Glucose sensing electrode yarn, fabric, preparation method and application thereof

Abstract

The present invention discloses a glucose sensing electrode yarn, fabric, preparation method, and application thereof. The glucose sensing electrode yarn includes a conductive inner core, the outer side of which is sequentially coated with a sensing layer and a conductive layer. The sensing layer includes a glucose sensing material. The conductive layer includes, from the inside to the outside, a hydrophilic polymer nanofiber layer and a hydrophobic polymer nanofiber layer. The average pore size of the hydrophilic polymer nanofiber layer is smaller than that of the hydrophobic polymer nanofiber layer. The conductive layer conducts sweat directionally to the conductive inner core. When the sensing fabric prepared with the glucose sensing electrode yarn is used in the field of wearable sweat sensors, it has a fast response speed and high sensitivity in a trace sweat environment. It can maintain high sensitivity and long-term monitoring during dynamic deformation processes such as bending, twisting, and shaking. After multiple washing and drying steps, it can still maintain a high sweat collection efficiency and sensing current.

Description

Technical Field

[0001] The invention relates to glucose sensing electrode yarn, fabric, preparation method and application thereof. Background Art

[0002] Currently, the traditional strategy for monitoring blood sugar is to periodically puncture the skin to collect blood, then wait for a non-wearable blood glucose meter to analyze the data. This method is invasive and cannot provide real-time, rapid, and continuous measurement. Monitoring blood sugar by detecting glucose in human sweat can achieve the goal of non-invasive and continuous monitoring, and has been a hot topic of research in recent years.

[0003] Wearable sweat sensors offer unique advantages such as wearability, portability, and low cost, making them the most attractive method for in situ sweat monitoring. For example, Chinese patent publication number CN116421177A discloses a method for preparing a CuO / Cu2O-modified graphene flexible sweat glucose sensor. However, this method uses a PET substrate, which has poor air permeability, significantly limiting its practical application and long-term comfort. Furthermore, capturing sufficient sweat and achieving stable contact between the electrodes and sweat is challenging, especially when only trace amounts of sweat are present during inactivity, resulting in poor detection sensitivity.

[0004] Therefore, there is an urgent need to develop a wearable sweat sensor that is comfortable and breathable, and has high detection sensitivity and detection stability, to monitor daily human health status in real time and non-invasively, as well as for early disease detection and management. Summary of the Invention

[0005] To overcome the shortcomings of existing wearable sweat sensors, which suffer from poor sensitivity and stability in detecting trace amounts of sweat, the present invention provides a glucose sensing electrode yarn and fabric, as well as preparation methods and applications. The glucose sensing fabric prepared in this invention is an electrochemical sensing fabric that stimulates perspiration and accumulates trace amounts of sweat. It maintains high sensitivity and good stability even in the presence of trace amounts of sweat and under dynamic deformation conditions.

[0006] Because common sweat glucose sensors can only passively and randomly collect sweat from the skin's surface, only a small amount of sweat can penetrate the sensing area, resulting in low sweat collection efficiency. This device can only be used for sweat analysis after prolonged exercise. For stable operation of the device, sufficient sweat must penetrate the sensing area to achieve stable circuit connection and activate the electrochemical sensing reaction.

[0007] In order to achieve the above objectives, the present invention adopts the following technical solutions.

[0008] The present invention provides a glucose sensing electrode yarn, comprising a conductive inner core, wherein the outer side of the conductive inner core is sequentially coated with a sensing layer and a conductive layer, wherein the sensing layer comprises a glucose sensing material, and the conductive layer comprises, from the inside to the outside, a hydrophilic polymer nanofiber layer and a hydrophobic polymer nanofiber layer, wherein the average pore size of the hydrophilic polymer nanofiber layer is smaller than the average pore size of the hydrophobic polymer nanofiber layer, and the conductive layer directionally conducts sweat to the conductive inner core.

[0009] The glucose sensing electrode yarn of the present invention, also known as the Janus sensing yarn, has an outer shell composed of a nanofiber conductive layer with asymmetric wettability and porosity. This outer shell utilizes the synergistic effect of surface energy gradients and porosity gradients to autonomously pump sweat into the conductive core of the Janus sensing yarn, reducing ineffective diffusion and significantly improving sweat collection efficiency. The outer hydrophobic polymer nanofiber layer helps retain sweat, preventing trace amounts of sweat from being lost, thereby preventing unstable detection.

[0010] In the present invention, the glucose sensing material can be a conventional glucose sensing material in the art, preferably a metal oxide glucose sensing material or an enzyme-based glucose sensing material, more preferably a metal oxide glucose sensing material, such as Cu2O. Enzyme-based glucose sensing materials have high fixed costs, low sensitivity, and low stability. Cu2O, as a glucose sensing material, offers low cost, high sensitivity, selectivity, and long-term stability, making it superior to glucose oxidase.

[0011] In the present invention, the conductive core can be a conventional conductive material in the art, preferably carbon fiber (CF). More preferably, the conductive core is composed of multiple bundles of carbon fibers. A conductive core composed of multiple bundles of carbon fibers has a higher specific surface area, which is conducive to the deposition of sensing materials and improves sensing sensitivity.

[0012] In the present invention, the polymers of the hydrophilic polymer nanofiber layer and the hydrophobic polymer nanofiber layer can be flexible polymers, such as polyurethane (PU), polyvinyl alcohol (PVA), or polycaprolactone (PCL), preferably polycaprolactone. Polycaprolactone is low in cost, has good spinnability, good biocompatibility, is non-irritating to the skin, is stable after contact with human sweat, and can be recycled in strong acid and alkali degradation environments, facilitating the disposal of electronic waste.

[0013] In some preferred embodiments of the present invention, the average pore size of the hydrophilic polymer nanofiber layer is 1.21 μm to 1.28 μm, for example, 1.26 μm; the average pore size of the hydrophobic polymer nanofiber layer is 6 μm to 6.4 μm, for example, 6.2 μm.

[0014] In some preferred embodiments of the present invention, the contact angle of the hydrophilic polymer nanofiber layer is 20° to 30°, for example, 26.2°; the contact angle of the hydrophobic polymer nanofiber layer is 158° to 165°, for example, 160.5°.

[0015] The present invention also provides a method for preparing the glucose sensor electrode yarn, which comprises the following steps:

[0016] S1, applying a glucose sensing material on the conductive inner core to form a sensing layer;

[0017] S2, coating the outer side of the sensing layer with a polymer nanofiber layer by an electrospinning process, and performing a hydrophilic treatment to form a hydrophilic polymer nanofiber layer;

[0018] S3. Covering the hydrophobic polymer nanofiber layer on the outside of the hydrophilic polymer nanofiber layer by an electrospinning process to form a conductive layer.

[0019] In step S1, the applying method is a conventional method in the art, such as electrodeposition.

[0020] In some preferred embodiments of the present invention, the glucose sensing material is Cu2O, and the method of applying Cu2O to the conductive inner core is: performing electrodeposition using a Cu-containing electrolyte.

[0021] In the above embodiment, the method for preparing the Cu-containing electrolyte may include: mixing a CuSO4.5H2O aqueous solution and a lactic acid solution, and then adding a NaOH aqueous solution to adjust the pH value to 10-11. The molar concentration of the CuSO4.5H2O aqueous solution is preferably 0.1-1 mol / L, for example, 0.3 mol / L; the molar concentration of the lactic acid solution is preferably 0.5-5 mol / L, for example, 1 mol / L; the molar concentration of the CuSO4.5H2O and the lactic acid is preferably (1-5):10, for example, 3:10; and the volume ratio of the CuSO4.5H2O aqueous solution to the lactic acid solution is 1:(1-2), for example, 1:1.

[0022] In the above embodiment, the electrodeposition conditions preferably include: a current density of 2 to 3 mA cm -2 ; The deposition time is 10 to 20 minutes, for example 15 minutes.

[0023] In some preferred embodiments of the present invention, the polymer is polycaprolactone, and in step S2 and step S3, the electrospinning process is performed using a polycaprolactone spinning solution.

[0024] The polycaprolactone spinning solution is prepared by dissolving polycaprolactone in a solvent. The solvent may be one or more of tetrahydrofuran, N,N-dimethylformamide, dichloroethane, and chlorobenzene, such as a mixed solvent of tetrahydrofuran and N,N-dimethylformamide. When the solvent is a mixed solvent of tetrahydrofuran and N,N-dimethylformamide, preferably, the volume ratio of tetrahydrofuran to N,N-dimethylformamide is (6-9):3, for example, 7:3.

[0025] In the above embodiment, in step S2, the concentration of the polycaprolactone spinning solution is 13 wt% to 17 wt%, for example, 13 wt%; wherein wt% represents the mass percentage of polycaprolactone in the polycaprolactone spinning solution.

[0026] In the above embodiment, in step S2, the electrospinning process satisfies one or more of the following conditions (a)-(d):

[0027] (a) The spinning voltage is 14 to 16 kV, for example 15 kV;

[0028] (b) the spinning humidity is 45% rh to 55% rh, for example 50% rh;

[0029] (c) the spinning temperature is 25 to 31° C., for example, 25° C.;

[0030] (d) The spinning time is 10 to 12 hours, for example, 10 hours.

[0031] In the above embodiment, in step S3, the electrospinning process uses a polycaprolactone spinning solution, wherein the concentration of the polycaprolactone spinning solution is 18wt% to 22wt%, for example, 18wt%; wherein wt% represents the mass percentage of polycaprolactone in the polycaprolactone spinning solution.

[0032] In the above embodiment, in step S3, the electrospinning process satisfies one or more of the following conditions (a)-(d):

[0033] (a) The spinning voltage is 7 to 9 kV, for example 8 kV;

[0034] (b) the spinning humidity is 45% rh to 55% rh, for example 50% rh;

[0035] (c) the spinning temperature is 25 to 31° C., for example, 25° C.;

[0036] (d) The spinning time is 10 to 12 hours, for example, 10 hours.

[0037] In step S2, the hydrophilic treatment is a conventional hydrophilic treatment method in the art, such as oxygen plasma treatment. The time of the oxygen plasma treatment is preferably 5 to 10 minutes, such as 5 minutes.

[0038] The present invention also provides a glucose sensing fabric, comprising woven and assembled glucose sensing electrode yarns, reference electrode yarns, counter electrode yarns and a heating electrode substrate, wherein the glucose sensing electrode yarns are the glucose sensing electrode yarns mentioned above.

[0039] In the present invention, the reference electrode yarn includes a conductive inner core, the outer side of which is sequentially coated with a reference layer and a conductive layer; the counter electrode yarn includes a conductive inner core, the outer side of which is coated with a conductive layer.

[0040] The material of the reference layer is a conventional reference layer material in the art, such as Ag / AgCl.

[0041] Preferably, the conductive inner core and the conductive layer are respectively the same as the conductive inner core and the conductive layer in the glucose sensing electrode yarn.

[0042] In the present invention, the heating electrode substrate is preferably a conductive woven fabric distributed with a super-hydrophobic flexible polymer.

[0043] The super-hydrophobic flexible polymer may be silicone rubber, polyvinylidene fluoride, or polytetrafluoroethylene. Preferably, the silicone rubber is polydimethylsiloxane (PDMS). PDMS is biocompatible and can safely contact human skin.

[0044] The conductive woven cloth can be woven from conventional conductive materials in the art. The conductive material is preferably carbon fiber, carbon nanotube fiber or graphene fiber, such as carbon fiber.

[0045] In some embodiments of the present invention, the method for preparing the heating electrode substrate comprises: distributing a PDMS prepolymer solution on a CF woven cloth and drying the solution.

[0046] The PDMS prepolymer solution is prepared by, for example, diluting the PDMS prepolymer by 3 to 5 times using ethyl acetate to obtain the PDMS prepolymer solution.

[0047] The distribution can be a conventional method in the art, for example, repeatedly vacuum filtering the PDMS prepolymer solution 3 to 5 times on CF woven cloth.

[0048] Wherein, the drying temperature is preferably 60°C to 70°C.

[0049] The present invention also provides application of the glucose sensing fabric in the field of sweat sensors.

[0050] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0051] The reagents and raw materials used in the present invention are commercially available.

[0052] The positive progress effect of the present invention is:

[0053] 1. The present invention sequentially coats the outer side of the conductive inner core with a sensing layer and a conductive layer, so that the prepared glucose sensing electrode yarn utilizes the synergistic effect of the surface energy gradient and the porosity gradient to autonomously pump sweat into the conductive inner core of the glucose sensing yarn. At the same time, the directional water transport structure can effectively slow down the evaporation and loss of sweat, and a stable circuit connection can be achieved under the condition of trace sweat (e.g., 0.06 μL), significantly improving the sweat collection efficiency.

[0054] 2. The glucose sensing fabric prepared by the present invention has a high detection sensitivity (for example, up to 36813.6 mA cm -2 mM -1 ); at the same time, it can ensure excellent detection stability and maintain long-term stable monitoring during dynamic deformation processes such as bending, twisting and shaking.

[0055] 3. The glucose sensing fabric prepared by the present invention is provided with a super-hydrophobic heating electrode substrate, and the working voltage is 2.20V and the heating voltage is 0.2W / cm 2 At low power density, the temperature can reach 50.1°C, which is much higher than the threshold of 42°C for thermal stimulation of skin perspiration. When the skin covered with the fabric prepared by the present invention sweats under thermal stimulation, an electrical signal of glucose response can be detected after 5 minutes, proving that electric heating can stimulate skin perspiration and make it have a faster reaction speed.

[0056] 4. The glucose sensing fabric prepared by the present invention can still maintain a high sweat collection efficiency after multiple washing and drying steps, and the sensing current of the sensing fabric remains stable in multiple washing cycle tests, with a retention rate close to 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Schematic diagram of the structure of the glucose sensing fabric prepared in Example 1.

[0058] Figure 2 (a) and (b) are SEM images of the hydrophilic small-pore nanofibers and the hydrophobic large-pore nanofibers in Example 1, respectively.

[0059] Figure 3 (a) and (b) are schematic diagrams of the water contact angles of the hydrophilic small-pore nanofibers and the hydrophobic large-pore nanofibers in Example 1, respectively.

[0060] Figure 4 (a) and (b) are the fiber diameter distribution diagrams of the hydrophilic small-pore nanofibers and the hydrophobic large-pore nanofibers in Example 1, respectively.

[0061] Figure 5 (a) and (b) are the pore size distribution diagrams of the hydrophilic small-pore nanofibers and the hydrophobic large-pore nanofibers in Example 1, respectively.

[0062] Figure 6 The middle is a diagram of the sweat collection process of Example 1.

[0063] Figure 7 (a) and (b) are schematic diagrams of water contact angles of Comparative Example 1 and Comparative Example 3, respectively.

[0064] Figure 8 is the linear fitting graph of glucose concentration and response current density.

[0065] Figure 9 3 is a graph showing the relationship between the resistance and the amount of sweat in Example 1 and Comparative Example 1 during the infiltration process.

[0066] Figure 10 This is a graph showing the change in resistance over time after sweat collection in Example 1.

[0067] Figure 11 2 is a graph showing the relationship between the resistance and the bending cycle of Example 1 and Comparative Example 2.

[0068] Figure 12 This is a graph showing changes in glucose concentration over time during the detection process of Application Example 1.

[0069] Figure 13 This is a comparison chart of sweat collection efficiency before and after a washing cycle test using the glucose sensing fabric prepared in Example 1 at different perspiration rates.

[0070] Figure 14 3 is a graph showing the retention rate of the sensing current of the glucose sensing fabric prepared in Example 1 after a washing cycle.

[0071] Figure 15 This is an infrared schematic diagram of the super-hydrophobic heating electrode substrate prepared in Example 1 before and after heating.

[0072] In the picture:

[0073] 1. Reference electrode yarn; 2. Counter electrode yarn; 3. Glucose sensing electrode yarn; 4. Heating electrode substrate. DETAILED DESCRIPTION

[0074] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0075] The following PDMS prepolymer is prepared by uniformly mixing a dimethylsilane gel matrix (model YLGARD 184, provided by Dow Corning) and a curing agent octamethylcyclotetrasiloxane (model YLGARD 18, Dow Corning) in a mass ratio of 10:1.

[0076] Polycaprolactone (PCL, MW = 80000) was purchased from Nantong Feiyu Biotechnology Co., Ltd., and N,N-dimethylformamide (DMF), tetrahydrofuran (THF), sodium hydroxide (NaOH), copper sulfate pentahydrate (CuSO4.5H2O), glucose, DL-lactic acid, polyvinyl butyral (PVB) and ethylene oxide block copolymer (Pluronic F-127) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0077] Ag / AgCl slurry was purchased from Shanghai Julong Electronic Technology Co., Ltd., and multi-walled carbon nanotubes (MWCNT, 8-15 nm, >95%) were provided by Chengdu Organic Chemistry Co., Ltd., Chinese Academy of Sciences.

[0078] Example 1

[0079] This embodiment provides a Janus glucose sensor electrode yarn, and the preparation method thereof comprises the following steps:

[0080] (1) In an electrolytic cell, 0.3 mol / L CuSO4.5H2O and 1 mol / L lactic acid solution were mixed in a volume ratio of 1:1. Then, 5 mol / L NaOH aqueous solution was added to adjust the pH value of the electrolyte to 11. The current density was maintained at 2 mA cm -2 , place CF, deposit for 15 min and then dry Cu2O-CF;

[0081] (2) preparing two solutions obtained by mixing tetrahydrofuran and N,N-dimethylformamide in a ratio of 7:3, dissolving an appropriate amount of PCL in each solution to obtain 15 wt% and 20 wt% spinning solutions, respectively;

[0082] (3) The Cu2O-CF obtained in step (1) was fixed on the rotating collector of the electrospinning machine, and spun for 10 h at 15 kV, 50% rh, and 25°C using a 15 wt% spinning solution. After removal, the Cu2O-CF was treated with oxygen plasma for 5 min, and a hydrophilic small-pore PCL nanofiber layer was coated on the outside of the Cu2O-CF;

[0083] (4) The product obtained in step (3) was fixed on an electrospinning machine, and then spun for 2 h at 8 kV, 50% rh, and 25 ° C using a 20 wt% spinning solution, and coated with a hydrophobic large-pore PCL nanofiber layer on the outside to obtain a Janus glucose sensor electrode yarn.

[0084] The structural diagram of the sensing fabric prepared in Example 1 is shown in FIG. Figure 1 shown.

[0085] Comparative Example 1

[0086] (1) In an electrolytic cell, 0.3 mol / L CuSO4.5H2O and 1 mol / L lactic acid solution were mixed in a volume ratio of 1:1. Then, 5 mol / L NaOH aqueous solution was added to adjust the pH value of the electrolyte to 11. The current density was maintained at 2 mA cm -2 , place CF, deposit for 15 min and then dry Cu2O-CF;

[0087] (2) preparing two solutions obtained by mixing tetrahydrofuran and N,N-dimethylformamide in a ratio of 7:3, and dissolving an appropriate amount of PCL in each solution to obtain a 13 wt% spinning solution;

[0088] (3) The Cu2O-CF obtained in step (1) was fixed on the rotating collector of the electrospinning machine, and spun for 10 h at 15 kV, 50% rh, and 25°C using a 13 wt% spinning solution. After removal, the Cu2O-CF was treated with oxygen plasma for 5 min, and a hydrophilic PCL nanofiber layer was coated on the outside of the Cu2O-CF;

[0089] (4) The product obtained in step (3) was fixed on an electrospinning machine, and then spun for 2 h at a voltage of 15 kV, 50% rh, and 25° C. using a 13 wt % spinning solution, and the hydrophobic PCL nanofiber layer was coated on the outside.

[0090] Comparative Example 2

[0091] (1) In an electrolytic cell, 0.3 mol / L CuSO4.5H2O and 1 mol / L lactic acid solution were mixed in a volume ratio of 1:1. Then, 5 mol / L NaOH aqueous solution was added to adjust the pH value of the electrolyte to 11. The current density was maintained at 2 mA cm -2 , place CF, deposit for 15 min and then dry Cu2O-CF;

[0092] (2) preparing two solutions obtained by mixing tetrahydrofuran and N,N-dimethylformamide in a ratio of 7:3, and dissolving an appropriate amount of PCL in each solution to obtain a 13 wt% spinning solution;

[0093] (3) The Cu2O-CF obtained in step (1) was fixed on the rotating collector of the electrospinning machine. First, a 13 wt% spinning solution was used and spun for 10 h at 15 kV, 50% rh, and 25 ° C. After removal, oxygen plasma treatment was performed for 5 min, and a hydrophilic PCL nanofiber layer was coated on the outside of the Cu2O-CF.

[0094] Comparative Example 3

[0095] (1) In an electrolytic cell, 0.3 mol / L CuSO4.5H2O and 1 mol / L lactic acid solution were mixed in a volume ratio of 1:1. Then, 5 mol / L NaOH aqueous solution was added to adjust the pH value of the electrolyte to 11. The current density was maintained at 2 mA cm -2 , place CF, deposit for 15 min and then dry Cu2O-CF;

[0096] (2) preparing two solutions obtained by mixing tetrahydrofuran and N,N-dimethylformamide in a ratio of 7:3, and dissolving an appropriate amount of PCL in each solution to obtain a 13 wt% spinning solution;

[0097] (3) The Cu2O-CF obtained in step (1) was fixed on the rotating collector of the electrospinning machine, and spun for 10 h at 15 kV, 50% rh, and 25°C using a 13 wt% spinning solution.

[0098] The parameter conditions of Example 1 and Comparative Examples 1-3 are shown in Table 1:

[0099] Table 1

[0100]

[0101]

[0102] Application Example 1

[0103] This embodiment provides a glucose sensing fabric, wherein the spinning solution is obtained by the method of Example 1, and the preparation method thereof comprises the following steps:

[0104] (1) Preparation of Janus reference electrode yarn

[0105] Ag / AgCl slurry was coated on CF, placed in a 60°C oven, and dried to obtain Ag / AgCl-CF; the Ag / AgCl-CF was fixed on the rotating collector of the electrospinning machine, first spun at a voltage of 15kV for 10 hours using a 15wt% spinning solution, removed and treated with oxygen plasma for 5 minutes, and then spun at a voltage of 8kV for 2 hours using a 20wt% spinning solution to obtain Janus reference electrode yarn.

[0106] (2) Preparation of Janus electrode yarn

[0107] The CF was fixed on the rotating collector of the electrospinning machine, and first spun at a voltage of 15 kV for 10 h using a 15 wt% spinning solution. After being removed, it was treated with oxygen plasma for 5 min, and then spun at a voltage of 8 kV for 2 h using a 20 wt% spinning solution to obtain Janus counter electrode yarn.

[0108] (3) Preparation of super-hydrophobic heating electrode substrate

[0109] The PDMS prepolymer was diluted 5 times with ethyl acetate to prepare a PDMS prepolymer solution, which was vacuum filtered onto CF woven cloth. After repeated vacuum filtration 3 times, it was placed in a 60°C oven and dried to obtain a superhydrophobic heating electrode substrate.

[0110] (4) Preparation of glucose sensing fabric

[0111] The Janus glucose sensor electrode yarn obtained in Example 1, the reference electrode yarn, the counter electrode yarn and the super-hydrophobic heating electrode prepared in this example were assembled together through a weaving process to obtain an electrochemical fabric, the structure of which is as follows: Figure 1 shown.

[0112] Comparative Application Example 1

[0113] This comparative example provides a glucose sensing fabric, wherein the sensing yarn is obtained by the method of comparative example 1, and the other steps are the same as those of application example 1.

[0114] Application Comparative Example 2

[0115] This comparative example provides a glucose sensing fabric, wherein the sensing yarn is obtained by the method of comparative example 2, and the other steps are the same as those of application example 1.

[0116] Effect Example 1 Fiber Performance Test

[0117] The performance of the hydrophilic small-pore nanofibers and the hydrophobic large-pore nanofibers in Example 1 were tested using conventional testing methods. The obtained SEM images, water contact angle diagrams, fiber diameter distribution diagrams, and pore size distribution diagrams are shown in FIG. Figure 2-Figure 5 shown.

[0118] Effect Example 2 Sensitivity Test

[0119] Take the electrochemical fabric obtained in Example 1, use wires to connect the three electrodes to a portable electrochemical workstation, use PBS solution to simulate the human sweat environment, continuously add glucose solutions of different concentrations, collect currents and fit the relationship curve between concentration and current as shown in the figure. Figure 8 As shown (each concentration was tested 5 times).

[0120] Effect Example 3 Dynamic Stability Test

[0121] A small amount of sweat was measured using a capillary tube with a diameter of 0.1 mm and added to the electrochemical fabric obtained in Example 1. The relationship between the resistance of the Janus sensor fiber in the sensor fabric and the amount of sweat is shown in the figure below: Figure 3 As shown in the figure; the resistance change of Janus sensing fiber during dynamic deformation such as bending, twisting and shaking is shown in the figure Figure 10 shown.

[0122] Effect Example 4 Response Speed ​​Test

[0123] Take the electrochemical fabric obtained in Example 1, connect it to a portable power source, connect it to the mobile phone software via Bluetooth, set the working voltage to 2.20V, and wear it on the arm of the volunteer. The relationship between the signal monitored by the device and time is as follows: Figure 12 shown.

[0124] Effect Example 5 Washing Stability Test

[0125] The electrochemical fabric obtained in Example 1 was washed and dried for 5 cycles with 10 minutes per cycle. The sweat collection efficiency of the sensing fabric before and after the washing cycle test was compared at different sweat release rates. Figure 13 As shown; the retention rate of the sensing current after the washing cycle is as follows Figure 14 shown.

[0126] Effect Example 6 Working temperature of heating electrode substrate

[0127] The super-hydrophobic heating electrode substrate prepared in Example 1 was heated at a working voltage of 2.20 V and a temperature of 0.2 W / cm 2 Heating is performed at low power density. The infrared images before and after heating are as follows: Figure 15 shown.

[0128] in conclusion:

[0129] (1) Sweat conduction of the sensor fibers prepared in Example 1 and Comparative Examples 1-3:

[0130] Reference Figure 6 , from left to right are schematic diagrams of sweat infiltration of the sensing fiber prepared in Example 1 at 0s, 1s, 2s, and 3s respectively. Figure 6 It can be seen that it only takes 3 seconds for the sensing fiber prepared in Example 1 to be completely soaked in sweat, which proves that the sweat soaking performance is good.

[0131] Reference Figure 7(a) Comparative Example 1 has only hydrophilic and hydrophobic differences, no pore size difference, and the hydrophilic nanofiber layer is inside and the hydrophobic nanofiber layer is outside. The contact angle is 102.8°, proving that it only has hydrophilic and hydrophobic differences and cannot conduct sweat when there is no pore size difference.

[0132] Reference Figure 7 (b) Comparative Example 3 is only coated with hydrophobic nanofibers; the water contact angle is 116.9°, and sweat cannot penetrate the yarn.

[0133] (2) Electrochemical sensitivity

[0134] Depend on Figure 8 It can be seen that in the glucose concentration range of 3 to 200 μM, the sensitivity of the electrochemical fabric is 36813.6 mA cm -2 mM -1 , proving that the sensing fabric prepared by the method of Application Example 1 has higher sensitivity.

[0135] (3) Amount of sweat required for circuit connection

[0136] Electrochemical sensing is achieved by generating electron transfer in the process of glucose being oxidized to gluconolactone, thereby generating current in the circuit. Therefore, the circuit in the electrochemical fabric must be connected for normal sensing. Figure 9 It can be seen that the electrochemical fabric prepared in Example 1 of the present application only requires 0.06 μL of artificial sweat to achieve stable circuit connection, and the resistance value becomes smaller and smaller over time. After the sensing yarn is completely soaked in sweat, the resistance value is about 1.25 kilohms / cm. However, the sensing yarn prepared in Comparative Example 1 still cannot achieve circuit connection after adding 40 μL of artificial sweat.

[0137] (4) Detection stability

[0138] Glucose sensing stability is one of the detection criteria for sensing materials, and the detection stability is determined by the yarn connectivity state, that is, the circuit resistance. Figure 10 and Figure 11 As can be seen, the resistance of the fabric device prepared using Example 1 remained stable during dynamic deformations such as bending, twisting, and shaking, and remained essentially unchanged after 10,000 bending cycles, demonstrating that the sensing fabric prepared using Example 1 maintained stable sensing during testing. In contrast, the resistance of the fabric prepared using Comparative Example 2 fluctuated and increased significantly during testing. This is because Comparative Example 2 is coated only with hydrophilic nanofibers. After sweat infiltrates the hydrophilic layer, the lack of an outer large-pore hydrophobic fiber layer causes trace amounts of sweat to rapidly escape, resulting in poor water retention and inability to stably detect sweat. This demonstrates that the Janus yarn directional water transport structure of Example 1 can effectively slow the evaporation and loss of sweat.

[0139] (5) Response speed

[0140] Depend on Figure 12 It can be seen that 5 minutes after the power is turned on, the textile device detects a signal, which proves that the electrochemical textile prepared in Example 1 has a faster response speed.

[0141] (6) Washing test

[0142] The sweat collection efficiency data of the sensor fabric prepared in Example 1 before and after the washing cycle test is shown in Table 2, and the data graph is shown in Figure 13 .Depend on Figure 2 and Figure 13 It can be seen that after multiple washing and drying steps, a high sweat collection efficiency can still be maintained.

[0143] Depend on Figure 14 It can be seen that the sensing current of the sensing fabric prepared in Example 1 remains stable throughout the multiple washing cycle tests, and the retention rate is close to 100%.

[0144] (7) Heating test

[0145] Depend on Figure 15 It can be seen that the super-hydrophobic heating electrode substrate prepared in Example 1 is heated at a working voltage of 2.20 V and a temperature of 0.2 W / cm 2 At low power density, the temperature can reach 50.1°C, which is much higher than the threshold of 42°C for thermal stimulation of skin sweating. Therefore, electric heating can stimulate skin sweating and improve sweat collection efficiency.

[0146] Table 2

[0147]

[0148]

[0149] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0150] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A glucose sensing electrode yarn, characterized in that: The invention comprises a conductive inner core, the outer side of which is sequentially coated with a sensing layer and a conducting layer, wherein the sensing layer comprises a glucose sensing material, and the conducting layer comprises, from the inside to the outside, a hydrophilic polymer nanofiber layer and a hydrophobic polymer nanofiber layer, wherein the average pore size of the hydrophilic polymer nanofiber layer is smaller than the average pore size of the hydrophobic polymer nanofiber layer, and the conducting layer conducts sweat directionally to the conductive inner core.

2. The glucose sensor electrode yarn according to claim 1, characterized in that: The glucose sensing material is a non-noble transition metal oxide; And / or, the conductive inner core is carbon fiber; and / or, the polymers in the hydrophilic polymer nanofiber layer and the hydrophobic polymer nanofiber layer are flexible polymers; and / or, the average pore size of the hydrophilic polymer nanofiber layer is 1.21 μm to 1.28 μm; and / or, the contact angle of the hydrophilic polymer nanofiber layer is 20° to 30°; and / or, the average pore size of the hydrophobic polymer nanofiber layer is 6 μm to 6.4 μm; And / or, the contact angle of the hydrophobic polymer nanofiber layer is 158° to 165°.

3. The glucose sensor electrode yarn according to claim 2, characterized in that: The glucose sensing material is Cu2O.

4. The glucose sensor electrode yarn according to claim 2, characterized in that: The conductive inner core is composed of multiple bundles of carbon fibers.

5. The glucose sensor electrode yarn according to claim 2, characterized in that: The polymer in the hydrophilic polymer nanofiber layer and the hydrophobic polymer nanofiber layer is polycaprolactone.

6. The glucose sensor electrode yarn according to claim 2, characterized in that: The average pore size of the hydrophilic polymer nanofiber layer is 1.26 μm.

7. The glucose sensing electrode yarn according to claim 2, characterized in that: The contact angle of the hydrophilic polymer nanofiber layer is 26.2°.

8. The glucose sensor electrode yarn according to claim 2, characterized in that: The average pore size of the hydrophobic polymer nanofiber layer is 6.2 μm.

9. The glucose sensor electrode yarn according to claim 2, characterized in that: The contact angle of the hydrophobic polymer nanofiber layer is 160.5°.

10. A method for preparing the glucose sensor electrode yarn according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, applying a glucose sensing material on the conductive inner core to form a sensing layer; S2. Coating the outer side of the sensing layer with a polymer nanofiber layer by an electrospinning process and performing a hydrophilic treatment to form a hydrophilic polymer nanofiber layer, wherein the electrospinning process uses a polycaprolactone spinning solution, wherein the concentration of the polycaprolactone spinning solution is 13 wt% to 17 wt%; S3. Covering the hydrophobic polymer nanofiber layer on the outside of the hydrophilic polymer nanofiber layer by an electrospinning process to form a conductive layer, wherein the electrospinning process uses a polycaprolactone spinning solution, wherein the concentration of the polycaprolactone spinning solution is 18 wt % to 22 wt %; Wt% represents the mass percentage of polycaprolactone in the polycaprolactone spinning solution.

11. The method for preparing the glucose sensor electrode yarn according to claim 10, characterized in that: In step S1, the applying method is electrodeposition.

12. The method for preparing the glucose sensor electrode yarn according to claim 11, characterized in that: In step S2, the electrospinning process satisfies one or more of the following conditions (a) to (d): (a) Spinning voltage is 14-16 kV; (b) Spinning humidity is 45% rh ~ 55% rh; (c) Spinning temperature is 25-31°C; (d) Spinning time is 10 to 12 hours; And / or, in step S2, the hydrophilic treatment is oxygen plasma treatment, and the time of the oxygen plasma treatment is 5 to 10 minutes.

13. The method for preparing the glucose sensor electrode yarn according to claim 12, wherein: In step S2, in the electrospinning process, the spinning voltage is 15 kV.

14. The method for preparing the glucose sensor electrode yarn according to claim 12, wherein: In step S2, in the electrospinning process, the spinning humidity is 50% rh.

15. The method for preparing the glucose sensor electrode yarn according to claim 12, wherein: In step S2, in the electrospinning process, the spinning temperature is 25°C.

16. The method for preparing the glucose sensor electrode yarn according to claim 12, wherein: In step S2, in the electrospinning process, the spinning time is 10 hours.

17. The method for preparing the glucose sensor electrode yarn according to claim 12, wherein: In step S2, in the electrospinning process, the hydrophilic treatment is oxygen plasma treatment, and the time of the oxygen plasma treatment is 5 minutes.

18. The method for preparing the glucose sensor electrode yarn according to claim 11, characterized in that: In step S3, the electrospinning process satisfies one or more of the following conditions (a) to (d): (a) Spinning voltage is 7-9 kV; (b) Spinning humidity is 45% rh ~ 55% rh; (c) Spinning temperature is 25-31°C; (d) Spinning time is 10 to 12 hours.

19. The method for preparing the glucose sensor electrode yarn according to claim 18, wherein: In step S3, in the electrospinning process, the spinning voltage is 8 kV.

20. The method for preparing the glucose sensor electrode yarn according to claim 18, wherein: In step S3, in the electrospinning process, the spinning humidity is 50% rh.

21. The method for preparing the glucose sensor electrode yarn according to claim 18, wherein: In step S3, in the electrospinning process, the spinning temperature is 25°C.

22. The method for preparing the glucose sensor electrode yarn according to claim 18, wherein: In step S3, in the electrospinning process, the spinning time is 10 hours.

23. A glucose sensing fabric, characterized in that: The invention comprises a glucose sensing electrode yarn, a reference electrode yarn, a counter electrode yarn and a heating electrode substrate which are woven and assembled. The glucose sensing electrode yarn is the glucose sensing electrode yarn according to any one of claims 1 to 9.

24. The glucose sensing fabric according to claim 23, characterized in that: The reference electrode yarn includes a conductive inner core, the outer side of which is sequentially coated with a reference layer and a conductive layer; the counter electrode yarn includes a conductive inner core, the outer side of which is coated with a conductive layer; Wherein, the material of the reference layer is Ag / AgCl; The conductive core and the conductive layer of the reference electrode yarn, and the conductive core and the conductive layer of the counter electrode yarn are respectively the same as the conductive core and the conductive layer of the glucose sensing electrode yarn.

25. The glucose sensing fabric according to claim 23, characterized in that: The heating electrode substrate is a conductive woven fabric distributed with a super-hydrophobic flexible polymer; Wherein, the super hydrophobic flexible polymer is polydimethylsiloxane; Wherein, the conductive woven cloth is made of carbon fiber, carbon nanotube fiber or graphene fiber.

26. Use of the glucose sensing fabric according to any one of claims 23 to 25 in a sweat sensor.

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