阅读说明：本技术 一种生物体无损血糖检测器件及其制备方法 (Organism nondestructive blood sugar detection device and preparation method thereof ) 是由 陈涛 姚瑶 吕甜 于 2020-06-12 设计创作，主要内容包括：本发明涉及一种生物体无损血糖检测器件及其制备方法,器件包括工作电极和对电极,工作电极包括工作电极柔性基底、设于工作电极柔性基底上的工作电极导电基底以及负载在工作电极导电基底上的葡萄糖氧化酶,对电极包括对电极柔性基底、设于对电极柔性基底上的对电极导电基底以及镀覆在对电极导电基底上的银/氯化银膜。制备方法具体为：先获得石墨烯/碳纳米管复合纤维织物,再取两个石墨烯/碳纳米管复合纤维织物,分别负载葡萄糖氧化酶得到工作电极,镀覆银/氯化银膜得到对电极,最后并排放置工作电极和对电极。与现有技术相比,本发明通过二电极体系确立了模拟组织间液与即时响应电流之间的关系,即可检测生物的血糖浓度变化,且灵敏度高。(The invention relates to a nondestructive blood sugar detection device for organisms and a preparation method thereof, wherein the device comprises a working electrode and a counter electrode, the working electrode comprises a working electrode flexible substrate, a working electrode conductive substrate arranged on the working electrode flexible substrate and glucose oxidase loaded on the working electrode conductive substrate, and the counter electrode comprises a counter electrode flexible substrate, a counter electrode conductive substrate arranged on the counter electrode flexible substrate and a silver/silver chloride film plated on the counter electrode conductive substrate. The preparation method specifically comprises the following steps: the method comprises the steps of firstly obtaining graphene/carbon nanotube composite fiber fabrics, then taking two graphene/carbon nanotube composite fiber fabrics, respectively loading glucose oxidase to obtain a working electrode, plating a silver/silver chloride film to obtain a counter electrode, and finally placing the working electrode and the counter electrode side by side. Compared with the prior art, the invention establishes the relationship between the simulated interstitial fluid and the instant response current through a two-electrode system, can detect the blood sugar concentration change of organisms and has high sensitivity.)

1. The device is characterized by comprising a working electrode and a counter electrode which are arranged side by side, wherein the working electrode comprises a working electrode flexible substrate, a working electrode conductive substrate arranged on the working electrode flexible substrate and glucose oxidase loaded on the working electrode conductive substrate, and the counter electrode comprises a counter electrode flexible substrate, a counter electrode conductive substrate arranged on the counter electrode flexible substrate and a silver/silver chloride film plated on the counter electrode conductive substrate.

2. The device for the nondestructive testing of blood glucose in living organisms according to claim 1, wherein the conductive substrate of the working electrode is made of graphene/carbon nanotube composite fiber fabric, and the flexible substrate of the working electrode is made of polydimethylsiloxane.

3. The device for the nondestructive testing of blood glucose in living body according to claim 1, wherein the conductive substrate of the counter electrode is made of graphene/carbon nanotube composite fiber fabric, and the flexible substrate of the counter electrode is made of polydimethylsiloxane.

4. A method for manufacturing the device for the non-destructive testing of blood glucose in living organisms according to any of claims 1 to 3, wherein the method for manufacturing comprises the following steps:

(a) sequentially growing a plurality of continuous graphene films, plating a catalyst layer and a buffer layer and growing an oriented carbon nanotube array on the surface of the pretreated nickel fiber fabric, then etching to remove the nickel fiber fabric, the catalyst layer and the buffer layer, and then cleaning and drying to obtain the graphene/carbon nanotube composite fiber fabric;

(b) taking the graphene/carbon nanotube composite fiber fabric obtained in the step (a), transferring the graphene/carbon nanotube composite fiber fabric to the surface of a flexible substrate of a working electrode, loading glucose oxidase on the graphene/carbon nanotube composite fiber fabric, and drying to obtain the working electrode;

(c) taking the graphene/carbon nano tube composite fiber fabric obtained in the step (a), transferring the graphene/carbon nano tube composite fiber fabric to the surface of a flexible substrate of a counter electrode, and plating a silver/silver chloride film on the graphene/carbon nano tube composite fiber fabric to obtain the counter electrode;

(d) and (c) placing the working electrode obtained in the step (b) and the counter electrode obtained in the step (c) side by side to obtain the organism nondestructive blood sugar detection device.

5. The method for preparing a device for the non-destructive examination of blood glucose in living organisms according to claim 4, wherein the pretreatment process of the nickel fiber fabric in the step (a) is specifically as follows: ultrasonically cleaning in acetone for 5-10 min, washing with deionized water and ethanol for 3-5 times, and finally drying at 60-80 ℃ for 10-20 min.

6. The method for preparing the device for nondestructive testing of blood sugar in an organism according to claim 4, wherein in the step (a), when a continuous multilayer graphene film is grown, a mixed gas of argon and hydrogen is used as a carrier gas, methane is used as a carbon source, the reaction temperature is 950-1050 ℃, the growth time is 2-15 min, and the volume ratio of argon, hydrogen and methane is 20 (2-8) to (2-5);

in the step (a), the pressure of plating is (8-30) x 10 when plating the catalyst layer and the buffer layer^-4Pa, the plating speed of the catalyst layer is 0.3-0.7 nm/s, and the plating speed of the buffer layer is 2-3 nm/s;

in the step (a), the component of the catalyst layer is Fe, and the component of the buffer layer is Al₂O₃The thickness ratio of the catalyst layer to the buffer layer is (0.05-0.15): 1;

in the step (a), when the oriented carbon nanotube array grows, mixed gas of argon and hydrogen is used as carrier gas, ethylene is used as a carbon source, the reaction temperature is 740-760 ℃, the growth time is 2-10 min, and the volume ratio of argon, hydrogen and ethylene is 40 (4-12) to (1-3);

in the step (a), the drying temperature is 70-85 ℃, and the drying time is 30-60 min.

7. The method for preparing a device for the nondestructive testing of blood sugar in an organism according to claim 4, characterized in that in step (a), a mixed solution of ferric chloride and nitric acid is used as an etching solution to etch the nickel fiber fabric, the catalyst layer and the buffer layer for 1-3 h, and the molar concentration ratio of ferric chloride to nitric acid is (1-3): 3.

8. The method for preparing a device for the nondestructive testing of blood sugar in an organism according to claim 4, characterized in that in step (b), glucose oxidase is loaded by phosphate buffer solution of glucose oxidase, and the dropping volume of the phosphate buffer solution of glucose oxidase is 50-100 μ L/(0.1-0.2 cm)²Graphene/carbon nanotube composite fiber fabric), wherein the mass concentration of the glucose oxidase in phosphate buffer solution of the glucose oxidase is 40-60 mg mL^-1；

In the step (b), drying is carried out at normal temperature and low pressure, wherein the low pressure is-50 to-70 kPa;

in the step (b), the preparation process of the flexible substrate of the working electrode comprises the following steps: uniformly mixing polydimethylsiloxane and a curing agent according to the mass ratio of (5-10) to 1, and heating and curing at 70-80 ℃ for 40-60 min to obtain the composite material.

9. The method for preparing a device for the non-destructive examination of blood glucose in living organisms according to claim 4, wherein in the step (c), the counter electrode flexible substrate is prepared by: uniformly mixing polydimethylsiloxane and a curing agent according to the mass ratio of (5-10) to 1, and heating and curing at 70-80 ℃ for 40-60 min to obtain the composite material.

10. The method for preparing a device for the non-invasive measurement of blood glucose in a living body according to claim 4, wherein the step (c) of plating the silver/silver chloride film comprises the following steps: firstly, taking a silver electrode as an anode, taking a graphene/carbon nanotube composite fiber fabric as a cathode, taking a mixed solution of potassium nitrate and silver nitrate as an electrolyte, plating a silver film on the graphene/carbon nanotube composite fiber fabric, then taking the silver-plated graphene/carbon nanotube composite fiber fabric as a working electrode, taking a platinum wire as a counter electrode, taking a saturated calomel electrode as a reference electrode, and taking a mixed solution of potassium chloride and hydrochloric acid as an electrolyte, and chlorinating the silver film to obtain the graphene/carbon nanotube/silver chloride composite fiber fabric;

in the mixed solution of the potassium nitrate and the silver nitrate, the molar concentration ratio of the potassium nitrate to the silver nitrate is (500-1500) to (3-7);

in the mixed solution of the potassium chloride and the hydrochloric acid, the molar concentration ratio of the potassium chloride to the hydrochloric acid is (50-150) to (5-15).

Technical Field

The invention belongs to the technical field of blood sugar detection, and particularly relates to a nondestructive blood sugar detection device for an organism and a preparation method thereof.

Background

According to relevant reports, the number of diabetic patients worldwide will reach 4 billion in 2030, which means that more and more people will be affected by the chronic disease, including its complications. For such patients, the current accurate blood glucose detection mode is mainly blood sampling detection through veins, but the mode can not continuously detect the change of blood glucose, but also seriously affects the life quality of patients and the compliance of long-term monitoring, so how to construct continuous, accurate and nondestructive blood glucose detection is a problem which is urgently needed to be solved at present.

To date, non-invasive blood glucose testing devices for humans have been reported to be based primarily on the detection of glucose concentrations in other bodily fluids of the human body, including tears, saliva, perspiration, and interstitial fluid. The method mainly comprises the steps of firstly extracting subcutaneous interstitial fluid to the surface of skin through pores by using a reverse iontophoresis method, then detecting the concentration of glucose in the extracted interstitial fluid, and finally achieving the purpose of human body nondestructive blood glucose detection.

Graphene materials are often used as conductive substrates of glucose sensors due to their excellent flexibility, conductivity and biocompatibility, however, complex modifications are usually required on the surfaces thereof to fix glucose oxidase on the electrode surfaces. In order to prevent the glucose oxidase from falling off, a perfluorosulfonic acid type polymer (Nafion) solution is usually coated, so that the conductivity of the electrode is reduced, and the sensitivity of the device is not ideal. Therefore, the development of a human body nondestructive blood sugar detection device with high accuracy, high sensitivity, simple structure and convenient operation has important significance.

Disclosure of Invention

The invention aims to provide a biological nondestructive blood sugar detection device and a preparation method thereof, which can directly establish the relationship between simulated interstitial fluid and instant response current through a two-electrode system, can detect the blood sugar concentration change of organisms and has high sensitivity.

The purpose of the invention is realized by the following technical scheme:

the utility model provides an organism nondestructive blood sugar detection device, detection device is including working electrode and the counter electrode that sets up side by side, working electrode includes the flexible basement of working electrode, locates the electrically conductive basement of working electrode on the flexible basement of working electrode and the glucose oxidase of load on the electrically conductive basement of working electrode, the counter electrode includes the flexible basement of counter electrode, locates the electrically conductive basement of counter electrode on the flexible basement of counter electrode and plates the silver/silver chloride membrane on the electrically conductive basement of counter electrode, forms two electrode systems. The graphene/carbon nanotube/silver chloride composite fiber fabric is formed by the working electrode conductive substrate and the glucose oxidase.

Preferably, the conductive substrate of the working electrode is made of graphene/carbon nanotube composite fiber fabric, the graphene/carbon nanotube composite fiber maintains a hollow structure, the thickness of the composite fiber fabric is 100-120 μm, preferably 120 μm, the number of graphene layers is 9-15, preferably 14, the thickness is 3-5 nm, preferably 5nm, and the thickness of the carbon nanotube is 10-30 μm, preferably 20 μm.

Preferably, the flexible substrate of the working electrode is made of polydimethylsiloxane, and the thickness of the flexible substrate of the working electrode is 0.8-1.5 mm, preferably 1.0 mm.

Preferably, the conductive substrate of the counter electrode is made of graphene/carbon nanotube composite fiber fabric, the graphene/carbon nanotube composite fiber maintains a hollow structure, the thickness of the composite fiber fabric is 100-120 μm, preferably 120 μm, the number of graphene layers is 9-15, preferably 14, the thickness is 3-5 nm, preferably 5nm, and the thickness of the carbon nanotube is 10-30 μm, preferably 20 μm.

Preferably, the counter electrode flexible substrate is made of polydimethylsiloxane, and the thickness of the counter electrode flexible substrate is 0.8-1.5 mm, preferably 1.0 mm. The polydimethylsiloxane flexible substrate is introduced into the organism nondestructive blood sugar detection device, so that the device has good flexibility, can be better attached to the skin of a human body without being damaged, and can be used for preparing a wearable human body nondestructive blood sugar detection device.

A preparation method of the organism nondestructive blood sugar detection device specifically comprises the following steps:

(a) sequentially growing a plurality of continuous graphene films, plating catalyst layers and buffer layers and growing oriented carbon nanotube arrays on the surface of the pretreated nickel fiber fabric, then etching to remove the nickel fiber fabric, the catalyst layers and the buffer layers, and cleaning and drying to obtain the graphene/carbon nanotube composite fiber fabric;

(b) directly transferring the graphene/carbon nanotube composite fiber fabric obtained in the step (a) to the surface of a flexible substrate of a working electrode, fixing the graphene/carbon nanotube composite fiber fabric by adopting silver colloid, loading glucose oxidase on the graphene/carbon nanotube composite fiber fabric, and drying to obtain the working electrode;

(c) directly transferring the graphene/carbon nanotube composite fiber fabric obtained in the step (a) to the surface of a flexible substrate of a counter electrode, fixing the graphene/carbon nanotube composite fiber fabric by using silver glue, and plating a silver/silver chloride film on the graphene/carbon nanotube composite fiber fabric by using an electrodeposition method twice to obtain the counter electrode;

(d) and (c) placing the working electrode obtained in the step (b) and the counter electrode obtained in the step (c) side by side to obtain the organism nondestructive blood sugar detection device.

Preferably, in the step (a), the nickel fiber fabric has a mesh number of 100 meshes, a diameter of 100 μm and an area of 0.75-1.5 cm²。

Preferably, in the step (a), the pretreatment process of the nickel fiber fabric is specifically as follows: ultrasonically cleaning in acetone for 5-10 min, washing with deionized water and ethanol for 3-5 times, and finally drying at 60-80 ℃ for 10-20 min.

Preferably, in the step (a), when a chemical vapor deposition method is adopted to grow the continuous multilayer graphene film, a mixed gas of argon and hydrogen is used as a carrier gas, methane is used as a carbon source, the reaction temperature is 950-1050 ℃, and the growth time is 2-15 min.

Preferably, when the continuous multilayer graphene film is grown by adopting a chemical vapor deposition method, the volume ratio of argon, hydrogen and methane is 20 (2-8) to (2-5), and preferably 20:4: 3.

Preferably, in step (a), the catalyst layer is plated by evaporation anda buffer layer with a vapor deposition pressure of (8-30) x 10^-4Pa, preferably 8X 10^-4Pa, the speed of evaporating the catalyst layer is 0.3-0.7 nm/s, preferably 0.5nm/s, and the speed of evaporating the buffer layer is 2-3 nm/s, preferably 2.5 nm/s.

Preferably, in the step (a), the composition of the catalyst layer is Fe, and the composition of the buffer layer is Al₂O₃。

Preferably, in the step (a), the thickness ratio of the catalyst layer to the buffer layer is (0.05-0.15): 1, preferably 0.1: 1.

Preferably, in the step (a), when the oriented carbon nanotube array is grown by a chemical vapor deposition method, a mixed gas of argon and hydrogen is used as a carrier gas, ethylene is used as a carbon source, a reaction temperature is 740 to 760 ℃, and a growth time is 2 to 10 min.

Preferably, when the oriented carbon nanotube array is grown by using a chemical vapor deposition method, the volume ratio of argon, hydrogen and ethylene is 40 (4-12) to (1-3), and preferably 40:8: 2.

The chemical vapor deposition method is a common method for growing graphene or carbon nanotubes, and the graphene or carbon nanotubes grown by the method have fewer impurities and structural defects, so the graphene or carbon nanotubes have good conductivity and biocompatibility and can be used as electrode materials of biosensors.

Preferably, in the step (a), a mixed solution of ferric chloride and nitric acid (deionized water is used as a solvent) is used as an etching solution to etch the nickel fiber fabric, the catalyst layer and the buffer layer for 1-3 hours, preferably 2 hours.

Preferably, in the step (a), the molar concentration ratio of the ferric chloride to the nitric acid is (1-3): 3, and preferably 1: 3.

Preferably, in the step (a), the drying temperature is 70-85 ℃, and the drying time is 30-60 min.

Preferably, in the step (b), glucose oxidase is loaded by using a dropping method and a phosphate buffer solution of glucose oxidase, and the dropping volume of the phosphate buffer solution of glucose oxidase is 50-100 [ mu ] L/(0.1-0.2 cm)²Graphene/carbon nanotube composite fiber fabric), preferably 100 μ L/0.15cm²Graphene/carbon nanotube composite fiber fabric.

Preferably, in the step (b), the mass concentration of the glucose oxidase in the phosphate buffer solution of the glucose oxidase is 40-60 mg mL^-1。

Preferably, in step (b), the drying is carried out at normal temperature and low pressure, the low pressure being-50 to-70 kPa. The low pressure drying avoids the activity reduction of the glucose oxidase.

Preferably, in step (b), the working electrode flexible substrate is prepared by the following steps: uniformly mixing polydimethylsiloxane and a curing agent according to the mass ratio of (5-10) to 1, preferably 10:1, and heating and curing at 70-80 ℃ for 40-60 min to obtain the composite material. The polydimethylsiloxane and the curing agent are both purchased from Dow Corning company and used in combination, and the type of the curing agent is 184.

Preferably, in the step (c), the counter electrode flexible substrate is prepared by the following steps: uniformly mixing polydimethylsiloxane and a curing agent according to the mass ratio of (5-10) to 1, preferably 10:1, and heating and curing at 70-80 ℃ for 40-60 min to obtain the composite material. The polydimethylsiloxane and the curing agent are both purchased from Dow Corning company and used in combination, and the type of the curing agent is 184.

Preferably, in the step (c), the process of plating the silver/silver chloride film is specifically as follows: firstly, taking a silver electrode as an anode, taking a graphene/carbon nanotube composite fiber fabric as a cathode, taking a mixed solution of potassium nitrate and silver nitrate (a solvent is deionized water) as an electrolyte, plating a silver film on the graphene/carbon nanotube composite fiber fabric, then taking the silver-plated graphene/carbon nanotube composite fiber fabric as a working electrode, taking a platinum wire as a counter electrode, taking a saturated calomel electrode as a reference electrode, and taking a mixed solution of potassium chloride and hydrochloric acid (a solvent is deionized water) as an electrolyte, and chlorinating the silver film to obtain the graphene/carbon nanotube/silver chloride composite fiber fabric. Preferably, in the mixed solution of potassium nitrate and silver nitrate, the molar concentration ratio of potassium nitrate to silver nitrate is (500-1500): 3-7, and preferably the molar concentration ratio of potassium nitrate to silver nitrate is 200: 1. More preferably, the molar concentration of potassium nitrate is 0.5 to 1.5mol L^-1The molar concentration of silver nitrate is 3-7 mmol L^-1。

Preferably, the molar concentration ratio of the potassium chloride to the hydrochloric acid in the mixed solution of the potassium chloride and the hydrochloric acid is (50-150): (5-15), and preferably the molar concentration ratio of the potassium chloride to the hydrochloric acid is 10: 1. More preferably, the molar concentration of the potassium chloride is 0.05-0.15 mol L^-1The molar concentration of the hydrochloric acid is 5-15 mmol L^-1。

The method comprises the following steps of growing a graphene/carbon nanotube composite fiber fabric on a nickel fiber fabric by a secondary chemical vapor deposition method, etching the nickel fiber fabric, a catalyst layer and a buffer layer, transferring the graphene/carbon nanotube composite fiber fabric to a flexible substrate, loading glucose oxidase on the surface of the graphene/carbon nanotube composite fiber fabric by a dripping coating method and a normal-temperature low-pressure drying method, constructing a working electrode of a biological body-nondestructive blood glucose detection device, plating a silver/silver chloride film on the graphene/carbon nanotube composite fiber fabric to obtain a counter electrode, forming a two-electrode system, and calculating the responsiveness of the device to a glucose solution by the following formula when the two-electrode system is used for measuring the glucose concentration: s (. mu.A mM)^-1cm^-2)＝ΔI(μA)/[Δc(mM)×A(cm²)]Wherein, S is sensitivity, Delta I is response current variation, Delta c is glucose concentration variation, and A is electrode area. Likewise, the invention can calculate the lowest detection limit of the device by the following formula: l is_oD3.3 σ/S, wherein L_oDAt the lowest detection limit, S is the slope of the linear relationship between the on-demand response current and the glucose concentration, and σ is the standard deviation of the data sets.

According to the invention, the glucose oxidase is loaded on the surface of the graphene/carbon nanotube composite fiber fabric in a normal-temperature low-pressure drying mode, and under a low-pressure environment, the carbon nanotubes can enter a protein shell of the glucose oxidase to serve as a redox medium between the glucose oxidase and an electrode to transmit electrons, so that the glucose oxidase and the electrode have good charge transmission, and the device has high sensitivity (12.39 muA muM)^-1cm^-2) Moreover, the glucose oxidase is not easy to fall off, thereby overcoming the defect that the glucose oxidase is difficult to straightenAnd the problem of electron transmission to the surface of the electrode is solved, the load process of the glucose oxidase is simplified, and other substances are not required to be coated to protect the glucose oxidase, so that the conductivity of the electrode is not reduced, and in addition, the carbon nano tube directly grows on the surface of the graphene to accelerate the transmission of charges, so that the device has good sensitivity. Therefore, the two-electrode system organism nondestructive testing blood sugar detection device provided by the invention has good stability, and the response current is still 80.8% of the initial response current after continuous testing for 15 days. Meanwhile, the two-electrode system organism nondestructive blood sugar detection device provided by the invention has good flexibility, the detection result is hardly influenced under different bending angles (0-90 degrees), 99.43% of response current retention rate can be kept, 90.94% of response current retention rate is still obtained after continuous bending for 50 times at 60 degrees, and good bending stability is obtained, because the graphene/carbon nanotube composite fiber fabric and the polydimethylsiloxane substrate have good flexibility, so that the device has excellent flexibility stability.

The invention combines the reverse iontophoresis method, can be used for measuring the blood sample detection of organisms including pigskin, nude mouse and human body, and particularly extracts the subcutaneous interstitial fluid of the human body to the skin surface, the glucose oxidase on the working electrode and the glucose in the glucose generate enzymatic reaction, the purpose of nondestructively detecting the blood sugar of the human body is realized by testing the electron transfer amount in the reaction process, the linear relation between the response current and the glucose concentration is established by in vitro experiments, and the device is attached to the skin surfaces of the nude mouse and volunteers for detection, and the experimental result shows that the two-electrode system organism nondestructive blood sugar detection device can realize accurate and nondestructive human blood sugar detection.

Compared with the prior art, the beneficial effects and originality of the invention are mainly embodied in the following aspects:

(1) the two-electrode system organism nondestructive blood sugar detection device designed by the invention greatly simplifies the structure of the device (the existing device structure is mostly a three-electrode system); and the relation between the simulated interstitial fluid and the instant response current is directly established through in vitro experiments, so that the result calculation process is simplified, and the blood sugar level can be quickly obtained. The invention realizes accurate and nondestructive human blood sugar detection and has great practical application value.

(2) According to the invention, the graphene/carbon nanotube composite fiber fabric is used as the conductive substrate of the organism nondestructive blood glucose detection device, and the carbon nanotube can be used as an oxidation-reduction medium between glucose oxidase and an electrode while the rapid electron transmission rate is achieved, so that the complex operation of glucose oxidase fixation is simplified, and the use of substances with poor conductivity to protect the glucose oxidase is avoided, so that the device has high sensitivity.

Drawings

Fig. 1a and 1b are scanning electron microscope photographs of graphene/carbon nanotube composite fiber fabrics at different magnifications;

FIG. 2 is a Raman spectrum of the graphene/carbon nanotube composite fiber fabric;

FIG. 3 is an infrared spectrum of a graphene/carbon nanotube composite fiber fabric, glucose oxidase, and a graphene/carbon nanotube/glucose oxidase composite fiber fabric;

fig. 4 is a scanning electron microscope photograph of the graphene/carbon nanotube/silver chloride composite fiber fabric;

FIG. 5a is a graph of the instantaneous current response of a two-electrode system biological non-destructive glucose testing device to different glucose concentrations;

FIG. 5b is a graph showing the relationship between the instantaneous current and the glucose concentration of the two-electrode system biological nondestructive blood glucose test device responding to different glucose concentrations;

FIG. 6 shows a two-electrode system for a 5mmol L non-destructive blood glucose test device for fifteen consecutive days^-1The instant response current change curve of the glucose solution;

FIG. 7a shows a two-electrode system for nondestructive blood glucose test of a living body with 5mmol L^-1The instant response current change curve of the glucose solution;

FIG. 7b is the result of the stability test of the two-electrode system organism nondestructive blood glucose test device after being continuously bent 50 times at a bending angle of 60 °;

FIG. 8 is a linear relationship between the response current and the glucose concentration in the simulated interstitial fluid, which is established in the in vitro experiment of the two-electrode system organism nondestructive blood glucose detection device;

FIG. 9a is a graph showing the response current with time after injecting a 10 wt% glucose solution into nude mice;

FIG. 9b is a graph comparing the change of blood glucose level with time after injecting a 10 wt% glucose solution into nude mice measured by a commercial blood glucose meter and by a bio-based non-destructive blood glucose test device;

FIG. 10a is a graph of response current versus time for a two-electrode system biological non-destructive blood glucose monitor device monitoring blood glucose levels in a volunteer for eight consecutive hours;

FIG. 10b is a graph of blood glucose concentration over time for a volunteer monitored for eight consecutive hours by a two-electrode system biological non-destructive blood glucose test device;

FIG. 11 is a schematic view showing the structure of a device for non-destructive examination of blood glucose in living body.

In the figure: 1-a working electrode; 101-graphene/carbon nanotube/glucose oxidase composite fiber fabric; 102-a working electrode flexible substrate; 2-a counter electrode; 201-graphene/carbon nanotube/silver chloride composite fiber fabric; 202-counter electrode flexible substrate.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.