate bond. Suitable sensing materials are further described in Feldmann et al, Diabetes Technology & Therapeutics, 5(5), 2003, 769-779, the contents of which are incorporated by reference. Suitable sensing materials may further include ferrocene-containing polyacrylamide-based viologen-modified redox polymers, pyrrole-2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)-pyrene, naphthoquinone-LPEI. The polymeric transition metal complex may represent a redox mediator incorporated into a crosslinked redox polymer network. This is advantageous because it may facilitate electron transfer between at least one enzyme or analyte and a conductive material. To avoid sensor drift, the redox mediator and enzyme may be covalently incorporated into the polymer structure.

[0073] In certain embodiments, the sensing material comprises at least an enzyme capable of catalyzing a chemical reaction consuming an analyte, in particular an H2O2 generating and / or consuming enzyme, a crosslinker and a polymeric transition metal complex. Specifically, the sensing material may comprise at least a polymeric transition metal complex and GOx, and a chemical crosslinker. More specifically, the sensing material may comprise a modified poly(vinylpyridine) backbone carrying a poly(biimidyl)Os complex, GOx, and a chemical crosslinker such as poly(ethylene glycol) diglycidyl ether (PEG-DGE) covalently bonded via a bidentate bond. Further suitable sensing materials are known to those skilled in the art.

[0074] In one embodiment, the sensing material may include a polymeric material and MnO2 particles.

[0075] A sensing material according to the present invention may comprise, for example, about 40-60 wt. % of a polymeric transition metal complex, about 30-40 wt. % of an enzyme capable of catalyzing at least an analyte-consuming chemical reaction, in particular an H2O2-producing and / or consuming enzyme, and about 0.5-25 wt. % of a crosslinker, based on the total dry weight of the sensing material.

[0076] After application to the substrate, the sensing material may be subjected to at least one curing step, in which at least a portion of the sensing material is crosslinked. The curing step may be performed as described above. In particular, the curing step may be performed after application and before drying. Furthermore, the curing step may be performed at least partially before any laser irradiation, or alternatively after performing the laser irradiation.

[0077] In certain aspects, the analyte sensor further comprises at least one biocompatible membrane disposed on the flux-limiting polymer membrane. The term "biocompatible membrane" refers to a polymer membrane that is different from the polyvinylpyridine-based flux-limiting polymer membrane described above.

[0078] For example, the biocompatible membrane may be a gel membrane, which may on the one hand be permeable to the body fluid or at least the analytes contained therein, and on the other hand be impermeable to the compounds contained in the analyte sensor, in particular the working electrode, thus preventing their migration into the body tissue.

[0079] The biocompatible layer may have a thickness of about 1 μm to about 10 μm, and in one embodiment, about 3 μm to about 6 μm. More specifically, the biocompatible layer at least partially or completely covers the analyte sensor. Even more specifically, the biocompatible layer may be the outermost layer of the analyte sensor. The biocompatible membrane layer may be or include the following materials: methacrylate-based polymers and copolymers, acrylamide-methacrylate-based copolymers, hyaluronic acid (HA), agarose, dextran, chitosan, and biodegradable polysaccharides such as poly(vinylpyridine)-based polymers. When the biocompatible membrane layer includes a poly(vinylpyridine)-based polymer, the poly(vinylpyridine)-based polymer may be the same as or different from the poly(vinylpyridine)-based polymer of the flux-limiting membrane. Preferably, it is different from the poly(vinylpyridine)-based polymer of the flux-limiting membrane.

[0080] The biocompatible membrane layer may be applied by techniques known to those skilled in the art using at least one coating process, particularly a wet coating process, as described above.

[0081] In certain aspects, the analyte sensor does not include a biocompatible membrane disposed on the flux-limiting polymeric membrane. In these embodiments, the polyvinylpyridine-based polymer of the present invention may be the outermost layer of the analyte sensor. Thus, the flux-limiting polymeric membrane may also function as a biocompatible membrane.

[0082] The present invention further relates to a polymeric membrane for use in an analyte sensor, the polymeric membrane having formula (I): TIFF2024500627000003.tif4560 (wherein x is about 2 to about 8 mol %) y is about 72 to about 98 mol %, z is 0 to about 20 mol %. The poly(vinylpyridine) based polymer comprises a poly(vinylpyridine) based polymer having the formula:

[0083] Preferably, the characteristics of the polymer membrane are as described above for the flux limiting polymer membrane.

[0084] The present invention further relates to a compound of formula (I): TIFF2024500627000004.tif4560 (wherein x is about 2 to about 8 mol %) y is about 72 to about 98 mol %, z is 0 to about 20 mol %. A polyvinylpyridine-based polymer having the formula: A cross-linking agent; Solvent and The present invention relates to a liquid composition suitable for applying a flux limiting polymer film to an analyte sensor, comprising:

[0085] Preferably, the characteristics of the polyvinylpyridine-based polymer and the crosslinking agent are as described above.

[0086] The solvent may comprise a non-aqueous organic solvent, particularly a water-miscible solvent, such as methanol, ethanol, propanol, or any combination thereof, or a mixture of a non-aqueous organic solvent and water. Preferably, the non-aqueous organic solvent is ethanol. Preferably, the composition comprises about 50% to about 90% (v / v) of a non-aqueous organic solvent, such as ethanol, and about 10% to about 50% (v / v) of water, preferably about 70% to about 90% (v / v) of a non-aqueous organic solvent, and about 10% to about 30% (v / v) of water, particularly about 80% (v / v) of a non-aqueous organic solvent, such as ethanol, and about 20% (v / v) of water. In a further embodiment, the solvent consists of a non-aqueous solvent, particularly ethanol.

[0087] In certain embodiments, the liquid composition may contain about 100 mg / ml to about 140 mg / ml of polymer and about 8 mg / ml to about 12 mg / ml of crosslinker, particularly about 120 mg / ml of polymer and about 10 mg / ml of crosslinker. The weight ratio of polymer to crosslinker is preferably about 12:1.

[0088] The present invention further provides a method for manufacturing an analyte sensor, comprising the steps of: a) providing a substrate having a first side and a second side, and at least one working electrode disposed on the first side of the substrate; b) forming a flux-limiting polymer membrane on at least one working electrode, the flux-limiting polymer membrane having the following formula (I): TIFF2024500627000005.tif4560 (wherein x is about 2 to about 8 mol %) y is about 72 to about 98 mol %, z is 0 to about 20 mol %. The present invention relates to a method comprising the step of:

[0089] Preferably, the polymer membrane has the characteristics described above.

[0090] In a particular embodiment, step b) comprises applying a liquid composition comprising a polymer, a crosslinker and a solvent onto the working electrode. In particular, step b) comprises coating at least one working electrode with a liquid composition comprising a polymer, a crosslinker and a solvent, curing the polymer and drying. Preferably, the characteristics of the liquid composition, the applying step, the curing step and the drying step are as described above.

[0091] In certain embodiments of the method according to the invention, in addition to the at least one flux-limiting polymeric membrane layer, at least a second membrane layer may be applied, which may be a biocompatible membrane layer, preferably a biocompatible membrane layer as described above.

[0092] The method according to the invention may further comprise at least one diffusion step, in which the cross-linking agent contained in the flux-limiting polymer membrane may at least partially diffuse into the sensing material. The diffusion may occur during application of the membrane layer to the sensing material. The diffusion of the cross-linking agent into the sensing material may allow at least partial cross-linking of the sensing material when the sensing material is applied to the substrate, independent of the amount of cross-linking agent in the sensing material.

[0093] The diffusion step may further include swelling of at least a portion of the sensing material. As used herein, the term "swelling" is a broad term and should be given its normal and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. The term may specifically refer to, but is not limited to, the binding of water and / or water-soluble solvents, such as ethanol, methanol, acetone, etc., to the material, specifically the binding of water and / or water-soluble solvents to the sensing material. The uptake of water and / or the uptake of water-soluble solvents into the sensing material may advantageously allow the diffusion of crosslinking agents into the sensing material, which may be required for efficient crosslinking. Swelling may also refer to the uptake of water from the membrane layer.

[0094] To allow for sufficient swelling in the method according to the invention, the polymeric material in the sensing material may be capable of uptake of at least 10% by weight of water and / or solvent from the membrane layer, more particularly at least 20% by weight, even more particularly at least 30% by weight, and even more particularly up to 90% by weight, based on the dry weight of the polymeric material, within a time frame of a few minutes, for example 1 to 15 minutes.

[0095] This swelling and / or uptake of water and / or solvent is advantageous as it may allow diffusion of the cross-linker from the membrane layer into the sensing material.

[0096] Furthermore, the present invention relates to the use of the above-mentioned analyte sensor for detecting at least one analyte in a sample, in particular in a sample of a body fluid, more particularly the analyte sensor is a sensor for continuous glucose measurement.

[0097] As used herein, the term "body fluid" refers to any body fluid of a subject that is known or suspected to contain the analyte of the present invention, including interstitial fluid, blood, plasma, tears, urine, lymph, cerebrospinal fluid, bile, stool, sweat and saliva. In general, any type of body fluid may be used. Preferably, the body fluid is a body fluid present in the user's body tissue, such as interstitial tissue. Thus, by way of example, the body fluid may be selected from the group consisting of blood and interstitial fluid. However, additionally or alternatively, one or more other types of body fluid may be used. The body fluid may generally be contained in a body tissue. Thus, in general, the detection of at least one analyte in the body fluid may preferably be determined in vivo.

[0098] The term "sample" is understood by those skilled in the art and relates to any subportion of a bodily fluid. Samples can be obtained by well-known techniques including, for example, venous or arterial puncture, superficial skin puncture, and the like.

[0099] The terms "user" and "subject" are used interchangeably herein and are broad terms that are to be given their ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The terms may specifically refer to, but are not limited to, a human or an animal, regardless of the fact that the human or animal, respectively, may be in a healthy state or may be suffering from one or more diseases. As an example, the subject may be a human or an animal suffering from diabetes. However, additionally or alternatively, the present invention may be applied to other types of subjects.

[0100] The present invention further relates to a method for determining an analyte in a sample comprising the analyte sensor described herein above.

[0101] The method of measuring an analyte of the invention may in particular be an in vivo method. Alternatively, the method of the invention may also involve the measurement of an analyte under in vitro conditions, for example in a sample of a body fluid obtained from a subject, in particular a human subject. In particular, the method may not involve the diagnosis of a disease based on the measurement.

[0102] A still further aspect of the present invention is a compound of formula (Ia): TIFF2024500627000006.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol % For a polymer having the formula The polymer is (i) Statistical polymers; (ii) a polymer having a weight average molecular weight of about 60 kDa to about 200 kDa, and / or (iii) A polymer crosslinked with a crosslinker that is N,N-diglycidyl-4-glycidyloxyaniline, particularly where the weight ratio of polymer to crosslinker is from about 8:1 (w / w) to about 16:1 (w / w), from about 10:1 (w / w) to about 14:1 (w / w), particularly about 12:1 (w / w).

[0103] Further aspects are analyte sensors as described herein comprising a polymer of Formula (Ia), and polymeric films as described herein comprising a polymer of Formula (Ia), liquid compositions as described herein comprising a polymer of Formula (Ia), and methods of making an analyte sensor as described herein comprising using a polymer of Formula (Ia).

[0104] Preferred features of the analyte sensor, polymeric membrane, liquid composition and method of manufacture are as described herein above for the polymer of formula (I).

[0105] Further optional features and embodiments are disclosed in more detail in the following description of the embodiments, preferably in conjunction with the dependent claims, where each optional feature may be realized in an independent manner as well as in any possible combination as understood by a person skilled in the art. The scope of the present invention is not limited by the preferred embodiments.

[0106] In summary, without excluding further possible embodiments, the following embodiments can be envisaged:

[0107] 1. An analyte sensor comprising at least one working electrode and a flux limiting polymer membrane disposed on the at least one working electrode, the flux limiting polymer membrane having the following formula (I): TIFF2024500627000007.tif4560 (wherein x is about 2 to about 8 mol %) y is about 72 to about 98 mol %, z is 0 to about 20 mol %. The analyte sensor includes a polymer having a

[0108] 2. x is about 2 to about 8 mol %, y is about 82 to about 88 mol %, Item 2. The analyte sensor of item 1, wherein z is about 7 to about 13 mol %.

[0109] 3. x is about 3 to about 7 mol %, y is about 83 to about 87 mol %, Item 3. The analyte sensor of item 1 or 2, wherein z is about 8 to about 12 mol %.

[0110] 4. x is about 4 to about 6 mol %, y is about 84 to about 86 mol %, Item 4. The analyte sensor of any one of Items 1 to 3, wherein z is about 9 to about 11 mol %.

[0111] 5. x is about 5 mol %, y is about 85 mol %, Item 5. The analyte sensor of any one of items 1 to 4, wherein z is about 10 mol %.

[0112] 6. The analyte sensor of any one of items 1 to 5, wherein the polymer is a statistical copolymer.

[0113] 7. The analyte sensor according to any one of items 1 to 6, wherein the polymer has a weight average molecular weight of about 60 kDa to about 200 kDa, about 80 kDa to about 160 kDa, about 100 kDa to about 140 kDa, in particular about 120 kDa.

[0114] 8. The analyte sensor according to any one of paragraphs 1 to 7, wherein the polymer has a number average molecular weight of about 4 kDa to about 90 kDa, about 40 kDa to about 70 kDa, in particular about 60 kDa.

[0115] 9. The analyte sensor according to any one of paragraphs 1 to 8, wherein the polymer has a polydispersity index of about 1.4 to about 3, in particular about 2.

[0116] 10. The analyte sensor of any one of paragraphs 1 to 9, wherein the polymer of formula (I) in the flux limiting polymer membrane is crosslinked by a crosslinking agent.

[0117] 11. The analyte sensor of item 10, wherein the weight ratio of polymer to crosslinker in the flux limiting polymer membrane is from about 8:1 (w / w) to about 16:1 (w / w), from about 10:1 (w / w) to about 14:1 (w / w), in particular about 12:1 (w / w).

[0118] 12. The analyte sensor of claim 10 or 11, wherein the crosslinker comprises at least one functional epoxide group.

[0119] 13. The analyte sensor according to any one of claims 10 to 12, wherein the cross-linking agent comprises at least two, in particular three, functional epoxide groups.

[0120] 14. The analyte sensor according to any one of items 10 to 13, wherein the cross-linking agent is N,N-diglycidyl-4-glycidyloxyaniline.

[0121] 15.(i) A substrate comprising: A first aspect and a second aspect; at least one conductive material disposed on the first side of the substrate; A substrate comprising: (ii) a working electrode comprising a sensing material at least partially covering a first side of the substrate, the sensing material comprising at least one enzyme; and (iii) a flux-limiting polymer membrane disposed on the at least one working electrode, the flux-limiting polymer membrane comprising a polymer of Formula (I); and Item 15. The analyte sensor according to any one of items 1 to 14, comprising:

[0122] 16. The analyte sensor comprising: (i) a substrate, A first aspect and a second aspect; at least one conductive material disposed on the first side of the substrate; A substrate comprising: (ii) the working electrode comprising a sensing material, the working electrode at least partially covering the first side of the substrate and at least partially disposed on the at least one conductive material; and Equipped with Item 15. The analyte sensor of any one of items 1 to 14, wherein the sensing material comprises at least one enzyme.

[0123] 17. The analyte sensor of claim 15 or 16, wherein the at least one conductive material disposed on the first side of the substrate is selected from gold, carbon, carbon paste, and any combination thereof.

[0124] 18. The analyte sensor of any one of claims 15 to 17, wherein the sensing material comprises the enzyme glucose oxidase (GOx).

[0125] 19. The analyte sensor of any one of claims 15 to 18, wherein the sensing material further comprises at least one cross-linking agent.

[0126] 20. The analyte sensor of any one of paragraphs 15 to 19, wherein the sensing material further comprises at least one polymeric metal-containing complex.

[0127] 21. The analyte sensor of clause 20, wherein the at least one polymeric metal-containing complex is selected from the group of polymeric transition metal-containing complexes.

[0128] 22. The analyte sensor of paragraph 21, wherein the at least one polymeric transition metal-containing complex is selected from an osmium complex, a ruthenium complex, a vanadium complex, a cobalt complex, and an iron complex.

[0129] 23. The analyte sensor of any of paragraphs 1 to 22, comprising at least one further electrode.

[0130] 24. The analyte sensor of clause 23, wherein the at least one additional electrode is selected from a counter electrode, a reference electrode, and a combination counter / reference electrode.

[0131] 25. The analyte sensor of claim 23 or 24, wherein the at least one further electrode is a combination counter / reference electrode.

[0132] 26. The analyte sensor of any one of paragraphs 1 to 25, which is a two-electrode sensor, in particular comprising one working electrode and one combined counter / reference electrode.

[0133] 27. The analyte sensor of any one of paragraphs 1 to 26, further comprising at least one biocompatible membrane disposed on the flux limiting polymeric membrane.

[0134] 28. The analyte sensor of any one of paragraphs 1 to 27, which does not include a biocompatible membrane disposed on the flux limiting polymeric membrane.

[0135] 29. The analyte sensor of any one of paragraphs 1 to 28, wherein the flux limiting polymer membrane is glucose permeable.

[0136] 30. The flux-limiting polymer membrane has a flux of at least about 1×10 -6 cm 2 / s, preferably about 1 × 10 -6 cm 2 / s~approx. 1×10 -10 cm 2 30. The analyte sensor according to any one of items 1 to 29, having a diffusion coefficient of glucose of 1 / s.

[0137] 31. Use of an analyte sensor according to any one of paragraphs 1 to 30 for detecting at least one analyte in a sample.

[0138] 32. A method for determining an analyte in a sample, comprising using an analyte sensor according to any one of paragraphs 1 to 30.

[0139] 33. A polymeric membrane for use in an analyte sensor, the polymeric membrane having the following formula (I): TIFF2024500627000008.tif4560 (wherein x is about 2 to about 8 mol %, y is about 72 to about 98 mol %, z is 0 to about 20 mol %. A polymeric film comprising a polymer having the formula:

[0140] 34. The polymeric film according to item 33, comprising at least one feature defined in any one of items 2 to 15.

[0141] 35. A liquid composition comprising the following formula (I): TIFF2024500627000009.tif4554 (wherein x is about 2 to about 8 mol %, y is about 72 to about 98 mol %, and z is from 0 to about 20 mol %. A cross-linking agent; Solvent and A liquid composition comprising:

[0142] 36. The liquid composition according to item 35, comprising at least one of the features defined in any one of items 2 to 15.

[0143] 37. The liquid composition according to item 35 or 36, wherein the solvent comprises ethanol and water, particularly about 70% to about 90% (v / v) ethanol and about 10% to about 30% (v / v) water, particularly about 80% (v / v) ethanol and about 20% (v / v) water.

[0144] 38. The liquid composition according to any one of items 35 to 37, comprising about 100 mg / ml to about 140 mg / ml of polymer and about 8 mg / ml to about 12 mg / ml of crosslinker, in particular about 120 mg / ml of polymer and about 10 mg / ml of crosslinker.

[0145] 39. A method for producing an analyte sensor, in particular an analyte sensor according to any one of paragraphs 1 to 30, comprising: a) providing a substrate having a first side and a second side, and at least one working electrode disposed on the first side of the substrate; b) forming a layer of a polymer film on the at least one working electrode, the polymer film having a structure represented by the following formula (I): TIFF2024500627000010.tif4560 (wherein x is about 2 to about 8 mol %, y is about 72 to about 98 mol %, z is 0 to about 20 mol %. The method includes the step of:

[0146] 40. The method according to claim 39, comprising at least one feature defined in any one of claims 2 to 15.

[0147] 41. The method of claim 39 or 40, wherein step b) comprises coating at least one working electrode with a liquid composition comprising a polymer, a cross-linking agent and a solvent, curing the polymer and drying.

[0148] 42. The method according to item 41, wherein the solvent comprises ethanol and water, particularly about 70% to about 90% (v / v) ethanol and about 10% to about 30% (v / v) water, particularly about 80% (v / v) ethanol and about 20% (v / v) water.

[0149] 43. The method according to item 41 or 42, wherein the liquid composition comprises from about 100 mg / ml to about 140 mg / ml of polymer and from about 8 mg / ml to about 12 mg / ml of crosslinker, in particular from about 120 mg / ml of polymer and about 10 mg / ml of crosslinker.

[0150] 44. An analyte sensor comprising at least one working electrode and a flux-limiting polymer membrane disposed on the at least one working electrode, wherein the flux-limiting polymer membrane has the following formula (Ia): TIFF2024500627000011.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol %. The analyte sensor includes a statistical polymer having:

[0151] 45. The analyte sensor of claim 44, comprising at least one feature defined in any one of claims 1 to 30.

[0152] 46. ​​A polymeric membrane for use in an analyte sensor, the polymeric membrane having the following formula (Ia): TIFF2024500627000012.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol %. 1. A polymeric film comprising a statistical polymer having:

[0153] 47. The polymeric film according to item 46, comprising at least one feature as defined in any one of items 33-34.

[0154] 48. A liquid composition comprising the following formula (Ia): TIFF2024500627000013.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol %. A statistical polymer having the formula: A cross-linking agent; Solvent and A liquid composition comprising:

[0155] 49. The liquid composition according to item 48, comprising at least one of the features defined in any one of items 35 to 38.

[0156] 50. A method for producing an analyte sensor, in particular an analyte sensor according to any one of paragraphs 44 to 45, comprising: a) providing a substrate having a first side and a second side, and at least one working electrode disposed on the first side of the substrate; b) forming a layer of a polymer film on the at least one working electrode, the polymer film having a structure represented by the following formula (Ia): TIFF2024500627000014.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol %. The method includes the step of:

[0157] 51. The method according to claim 50, comprising at least one feature defined in any one of claims 35 to 38.

[0158] 52. An analyte sensor comprising at least one working electrode and a flux-limiting polymer membrane disposed on the at least one working electrode, wherein the flux-limiting polymer membrane comprises a polymer having a weight average molecular weight of about 60 kDa to about 200 kDa, the polymer having a formula (Ia): TIFF2024500627000015.tif4560 (wherein x is about 2 to about 20 mol %); y is about 60 to about 98 mol %, z is about 0 to about 20 mol %. The analyte sensor comprises:

[0159] 53. The analyte sensor of clause 52, comprising at least one feature defined in any one of clauses 1 to 30.

[0160] 54. The polymer membrane has a weight average molecular weight of about 60 kDa to about 200 kDa and is represented by the following formula (Ia): TIFF2024500627000016.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol %. A polymeric film for use in an analyte sensor comprising a polymer having a

[0161] 55. The polymeric film according to item 54, comprising at least one feature defined in any one of items 33 to 34.

[0162] 56. A compound having a weight average molecular weight of about 60 kDa to about 200 kDa and the following formula (Ia): TIFF2024500627000017.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol %, A cross-linking agent; Solvent and A liquid composition comprising:

[0163] 57. The liquid composition according to item 56, comprising at least one of the features defined in any one of items 35 to 38.

[0164] 58. A method for producing an analyte sensor, in particular an analyte sensor according to any one of paragraphs 52 to 53, comprising: a) providing a substrate having a first side and a second side, and at least one working electrode disposed on the first side of the substrate; b) forming a layer of a polymer film on the at least one working electrode, the polymer film having a weight average molecular weight of about 60 kDa to about 200 kDa and a polymer having the following formula (Ia): TIFF2024500627000018.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is about 0 to about 20 mol %. The method comprises the steps of:

[0165] 59. The method according to claim 58, comprising at least one feature defined in any one of claims 35 to 38.

[0166] 60. An analyte sensor comprising at least one working electrode and a flux-limiting polymer membrane disposed on the at least one working electrode, the flux-limiting polymer membrane having the following formula (Ia): TIFF2024500627000019.tif4560 (wherein x is about 2 to about 20 mol %); y is about 60 to about 98 mol %, z is from about 0 to about 20 mol %, 1. The analyte sensor according to claim 1, wherein the polymer is crosslinked by a crosslinker that is N,N-diglycidyl-4-glycidyloxyaniline, and in particular the weight ratio of polymer to crosslinker is from about 8:1 (w / w) to about 16:1 (w / w), from about 10:1 (w / w) to about 14:1 (w / w), in particular about 12:1 (w / w).

[0167] 61. The analyte sensor of claim 60, comprising at least one feature defined in any one of claims 1 to 30.

[0168] 62. A polymeric membrane for use in an analyte sensor, the polymeric membrane having the following formula (Ia): TIFF2024500627000020.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is from about 0 to about 20 mol %, A polymer membrane, wherein the polymer is crosslinked with a crosslinking agent that is N,N-diglycidyl-4-glycidyloxyaniline, and in particular the weight ratio of polymer to crosslinking agent is from about 8:1 (w / w) to about 16:1 (w / w), from about 10:1 (w / w) to about 14:1 (w / w), in particular about 12:1 (w / w).

[0169] 63. The method according to claim 62, comprising at least one feature defined in any one of claims 33 to 34.

[0170] 64. A liquid composition comprising the following formula (Ia): TIFF2024500627000021.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is from about 0 to about 20 mol %, A cross-linking agent; a solvent; The method according to claim 1, wherein the crosslinker is N,N-diglycidyl-4-glycidyloxyaniline, and in particular the weight ratio of polymer to crosslinker is from about 8:1 (w / w) to about 16:1 (w / w), from about 10:1 (w / w) to about 14:1 (w / w), in particular about 12:1 (w / w).

[0171] 65. The liquid composition according to item 64, comprising at least one of the features defined in any one of items 35 to 38.

[0172] 66. A method for producing an analyte sensor, in particular an analyte sensor according to any one of paragraphs 60 to 61, comprising: a) providing a substrate having a first side and a second side, and at least one working electrode disposed on the first side of the substrate; b) forming a layer of a polymer film on the at least one working electrode, the polymer film having a structure represented by the following formula (Ia): TIFF2024500627000022.tif4560 (wherein x is about 2 to about 20 mol %) y is about 60 to about 98 mol %, z is from about 0 to about 20 mol %, The method, wherein step (b) comprises crosslinking the polymer with a crosslinking agent which is N,N-diglycidyl-4-glycidyloxyaniline, particularly wherein the weight ratio of polymer to crosslinking agent is from about 8:1 (w / w) to about 16:1 (w / w), from about 10:1 (w / w) to about 14:1 (w / w), particularly about 12:1 (w / w).

[0173] 67. The method according to claim 66, comprising at least one feature defined in any one of claims 35 to 38. [Brief description of the drawings]

[0174] [Figure 1] FIG. 1 shows the run-in current of six different analyte sensors. [Diagram 2] FIG. 2 shows the current of six different analyte sensors over a period of approximately 10 days. [Diagram 3] FIG. 3 shows the long-term change in sensitivity of analyte sensors containing different flux-limiting polymer membranes at a glucose concentration of 180 mg / dL.

[0175] The present invention is not limited to one of the above-mentioned embodiments, but can be modified in many different ways. Those skilled in the art will recognize that the embodiments according to the present invention can be easily adapted without departing from the scope of the present invention. Thus, simple adaptations are envisaged for the preparation of analyte sensors. The present invention allows the preparation of analytes with reproducible sensor sensitivity with reduced production costs. Further features, details and advantages of the present invention can be obtained from the following description of examples based on the claims and the drawings.

[0176] The contents of all references cited in this patent application are hereby incorporated by reference in their entirety and with respect to their respective specific disclosures. EXAMPLES

[0177] The following examples serve to illustrate the invention and should not be interpreted as limiting with regard to the scope of protection.

[0178] Example 1: Preparation and testing of analyte sensors containing different flux-limiting polymer membrane layers A sensor substrate based on a thin layer of polyethylene terephthalate and gold was coated with carbon paste by doctor blading. Suitable carbon conductive inks are available from Ercon, Inc. (Wareham, MA), EI du Pont de Nemours and Co. (Wilmington, DE), Emca-Remex Products (Montgomeryville, PA), or TEKRA, A Division of EIS, Inc. (New Berlin, WI). The carbon paste was then dried at 50°C for 12 hours.

[0179] A layer of the sensing material was applied by cannula coating onto the sensor substrate, followed by drying at ambient temperature, eg, about 25° C., for 10 minutes.

[0180] The sensing material contained 57 wt% of the polymeric transition metal complex (modified poly(vinylpyridine) backbone carrying poly(biimidyl)Os complex covalently bonded via bidentate bonds), 33 wt% of glucose oxidase, and 10 wt% of PEG-DGE (poly(ethylene glycol)-diglycidyl ether), based on the sum of the weight percentages of the polymeric transition metal complex, glucose oxidase, and PEG-DGE in each case. Water was used as the solvent. The total concentration of the polymeric transition metal complex, glucose oxidase, and PEG-DGE in water was 50 mg / ml.

[0181] A working electrode with dimensions of 0.5 mm × 0.6 mm and a layer thickness of 3 μm was prepared on the sensor substrate by laser ablation.

[0182] The working electrode of each sensor was coated with a different liquid composition containing a poly(vinylpyridine)-based polymer and a crosslinker, as shown in Table 1. In all cases, a mixture of 80% (v / v) ethanol and 20% (v / v) water was used as the solvent. In the table, Oxi-Ani means N,N-diglycidyl-4-glycidyloxyaniline, and PEG-DGE 200 means poly(ethylene glycol)-diglycidyl ether with a number average molecular weight of 200 Da.

[0183] [Table 1]

[0184] After coating, the sensor was dried and the polymer was crosslinked at room temperature to obtain a flux-limiting membrane on the working electrode. Silver / silver chloride was used as the counter / reference composite electrode.

[0185] Four sensors were prepared for each different flux-limiting membrane. The measurements described below were performed for each of the four sensors, and the median of the measurements obtained was calculated. All measurements were performed in vitro. All the following descriptions refer to the median of the measurements.

[0186] For all sensors, the current was measured over a period of about 10 days with various amounts of glucose. The measurements were performed in phosphate buffer. After a run-in time of about 6 hours, glucose was added. The glucose was exchanged periodically by flushing with phosphate buffer and phosphate glucose buffer at a fixed ratio for each step by an LC system (Jasco LC-4000 series). Each step had a duration of 90 minutes in pyramidal phase. The following glucose concentrations were used: 0 mg / dl, 36 mg / dl, 72 mg / dl, 108 mg / dl, 144 mg / dl, 216 mg / dl, 306 mg / dl, 414 mg / dl; 468 mg / dl, 360 mg / dl, 270 mg / dl, 180 mg / dl, 126 mg / dl, 90 mg / dl, 54 mg / dl, 14.4 mg / dl. The sensitivity was expressed at a glucose concentration of 180 mg / dl.

[0187] Figure 1 shows the median run-in time t in minutes for the different sensors. It can be seen that the sensors containing poly(ethylene glycol)-diglycidyl ether as crosslinker have a reduced run-in time compared to the sensors containing N,N-diglycidyl-4-glycidyloxyaniline as crosslinker. However, their run-in times are still short enough to allow their use as continuous glucose sensors.

[0188] Figure 2 shows the current I in minutes over time t for the different sensors. It can be seen that the current of the sensor containing 10 mol% sulfonato-vinylpyridinium in a poly(vinylpyridine)-based polymer decreases rapidly over time, while the sensor containing 5 mol% sulfonato-vinylpyridinium has an almost constant current over the measurement period.

[0189] Thus, sensors B3, B5 and B6 exhibit significantly increased long-term stability over sensors V1, V2 and V4.

[0190] Figure 3 shows the sensitivity in nA / mg / dl over time t in days for the different sensors. It can be seen that the sensitivity drop for sensors B3, B5, B6 is lower than sensors V1, V2, V4. This is advantageous as it indicates a higher stability of the sensors over a longer time period.

[0191] Example 2: Analyte sensors containing different flux-limiting polymer membrane layers A polyethylene terephthalate-based sensor substrate was coated with carbon paste by doctor blading. Suitable carbon conductive inks are available from Ercon, Inc. (Wareham, MA), EI du Pont de Nemours and Co. (Wilmington, DE), Emca-Remex Products (Montgomeryville, PA), or TEKRA, A Division of EIS, Inc. (New Berlin, WI). The carbon paste was then dried at 50°C for 12 hours.

[0192] A layer of the sensing material was applied by cannula coating onto the sensor substrate, followed by drying at ambient temperature, eg, about 25° C., for 10 minutes.

[0193] The sensing material contained 57 wt% of the polymeric transition metal complex (modified poly(vinylpyridine) backbone carrying poly(biimidyl)Os complex covalently bonded via bidentate bonds), 33 wt% of glucose oxidase, and 10 wt% of PEG-DGE (poly(ethylene glycol)-diglycidyl ether), based on the sum of the weight percentages of the polymeric transition metal complex, glucose oxidase, and PEG-DGE in each case. Water was used as the solvent. The total concentration of the polymeric transition metal complex, glucose oxidase, and PEG-DGE in water was 50 mg / ml.

[0194] A working electrode with dimensions of 0.5 mm × 0.6 mm and a layer thickness of 4 μm was prepared on the sensor substrate by laser ablation.

[0195] The working electrode of each sensor was coated (dip-coated, three times) with different liquid compositions containing a poly(vinylpyridine)-based polymer and a cross-linker, as shown in Table 2. In all cases, a mixture of 80% (v / v) ethanol and 20% (v / v) water was used as the solvent. In the table, Oxi-Ani means N,N-diglycidyl-4-glycidyloxyaniline, and PEG-DGE 200 means poly(ethylene glycol)-diglycidyl ether with a number-average molecular weight of 200 Da.

[0196] Sensors V1, V2 and B3 in Table 2 were prepared similarly to Example 1, and V1, V2 and B3 in Table 2 correspond to V1, V2 and B3 in Table 1.

[0197] In Table 2, Mn is the number average molecular weight of the polyvinylpyridine polymer, and PDI is the polydispersity index of the polyvinylpyridine polymer.

[0198] [Table 2]

[0199] After coating, the sensor was dried to obtain a flux-limiting membrane on the working electrode. If a crosslinker was included, the polymer was crosslinked at room temperature.

[0200] Silver / silver chloride was used as the combined counter / reference electrode.

[0201] Four sensors were prepared for each different flux-limiting membrane. The measurements described below were performed for each of the four sensors, and the median of the measurements obtained was calculated. All measurements were performed in vitro. All the following descriptions refer to the median of the measurements.

[0202] For all sensors, current measurements were performed over a period of approximately 7 days with various amounts of glucose in phosphate buffer.

[0203] Sensitivity was measured on the first day at a glucose concentration of 180 mg / dl. The mean drift was calculated at glucose concentrations of 180 mg / dl and 468 mg / dl.

[0204] As can be seen from Table 2, the sensors including the flux-limiting membrane of the present invention exhibit reduced drift compared to the comparative sensors, but still have sufficiently short run-in times. At the same time, they still have good sensitivity.

Claims

1. 1. An analyte sensor comprising: at least one working electrode; and a flux-limiting polymer membrane disposed on the at least one working electrode, wherein the flux-limiting polymer membrane has the following formula (I): (wherein x is 4 to 6 mol %), y is 72 to 98 mol %, z is 0 to 20 mol %, and The sum of the mole percentages of x, y and z is 100 mole percent.

1. An analyte sensor comprising a polymer having:

2. The analyte sensor of claim 1 , wherein the polymer is a statistical copolymer.

3. The sensor of claim 1 or 2, wherein the polymer has a weight average molecular weight in the range of 60 kDa to 200 kDa.

4. The analyte sensor of any one of claims 1 to 3, wherein the polymer of formula (I) in the flux limiting polymer membrane is crosslinked by a crosslinking agent.

5. The analyte sensor of claim 4, wherein the weight ratio of polymer to crosslinker in the flux-limiting polymer membrane is between 8:1 (w / w) and 16:1 (w / w).

6. The analyte sensor of claim 5, wherein the weight ratio of polymer to crosslinker in the flux-limiting polymer membrane is from 10:1 (w / w) to 14:1 (w / w).

7. The analyte sensor of claim 6, wherein the weight ratio of polymer to crosslinker in the flux-limiting polymer membrane is 12:1 (w / w).

8. The analyte sensor of any one of claims 4 to 7, wherein the cross-linking agent is N,N-diglycidyl-4-glycidyloxyaniline.

9. the analyte sensor (i) a substrate, a first side and a second side; at least one conductive material disposed on the first side of the substrate; a substrate comprising: (ii) the working electrode including a sensing material, the working electrode at least partially covering the first side of the substrate and being at least partially disposed on the at least one conductive material; Equipped with The analyte sensor of any one of claims 1 to 8, wherein the sensing material comprises at least one enzyme.

10. the at least one conductive material disposed on the first side of the substrate is selected from gold, carbon, carbon paste, and any combination thereof; and / or 10. The analyte sensor of claim 9, wherein the sensing material comprises the enzyme glucose oxidase (GOx).

11. The analyte sensor of claim 1, which is a two-electrode sensor including the working electrode and a counter / reference combination electrode.

12. further comprising at least one biocompatible membrane disposed on said flux-limiting polymeric membrane; or The analyte sensor of any one of claims 1 to 11, which does not include a biocompatible membrane disposed on the flux limiting polymer membrane.

13. Use of an analyte sensor according to any one of claims 1 to 12 for detecting at least one analyte in a sample.

14. A method for determining an analyte in a sample, comprising using an analyte sensor according to any one of claims 1 to 12.

15. 1. A polymeric membrane for use in an analyte sensor, said polymeric membrane comprising a polymer having the following formula (I): (wherein x is 4 to 6 mol %), y is 72 to 98 mol %, z is 0 to 20 mol %, and The sum of the mole percentages of x, y and z is 100 mole percent. A polymer film comprising a polymer having:

16. A liquid composition comprising a compound of the following formula (I): (wherein x is 4 to 6 mol %), y is 72 to 98 mol %, z is 0 to 20 mol %, and the sum of the mole percent of x, y and z is 100 mole percent; a cross-linking agent, and solvent, A liquid composition comprising:

17. 17. The liquid composition of claim 16, wherein the solvent comprises ethanol and water.

18. The liquid composition of claim 17, wherein the solvent comprises 70% to 90% (v / v) ethanol and 10% to 30% (v / v) water.

19. The liquid composition of claim 18, wherein the solvent comprises 80% (v / v) ethanol and 20% (v / v) water.

20. A liquid composition according to any one of claims 16 to 19, comprising 100 mg / ml to 140 mg / ml of polymer and 8 mg / ml to 12 mg / ml of crosslinker.

21. The liquid composition of claim 20, comprising 120 mg / ml of polymer and 10 mg / ml of crosslinker.

22. A method for manufacturing an analyte sensor according to any one of claims 1 to 12, comprising the steps of: a) providing a substrate having a first side and a second side, and at least one working electrode disposed on the first side of the substrate; b) forming a layer of a flux-limiting polymer film on the at least one working electrode, the flux-limiting polymer film having the following formula (I): (wherein x is 4 to 6 mol %), y is 72 to 98 mol %, z is 0 to 20 mol %, and The sum of the mole percentages of x, y and z is 100 mole percent. and A method comprising:

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