CN110044986B

CN110044986B - Glucose monitoring probe

Info

Publication number: CN110044986B
Application number: CN201811640898.3A
Authority: CN
Inventors: 方骏飞; 夏斌; 赵瑜
Original assignee: Shenzhen Guiji Sensing Technology Co ltd; Shenzhen Sibionics Technology Co Ltd
Current assignee: Shenzhen Guiji Sensing Technology Co ltd; Shenzhen Silicon Bionics Technology Co ltd
Priority date: 2017-12-29
Filing date: 2018-12-29
Publication date: 2020-05-05
Anticipated expiration: 2038-12-29
Also published as: CN209878658U; CN110044986A; CN209878659U

Abstract

The present disclosure relates to a working electrode of a glucose monitoring probe, which includes: a base layer; a glucolase sensing layer formed on the base layer and having a glucolase capable of chemically reacting with glucose; a semipermeable membrane formed on the glucose enzyme sensing layer for controlling the passing rate of glucose molecules; and a biocompatible membrane formed on the semipermeable membrane, wherein a porous nanoparticle layer that catalyzes a glucose reaction is provided between the base layer and the glucosidase sensing layer, and the glucosidase permeates the nanoparticle layer. According to the glucose monitoring probe, the working voltage of the working electrode can be reduced, the interference is reduced, the service life of the glucose monitoring probe is prolonged, and the reaction sensitivity to glucose is improved.

Description

Glucose monitoring probe

Technical Field

The disclosure relates to the field of glucose monitors, in particular to a glucose monitoring probe.

Background

Biosensors are analytical devices that tightly bind biological, biologically derived, or biomimetic materials to optical, electrochemical, temperature, piezoelectric, magnetic, or micromechanical physicochemical sensors or sensing microsystems. To date, the most commercially successful biosensor used is the amperometric enzyme glucose sensor. The market share of amperometric enzyme glucose sensors occupies almost 85% of today's global market. Amperometric enzyme glucose sensors are used to detect diabetes, and the larger the market share, the more people with diabetes are reflected.

Diabetes is a series of metabolic disorder syndromes of sugar, protein, fat, water, electrolyte and the like, and is caused by hypofunction of pancreatic islets, insulin resistance and the like caused by the action of various pathogenic factors such as genetic factors, immune dysfunction, microbial infection and toxins thereof on organisms. If diabetes is not well controlled, complications such as ketoacidosis, lactic acidosis, chronic renal failure and retinopathy may arise. With the increasing incidence of diabetes, diabetes has become a public health problem worldwide.

At present, no radical cure method is available for diabetes, and only a control method is available. For diabetic patients, if the patients can monitor glucose continuously in real time on a daily basis, the occurrence of complications such as low glucose and high glucose in insulin-dependent diabetic patients can be reduced and reduced preferentially.

Typically, glucose monitoring is accomplished by a glucose meter in an amperometric enzyme glucose sensor. The sensing probe of a glucose meter is generally implanted in the body to monitor the glucose concentration in interstitial fluid and the rate of change of the glucose concentration in the surrounding blood flow, metabolism and blood vessels. Studies have shown that glucose concentration changes in interstitial fluid are generally delayed from glucose concentration changes in blood by 2-45 minutes with an average delay of about 6.7 minutes. However, when the glucose concentration in the blood begins to decrease, the glucose concentration in the interstitial fluid first decreases compared to the glucose concentration in the blood, indicating that a decrease in glucose concentration in the interstitial fluid can be predicted for an impending low glucose.

With the development of the technological level, various portable glucose monitors are introduced into the eyes of people, and especially some implantable continuous glucose monitoring devices are favored by diabetics and hospitals. However, implantable continuous glucose meters tend to have a short lifetime and are susceptible to immune reactions in the body and to other impurities in the blood that reduce sensitivity. Therefore, how to better construct the detection device, prolong the service life of the sensing probe of the glucose detector and reduce the influence of other factors becomes the biggest problem at present.

Disclosure of Invention

The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a working electrode of a glucose monitoring probe that extends the service life of the probe, reduces interference, and improves sensitivity of a reaction to glucose.

To this end, one aspect of the present disclosure provides a working electrode of a glucose monitoring probe, comprising: a base layer; a glucolase sensing layer formed on the base layer and having a glucolase capable of chemically reacting with glucose; a semipermeable membrane formed on the glucose enzyme sensing layer for controlling the passing rate of glucose molecules; and a biocompatible membrane formed on the semi-permeable membrane, wherein a porous nanoparticle layer that catalyzes a glucose reaction is provided between the substrate layer and the glucosidase sensing layer, and the glucosidase permeates the nanoparticle layer.

In an aspect of the disclosure, the nanoparticle layer is disposed between the substrate layer and the glucosidase sensing layer. Under the condition, the catalytic action of the nanoparticles on the glucose reaction enables the working voltage required by the normal work of the working electrode to be reduced, and the interference of the current generated by the electrochemical reaction of the electroactive substances under partial high voltage on the working electrode is reduced; meanwhile, the reaction sensitivity of the probe to glucose is improved, the linear range of the response of the probe to the glucose is enlarged, and the service life of the probe is prolonged.

In one aspect of the disclosure, the working electrode of the glucose monitoring probe further includes a reference electrode, and the reference electrode and the working electrode have a potential difference. Thus, the reference electrode and the working electrode form a potential difference, and the electrode potential applied by the working electrode is accurately grasped.

In the working electrode of the glucose monitoring probe according to one aspect of the present disclosure, a nanofiber three-dimensional network structure is disposed between the glucosidase sensing layer and the nanoparticle layer. Therefore, a large amount of the glucolase can be better fixed, so that the glucolase can be more firmly fixed in a three-dimensional network structure, and the utilization rate of the glucolase is improved.

In a working electrode of a glucose monitoring probe according to an aspect of the present disclosure, the semi-permeable membrane includes a diffusion-controlling layer that controls diffusion of glucose molecules. In this case, when glucose molecules in interstitial fluid or blood enter the semipermeable membrane, the number of glucose molecules is reduced in a certain proportion, so that when glucose reacts with the glucose-enzyme sensing layer, the glucose-enzyme sensing layer is in an excessive state, the glucose concentration becomes the only factor for limiting the current of the working electrode, and the linear range of the glucose monitoring probe in monitoring the glucose concentration is expanded.

In a working electrode of a glucose monitoring probe according to an aspect of the present disclosure, the semi-permeable membrane includes an anti-interference layer that blocks non-glucose species. In this case, other components in the interstitial fluid or blood are prevented from entering the semi-permeable membrane, and the influence of other electroactive substances which can also generate current on the working electrode, which leads to inaccurate glucose detection results, is avoided.

In a working electrode of a glucose monitoring probe according to an aspect of the present disclosure, the nanoparticle layer includes metal platinum nanoparticles. This promotes the reaction between the glucosidase and glucose.

In a working electrode of a glucose monitoring probe according to an aspect of the present disclosure, the thickness of the glucose enzyme sensing layer is 0.1 μm to 100 μm. This makes it possible to provide sufficient glucosidase while ensuring sufficient reaction and firm adhesion.

In a working electrode of a glucose monitoring probe according to an aspect of the present disclosure, the probe has a lifetime of 3 days to 24 days. Therefore, patients with different requirements can conveniently select corresponding service lives.

Another aspect of the present disclosure provides a method for manufacturing a working electrode of a glucose monitoring probe, including: preparing a flexible substrate; depositing a base layer on the flexible substrate, and depositing a nanoparticle layer on the base layer; coating a glucolase sensing layer capable of reacting with glucose on the nanoparticle layer; forming a semi-permeable membrane for controlling the passing rate of glucose molecules on the glucose enzyme sensing layer; and a biocompatible membrane is formed on the semi-permeable membrane.

In another aspect of the present disclosure, a nanoparticle layer for catalyzing a glucose reaction is deposited on the prepared substrate layer. Therefore, the working voltage of the working electrode is reduced, the interference of other factors is reduced, the reaction sensitivity of the probe to glucose is improved, the linear range of the response of the probe to the glucose is enlarged, and the service life of the probe is prolonged.

In the method for manufacturing the working electrode of the glucose monitoring probe, the nanofiber three-dimensional network is arranged on the nanoparticle layer. Thereby, the glucolase can be better attached to the nanoparticles.

Still another aspect of the present disclosure provides a glucose monitoring probe having the working electrode of any one of the glucose monitoring probes described above.

According to the present disclosure, it is possible to provide a working electrode of a glucose monitoring probe that extends the service life of the probe, reduces interference, and improves the sensitivity of the reaction to glucose, and a glucose monitoring probe using the working electrode.

Drawings

Fig. 1 is a schematic diagram showing a use state of a glucose monitoring probe according to an embodiment of the present disclosure.

Fig. 2 is a schematic diagram showing the structure of a glucose monitoring probe according to an embodiment of the present disclosure.

FIG. 3 is a schematic diagram showing the glucose monitoring probe of FIG. 2 in a bent state.

Fig. 4 is a schematic diagram showing the structure of the working electrode of the glucose monitoring probe according to the embodiment of the present disclosure.

Fig. 5 is a schematic diagram illustrating a glucose response of a glucose monitoring probe with tissue according to an embodiment of the present disclosure.

Fig. 6 is a schematic diagram showing the structure of a semipermeable membrane of a working electrode of a glucose monitoring probe according to an embodiment of the present disclosure.

Fig. 7 is a schematic diagram illustrating a method of manufacturing a working electrode of a glucose monitoring probe according to an embodiment of the present disclosure.

Fig. 8 is a flowchart illustrating a method for manufacturing a working electrode of a glucose monitoring probe according to an embodiment of the present disclosure.

Fig. 9 is a flowchart illustrating a method for manufacturing a semipermeable membrane for a working electrode of a glucose monitoring probe according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals, and redundant description thereof is omitted. The drawings are schematic and the ratio of the dimensions of the components and the shapes of the components may be different from the actual ones.

In addition, the headings and the like referred to in the following description of the present disclosure are not intended to limit the content or scope of the present disclosure, but merely serve as a reminder for reading. Such a subtitle should neither be understood as a content for segmenting an article, nor should the content under the subtitle be limited to only the scope of the subtitle.

Fig. 1 is a schematic diagram showing a use state of a glucose monitoring probe according to an embodiment of the present disclosure. Fig. 2 is a block diagram illustrating a glucose monitoring probe according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram showing the glucose monitoring probe of FIG. 2 in a bent state.

In the present embodiment, the glucose monitoring probe 1 may be referred to as an implantable glucose monitoring probe, a probe 1 of a glucose monitor, or a probe 1.

In this embodiment, the portable glucose monitor G may include a glucose monitoring probe 1 and an electronic system 2 connected to the glucose monitoring probe 1. Through implanting the body surface with the glucose monitoring probe 1 of portable glucose monitor G, with the tissue fluid contact of body surface to can utilize the glucose concentration signal of 1 sensing tissue fluid of glucose monitoring probe, through giving electronic system 2 with this glucose concentration signal transmission, thereby can obtain corresponding glucose concentration.

Specifically, a part (particularly, a sensing part) of the glucose monitoring probe 1 may be implanted on, for example, the body surface of a human body to be in contact with interstitial fluid in the body. In addition, another part of the glucose monitoring probe 1 is also connected with an electronic system 2 positioned on the body surface. When the portable glucose monitor G is in operation, the glucose monitoring probe 1 reacts with tissue fluid in the body to generate a sensing signal (e.g., a current signal) and transmits the sensing signal to the electronic system 2 on the body surface, and the electronic system 2 processes the sensing signal to obtain the glucose concentration. Although fig. 1 shows the arrangement position of the glucose monitoring probe 1, the present embodiment is not limited thereto, and the glucose monitoring probe 1 may be arranged on the abdomen, waist, legs, and the like, for example.

In the present embodiment, although the glucose monitoring probe 1 directly detects glucose in interstitial fluid, the glucose concentration in interstitial fluid and the glucose concentration in blood are strongly correlated, and the glucose concentration in blood can be determined from the glucose in interstitial fluid.

In the present embodiment, the glucose monitoring probe 1 may include a substrate S, and a working electrode 10, a reference electrode 20, and a counter electrode 30 (see fig. 2) provided on the substrate S. In addition, the glucose monitoring probe 1 may further include a contact 40 connected to the working electrode 10 via a lead, a contact 50 connected to the working electrode 20 via a lead, and a contact 60 connected to the working electrode 30 via a lead. In some examples, the glucose monitoring probe 1 may be connected with the electronic system 2 via

contacts

40, 50, and 60.

In some examples, the substrate S may be a flexible substrate. The flexible substrate may be substantially made of at least one of Polyethylene (PE), polypropylene (PP), Polyimide (PI), Polystyrene (PS), polyethylene terephthalate (PET), polyethylene naphthalate (PEN). In addition, in other examples, the flexible substrate may also be made of substantially metal foil, ultra-thin glass, a single-layer inorganic thin film, a multi-layer organic thin film, a multi-layer inorganic thin film, or the like.

In some examples, the substrate S may also be a non-flexible substrate. The non-flexible substrate may generally comprise a less conductive ceramic, alumina, silica, or the like. In this case, the glucose monitoring probe 1 with the non-flexible substrate may at the same time have a sharp point or a sharp edge, so that the glucose monitoring probe 1 can be implanted into the skin (e.g., the superficial layer of the skin, etc.) without the need for an auxiliary implantation device (not shown).

In the present embodiment, for convenience of explanation, the glucose monitoring probe 1 may be divided into a connection part 1a and an implantation part 1b (see fig. 3). The line A-A' in FIG. 3 generally shows the approximate location of the skin when the glucose monitoring probe 1 is implanted on the body surface of a tissue.

In addition, in some examples, both the connection portion 1a and the implantation portion 1b may include a flexible substrate, but the present embodiment is not limited thereto, and for example, only the implantation portion 1b may include a flexible substrate while the connection portion 1a includes a non-flexible substrate such as a rigid substrate.

In the present embodiment, the implanted portion 1b of the glucose monitoring probe 1 may be provided in a puncture needle (not shown), and the implanted portion 1b may be separable from the puncture needle. Specifically, it is possible to pierce the piercing needle into the tissue, and then to withdraw and separate the piercing needle from the implanted portion 1b of the glucose monitoring probe 1, whereby the implanted portion 1b is left at the superficial layer of the skin and the electronic system 2 is brought into close contact with the skin surface to which the connection portion 1a (see fig. 3) of the glucose monitoring probe 1 is connected to the electronic system 2 and located.

In this embodiment, the puncture needle may have a notch, and the implanted portion 1b is placed in the notch of the puncture needle. Wherein, the puncture needle is made of stainless steel. In this case, the risk of use of the puncture needle is reduced, and the puncture needle has sufficient hardness to facilitate skin puncture. Is beneficial to the use of patients. Additionally, in some examples, the needle may also be made of plastic, glass, or metal. Thus, the manufacturing cost of the puncture needle can be controlled.

In this embodiment, an auxiliary implanting device (not shown), such as a needle assist device, may be used to pierce the piercing needle into the skin. Under the condition, the puncture depth can be configured in advance by using the needle assisting device, and the purposes of quick puncture, painless puncture and the like are realized by using the needle assisting device, so that the pain of a user is reduced. In addition, one-handed operation is also facilitated by the auxiliary implantation device. However, the present embodiment is not limited to this, and for example, when the glucose monitoring probe 1 is a rigid substrate, the glucose monitoring probe 1 may be implanted in the skin without the use of a puncture needle.

In the present embodiment, the depth of the glucose monitoring probe 1 implanted under the skin is determined according to the position to be penetrated, and when the fat layer is thick, the glucose monitoring probe is implanted deeper, for example, the abdomen of a human body, and the implantation depth is about 10mm to 15 mm. When the fat layer is thinner, the implantation depth is shallower, for example, at the arm, and the implantation depth is about 5mm to 10 mm.

The present embodiment is not limited thereto, and for example, the implanted portion 1b and the connecting portion 1a may be entirely penetrated into the shallow layer of the skin, and in this case, the width of the connecting portion 1a may be limited to about 2mm or less, and in addition, the width of the connecting portion 1a may be limited to about 0.5mm or less. In this case, not only is it possible to make the connecting portion 1a more easily insertable into the skin, but also the width of the implanted portion 1b can be limited by limiting the width of the connecting portion 1 a. Generally, the narrower the width of the glucose monitoring probe 1, the less pain the user will experience during and after implantation.

In the present embodiment, as shown in fig. 2, the glucose monitoring probe 1 may include a working electrode 10, and specifically, as shown in fig. 3, the implanted portion 1b may include the working electrode 10.

Fig. 4 is a schematic diagram showing the structure of the working electrode of the glucose monitoring probe according to the embodiment of the present disclosure. Fig. 5 is a schematic diagram illustrating a glucose response of a glucose monitoring probe with tissue according to an embodiment of the present disclosure. Fig. 6 is a schematic diagram showing the structure of a semipermeable membrane on a working electrode of a glucose monitoring probe according to an embodiment of the present disclosure.

In this embodiment, the working electrode 10 includes a substrate layer 110, a nanoparticle layer 120, a glucolase sensing layer 130, a semi-permeable membrane 140, and a biocompatible membrane 150 (see fig. 4). In some examples, the substrate layer 110, the nanoparticle layer 120, the glucolase sensing layer 130, the semi-permeable membrane 140, and the biocompatible membrane 150 may be sequentially stacked.

In this embodiment, the base layer 110 may be electrically conductive. In some examples, the base layer 110 may be made of at least one selected from gold, glassy carbon, graphite, silver chloride, palladium, titanium, iridium. In this case, the base layer 110 has good conductivity, and the electrochemical reaction of the base layer 110 can be suppressed, thereby improving the stability of the base layer 110.

In the present embodiment, the base layer 110 may be disposed on the substrate by a deposition or plating method in some examples. In some examples, the method of deposition may include physical vapor deposition, chemical vapor deposition, and the like. The plating method may include electroplating, electroless plating, vacuum plating, and the like. Additionally, in some examples, the base layer 110 may also be disposed on the substrate S by screen printing, extrusion, or electrolytic deposition, among others.

In this embodiment, the base layer 110 may be provided on a flexible substrate. Under the condition, the flexible substrate enables the whole product to be light and convenient, has strong shock resistance and reduces foreign body sensation after implantation. In other examples, the base layer 110 may also be disposed on a rigid substrate.

In the present embodiment, as shown in fig. 4, a nanoparticle layer 120 may be disposed on the substrate layer 110. That is, between the substrate layer 110 and the glucosidase sensing layer 130, the nanoparticle layer 120 may be disposed. In this case, the nanoparticles of platinum metal catalyze the reaction of glucose oxidase or dehydrogenase with glucose, reducing the operating voltage required for the reaction and increasing the reaction rate.

In some examples, the nanoparticle layer 120 may be porous. In this case, the glucosidase in the glucosidase sensing layer may penetrate into the nanoparticle layer 120, and thus, the nanoparticle layer 120 may be able to sufficiently contact and catalyze the reaction of a product (e.g., hydrogen peroxide) during the glucose reaction, thereby being able to more effectively promote the glucose reaction.

In some examples, the nanoparticles in the nanoparticle layer 120 are made of metallic platinum. In other examples, the nanoparticle layer 120 may also be composed of at least one of titanium, gold, and carbon. In this case, the nanoparticle layer 120 may also function to catalyze the redox reaction.

In the present embodiment, the thickness of the nanoparticle layer 120 is about 100nm to 2 μm, and preferably 500nm to 2 μm. In one example, the nanoparticle layer 120 may be, for example, about 1 μm.

In the present embodiment, the nanoparticle layer 120 may be disposed on the substrate layer 110 by deposition. However, the present embodiment is not limited to this, and may be provided on the base layer 110 by plating, electroless plating, evaporation, printing, extrusion, or the like.

In the present embodiment, the glucose enzyme sensing layer 130 may be a glucose oxidase sensing layer or a glucose dehydrogenase sensing layer. In some examples, as shown in fig. 4, a glucosidase sensing layer 130 may be coated on the nanoparticle layer 120.

Following, in conjunction with FIG. 5, with GO_X(FAD) As an example of glucose oxidase, the reaction occurring in the glucose sensing layer 130 will be described.

In the glucose sensing layer 130, when GO_X(FAD) when it encounters glucose in the tissue, the following reactions occur:

glucose + GOx (FAD) → gluconolactone + GOx (FADH)₂) … … reaction formula (I)

GOx(FADH₂)+O₂→GOx(FAD)+H₂O₂… … reaction formula (II)

As can be seen in the above reaction process, oxygen (O) is generated in the chemical reaction₂) Is consumed, O₂The reaction rate of the reaction of the formula (II) and the formula (I) is limited by O₂The reaction with tissue glucose may slow, resulting in failure of the glucose monitoring probe 1. In addition, in the above reaction process, in the reaction formula (II)Has H₂O₂Product of (A), H₂O₂This accumulation may decrease the enzyme activity in the sensing layer and may also lead to failure of the glucose monitoring probe 1. Therefore, by providing the nanoparticle layer 120 between the base layer 110 and the glucosidase sensing layer 130, H can be caused to react with the nanoparticle layer 120 acting as a catalyst₂O₂Decomposition reaction occurs, and the specific reaction is as follows:

H₂O₂→2H⁺+O₂+2e^-… … reaction formula (III)

The reaction with tissue glucose can be continued by the above reaction formulae (I) to (III). In addition, the nanoparticle layer is used to catalyze the hydrogen peroxide decomposition reaction, thereby accelerating the reaction (III) and reducing the voltage to be applied during the reaction, which is advantageous for improving the sensitivity of the glucose monitoring probe 1, prolonging the service life of the glucose monitoring probe 1, and obtaining a low operating voltage. In other words, through the nanoparticle layer 120, a high-sensitivity sensing signal of tissue glucose can be continuously obtained, the service life of the glucose monitoring probe 1 is prolonged, and meanwhile, the low working voltage is beneficial to improving the anti-interference performance.

In some examples, glucose oxidase or dehydrogenase may also be disposed in the conductive polymer nanofiber three-dimensional network, i.e., the nanofiber three-dimensional network is disposed between the nanoparticle layer 120 and the glucosidase sensing layer 130. This increases the adhesion of glucose oxidase or dehydrogenase to the nanoparticle layer 120, and increases the amount of glucose oxidase or dehydrogenase immobilized.

In some examples, the glucose oxidase or dehydrogenase may also be disposed on carbon nanotubes, wherein the carbon nanotubes are disposed on the nanoparticle layer 120. Thereby, the adhesion and fixation amount of glucose oxidase or dehydrogenase on the nanoparticle layer 120 are increased.

In other examples, the glucose oxidase or dehydrogenase may also be disposed on graphene, porous titanium dioxide, or a conductive organic salt. Thereby, the adhesion and immobilization amount of glucose oxidase or dehydrogenase on the nanoparticle layer 120 is increased.

In the present embodiment, the glucose monitoring probe 1 is implanted in the skin of a human body, and can continuously sample the glucose in the blood, convert the glucose into a corresponding current signal, and transmit the current signal to the electronic system 2 outside the body. In addition, sampling refers to a chemical reaction of glucose oxidase or dehydrogenase on the glucose-enzyme sensing layer 120 with glucose.

In the present embodiment, the thickness of the glucolase sensing layer 130 may be about 0.1 μm to about 100 μm, preferably about 2 μm to about 10 μm, and in one example, the thickness of the glucolase sensing layer 130 may be about 10 μm. Under the condition, the thickness of the glucose oxidase or dehydrogenase is controlled within a certain degree, so that the problems that the adhesion force is reduced due to the fact that the glucose oxidase or dehydrogenase is too much, the materials fall off in vivo, the reaction is insufficient due to the fact that the glucose oxidase or dehydrogenase is too little, and normal glucose concentration information cannot be fed back are solved.

In the present embodiment, as shown in fig. 4 and 6, the semi-permeable membrane 140 may be distributed on the glucolase sensing layer 130, that is, the semi-permeable membrane 140 may be disposed on the glucolase sensing layer 130.

In this embodiment, as shown in fig. 6, the semi-permeable membrane 140 may further include a diffusion-controlled layer 141 and a tamper-resistant layer 142 stacked on the diffusion-controlled layer 141. In some examples, diffusion-control layer 141 may be disposed outside of immunity layer 142. In the semi-permeable membrane 140, the diffusion control layer 141 may control diffusion of glucose molecules, and the interference rejection layer 142 may prevent diffusion of non-glucose species. Thus, tissue fluid or blood components passing through the semipermeable membrane 140 can be reduced, and the interference-preventing layer 142 can block the interfering substance outside the semipermeable membrane 140. Common interferents may include uric acid, ascorbic acid, acetaminophen, etc., which are ubiquitous in the body.

In other examples, not limited to the example of fig. 6, the immunity layer 142 may also be disposed outside the diffusion control layer 141. Therefore, the interference of impurities on the working electrode 10 can be reduced, the detection result is inaccurate, and the service life of the glucose monitoring probe 1 is prolonged.

In this embodiment, the semi-permeable membrane 140 can control the rate of passage of glucose molecules, i.e., the semi-permeable membrane 140 can limit the number of glucose molecules in the interstitial fluid or blood that reach the glucolase sensing layer 130. Specifically, the diffusion-controlling layer 141 of the semi-permeable membrane 140 may effectively reduce the amount of glucose that diffuses into the glucolase sensing layer 130 by a certain ratio.

In the present embodiment, the rate of reducing the amount of the entering matter by the diffusion control layer 141 is 10 to 100 times, preferably 30 to 80 times, for example, 50 times. In this case, the amount of glucose diffusing into the glucose-sensing layer can be reduced, and a sufficient amount of glucose oxidase or dehydrogenase and other substances participating in the reaction can be ensured, while the glucose concentration becomes a factor that mainly (substantially only) limits the magnitude of the electrode current, so that the magnitude of the current can correctly reflect the glucose concentration, and the linear range of the glucose monitoring probe 1 can be increased to a great extent.

In this embodiment, a biocompatible membrane 150 may be disposed on the semi-permeable membrane 140 (see fig. 4).

In some examples, the biocompatible membrane 150 may be made of a plant material. The plant material may be sodium alginate, tragacanth gum, pectin, acacia gum, xanthan gum, guar gum, agar, or derivatives of natural materials including: starch derivatives, cellulose derivatives, and the like.

In other examples, the biocompatible membrane 150 may also be made of a synthetic material. The synthetic material may be a polyolefin: povidone, polyvinyl alcohol, polyisobutylene pressure-sensitive adhesive, ethylene-vinyl acetate copolymer, and the like; it may also be a polyacrylic: acrylic resin, carboxyvinyl-sucrose, carboxyvinyl-pentaerythritol copolymer, polyacrylate pressure-sensitive adhesive and the like; or polyoxyethylenes: polyesters such as polyoxyethylene fatty acid esters and polyoxyethylene-polyoxypropylene copolymers: polylactic acid, polyglycolide-lactide, polynearyl dinonyl sebacate, polycyanoalkyl amino ester, polyether polyurethane, and the like. Therefore, the immune response of the human body to the glucose monitoring probe 1 can be reduced, and the service life of the glucose monitoring probe 1 is prolonged.

Additionally, in some examples, the semi-permeable membrane 140 may also be biocompatible. Thus, the use of the biocompatible film 150 can be avoided, and the manufacturing cost can be reduced.

In other examples, the permeability of the formed membrane to the analyte of interest may be adjusted by a modifying agent. For example, hydrophilic modifiers include: polyethylene glycol, hydroxyl or polyhydroxy modifiers. Thus, the biocompatibility of the film formed by the polymer can be increased, so as to replace the biocompatible film.

In this embodiment, the layer of biocompatible membrane 150 covers the entire glucose monitoring probe 1. This reduces the precision requirements for the process.

In some examples, the biocompatible membrane 150 covers only the implanted portion 1b of the glucose monitoring probe 1 that is implanted in the body. This can reduce the use of raw materials.

In the present embodiment, the glucose monitoring probe 1 may be used for a period of 1 to 24 days, preferably 7 to 14 days. In addition, as described above, the semi-permeable membrane 140 restricts the entrance of some glucose molecules and electroactive interfering substances and effectively expands the linear range of the probe 1, and the glucose oxidase or dehydrogenase is preferably provided in the glucose-enzyme sensing layer 130, so that the life cycle of the glucose monitoring probe 1 can be maintained stably.

In addition, the glucose monitoring probe 1 can also be used in general detection, such as word detection or short-time monitoring. For example, the monitoring time may be 1 hour to 24 hours.

In addition, the addition of the biocompatible membrane 150 enables the use period of the glucose monitoring probe 1 to be maintained from 1 day to 24 days, thereby enabling a user to conveniently select glucose monitors having glucose monitoring probes 1 with different use periods according to different needs (e.g., price, etc.).

In the present embodiment, as described above, the glucose monitoring probe 1 may further include the reference electrode 20 and the counter electrode 30 (see fig. 2). Specifically, as shown in fig. 3, the implanted portion 1b of the glucose monitoring probe 1 may include a reference electrode 20 and a counter electrode 30.

In the present embodiment, the glucose monitoring probe 1 after piercing the skin can generate a current signal by performing an oxidation-reduction reaction between glucose in interstitial fluid or blood and glucose in the working electrode 10 through a glucose oxidase or dehydrogenase, and forming a circuit with the counter electrode 30.

In this embodiment, the reference electrode 20 may form a known and fixed potential difference with the interstitial fluid or blood. In this case, the potential difference between the working electrode 10 and the tissue fluid or blood can be measured by the potential difference formed between the reference electrode 20 and the working electrode 10, so that the voltage generated by the working electrode 10 can be accurately grasped. Therefore, the electronic system 2 can automatically adjust and maintain the stability of the voltage at the working electrode according to the preset voltage value so as to ensure that the measured current signal can accurately reflect the glucose concentration value.

In addition, in the present embodiment, the working electrode 10, the reference electrode 20, and the counter electrode 30 of the implanted portion 1b are disposed in a dispersed manner, but the embodiments of the present disclosure are not limited thereto, and may include a side-by-side (parallel) arrangement.

In addition, in the present embodiment, the glucose monitoring probe 1 is not limited to a planar probe, but may be a linear probe, a probe having stacked electrodes or layered electrodes, and a probe having coplanar electrodes in which electrodes are provided on the same plane.

In some examples, the reference electrode may not be used when the potential difference between the working electrode and the interstitial fluid or blood does not fluctuate much. Thus, the manufacturing cost of the glucose monitoring probe 1 is saved.

In the present embodiment, the counter electrode 30 may be made of platinum, silver chloride, palladium, titanium, or iridium. Thereby, the electrochemical reaction at the working electrode 10 can be not affected with good conductivity. However, the present embodiment is not limited thereto, and in other examples, the counter electrode 30 may be made of at least one selected from gold, glassy carbon, graphite, silver chloride, palladium, titanium, or iridium. This can reduce the influence on the working electrode 10 while having good conductivity.

In addition, in some examples, the same material may be used for working electrode 10, counter electrode 30, and reference electrode 20.

In addition, in the present embodiment, the glucose monitoring probe 1 may include two, or three or more electrodes. For example, glucose monitoring probe 1 may include only two electrodes, working electrode 10 and counter electrode 30, and further, glucose monitoring probe 1 may include additional reference electrodes in addition to working electrode 10, reference electrode 20, and counter electrode 30. In this case, it is possible to obtain the potential difference of the working electrode and grasp the voltage of the working electrode more accurately, thereby obtaining a more accurate current.

In the present embodiment, as described above, the connection portion 1a of the glucose monitoring probe 1 includes a plurality of contacts (feelers). The number of contacts is equal to the number of electrodes of the implanted portion 1b of the glucose monitoring probe 1. The contact is connected with the electrode of the implanted portion 1b through a lead (wire).

In the present embodiment, as shown in fig. 3, the number of electrodes of the implanted portion 1b of the glucose monitoring probe 1 is three. Accordingly, the connection portion 1a includes three contacts (contact tips), which are the contact 40, the contact 50, and the contact 60, respectively. However, the present embodiment is not limited to this, and for example, the number of electrodes of the implanted portion 1b may be two or more than four electrodes, and accordingly, the connection portion 1a may include two or more than four contacts (contacts).

In the present embodiment, the

contacts

40, 50, and 60 may each have a disk shape. In other examples, the

contacts

40, 50, and 60 may also be rectangular, oval, or other irregular shapes.

In the present embodiment, the current signal generated by the implanted portion 1b of the glucose monitoring probe 1 can be transmitted to the contact of the connection portion 1a through the base layer 110 and the transmission wire. That is, the implanted portion 1b of the glucose monitoring probe 1 is connected to the connection portion 1a, and the connection portion 1a is connected to the electronic system 2 via a plurality of contacts, so that the current signal obtained by the working electrode 10 is transmitted to the electronic system 2 through the contacts of the connection portion 1a for analysis. The electronic system 2 can analyze and process the current signal to obtain a glucose concentration signal. In addition, the electronic system 2 can transmit through wireless communication modes such as Bluetooth, wifi, and the like. An external reading device (not shown) may receive the glucose concentration signal from the electronic system and display the glucose concentration value. Further, since the glucose monitoring probe 1 according to the present embodiment can achieve continuous monitoring, it is possible to achieve the purpose of continuously monitoring the human glucose concentration value for a long period of time (for example, 1 to 24 days). Additionally, in some examples, the reading device may be a reader or a cell phone APP.

In addition, in this embodiment, the glucose monitoring probe 1 and the electronic system 2 may not require calibration during in vivo use. In addition, the glucose monitoring probe 1 and the electronic system 2 may be calibrated in advance at the time of factory shipment. Thus, the user is eliminated from having to calibrate the monitoring system by finger blood on a regular basis, and the potential source of monitoring module reading errors during use is also reduced.

In the present embodiment, the electronic system 2 may be made of a flexible PCB and a flexible battery. Therefore, the skin can be attached to the skin, and the influence on the daily life of the user is reduced. In some examples, the outer shape of the electronic system 2 may be circular. In addition, in some examples, the electronic system 2 may also have a waterproof housing and a waterproof band-aid, thereby enabling use without affecting daily activities such as swimming or bathing.

In the present embodiment, the glucose monitoring probe 1 can acquire the glucose concentration in interstitial fluid or blood. However, the present embodiment is not limited to this, and for example, by changing the sensing layer on the glucose monitoring probe 1, it is possible to acquire body fluid component data other than glucose, and body fluid components such as acetylcholine, amylase, bilirubin, cholesterol, chorionic gonadotropin, creatine kinase, creatine, creatinine, DNA, fructosamine, glucose, glutamine, growth hormone, ketone body, lactate, oxygen, peroxide, prostate-specific antigen, prothrombin, RNA, thyroid stimulating hormone, troponin, and the like.

In other examples, the concentration of a drug in a bodily fluid may also be monitored, such as antibiotics (e.g., gentamicin, vancomycin, and the like), digitoxin, digoxin, theophylline, and warfarin (warfarin), among others.

In this embodiment, first, a nanoparticle layer 120 for catalyzing the reaction of glucose oxidase or dehydrogenase with glucose is disposed on a substrate layer 110 of a working electrode 10, and then a glucose enzyme sensing layer 130 is formed, a semipermeable membrane 140 coating is formed on the glucose enzyme sensing layer 130, and finally a biocompatible membrane 150 is formed on the semipermeable membrane 140 coating. Therefore, the service life of the glucose monitoring probe 1 is prolonged, the interference of other factors is reduced, and the reaction speed of the glucose monitoring probe 1 to glucose is increased.

The method of making the working electrode of the glucose monitoring probe 1 is described in detail below with reference to the accompanying drawings.

Fig. 7 is a schematic diagram illustrating a method of manufacturing a working electrode of a glucose monitoring probe according to an embodiment of the present disclosure. Fig. 8 is a flowchart illustrating a method for manufacturing the working electrode of the glucose monitoring probe 1 according to the embodiment of the present disclosure. Fig. 9 is a flowchart illustrating a method for manufacturing a semipermeable membrane for a working electrode of the glucose monitoring probe 1 according to the embodiment of the present disclosure.

In the present embodiment, the method for manufacturing the working electrode of the glucose monitoring probe 1 may include (see fig. 7 and 8): first, a conductive substrate layer 110 is deposited on a prepared flexible substrate (step S110), a nanoparticle layer 120 for catalyzing a reaction of glucose oxidase or dehydrogenase with glucose is deposited on the substrate layer 110 (step S120), a glucolase sensing layer 130 capable of reacting with glucose is coated on the nanoparticle layer 120 (step S130), a semi-permeable membrane coating 140 is formed on the glucolase sensing layer 130 (step S140), and a biocompatible membrane layer 150 is formed on the semi-permeable membrane coating 140 (step S150). Therefore, the service life of the glucose monitoring probe 1 is prolonged, the interference of external factors is reduced, and the reaction speed of the glucose monitoring probe 1 to glucose is increased.

In the present embodiment, the glucose enzyme sensing layer 130 in step S130 may be a glucose oxidase sensing layer or a glucose dehydrogenase sensing layer.

As shown in fig. 9, the manufacturing method according to the present embodiment further includes, in step S140, forming the interference preventing layer 142 on the glucose sensor layer 130 (step S141), and further forming the diffusion controlling layer 141 on the interference preventing layer (step S142). Thus, the tissue fluid or blood components passing through the semipermeable membrane 140 can be reduced by the tamper resistant layer 142, and the interfering substance can be blocked outside the semipermeable membrane 140 by the diffusion control layer 141.

In some examples, in step S140, the order of step S141 and step S142 may be interchanged. That is, the diffusion control layer may be formed on the glucose oxidase or dehydrogenase layer (step S142), and then the interference suppression layer may be formed on the interference suppression layer (step S141). Therefore, the interference of impurities on the working electrode 10 can be reduced, the inaccurate detection result can be prevented, and the service life of the glucose monitoring probe 1 can be prolonged.

The substrate layer 110 or the nanoparticle layer 120 may be formed by one or more of plating, evaporation, printing, extrusion, or the like.

In addition, the manufacturing method according to the present embodiment further includes providing a nanofiber three-dimensional network structure on the nanoparticle layer 120. Therefore, the glucose oxidase or dehydrogenase can be better attached to the nano-particles with the three-dimensional network structure of the nano-fibers.

In other examples, the nanoparticle layer 120 may be covered with a nanofiber membrane. Thereby, the requirements for the process are reduced, and the glucose oxidase or dehydrogenase can be better attached to the nanoparticles.

While the present disclosure has been described in detail in connection with the drawings and examples, it should be understood that the above description is not intended to limit the disclosure in any way. Those skilled in the art can make modifications and variations to the present disclosure as needed without departing from the true spirit and scope of the disclosure, which fall within the scope of the disclosure.

Claims

1. A working electrode of a glucose monitoring probe is characterized in that,

the disclosed device is provided with:

a base layer disposed on a flexible substrate;

a glucolase sensing layer formed on the base layer and having a glucolase capable of chemically reacting with glucose;

a semipermeable membrane formed on the glucose enzyme sensing layer for controlling the passing rate of glucose molecules; and

a biocompatible membrane formed on the semi-permeable membrane,

wherein a porous nanoparticle layer that catalyzes a glucose reaction is provided between the substrate layer and the glucosidase sensing layer, the nanoparticle layer has nanoparticles, and the glucosidase permeates into the nanoparticle layer to be attached to the nanoparticles;

and a nanofiber three-dimensional network structure is arranged between the glucolase sensing layer and the nanoparticle layer, so that the glucolase is fixed in the nanofiber three-dimensional network structure.

2. The working electrode of claim 1,

the semi-permeable membrane includes a diffusion controlling layer that controls diffusion of glucose molecules.

3. The working electrode of claim 1,

the base layer has electrical conductivity.

4. The working electrode of claim 1,

the semi-permeable membrane includes an anti-interference layer that blocks non-glucose species.

5. The working electrode of claim 1,

the nanoparticle layer comprises metallic platinum nanoparticles.

6. The working electrode of claim 1,

the thickness of the glucose enzyme sensing layer is 0.1 μm to 100 μm.

7. The working electrode of claim 1,

the service life of the probe is 1 to 24 days.

8. A glucose monitoring probe is characterized in that,

working electrode provided with a glucose monitoring probe according to any of claims 1 to 7.