Wearable patch for detecting glucose in sweat as well as preparation method and application of wearable patch

Abstract

The invention belongs to the technical field of wearable sensing, and discloses a wearable patch for detecting glucose in sweat as well as a preparation method and application of the wearable patch. The wearable patch comprises a bonding layer, a microfluid channel, an electrochemical glucose biosensor, a temperature sensor and an electrothermal film which are sequentially arranged from inside to outside. The wearable patch is made of a flexible material, is resistant to high temperature and can be well attached to the skin, and meanwhile, the electrothermal film can be repeatedly used and is low in cost and easy to operate. Novel glucose detection equipment prepared based on the wearable patch can monitor glucose in sweat in a non-invasive mode, skin sweats in a thermal stimulation mode, a temperature control module is additionally arranged to serve as a protection mechanism, pain caused by a traditional blood sampling mode is avoided, glucose in sweat can be detected in situ in a resting state, and the detection accuracy is improved. The system is an ideal wearable real-time glucose monitoring platform, and has a wide application prospect in the aspect of early prevention of diabetes mellitus.

Description

Technical Field

[0001] The present invention relates to the field of wearable sensor technology, and in particular to a wearable patch for detecting glucose in sweat, and a preparation method and application thereof. Background Art

[0002] With the intensification of the aging population and the general increase in chronic diseases, people pay more and more attention to health, such as cardiovascular disease, obesity, diabetes, etc. These diseases are often related to bad living habits and lack of effective health monitoring. Health management has become an important part of the pursuit of a happy life. Traditional health monitoring methods usually need to be carried out in hospitals or clinics, and can only obtain short-term monitoring data. They are usually large and bulky, and cannot be monitored anytime and anywhere. There are time and space limitations, and it is impossible to monitor and analyze the health status of individuals in real time. Therefore, a convenient and efficient health monitoring tool is needed to meet people's needs. Wearable technology, as an innovative technology that has rapidly emerged in recent years, has become a popular choice for health monitoring with its small, portable and intelligent characteristics. Wearable health monitoring sensors combine sensor technology, Internet of Things technology and cloud computing technology, which can monitor the physiological parameters and activity status of individuals in real time, and provide personalized health management suggestions through data analysis.

[0003] Wearable electrochemical sensors are a new type of sensor that integrates electrochemical sensing technology and wearable devices. They can monitor human physiological indicators, environmental parameters or chemicals in real time and transmit data to smartphones or other devices for analysis and processing. This type of sensor usually contacts the human body in a flexible and comfortable way, can bend freely with the movement of the body, and is suitable for long-term wear. It can be used to monitor physiological indicators such as biomarkers, glucose levels, electrolyte concentrations in the blood, and can also be used to detect pollutants or chemicals in the environment. By combining electrochemical sensors with wearable devices, people can more conveniently monitor their health status in real time and take timely actions. This is of great significance in the fields of chronic disease management, physiological monitoring of athletes, environmental monitoring, etc. With the continuous advancement of materials science, nanotechnology and medical technology, wearable electrochemical sensors will have a wider range of application prospects.

[0004] Diabetes is a chronic disease that often has no obvious symptoms in the early stages, so it is difficult to be diagnosed in time. By monitoring the glucose concentration in sweat, signs of abnormal blood sugar can be detected in the early stages of the disease, providing an early warning function. Traditional blood sampling requires puncture to draw blood, which is painful for patients and has disadvantages such as inconvenience. Monitoring glucose in sweat is a non-invasive method that is more suitable for large-scale early screening. Studies in recent years have found that there is a certain correlation between the glucose concentration in sweat and the glucose concentration in blood. This means that by analyzing the glucose concentration in sweat, the blood sugar status inside the human body can be indirectly reflected, providing a new idea for health monitoring.

[0005] Therefore, it is of great significance to develop a wearable electrochemical analysis device for glucose detection that can provide early warning for diabetes and can monitor non-invasively. Summary of the invention

[0006] In view of this, the present invention provides a wearable patch for detecting glucose in sweat, and a preparation method and application thereof, so as to solve the problems that traditional blood sampling requires blood puncture, which makes patients painful and inconvenient, and the existing methods cannot provide early warning of diabetes.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The present invention provides a wearable patch for detecting glucose in sweat. The wearable patch comprises an adhesive layer, a microfluidic channel, an electrochemical glucose biosensor, a temperature sensor and an electric heating film which are sequentially arranged from inside to outside.

[0009] Preferably, the material of the adhesive layer is double-sided tape.

[0010] Preferably, the material of the microfluidic channel is polyethylene terephthalate; the microfluidic channel includes a sweat-enriched area, a sweat channel, a sweat analysis area and a sweat outlet, and the sweat-enriched area and the sweat analysis area are connected through the sweat channel; the sweat-enriched area and the sweat analysis area are independently through holes with a diameter of 0.3 to 1 cm; the width of the sweat channel is independently 0.03 to 0.05 cm.

[0011] Preferably, the preparation of the electrochemical glucose biosensor comprises the following steps:

[0012] (1) Using polyimide as the electrode substrate, conductive ink as the working electrode and counter electrode, and Ag / AgCl as the reference electrode, the SPE membrane electrode was obtained by screen printing;

[0013] (2) activating, removing impurities and performing constant potential deposition on the SPE membrane electrode in sequence to obtain a carbon / Prussian blue electrode;

[0014] (3) The chitosan-glucose oxidase solution is drop-casted on the surface of the electrode carbon / Prussian blue electrode for constant potential deposition to obtain an electrochemical glucose biosensor.

[0015] Preferably, the activation method is cyclic voltammetry; the reagent used for the activation is sulfuric acid; the reagent used for the constant potential deposition is Prussian blue solution, which is an aqueous solution composed of K4[Fe(CN)6], FeCl3, KCl and HCl, and the concentration of K4[Fe(CN)6] in the Prussian blue solution is 2-2.5mmol / L, the concentration of FeCl3 is 2-2.5mmol / L, the concentration of KCl is 0.1-0.3mol / L, and the concentration of HCl is 0.1-0.3mol / L; the reference electrode used for the constant potential deposition is Ag / AgCl, and the counter electrode used is Pt; the potential of the constant potential deposition is 0.4-0.6V, and the time of the constant potential deposition is 360-380s.

[0016] Preferably, the chitosan-glucose oxidase solution is prepared by mixing glucose oxidase solution and chitosan solution in a volume ratio of 1:1 to 1.5; the glucose oxidase solution is a PBS solution of glucose oxidase, and the concentration of the glucose oxidase solution is 8 to 12 mg / mL; the chitosan solution is an acetic acid solution of chitosan, and the mass fraction of the chitosan solution is 0.5 to 2%.

[0017] Preferably, the preparation of the electric heating film comprises the following steps:

[0018] The silver nanowire suspension is enriched on the filter membrane by vacuum filtration to obtain a filter membrane sheet; polyimide is used as a substrate, the filter membrane sheet is attached to one surface of the polyimide, a conductive silver paste is coated in the width direction of the surface of the polyimide to which the filter membrane sheet is attached, and a power line is arranged in the length direction of the polyimide to obtain an electric heating film.

[0019] Preferably, the diameter of the silver nanowires in the silver nanowire suspension is 28-32 nm, and the length is 28-32 μm; the length of the polyimide and filter membrane sheet is 4-4.5 cm, and the width is 2-2.5 cm.

[0020] The present invention also provides a method for preparing the wearable patch for detecting glucose in sweat, comprising the following steps:

[0021] The wearable patch is fabricated by sequentially laminating an adhesive layer, a microfluidic channel, an electrochemical glucose biosensor, a temperature sensor, and an electrothermal film;

[0022] The adhesive layer, microfluidic channel, electrochemical glucose biosensor, temperature sensor and electrothermal film are independently bonded by ultraviolet curing UV glue.

[0023] The present invention also provides use of the wearable patch for detecting glucose in sweat in preparing a device for detecting glucose in sweat.

[0024] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0025] The wearable patch of the present invention is made of flexible material, is resistant to high temperature, and can fit the skin well. At the same time, the electric heating film is reusable, has low cost and is easy to operate. In addition, a new type of glucose detection device prepared based on this wearable patch can non-invasively monitor glucose in sweat, uses thermal stimulation to make the skin sweat, and uses an external temperature control module as a protection mechanism to avoid the pain caused by traditional blood sampling methods. Glucose in sweat can also be detected in situ in a resting state. It is an ideal platform for realizing wearable real-time monitoring of glucose and has broad application prospects in the early prevention of diabetes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 This is a schematic diagram of circuit connections of the device for detecting glucose in sweat according to the present invention;

[0028] Figure 2 Schematic diagram of the three-dimensional structure of the wearable patch, wherein: 1-adhesive layer, 2-microfluidic channel, 3-electrochemical glucose biosensor, 4-temperature sensor, 5-electrical heating film;

[0029] Figure 3 It is a schematic diagram of the structure of the microfluidic channel, wherein 20 is a microfluidic channel, 21 is a sweat collection area, 22 is a sweat analysis area, and 23 is a sweat outlet;

[0030] Figure 4 The schematic diagram of the structure and preparation flow chart of the electrochemical glucose biosensor, wherein 30 is an electrode substrate, 31 is a counter electrode, 32 is a working electrode, and 33 is a reference electrode;

[0031] Figure 5 The cross-sectional structure diagram of the wearable patch along the width direction of the polyimide in the electrothermal film;

[0032] Figure 6This is the current response curve of the electrochemical glucose biosensor in Example 1 when detecting glucose in sweat. DETAILED DESCRIPTION

[0033] The present invention provides a wearable patch for detecting glucose in sweat. The wearable patch comprises an adhesive layer, a microfluidic channel, an electrochemical glucose biosensor, a temperature sensor and an electric heating film which are sequentially arranged from inside to outside.

[0034] In the present invention, the material of the adhesive layer is double-sided tape.

[0035] In the present invention, the size of the adhesive layer is the same as that of the electric heating film; the adhesive layer contains four through holes, and the positions and sizes of the four through holes are the same as those of the sweat-enriched area in the microfluidic channel.

[0036] In the present invention, the material of the microfluidic channel is polyethylene terephthalate; the microfluidic channel includes a sweat-enriched area, a sweat channel, a sweat analysis area and a sweat outlet, and the sweat-enriched area and the sweat analysis area are connected through the sweat channel; the sweat-enriched area and the sweat analysis area are independently preferably through holes with a diameter of 0.3 to 1 cm, more preferably through holes with a diameter of 0.5 to 0.9 cm, and more preferably through holes with a diameter of 0.6 to 0.8 cm; the width of the sweat channel is independently preferably 0.03 to 0.05 cm, and more preferably 0.04 cm.

[0037] In the present invention, the thickness of the microfluidic channel is preferably 200-300 μm, further preferably 220-280 μm, and more preferably 250-260 μm; the size of the microfluidic channel is the same as the size of the heating area in the electric heating film, specifically a square with a side length the same as the width of the filter membrane in the electric heating film.

[0038] In the present invention, the preparation of the microfluidic channel comprises the following steps:

[0039] Using polyethylene terephthalate as the substrate, microfluidic channels were engraved using a CO2 laser.

[0040] In the present invention, the working process of the microfluidic channel is: sweat is collected in four sweat collection areas, then flows into the sweat analysis area through the sweat channel for analysis, and finally discharged from the sweat outlet; this not only shortens the sweat collection time, but also prevents the sweat from being disturbed by the surrounding environment.

[0041] In the present invention, the preparation of the electrochemical glucose biosensor comprises the following steps:

[0042] (1) Using polyimide as the electrode substrate, conductive ink as the working electrode and counter electrode, and Ag / AgCl as the reference electrode, the SPE membrane electrode was obtained by screen printing;

[0043] (2) activating, removing impurities and performing constant potential deposition on the SPE membrane electrode in sequence to obtain a carbon / Prussian blue electrode;

[0044] (3) The chitosan-glucose oxidase solution is drop-casted on the surface of the electrode carbon / Prussian blue electrode for constant potential deposition to obtain an electrochemical glucose biosensor.

[0045] In the present invention, the activation method is cyclic voltammetry; the activation reagent is sulfuric acid, and the concentration of sulfuric acid is preferably 0.5-1 mol / L, more preferably 0.6-0.9 mol / L, and more preferably 0.7-0.8 mol / L.

[0046] In the present invention, the reagent used for the constant potential deposition is a Prussian blue solution, which is an aqueous solution composed of K4[Fe(CN)6], FeCl3, KCl and HCl. The concentration of K4[Fe(CN)6] in the Prussian blue solution is 2-2.5 mmol / L, the concentration of FeCl3 is 2-2.5 mmol / L, the concentration of KCl is 0.1-0.3 mol / L, and the concentration of HCl is 0.1-0.3 mol / L; wherein the concentration of K4[Fe(CN)6] is preferably 2.1-2.4 mmol / L, and more preferably 2.2-2.3 mmol / L; the concentration of FeCl3 is preferably 2.1-2.4 mmol / L, and more preferably 2.2-2.3 mmol / L; the concentration of KCl is preferably 0.2-0.25 mol / L; and the concentration of HCl is preferably 0.2-0.25 mol / L.

[0047] In the present invention, the reference electrode used for the constant potential deposition is Ag / AgCl, and the counter electrode used is Pt; the potential of the constant potential deposition is preferably 0.4-0.6V, and more preferably 0.5V; the time of the constant potential deposition is preferably 360-380s, and more preferably 370s; after the constant potential deposition is completed, the obtained electrode is dried; the drying temperature is preferably room temperature.

[0048] In the present invention, the chitosan-glucose oxidase solution is prepared by configuring the glucose oxidase solution and the chitosan solution in a volume ratio of 1:1 to 1.5; the volume ratio of the glucose oxidase solution and the chitosan solution is preferably 1:1.1 to 1.4, and more preferably 1:1.2 to 1.3; the glucose oxidase solution is a PBS solution of glucose oxidase, and the concentration of the glucose oxidase solution is preferably 8 to 12 mg / mL, and more preferably 9 to 11 mg / mL, and more preferably 10 mg / mL; the chitosan solution is an acetic acid solution of chitosan, and the mass fraction of the chitosan solution is preferably 0.5 to 2%, and more preferably 1 to 1.5%; the thickness of the drop casting is preferably 0.5 to 0.6 mm, and more preferably 0.52 to 0.58 mm, and more preferably 0.23 to 0.55 mm; after the drop casting is completed, it is dried at room temperature to obtain an electrochemical glucose biosensor.

[0049] In the present invention, the size and position of the three-electrode area in the electrochemical glucose biosensor are the same as the size and position of the sweat analysis area in the microfluidic channel; the size of the polyimide in the electrochemical glucose biosensor is the same as the size of the heating area in the electrothermal film, specifically a square with a side length the same as the width of the filter membrane in the electrothermal film.

[0050] In the present invention, the preparation of the electric heating film comprises the following steps:

[0051] The silver nanowire suspension is enriched on the filter membrane by vacuum filtration to obtain a filter membrane sheet; polyimide is used as a substrate, the filter membrane sheet is attached to one surface of the polyimide, a conductive silver paste is coated in the width direction of the surface of the polyimide to which the filter membrane sheet is attached, and a power line is arranged in the length direction of the polyimide to obtain an electric heating film.

[0052] In the present invention, the diameter of the silver nanowires in the silver nanowire suspension is preferably 28 to 32 nm, more preferably 29 to 31 nm, more preferably 30 nm, and the length is preferably 28 to 32 μm, more preferably 29 to 31 μm, more preferably 30 μm; the length of the polyimide and the filter membrane is preferably 4 to 4.5 cm, more preferably 4.1 to 4.4 cm, more preferably 4.2 to 4.3 cm, and the width is preferably 2 to 2.5 cm, more preferably 2.1 to 2.4 cm, more preferably 2.2 to 2.3 cm; the polyimide and the filter membrane are the same size.

[0053] In the present invention, the thickness of the polyimide in the electrochemical glucose biosensor and the electrothermal film is independently preferably 100 to 150 μm, more preferably 110 to 140 μm, and even more preferably 120 to 130 μm.

[0054] The present invention also provides a method for preparing the wearable patch for detecting glucose in sweat, comprising the following steps:

[0055] The wearable patch is fabricated by sequentially laminating an adhesive layer, a microfluidic channel, an electrochemical glucose biosensor, a temperature sensor, and an electrothermal film;

[0056] The adhesive layer, microfluidic channel, electrochemical glucose biosensor, temperature sensor and electrothermal film are independently bonded by ultraviolet curing UV glue.

[0057] In the present invention, the specific steps of sequentially laminating the adhesive layer, the microfluidic channel, the electrochemical glucose biosensor, the temperature sensor and the electric heating film are as follows:

[0058] First, the adhesive layer and the microfluidic channel are laid in sequence to ensure that the position of the through hole in the adhesive layer corresponds to the position of the sweat collection area in the microfluidic channel; then the electrochemical glucose biosensor is laid on the surface of the microfluidic channel to ensure that the polyimide in the electrochemical glucose biosensor is in contact with the microfluidic channel; finally, the temperature sensor and the electric heating film are laid in sequence.

[0059] The present invention also provides use of the wearable patch for detecting glucose in sweat in preparing a device for detecting glucose in sweat.

[0060] In the present invention, the device for detecting glucose in sweat includes a power supply, a switch, a digital display temperature control module, a voltage reduction module, a portable electrochemical workstation and a wearable patch.

[0061] In the present invention, the working process of the device for detecting glucose in sweat is:

[0062] Connect the power supply, switch, digital display temperature control module, step-down module, portable electrochemical workstation and wearable patch in sequence. Turn on the switch, and the electric heating film in the wearable patch starts to heat up until sweat is produced on the skin surface. The electrochemical glucose biosensor in the wearable patch starts to analyze the glucose in the sweat. The portable electrochemical workstation records the electrochemical signal generated by the electrode and transmits it to the smartphone. After analysis, the detection is completed and the results are obtained.

[0063] In the present invention, the heating temperature is preferably 48 to 48.5° C., and the heating time is preferably 15 to 18 minutes; the heating temperature is displayed by a digital temperature control module.

[0064] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0065] The preparation of the silver nanowire suspension used in the following examples includes the following steps:

[0066] AgNWs were prepared by seed-mediated method: First, 0.25 mL of ice-cold NaBH4 solution (25.0 mmol / L) was added to 10.0 mL of CTAC solution (50 mmol / L), which contained HAuCl4 (0.25 mmol / L) and citric acid (5 mmol / L). After strong magnetic stirring for 2 min, the mixture was heated at 80 °C with gentle stirring for 90 min. Finally, the gold seed solution was cooled to room temperature. In a three-necked round-bottom flask, 4.6 mL of H2O, 2 mL of the prepared gold seed solution, 60 μL of CTAB (50 mmol / L) and 0.3 mL of NH3 were added. Mix. Subsequently, the mixture was heated to 50 °C under strong magnetic stirring. Then, AgNO3 (5 mmol / L, 4 mL) and AA (15 mmol / L, 4 mL) aqueous solutions were added sequentially at a rate of 0.8 mL / min. After all chemicals were added to the flask, the mixture was kept for 15 min and quenched in an ice-water bath. The silver nanorod (AgNRs) solution was obtained. To prepare silver nanowires (AgNWs), the seed solution, reducing solution and feed solution were prepared as follows: the seed solution was prepared by mixing 1 mL of AgNRs solution, 0.3 mL of NH3-H2O (50 mmol / L), 60 μL of CTAB (50 mmol / L), 3 mL of HNO3 (50 mmol / L), and 3.5 mL of H2O; the reducing solution was prepared by 3.7 mL of CTAC (50 mmol / L), 6.0 mL of AA (20 mmol / L), 120 μL of CTAB (50 mmol / L), and 0.3 mL of NH3-H2O (50 mmol / L); the feed solution was 10 mL of AgNO3 (4 mmol / L) solution. The seed solution was heated to 60 °C. Then, the reducing solution and the feeding solution were added sequentially at a rate of 0.8 mL / min. The mixture was stored at 60 ° C for 3 h and finally cooled naturally to room temperature. The prepared AgNWs solution was allowed to stand overnight for static stratification. Then, the supernatant containing short AgNWs and nanoparticles was removed with a pipette. Subsequently, 20 mL of CTAC (10.0 mmol / L) solution was added to redisperse the precipitated AgNWs. After stirring for 2 h, the supernatant containing short AgNWs and nanoparticles was removed with a pipette. Finally, high-purity silver nanowires were obtained. The silver nanowires were dispersed in 50 mL of H2O to obtain a silver nanowire suspension.

[0067] Example 1

[0068] This embodiment provides a device for detecting glucose in sweat, and the preparation and detection methods of the device are as follows:

[0069] Equipment preparation:

[0070] The preparation method of the wearable patch is as follows:

[0071] (1) According to the design structure, a 200 μm thick polyethylene terephthalate substrate was used and a CO2 laser was used to engrave the designed pattern (pattern such as Figure 3 As shown, the four sweat-enriched areas are all through holes with a diameter of 0.3 cm, the sweat analysis area is a through hole with a diameter of 1 cm, and the width of the sweat channel is 0.03 cm). The defects near the channel are polished clean with sandpaper to obtain a microfluidic channel; the size of the microfluidic channel is the same as the size of the heating area in the electrothermal film, specifically a square with a side length the same as the width of the filter membrane in the electrothermal film, that is, 2.5 cm×2.5 cm (length×width);

[0072] (2) The silver nanowire suspension is filtered to obtain a filter membrane (polyvinylidene fluoride (PVDF) film, pore size: 220 μm); the filter membrane is dried at room temperature, and then the dried filter membrane is cut into a size of 4.5 cm×2.5 cm (length×width), and a conductive silver paste of 2.5 cm×1 cm (length×width) is scraped on the width direction of the filter membrane. The filter membrane coated with the conductive silver paste is adhered to a polyimide with a thickness of 100 μm and a size of 4.5 cm×2.5 cm (length×width) by ultraviolet curing UV glue to increase its toughness, thereby preparing an electric heating film with a heating area of ​​only 2.5 cm×2.5 cm (length×width);

[0073] (3) A 100 μm thick polyimide surface was cleaned with a detergent and placed in ethanol for 30 min of ultrasonic treatment. After drying at 50°C, commercial ink and Ag / AgCl were screen-printed on the substrate and dried at 60°C for 20 min to obtain a SPE membrane electrode. The SPE membrane electrode was first activated by cyclic voltammetry in a 1 mol / L H2SO4 solution, with a scanning range of -1.0 to +1.0 V, and the scanning cycle was repeated for 10 cycles, then impurities were removed, and then constant potential deposition was used in an aqueous solution composed of 2.5 mM K4[Fe(CN)6], 2.5 mMFeCl3, 0.1 M KCl and 0.1 M HCl to form Prussian blue. The reference electrode used for constant potential deposition was Ag / AgCl, and the counter electrode used was Pt. The potential of the constant potential deposition was 0.4 V, and the constant potential deposition time was 360 s. After drying at room temperature, a carbon / Prussian blue electrode was obtained. 10 μL of chitosan-glucose oxidase solution (acetic acid solution with a mass fraction of 1% chitosan and PBS solution with a volume ratio of 1:1) was drop-cast onto the SPE working electrode area of ​​the carbon / Prussian blue electrode. After the solution was dried at room temperature, an electrochemical glucose biosensor was obtained.

[0074] (4) First, double-sided adhesive and microfluidic channels are laid in sequence to ensure that the position of the through hole in the adhesive layer corresponds to the position of the sweat collection area in the microfluidic channel; then, an electrochemical glucose biosensor is laid on the surface of the microfluidic channel to ensure that the polyimide in the electrochemical glucose biosensor is in contact with the microfluidic channel; finally, a temperature sensor and an electrothermal film are laid in sequence to obtain a wearable patch; the adhesive layer, the microfluidic channel, the electrochemical glucose biosensor, the temperature sensor and the electrothermal film are all bonded together by ultraviolet curing UV glue.

[0075] 1. Equipment Preparation:

[0076] (1) The adhesive layer of the wearable patch is attached to the human skin.

[0077] (2) Connect the power supply, switch, digital temperature control module, step-down module, portable electrochemical workstation and wearable patch in sequence.

[0078] The power supply is a 12V lithium-ion battery with a capacity of 1500mAh and a size of 55.7mm×18.8mm×69.8mm (length×width×height); the driving voltage of the digital temperature control module is 12V, which controls the circuit to be closed when T≤48°C and to be disconnected when T≥48.5°C, with a size of 78mm×51mm×25mm (length×width×height); the input voltage of the step-down module is 12V, the output voltage is 1V, and the size is 43mm×21mm×14mm (length×width×height); the driving voltage of the portable electrochemical workstation is 12V, and the size is 12cm×7cm×2.5cm (length×width×height); the input voltage of the electric heating film is 1.5V, the heating time is 15min, and the heating temperature is 48-48.5°C.

[0079] The detection method is as follows:

[0080] Turn on the switch, the electric heating film in the wearable patch starts to heat up until sweat is produced on the skin surface. The electrochemical glucose biosensor in the wearable patch starts to analyze the glucose in the sweat. The portable electrochemical workstation records the electrochemical signals generated by the electrodes and transmits them to the smartphone. After analysis, the test is completed and the results are obtained.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A wearable patch for detecting glucose in sweat, characterized in that: The wearable patch comprises an adhesive layer, a microfluidic channel, an electrochemical glucose biosensor, a temperature sensor and an electric heating film which are arranged in sequence from the inside to the outside.

2. The wearable patch for detecting glucose in sweat according to claim 1, characterized in that: The material of the adhesive layer is double-sided adhesive.

3. The wearable patch for detecting glucose in sweat according to claim 1 or 2, characterized in that: The material of the microfluidic channel is polyethylene terephthalate; the microfluidic channel includes a sweat-enriched area, a sweat channel, a sweat analysis area and a sweat outlet, and the sweat-enriched area and the sweat analysis area are connected through the sweat channel; the sweat-enriched area and the sweat analysis area are independently through holes with a diameter of 0.3 to 1 cm; the width of the sweat channel is independently 0.03 to 0.05 cm.

4. The wearable patch for detecting glucose in sweat according to claim 3, characterized in that: The preparation of the electrochemical glucose biosensor comprises the following steps: (1) Using polyimide as the electrode substrate, conductive ink as the working electrode and counter electrode, and Ag / AgCl as the reference electrode, the SPE membrane electrode was obtained by screen printing; (2) activating, removing impurities and performing constant potential deposition on the SPE membrane electrode in sequence to obtain a carbon / Prussian blue electrode; (3) The chitosan-glucose oxidase solution is drop-casted on the surface of the electrode carbon / Prussian blue electrode for constant potential deposition to obtain an electrochemical glucose biosensor.

5. The wearable patch for detecting glucose in sweat according to claim 4, characterized in that: The activation method is cyclic voltammetry; the reagent used for the activation is sulfuric acid; the reagent used for the constant potential deposition is a Prussian blue solution, which is an aqueous solution composed of K4[Fe(CN)6], FeCl3, KCl and HCl, and the concentration of K4[Fe(CN)6] in the Prussian blue solution is 2-2.5 mmol / L, the concentration of FeCl3 is 2-2.5 mmol / L, the concentration of KCl is 0.1-0.3 mol / L, and the concentration of HCl is 0.1-0.3 mol / L; the reference electrode used for the constant potential deposition is Ag / AgCl, and the counter electrode used is Pt; the potential of the constant potential deposition is 0.4-0.6 V, and the time of the constant potential deposition is 360-380 s.

6. The wearable patch for detecting glucose in sweat according to claim 4 or 5, characterized in that: The chitosan-glucose oxidase solution is prepared by mixing glucose oxidase solution and chitosan solution in a volume ratio of 1:1-1.5; the glucose oxidase solution is a PBS solution of glucose oxidase, and the concentration of the glucose oxidase solution is 8-12 mg / mL; the chitosan solution is an acetic acid solution of chitosan, and the mass fraction of the chitosan solution is 0.5-2%.

7. A wearable patch for detecting glucose in sweat according to claim 1, 2, 4 or 5, characterized in that: The preparation of the electric heating film comprises the following steps: The silver nanowire suspension is enriched on the filter membrane by vacuum filtration to obtain a filter membrane sheet; polyimide is used as a substrate, the filter membrane sheet is attached to one surface of the polyimide, a conductive silver paste is coated in the width direction of the surface of the polyimide to which the filter membrane sheet is attached, and a power line is arranged in the length direction of the polyimide to obtain an electric heating film.

8. The wearable patch for detecting glucose in sweat according to claim 7, characterized in that: The diameter of the silver nanowires in the silver nanowire suspension is 28-32 nm, and the length is 28-32 μm; the length of the polyimide and filter membrane sheet is 4-4.5 cm, and the width is 2-2.5 cm.

9. The method for preparing a wearable patch for detecting glucose in sweat according to any one of claims 1 to 8, characterized in that: The steps include: The wearable patch is fabricated by sequentially laminating an adhesive layer, a microfluidic channel, an electrochemical glucose biosensor, a temperature sensor, and an electrothermal film; The adhesive layer, microfluidic channel, electrochemical glucose biosensor, temperature sensor and electrothermal film are independently bonded by ultraviolet curing UV glue.

10. Use of the wearable patch for detecting glucose in sweat according to any one of claims 1 to 8 in preparing a device for detecting glucose in sweat.

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