Photonic interpenetrating polymeric network structure based-glucose biosensor, manufacturing method therefor, and skin-attachable sweat-based glucose biosensor patch comprising same

Abstract

The present invention relates to: a photonic interpenetrating polymeric network structure-based glucose biosensor in which a cholesteric liquid crystal in a solid state and a cationic polymer electrolyte are combined; a manufacturing method therefor; and a skin-attachable sweat-based glucose biosensor patch comprising same. The photonic interpenetrating polymeric network structure-based glucose biosensor according to the present invention is easy to manufacture, can be manufactured as a film, can be attached to the skin, and can visually detect the glucose concentration in the body quickly and accurately using only a small amount of sweat.

Description

Glucose biosensor based on an interpenetrating polymer network structure with optical properties, method for manufacturing the same, and skin-attachable sweat-based glucose biosensor including the same

[0001] The present invention relates to a glucose biosensor based on an interpenetrating polymer network structure with optical properties, a method for manufacturing the same, and a skin-attachable sweat-based glucose biosensor patch comprising the same.

[0002]

[0003] Diabetes mellitus is a metabolic and physiological disease affecting millions of people worldwide, posing a serious health problem characterized by high morbidity and mortality rates, as well as high treatment costs. This condition is generally associated with immune system dysfunction, genetic factors, and other conditions affecting insulin production, leading to imbalances in the body's glucose levels, hyperglycemia, and impaired glucose metabolism.

[0004] Since accurately measuring a patient's blood glucose levels is crucial for monitoring or preventing diabetes, significant interest is being focused on the development of non-invasive blood glucose monitoring systems that test bodily fluids such as saliva, tears, sweat, and urine without penetrating the skin. In particular, wearable biosensors have become a key research focus due to their potential to provide continuous, real-time physiological information. Consequently, based on advancements in materials science, nanotechnology, wireless communication, and biotechnology, a diverse range of stable and practical wearable biosensing devices are being manufactured for use in personalized medicine and telemedicine. Wearable biosensors must be miniaturized and lightweight to facilitate easy integration into wearable devices and ensure user comfort during use. To guarantee optimal performance, functions that adapt to the shape and movement of the human body are also important; therefore, the materials used in biosensors must be flexible and stretchable. Furthermore, these materials must be reusable, biocompatible, and possess biosafety that allows for long-term use without adverse effects on the user's health.

[0005] Sweat is one of the most convenient body fluid targets for non-invasive biosensors, but efficient and uncontaminated sweat collection is required for accurate analysis. Glucose tests using sweat induced without physical exercise or heating are the most convenient form of non-invasive testing; however, the amount of naturally produced sweat without physical exercise or heating is small, with an average of 0.013–0.023 mL / cm² across the body at 35°C. -2 min -1 There is a limitation in that sweat is generated only at a certain rate. Therefore, glucose biosensors that measure naturally generated sweat without exercise or heating require sufficiently high sensitivity to overcome this limitation.

[0006] Accordingly, the present invention was completed by developing a novel sweat-based skin-attachable glucose biosensor patch with improved sensitivity, specificity, and detection speed based on an Interpenetrating Polymer Networks (IPN) structure.

[0007]

[0008] The present invention provides a novel sweat-based skin-attachable glucose biosensor with improved sensitivity, specificity, and detection speed based on an optical interpenetrating polymer network (IPN) structure, and a method for manufacturing the same.

[0009] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below.

[0010]

[0011] To achieve the above objective, the present invention provides a method for manufacturing a glucose biosensor comprising the steps of: cleaning a substrate and then coating it with an aqueous polyvinyl alcohol (PVA) solution; preparing a Cholesteric Liquid Crystal (CLC) mixture by mixing a reactive mesogen, a liquid crystal porogen, and a chiral dopant; coating the Cholesteric Liquid Crystal mixture onto the substrate coated with the aqueous polyvinyl alcohol (PVA) solution and then UV curing to produce a solid Cholesteric Liquid Crystal film; cleaning the Cholesteric Liquid Crystal film to remove unreacted liquid crystal porogen; infiltrating a cationic polymer electrolyte into the space where the unreacted liquid crystal porogen of the Cholesteric Liquid Crystal film has been removed to form a complex having an interpenetrating polymer network (IPN) structure; and immobilizing glucose oxidase (GOx) on the complex having the interpenetrating polymer network (IPN) structure.

[0012] The liquid crystal porogen may be included in an amount of 46 to 54 parts by weight per 100 parts by weight of the mixture of the reactive mesogen and the liquid crystal porogen.

[0013] The chiral dopant can be mixed in an amount of 1 to 10 parts by weight per 100 parts by weight of the mixture of the reactive mesogen and liquid crystal porogen.

[0014] The above cationic polymer electrolyte may be 2-dimethylaminoethyl methacrylate (DMAEMA).

[0015] In addition, the present invention provides a glucose biosensor characterized by being manufactured by the above-described manufacturing method.

[0016] The glucose biosensor above can respond to glucose in a linear range of glucose concentrations from 0.2 to 6 mM.

[0017] In addition, the present invention provides a skin-attachable sweat-based glucose biosensor patch comprising: the glucose biosensor above; a sweat-absorbing substrate disposed at the bottom of the glucose biosensor; and a transparent band disposed at the top of the glucose biosensor.

[0018] The sweat-absorbing substrate may be a polyurethane foam with a porous open-cell structure.

[0019]

[0020] By means of the solution to the above problem, the present invention can provide a sweat-based skin-attachable glucose biosensor with improved sensitivity, specificity, and detection speed based on an interpenetrating polymer network (IPN) structure with optical properties.

[0021] In addition, the glucose biosensor according to the present invention is easy to manufacture and can rapidly and accurately detect glucose concentration in the body visually even with a small amount of sweat.

[0022] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0023]

[0024] FIG. 1 is (a) a photonic IPN according to the present invention. PDMAEMA-GOx (b) manufacturing process of the film and (b) skin-attachable IPN composed of three layers PDMAEMA-GOx Schematic diagram of a glucose biosensor and (c) an IPN attachable to a human fingertip PDMAEMA-GOx This shows a picture of a biosensor film attached to the skin.

[0025] Figure 2 shows (a) an aqueous glucose solution (C g elapsed times (t) of 1, 5, 10, and 15 minutes at = 0.8, 1.0, and 10 mM). elaps After testing for ) 5CB = IPN prepared at 65, 55, 50, 45, and 40 wt%PDMAEMA-GOx Photographic image of the film sample, (b) different 5CB (Horizontal axis) and LC756 Matrix photograph of the RMM / 5CB / LC756 mixture prepared using (vertical axis) and (c) for LC756 in the RMM / 5CB ​​mixture based on the photographic image of (b). 5CB This represents the helical twisting power (HTP) calculated as a function of .

[0026] Fig. 3 is 5CB = 50 wt% and LC756 IPN at = 3.0-4.2 wt% before UV crosslinking (i=1), after crosslinking (i=2), after 5CB removal (i=3), after DMAEMA infiltration and UV crosslinking (i=4), and after swelling for 10 minutes in pH 2 solution (i=5). PDMAEMA CLC during film manufacturing solid This represents a photographic image of the film.

[0027] Fig. 4 is (a) 5CB = 50 wt% manufactured IPN PDMAEMA λ of the film dominant vs LC756 Plot of (before UV crosslinking (λ1), after crosslinking (λ2), after 5CB removal (λ3), after DMAEMA infiltration and UV crosslinking (λ4), after swelling in pH 2 solution for 10 minutes (λ5)), (b) ratios of (i) λ1 / λ2, (ii) λ3 / λ1, (iii) λ4 / λ3, and (iv) λ5 / λ4 LC756 Graph shown as a function, (c) IPN PDMAEMA-GOx log C measured based on the inserted photographic image of the film sample g λPBG, UV-vis values ​​expressed as a function of (linear lines indicate the linear range) and (d) C g= 0.005, 0.010, 0.015, 0.02 mL of sweat (V) at 0.1, 0.2, 0.4, 1.0, 4.0 mM sweat Circular IPN in a volume-filled well PDMAEMA-GOx This shows a photograph of a custom test chamber consisting of 6 x 5 circular wells designed to hold a liquid sample of up to 0.157 mL (inner diameter = 1 cm; depth = 0.5 mm) after placing a film sample.

[0028] Fig. 5 shows (a) an inserted IPN PDMAEMA Photograph of a film sample (λ dominant λ as a function of pH measured from ) dominant (b) values ​​and (b) IPN exposed to various pH levels PDMAEMA This shows the CIE 1931 xy chromaticity diagram connecting the origin (white dot) of the film sample photograph and each experimental point (x, y) with a line.

[0029] FIG. 6 is (a) IPN in a glucose aqueous solution (3 mM). PDMAEMA-GOx Elapsed time (t) measured for the film image elaps λ as a function of ) dominant (b) values ​​and (b) IPN tested for 10 minutes with DI water and 1 mM glucose, galactose, fructose, lactose, urea, and hemoglobin PDMAEMA-GOx λ of the film sample dominant It represents the value (the insert displays the corresponding photo image).

[0030] Figure 7 is C g = IPN for artificial sweat at concentrations of 0 and 1 mM (including other major sweat components) PDMAEMA-GOx λ of the film sample dominant It represents the value.

[0031] Fig. 8 is (a) C g Circular IPNs attached to fingertips pre-moistened with glucose aqueous solution (0.015 mL) at concentrations of 0, 0.1, 0.3, 0.6, 1, and 6 mM. PDMAEMA-GOx C derived from the photographic image of the sample (diameter = 1 cm)g λ as a function of dominant Values, (b, c) (b) (i, iii) healthy adult forearms in a dry state and (ii, iv) wet state with aqueous glucose solution (6 mM, 0.015 mL) for 5 minutes and (c) (i, ii) circular IPN on the forehead of a volunteer at a gym (i, iii) before exercise and (ii, iv) after exercise. PDMAEMA-GOx (iii, iv) photographic images of film samples (diameter = 1 cm) and uploaded images containing chromaticity coordinates (x, y) and hexadecimal (HEX) values ​​extracted from a color finding website and (d) spiked human sweat samples (HypoG1, HypoG2, NormalG, HyperG1, and HyperG2 in Table 1) of various C g IPN tested at PDMAEMA-GOx C measured from the film image (inset) g λ as a function of dominant It represents the value.

[0032] Figure 9 is taken from UV-vis spectroscopy. PBG and 5CB , LC756 and C g λ taken from a photographic image of another photonic IPNPDMAEMA-GOx film dominant This is a graph represented as a function of .

[0033]

[0034] The terms used in this invention have been selected based on currently widely used general terms, taking into account their functions within the invention; however, these terms may vary depending on the intent of those skilled in the art, case law, the emergence of new technologies, etc. Additionally, in specific cases, terms have been arbitrarily selected by the applicant, and in such cases, their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this invention should be defined not merely by their names, but based on their meanings and the overall content of the invention.

[0035] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0036] When a part of a specification is described as “comprising” a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0037] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0038]

[0039] The present invention will be described in detail below.

[0040]

[0041] The present invention provides a method for manufacturing a glucose biosensor comprising the steps of: cleaning a substrate and then coating it with an aqueous polyvinyl alcohol (PVA) solution; preparing a Cholesteric Liquid Crystal (CLC) mixture by mixing a reactive mesogen, a liquid crystal porogen, and a chiral dopant; coating the Cholesteric Liquid Crystal mixture onto a glass substrate coated with the aqueous polyvinyl alcohol (PVA) solution and then UV curing it to produce a solid Cholesteric Liquid Crystal film; cleaning the Cholesteric Liquid Crystal film to remove unreacted liquid crystal porogen; infiltrating a cationic polymer electrolyte into the space where the unreacted liquid crystal porogen of the Cholesteric Liquid Crystal film has been removed to form a complex having an interpenetrating polymer network (IPN) structure; and immobilizing glucose oxidase (GOx) on the complex having the interpenetrating polymer network (IPN) structure.

[0042] First, a step of cleaning the substrate and then coating it with an aqueous polyvinyl alcohol (PVA) solution can be performed.

[0043] The above substrate may be a glass substrate, but is not limited thereto.

[0044] The step of coating the substrate with an aqueous polyvinyl alcohol (PVA) solution after cleaning may include: a step of ultrasonically cleaning the substrate in ethanol, then cleaning it with deionized water and drying it; a step of treating the cleaned substrate with oxygen plasma, then coating it with an aqueous polyvinyl alcohol (PVA) solution; and a step of drying the substrate coated with the aqueous polyvinyl alcohol solution.

[0045] The step of coating the above polyvinyl alcohol (PVA) aqueous solution may utilize a spin coating technique and may be coated at 1000 to 2000 rpm for 10 to 50 seconds.

[0046] The step of drying the substrate coated with the above-mentioned polyvinyl alcohol aqueous solution can be performed at 50 to 100°C for 2 to 10 hours.

[0047] Next, a step of preparing a Cholesteric Liquid Crystal (CLC) mixture by mixing a reactive mesogen, a liquid crystal porogen, and a chiral dopant can be performed.

[0048] The above reactive mesogen may be a reactive nematic liquid crystal mesogen and a mixture thereof, preferably one or more reactive nematic liquid crystal mesogens selected from the group consisting of RMM727, RM105, RM257 and RM82 and a mixture thereof.

[0049] The liquid crystal porogen may be a non-reactive nematic liquid crystal mesogen and a mixture thereof, preferably one or more selected from the group consisting of 4-cyano-4'-pentylbiphenyl (5CB) and E7, but is not limited thereto.

[0050] The liquid crystal porogen may be included in an amount of 46 to 54 parts by weight per 100 parts by weight of the mixture of the reactive mesogen and the liquid crystal porogen. Preferably, it may be included in an amount of 48 to 52 parts by weight, and more preferably in an amount of 50 parts by weight, but is not limited thereto.

[0051] The higher the mixing ratio of the liquid crystal porogen, the more cationic polymer electrolyte can be incorporated to increase sensitivity. However, if manufactured using a cholesteric liquid crystal mixture containing an excessive level of liquid crystal porogen, it may be more brittle and prone to rupture due to a weakened cholesteric liquid crystal network and stress caused by swelling induced by glucose. Therefore, it is necessary to optimize the mixing ratio to achieve an effective balance between the structural integrity and glucose sensitivity of the glucose biosensor based on the interpenetrating polymer network (IPN) structure according to the present invention.

[0052] If liquid crystal porogen is included in an amount exceeding the above range, the biosensor structure may be weakened in a glucose solution and wrinkles may occur, and if liquid crystal porogen is included in an amount below the above range, it may be less sensitive to glucose.

[0053] The chiral dopant may be mixed in an amount of 1 to 10 parts by weight per 100 parts by weight of the mixture of the reactive mesogen and the liquid crystal porogen. Preferably, it may be mixed in an amount of 2 to 6 parts by weight, and more preferably in an amount of 3 to 5 parts by weight, but is not limited thereto.

[0054] The color of the reflected light can be changed as the wavelength of the optical band gap and the helical structure formed according to the mixing ratio of the chiral dopants change.

[0055] Next, a step of manufacturing a solid cholesteric liquid crystal film can be performed by coating the cholesteric liquid crystal mixture onto a substrate coated with the above-mentioned polyvinyl alcohol (PVA) aqueous solution and then UV curing it.

[0056] The step of manufacturing a solid cholesteric liquid crystal film by coating the cholesteric liquid crystal mixture onto a substrate coated with the above-mentioned polyvinyl alcohol (PVA) aqueous solution and then UV curing it may involve coating the cholesteric liquid crystal mixture using a bar coater.

[0057] After the step of manufacturing the above-mentioned solid cholesteric liquid crystal film, a step of cooling to 20 to 30°C may be further included.

[0058] The above UV curing is 20 to 30 mW cm⁻¹ -2 It can be UV cured for 5 to 20 minutes.

[0059] A completely solid cholesteric liquid crystal can be formed through the above curing process. As the cholesteric liquid crystal remains in a solid form, it can have improved effects in terms of stability and durability.

[0060] Next, the step of washing the solid cholesteric liquid crystal film to remove unreacted liquid crystal porogen can be performed.

[0061] The step of washing the above-mentioned solid cholesteric liquid crystal film to remove unreacted liquid crystal porogen may be performed using acetone, but is not limited thereto.

[0062] After the step of removing the unreacted liquid crystal porogen, the method may further include the step of separating the solid cholesteric liquid crystal film from the substrate from which the unreacted liquid crystal porogen has been removed.

[0063] The step of separating the solid cholesteric liquid crystal film from the substrate, from which the unreacted liquid crystal porogen has been removed, can be performed by immersing the cholesteric liquid crystal film in deionized water.

[0064] Next, a step may be performed to form a composite of an interpenetrating polymer network (IPN) structure by infiltrating a cationic polymer electrolyte into the space where the unreacted liquid crystal porogen of the cholesteric liquid crystal film has been removed.

[0065] The above-mentioned interpenetrating polymer network (IPN) is a polymer comprising two or more networks that are at least partially entangled at the molecular scale but are not covalently bonded to each other and cannot be separated unless chemical bonds are broken. It can be prepared by infiltrating monomers into a pre-formed cross-linked structure and forming a second cross-linked structure among the infiltrated monomers.

[0066] The above cationic polymer electrolyte may be 2-dimethylaminoethyl methacrylate (DMAEMA).

[0067] The above-mentioned cationic polymer electrolyte can act as a catalyst for an enzymatic reaction that selectively converts glucose into gluconic acid.

[0068] The step of forming a composite of an interpenetrating polymer network (IPN) structure by infiltrating a cationic polymer electrolyte into the space where unreacted liquid crystal porogens have been removed from the cholesteric liquid crystal film can be performed by immersing the solid cholesteric liquid crystal film in a cationic polymer electrolyte mixed solution prepared by mixing the cationic polymer electrolyte, acrylic acid, a crosslinking agent, and a photoinitiator, thereby infiltrating the cationic polymer electrolyte into the space where the liquid crystal porogens have been removed. The acrylic acid may be included in the cationic polymer electrolyte mixed solution to compensate for the lack of reaction sites for enzyme immobilization via EDC binding reactions in the cationic polymer electrolyte.

[0069] The above cationic polymer electrolyte mixed solution can be prepared by mixing the cationic polymer electrolyte, acrylic acid, a crosslinking agent, and a photoinitiator, and mixing them using a magnetic stirrer at 300 to 400 rpm and 10 to 30 ℃ for 1 to 5 hours.

[0070] After the step of forming a composite of an interpenetrating polymer network (IPN) structure by infiltrating a cationic polymer electrolyte into the space where the unreacted liquid crystal porogen of the separated solid cholesteric liquid crystal film has been removed, the method may further include the step of polymerizing the composite of the interpenetrating polymer network (IPN) structure infiltrated with the cationic polymer electrolyte by UV irradiation, and then immersing it in deionized water to remove excess hydrogel from the surface of the composite.

[0071] Next, a step of immobilizing glucose oxidase (GOx) on the complex of the interpenetrating polymer network (IPN) structure can be performed.

[0072] The step of immobilizing glucose oxidase (GOx) on the complex of the IPN structure may include: activating the complex of the IPN structure by immersing it in a mixed solution of N-hydroxysuccinimide (NHS) and (3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC-HCl); and immobilizing glucose oxidase by immersing the activated complex of the IPN structure in a glucose oxidase solution.

[0073] The above glucose oxidase can oxidize glucose into gluconic acid.

[0074] In the glucose biosensor, the pH is reduced by the gluconic acid, and the cationic polymer electrolyte is protonated by the generated hydrogen ions. Due to electrostatic repulsion, the cationic polymer electrolyte network expands, and as a result, the IPN structure expands due to an increase in the pitch of the CLC structure within the glucose biosensor with the IPN structure, which can change the optical bandgap wavelength range. Through this, glucose can be detected by changing the optical color of the biosensor due to the change in the optical bandgap wavelength.

[0075] In addition, the present invention provides a glucose biosensor characterized by being manufactured by the above-described manufacturing method.

[0076] The glucose biosensor above can respond to glucose in a linear range of glucose concentrations from 0.2 to 6 mM.

[0077] The glucose biosensor described above may be in the form of a film, but is not limited thereto.

[0078] In addition, the present invention provides a skin-attachable sweat-based glucose biosensor patch comprising: the glucose biosensor above; a sweat-absorbing substrate disposed on the top of the glucose biosensor; and a transparent band disposed on the bottom of the glucose biosensor.

[0079] The sweat-absorbing substrate may be a polyurethane foam with a porous open-cell structure. More specifically, the polyurethane foam has a phase-separated molecular structure composed of hard and soft parts, and the porous open-cell structure provides the ability to absorb liquid while maintaining softness, elasticity, and structural integrity. The polyurethane foam has a low density and light weight due to cells filled with a large amount of air, and its properties can be optimized for various applications by adjusting the cell size.

[0080] The skin-attachable sweat-based glucose biosensor patch of the present invention is covered with the transparent band so that it can be fixed in place and prevent sweat evaporation. The transparent band can maintain the moisture of the biosensor until the optical color change of the patch becomes saturated.

[0081] The skin-attachable sweat-based glucose biosensor patch of the present invention absorbs sweat from the skin surface through the sweat-absorbing substrate, and the absorbed sweat comes into contact with the surface of a biosensor film having an IPN structure, causing the optical color to change according to the glucose concentration in the sweat. This system does not require complex circuits, batteries, or conductive paths, thereby reducing the structural burden on the device and improving wearability. The skin-attachable sweat-based glucose biosensor patch according to the present invention is convenient due to a simple detection process based on visual analysis, and can track the user's health using small amounts of sweat from the forehead or fingertips. Furthermore, λ measured from photographic images taken with a smartphone without the need for advanced analysis tools dominant The value can be utilized to quantify glucose analytes in human sweat samples. The optical biosensor patch of the present invention is a simple, inexpensive, and user-friendly biosensor that can be easily applied to various other sensing applications.

[0082]

[0083] Hereinafter, the present invention will be described in detail with reference to examples to specifically explain the invention. However, the embodiments according to the present invention may be modified in various different forms, and the scope of the present invention is not to be interpreted as being limited to the embodiments described below. The embodiments of this specification are provided to more completely explain the present invention to those with average knowledge in the art.

[0084]

[0085] <Example>

[0086] ingredient

[0087] Poly(vinyl alcohol) (PVA, Yakuri, Japan), bare glass slide (Marienfeld, Germany), 4-cyano-4'-pentylbiphenyl (5CB, Synthon, Germany), (3R,3aS,6aS)-hexahydrofuro[3,2-b]furan-3,6-diylbis(4-(4-((4-(acrylooxy)butoxy)carbonyloxy)benzoate) (LC756, Synthon Chemical, Germany), RMM727 (liquid crystal reaction mixture, Merck, UK), acrylic acid (AA, Junsei, Japan), Irgacure 500 (photoinitiator, Ciba Inc., Switzerland), acetone (Duksan, Korea), and PBS buffer (Samchun, Korea) were all used as supplied. In addition, (3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC-HCl), glucose oxidase (GOx), D-fructose, lactose, and 2-dimethylaminoethyl methacrylate (DMAEMA) were used. N-hydroxysuccinimide (NHS), D-(+)-glucose, hemoglobin, galactose, and tri(propylene glycol)diacrylate (TPGDA) were purchased from Sigma-Aldrich and used as received. AA, DMAEMA, and TPGDA were purified by passing through an activated alumina column, while all other chemicals were used as is without further purification. Deionized water (DI) was purified using a reverse osmosis system (μPure RO, Romax, Korea). Clear reactive CLC mixtures were prepared by mixing RMM727, LC756, and 5CB by magnetic stirring at 70°C for 3 hours. The levels of LC756 and 5CB in the reactive mixtures were, respectively LC756 and 5CB It is displayed as.

[0088]

[0089] 1. Photonic IPN film (IPN PDMAEMA ) manufacturing

[0090] Figure 1(a) shows the manufacturing process of a photonic IPN film.

[0091] Referring to Fig. 1, the glass substrate was ultrasonically cleaned in ethanol for 15 minutes, washed with DI water, and dried using high-pressure air. The clean glass slide was treated with oxygen plasma, and then uniformly coated with an aqueous solution of Poly(vinyl alcohol) (PVA) (10 wt%) at 1500 rpm for 25 seconds using a spin coating technique. It was then dried in an oven at 70 °C for 5 hours.

[0092] A cholesteric liquid crystal (CLC) mixed solution was prepared using a reactive mesogen mixture (RMM727) : 4-cyano-4'-pentylbiphenyl (5CB) = 50:50 (wt%), (3R,3aS,6aS)-hexahydrofuro[3,2-b]furan-3,6-diyl bis(4-(4-((4-(acryloyloxy)butoxy)carbonyloxy) benzoyloxy)benzoate) (LC756) (3.8 wt% of the RMM / 5CB ​​mixture), and the cholesteric liquid crystal (CLC) mixture was coated onto PVA-coated glass using a bar coater with 20 μm spacers, cooled to 25°C, and then 22 mW cm⁻¹. -2 UV cured for 10 minutes. Afterwards, solid-state CLC (CLC) on PVA-coated glass solid The film was washed with acetone to remove unreacted 5CB from the layer. The film was immersed in DI water at room temperature (25 °C) and CLC solid The film was separated from the PVA-coated glass. Then, the film was immersed for 1 hour in a DMAEMA mixed solution prepared by mixing 2-dimethylaminoethyl methacrylate (DMAEMA, 84 wt%), acrylic acid (AA, 14.5 wt%), tri(propylene glycol) diacrylate (TPGDA, 0.5 wt%), and Irgacure 500 (1 wt%) to fill the void created by the removal of 5CB.

[0093]

[0094] 2. Photonic IPN Glucose Biosensor Film (IPN PDMAEMA-GOx ) manufacturing

[0095] Aqueous solutions of N-hydroxysuccinimid (NHS, 2M) and (3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC-HCl, 2M) were mixed in a ratio of 2:1 (v / v) and magnetically stirred at 300 rpm for 1 hour. Subsequently, IPN PDMAEMA The film was immersed in a water-soluble EDC-HCl / NHS (0.1 mL) solution for 3 hours to activate it for enzyme immobilization, after which the unreacted NHS / EDC-HCl was washed off the film surface and dried at 25 °C. Activated IPN PDMAEMA The film was immersed in a GOx solution (50 μM, 0.1 mL) for 5 hours for enzyme immobilization via an EDC binding reaction. The resulting photonic GOx-immobilized IPN PDMAEMA-GOx The film was rinsed with DI water to remove unbound GOx and dried at room temperature (25 ℃) for a glucose detection test.

[0096]

[0097] 3. Manufacture of Skin-Attached IPN Glucose Biosensor

[0098] The skin-attachable IPN glucose biosensor consisted of three layers (Fig. 1b). The bottom layer was a biocompatible, sweat-absorbing black polyurethane (PU) foam sponge (thickness = 35 μm; width = 1.5 mm; length = 1.5 mm; pore count per inch (ppi) 35; pore diameter = 1.25 mm; density = 0.01 gm -3 )(DH-23, Dongguan Dihui Foam Sponge, China), the middle layer is the above-manufactured IPN PDMAEMA-GOxFor the film, the top layer used a transparent medical single-sided waterproof PU adhesive bandage (thickness = 0.022 mm; width = 99 mm; length = 99 mm, Icardon, China). To provide more suitable color contrast when measuring optical color, the bottom layer was made black.

[0099] Fig. 1c is a skin-attached IPN designed for the fingertip of a human finger. PDMAEMA-GOx This presentation displays a diagram illustrating the glucose detection process in sweat using a biosensor, along with photographic images analyzed using the Color Grab application installed on a smartphone. Sweat from the skin surface can enter the porous PU foam via the force of capillaries. When the absorbed sweat comes into contact with the surface of the IPN film, the optical color changes according to the glucose concentration within the sweat.

[0100]

[0101] <Experimental Example>

[0102] Density and reflection index measurements

[0103] The densities of 5CB, RMM727, and LC756 are 1.008, 1.016, and 1.410 g cm⁻³, respectively. -3 It is. Solid-state CLC (CLC) prepared from an RMM727 / 5CB / LC756 mixture after UV curing and 5CB removal solid To measure the density of the film, a flotation technique was used with an ethanol / water mixture as the ambient medium, and the densities of ethanol and water were 0.789 and 1.000 g cm⁻³, respectively. -3 It was. The ethanol / water mixing ratio was CLC solid The sample is adjusted until it has neutral buoyancy, indicating that the density of the medium is equal to the density of the floating film. The CLC measured in this way solid The density of the film is 0.873 g cm⁻¹ -3 It was determined as follows. Using this flotation method, photonic IPN using a glycerol / water mixture at 20 °C. PDMAEMA-GOxThe density of the film was measured. Since the density of the suspended photonic IPN film is higher than the density of water, glycerol (density = 1.261 g cm⁻¹) -3 ) was used. IPN PDMAEMA-GOx The measured density of the film is 1.105 g cm⁻³ -3 For floating measurements, the film samples were cut into circular shapes to avoid irregular shapes that could cause measurement errors due to surface tension effects at the liquid-solid film interface. Additionally, an Abbe refractometer (NAR-1T SOLID, ATAGO, Japan) was used to measure the refractive indices of the CLC mixture and individual components at 40 °C.

[0104] Detection limit measurement

[0105] The limit of detection (LOD) of the fabricated biosensor is photonic IPN PDMAEMA-GOx log C for the film (Fig. 4c) g λ for the (x-axis) PBG,UVvis It was determined based on the plot of the (y-axis), from which the linear range was obtained using Equation (1). The LOD was calculated using Equation (3):

[0106] λ PBG = a × logC g + b, (1)

[0107] λ LOD = λ blank + 3 × s blank, (2)

[0108] LOD = 10 x (λ LOD -b / a), (3)

[0109] Here, a and b are the slope and y-intercept, respectively, and λ blank Wow s blank are the mean and standard deviation of the blank samples, respectively. s for optical color change blank C is the minimum concentration within the linear range that induces an optical color change. g= 0.2 mM was measured using 5 copies. Accuracy was calculated using Equation (4):

[0110] Accuracy (%) = 100 - |Input C g - Output C g | / Input C g × 100, (4)

[0111] Here, Input and Output C g represents the control concentration (due to dilution) and the measured concentration calculated from the calibration curve, respectively.

[0112] Glucose concentration in human sweat was analyzed using a high-performance liquid chromatography (HPLC) instrument (Model 600E, Waters, USA), a Sugar-Pak I column (6.5 × 300 mm, Waters, USA), and a refractive index detector (Model 410, Waters, USA). Mobile aqueous Ca-EDTA solution (0.01 M, 50 mg L⁻¹) -1 in DI water, 20 μL) at 0.5 mL min. -1 It was injected at a flow rate of .

[0113] Measurement of helical twisting power (HTP) of chiral dopants

[0114] The helical torsional force (HTP) of the chiral dopant depends on the LC matrix material. The pitch of the CLC is determined by Equation (5):

[0115] P = λ PBG / n = 1 / HTP × c (5)

[0116] Here, P, λ PBG , n, and c are the pitch, wavelength of the optical band gap (PBG), mean reflection index, and concentration of the chiral dopant, respectively. HTP is λ PBG vs 1 / LC756It is obtained from the slope of the linear regression equation for, and the slope becomes n / HTP (the measured n is 1.65).

[0117] Image analysis using a smartphone

[0118] In this invention, mobile phone images were used for the quantitative analysis of glucose. A digital photograph was loaded into a smartphone color grab application, and the dominant wavelength (λ) at the midpoint of the line connecting the origin (white dot) and each experimental point (x, y) at the boundary of the CIE 1931 xy chromaticity diagram of the photographic image was dominant ) was derived. Figure 9 shows λ for various images captured in this study. UV-vis (derived from ultraviolet spectroscopy) is λ dominant It is shown as a function of (taken from the photo image). The linear equation of the regression analysis has a slope of ~1 and R 2 Since α is 0.99935, λ UV-vis λ dominant It indicates that it is almost identical to . Therefore, λ dominant Using λ in the photographic image PBG It can measure, and unless otherwise noted, the measured λ dominant λ PBG It was used as a substitute for.

[0119]

[0120] <Experimental Example 1> Optical structure of RMM / 5CB / LC756 mixture

[0121] To enhance the performance and functionality of the proposed sweat-based skin-attached biosensor, it is necessary to optimize the components of the CLC mixture to control optical color. By carefully selecting and balancing the components of the CLC mixture, the photonic IPN structure can provide detailed information regarding the concentration of the target analyte based on a wide range of visual colors.

[0122] The CLC mixture consists of a reactive mesogen mixture, a reactive chiral dopant, and RMM, LC756, and 5CB acting as LC porogens, respectively. The greater the amount of PDMAEMA network occupying the void created by removing 5CB, the higher the IPN PDMAEMA-GOx The performance of the glucose biosensor was shown to improve. Therefore, photonic IPN structures generated with high levels of 5CB had the potential to increase sensitivity by incorporating more PDMAEMA. However, IPN fabricated using a CLC mixture containing excessive levels of 5CB PDMAEMA-GOx The film can be more brittle and prone to rupture due to a weaker CLC network and stress caused by glucose-induced edema. Therefore, IPN PDMAEMA-GOx Optimal level of mixture to achieve the most effective balance between the structural integrity of the biosensor and glucose sensitivity ( 5CB Decided on ).

[0123] Fig. 2a is a glucose aqueous solution (C g elapsed time (t) at = 0.8, 1.0, and 10 mM) elaps After testing for up to 15 minutes 5CB IPN prepared at 65, 55, 50, 45, and 40 wt% PDMAEMA-GOx Shows the photographic image of the film. 5CB IPNP prepared at = 65 and 55 wt% PDMAEMA-GOx The film wrinkled after 15 minutes in all test glucose solutions, indicating high levels of LC porogen ( 5CB It was indicated that it becomes weaker when using ≥ 55 wt%). 5CB IPN prepared at = 45 and 40 wt% PDMAEMA-GOx The film 5CB= Compared to 50 wt%, the color is blue-shifted, indicating less sensitivity to glucose. Therefore, for further analysis 5CB An IPN film manufactured using 50 wt% was used.

[0124] To adjust the optical color, the helical twisting power (HTP) of chiral dopants in CLC mixtures was carefully analyzed for various RMM / 5CB ​​mixing ratios. HTP depends on the LC matrix, and in this system, the LC matrix of LC756 is an RMM / 5CB ​​mixture, which means that HTP is affected by the RMM / 5CB ​​mixing ratio.

[0125] Fig. 2b shows different 5CB and LC756 As a matrix image of the RMM / 5CB / LC756 mixture, since images of other regions are outside the visible light range 5CB and LC756 It generates optical color only within a specific range. Matrix photography uses visible light colors 5CB and LC756 It shows that it depends heavily on everyone. Then, of the RMM / 5CB / LC756 mixture 5CB and based on the results presented in Fig. 2c, the HTP of LC756 was obtained. y = 1776 x exp(-x / 27.2) (R 2 = 0.982) According to the formula 5CB As this increases, HTP decreases exponentially, so the HTP of LC756 is 5CB ( 5CB = RMM( 5CB= indicates that it is higher at 0 wt%). Therefore, the optical color of the RMM / 5CB / LC756 mixture can be predicted using the following equation (6):

[0126] λ1 = 1.65 / (HTP× LC756 ) = 1.65 / (1776×exp(- 5CB / 27.2)× LC756 ) (6)

[0127] The optical band gap wavelength (λ) of the optical IPN film at each manufacturing stage PBG The λ values ​​were measured (Fig. 3). λ was measured before (i=1) and after (i=2) UV curing, after 5CB removal (i=3), after DMAEMA mixture penetration and UV curing (i=4), and after immersing the IPN film in a pH 2 solution for 10 minutes (i=5). PBG The values ​​are denoted as λ1, λ2, λ3, λ4, and λ5, respectively. Figures 4a and 4b show the observed λ, respectively. i The values ​​and the ratios of λ1 / λ2, λ3 / λ1, λ4 / λ3, and λ5 / λ4 LC756 It is expressed as a function. λ2 was almost the same as λ1, and all LC756 It showed a slightly lower value of 99% (λ2 / λ1=~0.99, Fig. 4b(i)), indicating that UV curing did not significantly alter the optical structure. However, λ3 is all LC756 The value was 23% lower than λ1 (λ3 / λ1 = ~0.77, Fig. 4b(ii)). This reduction is due to the pitch being shortened by the removal of 5CB. λ4 / λ3 (Fig. 4b(iii)) is all LC756 The value is ~1.08, and λ4 / λ1 (=λ4 / λ3 x λ3 / λ1) is 0.83. A value less than 1 indicates that the space remaining after removing 5CB was not completely filled by the DMAEMA mixture, and thus the expansion after UV curing may have been greater.

[0128] PDMAEMA with an entangled structure is known to swell under acidic conditions. λ5 represents the wavelength associated with maximum swelling at pH 2. Interestingly, λ5 is all LC756 The value was higher than λ1 (Fig. 4a), suggesting that the entangled CLC network expanded more significantly than the original chain shape. λ5 / λ4 is all LC756 For the value, it was ~1.25 (Fig. 4b(iv)). λ PBG (= λ5- λ4) can be used as the detection range of the developed optical IPN sensor. The measured Δλ PBG is all LC756 The value was ~168±5 nm, which was relatively high compared to the highest value reported in other systems, which was 120 nm for optical IPN array dots. Therefore, the system developed in this invention has the potential to be utilized as a sensitive glucose biosensor.

[0129]

[0130] <Experimental Example 2> IPN PDMAEMA pH reaction of the film

[0131] Since many biological processes are related to changes in pH levels, the proposed IPN PDMAEMA The pH responsiveness of the film was evaluated. The entangled and weak polymer electrolyte network of the IPN film can respond to pH changes through expansion or contraction as a transducer mechanism. The inset in Fig. 5a shows IPN films on a black background substrate immersed in buffer solutions of various pH levels. PDMAEMA Film images are shown, and Fig. 5b shows the corresponding CIE 1931 xy chromaticity diagram. The optical color of the film sample was gradually red-shifted from blue to green at pH 10⁻⁶, to orange at pH 5 and 4, and to red at pH 3. PDMAEMA is a proton (H +Due to the high concentration of ) ions, protonation occurs at low pH levels, causing the optical IPN structure to swell due to electrostatic repulsion of cations and an increase in the helical pitch of the CLC network. Therefore, as shown in Fig. 5b, the λ of the optical IPN film (Fig. 5a) dominant It increased as pH decreased. IPN PDMAEMA Films are suitable for use as optical biosensors because they have a strong dependence on pH. These pH-responsive hydrogels can be used for real-time biosensing because they can be fabricated quickly and simply in the form of skin-attachable platforms compared to other stimulus-responsive hydrogels.

[0132]

[0133] <Experimental Example 3> Glucose Detection

[0134] IPN for glucose detection PDMAEMA-GOx The sensitivity of the film is C g It was evaluated using aqueous glucose solutions with different glucose concentrations. Figure 4c shows the IPN. PDMAEMA-GOx λ of the film PBG log C g It is expressed as a function of, and the inserted image shows each corresponding photographic image. C of the aqueous solution g It was controlled to fall within a range including typical levels (0.1–0.6 mM) found in human sweat and high levels up to 12 mM found in diabetic patients. Glucose was IPN PDMAEMA-GOx In the film, it is oxidized to gluconic acid and H2O2 by glucose oxidase (GOx). Then, the pH of the local medium is reduced by the gluconic acid, and the generated H + The -N(CH3)2 group of PDMAEMA is protonated by ions. The protonated -N due to electrostatic repulsion. +(CH3)2 promotes the expansion of the PDMAEMA network and increases the pitch of the coupled optical CLC structure, causing a red shift in the reflected color. Although there is no direct relationship between the two, glucose levels in sweat are generally known to reflect blood glucose levels. C g When the concentration was increased from 0.1 mM to 10 mM, the optical color changed from blue to red (i.e., across the entire visible light range).

[0135] IPN PDMAEMA-GOx λ of the film PBG The linear response range of is log C g The scale ranged from 0.2 to 6 mM. Referring to Fig. 4c, the slope and intercept of Equation (1) are 27.9 and 545.2, respectively. From this, an LOD of 0.02 mM was calculated using Equation (3). These results demonstrate the developed photonic IPN PDMAEMA-GOx This suggests that the film provides a wide dynamic range and high sensitivity for glucose detection at physiologically appropriate concentrations.

[0136]

[0137] <Experimental Example 4> Required Amount of Sweat and Detection Speed

[0138] IPN using a custom test chamber designed to hold a 0.157 mL liquid sample (internal diameter = 1 cm, depth = 0.5 mm). PDMAEMA-GOx The amount of sweat required to fully measure the optical color change of the film was determined (Fig. 4d). V sweat is C g Because it varies depending on, various C g Tested at the level. Tested V sweat and C g The values ​​were 0.00, 0.005, 0.015, 0.02, and 0.025 mL (rows in Fig. 4d) and 0.1, 0.2, 0.4, 1.0, and 4.0 mM (columns in Fig. 4d), respectively. For the optical color change test, a circular IPN was applied over the solution in the wells. PDMAEMA-GOxFilm samples (diameter = 1 cm) were placed (Fig. 4d). The saturated optical colors were for all tested IPNs. PDMAEMA-GOx For the film sample, 0.015 mL (0.0048 mL cm -2 )'s V sweat Each C g It was observed that in a warm environment (35°C), human sweat production is 0.013–0.023 mL cm⁻¹. -2 min -1 Assuming that, it takes only about 16 seconds to obtain this amount. This ability to respond to such small amounts of body fluid enables non-invasive on-site glucose monitoring at mild temperatures without physical exercise or heating for body parts with low sweat gland density, as an IPN. PDMAEMA-GOx It exhibits the excellent sensitivity of the film. Therefore, the IPN of the present invention PDMAEMA-GOx The novel architectural design and optimization of the film have proven suitable for use as a highly sensitive and effective sweat-based IPN biosensor that provides maximum saturation in response to minimal analyte input.

[0139] IPN using glucose solution (3 mM) PDMAEMA-GOx λ of the film dominant saturation t elaps ... was measured (Fig. 6a). It took 2.5 minutes to reach the saturated optical color change from 468 nm to 594 nm. Therefore, the proposed IPN PDMAEMA-GOx It can be seen that the glucose sensor is fast enough to detect glucose in real time.

[0140]

[0141] <Experimental Example 5> IPN PDMAEMA-GOx Selectivity of the film

[0142] Photonic IPN for glucose for actual glucose biosensing applications PDMAEMA-GOxThe selectivity of the film was evaluated against potential interfering substances found in human sweat, such as other sugars (fructose, galactose, lactose), nitrogen compounds (urea), and proteins (hemoglobin). Figure 6b shows the IPN tested for 10 minutes with DI water and 1 mM glucose, galactose, fructose, lactose, urea, and hemoglobin. PDMAEMA-GOx λ for a film sample (diameter = 1 cm) dominant It shows λ dominant The values ​​were 485, 553, 488, 487, 487, 485, and 485 nm for DI water, glucose, galactose, fructose, lactose, urea, and hemoglobin, respectively. Only glucose showed a change in optical color from blue to green, which is IPN. PDMAEMA-GOx This indicates that the film is sufficiently selective for use on human sweat.

[0143]

[0144] <Experimental Example 6> Evaluation of Artificial Sweat Samples

[0145] Artificial sweat samples are in the absence of glucose (i.e., C g = 0 mM) and in the presence of glucose (C g Prepared as = 1 mM, other components of human sweat photonic IPN PDMAEMA-GOx The effect on the optical color change of the film was investigated. To simulate a skin-attached biosensor system, IPN was applied to a sweat-soaked substrate. PDMAEMA-GOx The film was placed, and only one side of the film was brought into contact with the wet surface. Fig. 7 shows C g = Photonic IPN for artificial sweat at concentrations of 0 and 1 mM (including other major sweat components) PDMAEMA-GOx λ of the film sample dominant Representing the value, the inserted image of Fig. 7 is C g IPN covered with a transparent bandage on a black surface of a substrate wetted with a predetermined amount of artificial sweat (0.015 mL) at = 0 and 1 mM PDMAEMA-GOx It represents a photograph on film. The blue color of the film is C g= It did not change at 0 mM, but C g = At 1 mM, it turned dark green. This indicates that the sweat components of a person without glucose are optical IPN PDMAEMA-GOx It indicates that it does not affect the optical color of the film.

[0146]

[0147] <Experimental Example 7> IPN PDMAEMA-GOx Applications of patches

[0148] Skin-attachable optical IPN PDMAEMA-GOx To simulate a skin sweat glucose test using a patch, C g A different glucose aqueous solution (0.015 mL) was dropped directly onto the fingertip to mimic the natural process of sweat production and glucose secretion. Fig. 8a shows a glucose aqueous solution (C g Circular IPN attached to a fingertip pre-soaked with (= 0, 0.1, 0.3, 0.6, 1, 6 mM) PDMAEMA-GOx C derived from the photographic image of the patch (diameter = 1 cm) g λ as a function of dominant Shows. C g When the concentration is increased from 0.1 mM to 6 mM, the optical color of the patch changes from blue to orange, resulting in a circular IPN. PDMAEMA-GOx This indicates that the patch functioned well as a stable and effective non-invasive glucose monitoring device.

[0149] Skin-attached IPN PDMAEMA-GOx The patch was also tested on the forearm of a healthy adult. Figure 8b shows a circular IPN attached to the forearm. PDMAEMA-GOxThis is a photographic image of the patch. The patch in a dry state (Fig. 8b(i)) changed to a purplish-blue optical color when wetted with an aqueous glucose solution (6 mM) (Fig. 8b(ii)). To analyze this color change, photographs taken before and after exposure to the glucose solution were uploaded to an online image color finding tool to derive chromaticity coordinates (x, y) and hexadecimal (HEX) values. The analysis results showed a significant shift from 468 nm (Fig. 8b(iii)) to 596 nm (Fig. 8b(iv)), and λ using a mobile phone application PBG It was demonstrated that real-time evaluation is possible, and the 6 mM C derived from the calibration curve (Fig. 4c) g Value input C g It was found to be close to.

[0150] IPN even in real-life situations during outdoor exercise PDMAEMA-GOx The patch was tested. Figure 8c shows photonic IPN on the forehead of a healthy volunteer before and after running for 25 minutes. PDMAEMA-GOx Shows a photo image of the patch being worn. IPN PDMAEMA-GOx The patch changed color from blue to sky blue after the workout, and λ dominant The redshift shifted from 468 nm to 497 nm. λ at 497 nm dominant C of 0.2 mM based on the standard curve g It corresponds to, which falls within the general glucose range of non-diabetic patients. These results are based on the IPN according to the present invention. PDMAEMA-GOx This suggests that the band has the potential to directly analyze glucose from human sweat samples. IPN of the optical properties of the present invention PDMAEMA-GOx The film can be used for continuous health monitoring during military and sports activities (e.g., long-distance running and rock climbing), long-duration space missions, and high-risk industrial activities.

[0151]

[0152] <Experimental Example 8> Detection of glucose in spike samples

[0153] IPN is also used to detect glucose in human sweat samples. PDMAEMA-GOx Sensors were used. Fig. 8d shows C at 0.2, 0.4, 0.6, 1.0, and 1.2 mM, respectively. g Photographic image (inset) and measured λ in spiked human sweat solution having values dominant This represents the values. For the HypoG2, HypoG1, NormalG, HyperG2, and HyperG1 samples, Normal, Hyper, and Hypo represent original, concentrated, and diluted human sweat, respectively, and G represents glucose. The concentrated and diluted samples were prepared by adding glucose and mixing with DI water, respectively. IPN PDMAEMA-GOx The reflected color of the film is C g At < 0.6 mM (HypoG1, HypoG2), it maintained a greenish-blue color, but C g At 0.6 mM (NormalG), it is dark green, C g = 1.0 mM (HyperG2) and C g At 1.2 mM (HyperG1), it turned bright green. The corresponding λ dominant The values ​​were 498, 515, 527, 550, and 553 nm, and the corresponding C obtained from the calibration curve (Fig. 4c). g The values ​​were 0.21, 0.37, 0.55, 1.15, and 1.29 mM, input C g Accuracy of 95.0%, 92.5%, 91.7%, 85.0%, and 92.5% was demonstrated at values ​​of 0.2, 0.4, 0.6, 1, and 1.2 mM, respectively (see Table 1). This high accuracy demonstrates the potential for IPN to measure glucose levels in human sweat samples without significant interference from other components of sweat using a skin-attachable sensor for non-invasive glucose monitoring. PDMAEMA-GOx Indicates that film can be used.

[0154] SampleInput C g (mM)λ dominant (nm)Output Cg (mM)Accuracy(%)HyperG11.25531.2992.5HyperG215501.1585NormalG0.65270.5591.7HypoG10.45150.3792.5HypoG20.24980.2195

[0155] Specific embodiments of the present invention have been examined so far. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the present invention.

Claims

1. A step of coating a polyvinyl alcohol (PVA) aqueous solution after cleaning the substrate; A step of preparing a Cholesteric Liquid Crystal (CLC) mixture by mixing a reactive mesogen, a liquid crystal porogen, and a chiral dopant; A step of manufacturing a solid cholesteric liquid crystal film by coating the cholesteric liquid crystal mixture onto a substrate coated with the above-mentioned polyvinyl alcohol (PVA) aqueous solution and then UV curing it; A step of washing the above cholesteric liquid crystal film to remove unreacted liquid crystal porogen; A step of forming a composite of an interpenetrating polymer network (IPN) structure by infiltrating a cationic polymer electrolyte into the space where unreacted liquid crystal porogens of the above cholesteric liquid crystal film have been removed; and A method for manufacturing a glucose biosensor comprising the step of immobilizing glucose oxidase (GOx) on a complex of the above-mentioned interpenetrating polymer network (IPN) structure.

2. In Paragraph 1, A method for manufacturing a glucose biosensor characterized by including 46 to 54 parts by weight of the liquid crystal porogen per 100 parts by weight of the mixture of the reactive mesogen and the liquid crystal porogen.

3. In Paragraph 1, A method for manufacturing a glucose biosensor characterized by mixing 1 to 10 parts by weight of the chiral dopant with respect to 100 parts by weight of the mixture of the reactive mesogen and the liquid crystal porogen.

4. In Paragraph 1, A method for manufacturing a glucose biosensor characterized in that the above-mentioned cationic polymer electrolyte is 2-dimethylaminoethyl methacrylate (DMAEMA).

5. A glucose biosensor characterized by being manufactured by the manufacturing method of claim 1.

6. In Paragraph 5, The glucose biosensor is characterized by responding to glucose in a linear glucose concentration range of 0.2 to 6 mM.

7. Glucose biosensor according to paragraph 5; A sweat-absorbing substrate disposed at the bottom of the glucose biosensor; and A skin-attachable sweat-based glucose biosensor patch comprising a transparent band positioned on top of the glucose biosensor.

8. In Paragraph 7, A skin-attachable sweat-based glucose biosensor patch characterized in that the sweat-absorbing substrate is a polyurethane foam with a porous open-cell structure.

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