CN107727723A - Ultrathin flexible glucose measuring sensor of one species skin and preparation method thereof - Google Patents

Abstract

The invention discloses a skin-like ultra-thin flexible glucose measurement sensor and a preparation method thereof. The invention prepares the pattern of nanoscale counter electrode and working electrode on the ultra-thin and flexible insulating support layer and bonding layer, forms a Prussian blue film on the pattern of the working electrode, and forms a glucose oxidase-fixed Prussian blue film on the Prussian blue film. Chitosan film, pasted on the skin surface, glucose produces hydrogen peroxide under the action of glucose oxidase, hydrogen peroxide catalyzes reaction with accumulated Prussian blue film, generates water and free electrons, and measures the reaction current to obtain the concentration of glucose The sensor of the present invention has the characteristics of ultra-thin and flexible, and can be attached to any position on the surface of the human skin, without affecting the movement of the human body and normal life, it can non-invasively and accurately measure the concentration of glucose present on the surface of the skin, and realize the anti-diabetes Non-invasive monitoring of blood glucose in patients.

Description

A skin-like ultra-thin flexible glucose measurement sensor and its preparation method

technical field

The invention relates to biosensor technology, in particular to a skin-like ultra-thin flexible glucose measurement sensor and a preparation method thereof.

Background technique

Glucose is the main component of carbohydrates in animals and plants, so the quantitative determination of glucose plays an important role in biochemistry, clinical chemistry and food analysis. In 1954, Clark's oxygen electrode analysis method made it possible to measure the oxygen partial pressure of living tissue non-destructively, thus opening the research field of biosensors. The research and development of biosensors by researchers from various countries for more than 50 years has enabled glucose sensors to be applied and played an important role in many aspects such as food analysis, fermentation control, and clinical testing. This paper makes a brief overview of the classification, principle and development of glucose biosensors. Glucose sensor is the most studied and commercialized biosensor in the field of biosensors. It is composed of glucose oxidase (glucose oxidase, GOD) after solidification and oxygen electrodes. Enzymes have high selectivity, high affinity, and can also catalyze substrate reactions under milder conditions, so they are selected as the preferred biologically active substances in biosensors. Enzyme sensors are also called enzyme electrodes because they are mostly composed of immobilized enzymes and electrochemical devices (electrodes). GOD is immobilized on a membrane that can permeate glucose and oxygen, and then fixed on the front of the oxygen electrode. When glucose exists in the solution, glucose is oxidized by GOD when it passes through the immobilized enzyme membrane. Oxygen consumption is required for the reaction to take place, and this consumption can be measured with an oxygen electrode, thus allowing the glucose content to be checked. However, changes in the partial pressure of oxygen in the atmosphere will lead to changes in the concentration of dissolved oxygen in the solution, thereby affecting the accuracy of the measurement. This is a problem to be solved in the application of the enzyme electrode glucose biosensor.

The classic glucose oxidase sensor uses a hydrogen peroxide electrode as the basic electrode, and detects the glucose content in serum by detecting the amount of H2O2 produced. The advantage is that the glucose concentration has an equivalent relationship with the produced H2O2 and is not affected by changes in the oxygen concentration in the blood. The biosensor using hydrogen peroxide as the basic electrode is the earliest biosensor.

Since the birth of the first biosensor in 1962, glucose sensors have played an important role in all stages of the development of biosensors. In terms of commercialization, the application of glucose biosensors is unmatched by any other biosensors. Now the annual production of enzyme electrodes for blood glucose testing in the world has reached billions. In the fermentation industry, glucose sensors have also been widely used in raw material analysis and remote control. In the field of research, compared with other biosensors, the proportion of papers published by the glucose sensor has always occupied the first place. In recent years, the research reports on nanometer biosensors and DNA biosensors have increased rapidly, but the proportion of glucose biosensors in the whole sensor research reports has not changed significantly. This is because many new biosensor studies are related to glucose sensors.

Contents of the invention

Aiming at the above problems in the prior art, the present invention proposes a skin-like ultra-thin flexible glucose measurement sensor and a preparation method thereof, which are used to detect the concentration of glucose present on the skin surface.

One object of the present invention is to propose a skin-like ultra-thin flexible glucose measurement sensor.

The skin-like ultra-thin flexible glucose measurement sensor of the present invention comprises: a flexible film substrate, an insulating support layer, an adhesive layer, a counter electrode, a working electrode, and a chitosan film immobilized with glucose oxidase; printing layer, an insulating support layer is formed on the transfer layer, an adhesive layer is formed on the insulating support layer, and a conductive layer is formed on the adhesive layer; the conductive layer is etched on the surface to the upper surface of the insulating support layer, and an opposite layer is formed on the conductive layer. The pattern of the electrode and the pattern of the working electrode, the pattern of the counter electrode and the pattern of the working electrode are insulated, and a Prussian blue film is formed on the pattern of the working electrode, and the pattern of the working electrode and the Prussian blue film formed on it constitute the working electrode. The pattern of the electrode is used as a counter electrode; a chitosan film immobilized with glucose oxidase is formed on the working electrode; an insulating support layer, an adhesive layer, a counter electrode, a working electrode and a chitosan film immobilized with glucose oxidase constitute a multilayer structure; the multilayer structure is peeled off from the transfer layer and transferred to the flexible film substrate; the counter electrode and the working electrode are connected to the electrochemical workstation or the measurement circuit through wires; the chitosan film immobilized with glucose oxidase is pasted on the skin On the surface, the glucose on the skin surface produces hydrogen peroxide under the action of glucose oxidase, and the hydrogen peroxide reacts catalytically with the accumulated Prussian blue film to generate water and free electrons. The number of free electrons produced is proportional to the concentration of glucose, and the free electrons The Prussian blue film is transmitted to the electrochemical workstation or the measurement circuit to form a reaction current, and the electrochemical workstation is in the measurement mode or uses the measurement circuit to measure the current generated by the reaction to obtain the concentration of glucose.

The thickness of the counter electrode and the working electrode is 100nm-1cm, and the counter electrode and the working electrode have the characteristics of being bendable and foldable. The thickness of the counter electrode and the working electrode of the present invention is small, and it is easy to attach the glucose measurement sensor to the skin, thereby ensuring that the working electrode can be closely attached to the skin surface. The shape of the working electrode and the counter electrode is a flat electrode, an interdigitated electrode or a wire electrode. The wire electrode refers to the working electrode and the counter electrode are respectively a metal wire, or an organic material filament with a conductive material layer on the surface of electroplating, electrochemical deposition, vapor deposition, or magnetron sputtering.

The counter electrode and working electrode of the present invention have transferable characteristics, that is, the multilayer structure can be peeled off from the surface of the substrate to form an independent thin film electrode, and the insulating support layer can play a role in bonding the thin film electrode and the measurement circuit. The insulation effect prevents intercommunication interference. At the same time, the insulating support layer can be used as a support layer, and the conductive layer with a thickness of nanometers can be used as a support to become an independent flexible film. The adhesive layer and the insulating support layer have strong adhesion. The conductive layer It has strong adhesion with the bonding layer, and the conductive layer and the insulating layer can be closely adhered together through the function of the bonding layer, reducing the probability of the conductive layer on the surface of the electrode falling off.

The insulating support layer adopts one of polyimide (Polyimide, PI), polyethylene terephthalate (Polyethylene terephthalate, PET) and polyvinyl alcohol (Polyvinyl Alcohol, PVA). It is prepared by spin coating or scraping film, or it is pasted and fixed on the surface of the transfer layer with a ready-made thin film insulating material, and the subsequent deposition of the adhesive layer and the conductive layer is performed. The thickness of the insulating support layer is ≤1cm.

The bonding layer is made of Cr or Pt, and the thickness is ≤0.5cm. The conductive layer is obtained by means of electroplating, electrochemical deposition, vapor deposition or magnetron sputtering; the material of the conductive layer is one of Au, Cu, Al, Ag and ITO. Forming a nanoscale microstructure on the surface of the conductive layer by means of surface etching can improve electrochemistry.

The preparation of the Prussian blue thin film adopts the pattern of the working electrode connected to the electrochemical workstation, the pattern of the working electrode is immersed in the mixed solution of KCl, K ₃ [Fe(CN) ₆ ], FeCl ₃ and HCl, and on the pattern of the working electrode Electrochemical deposition is carried out to form a Prussian blue film; or Prussian blue is made into an ink solution, and the ink is dropped on the surface of the electrode by printing, printing, spin coating, or drop coating, and the Prussian blue film can also be obtained after the ink is dried. The nano-scale Prussian blue film was obtained by means of short-term constant potential deposition. Thanks to the flexible conductive layer of the film with the surface microstructure, the oxidation-reduction potential of the Prussian blue film was obvious under the electrochemical cyclic voltammetry test. Larger, and the scanning curve is stable after multi-turn scanning. The Prussian blue film obtained after electrochemical deposition was subjected to cyclic voltammetry scanning in an electrochemical workstation, heated until the Prussian blue film was dry, and then subjected to constant potential activation at a low potential, and then cyclic voltammetric scanning was performed again. The cyclic voltammetry scan after electrochemical deposition can make the Prussian blue film undergo redox reactions at different potentials, stabilize the deposited Prussian blue film, release internal cracks and defects, and heat the film to the inside of the dried Prussian blue film The structure becomes denser, the water in the pores is removed, and the low-potential constant potential activation is performed again to improve the reactivity of the Prussian blue film near the low potential and enhance the glucose measurement effect on the body surface. The thickness of the Prussian blue film is ≤10μm.

The working electrode is connected to the electrochemical workstation or the measurement circuit through the flexible wire of the anisotropic conductive film ACF. The flexible ACF wire is a wire composed of conductive metal particles with a polymer as the base material. The cross section is flat, the thickness is small, and the flexibility is good. It can work with the flexibility of the Prussian blue film by electrochemical deposition by heating and pressing. The surface connection of the electrode will not cause the height of the working electrode to increase too much. At the same time, the characteristics of flexibility and low elastic modulus reduce the stress concentration at the connection between the flexible wire and the working electrode, preventing the bending deformation of the flexible wire or the flexible working electrode. Cause electrode rupture and wire debonding. Alternatively, the metal columnar wire is connected to the working electrode on which the Prussian blue film is electrochemically deposited by means of silver glue bonding or soldering, and is connected to the electrochemical workstation or the measuring circuit.

The surface of the working electrode forms a chitosan film with glucose oxidase fixed, and glycerol is added to the chitosan solution with glucose oxidase fixed to improve the toughness of the chitosan film formed after the chitosan solution is dried, preventing It breaks.

Another object of the present invention is to provide a method for preparing a skin-like ultra-thin flexible glucose sensor.

The preparation method of the skin-like ultra-thin flexible glucose measurement sensor of the present invention comprises the following steps:

1) Provide a clean and dry substrate;

2) Spin-coat the transfer layer on the substrate;

3) Spin coating or scraping film on the transfer layer, or use ready-made film insulation material to paste and fix on the transfer layer

The surface of the layer is used to prepare an insulating support layer;

4) sputtering the bonding layer on the insulating support layer;

5) Prepare the conductive layer by means of electroplating, electrochemical deposition, vapor deposition or magnetron sputtering on the bonding layer;

6) Surface etching the conductive layer to the upper surface of the insulating support layer, forming the pattern of the counter electrode and the pattern of the working electrode on the conductive layer

pattern, insulation between the pattern of the counter electrode and the pattern of the working electrode;

7) Form a Prussian blue film on the pattern of the working electrode, the pattern of the working electrode and the Prussian blue film formed on it

Constitute the working electrode, and the pattern of the counter electrode is used as the counter electrode;

8) A chitosan solution immobilized with glucose oxidase is added dropwise on the working electrode, and the solution is evaporated to dryness to form a solution immobilized with glucose.

Chitosan membrane for oxidase;

9) Insulating support layer, adhesive layer, counter electrode, working electrode and chitosan film immobilized with glucose oxidase constitute a multilayer

Structure, the multi-layer structure is peeled off from the transfer layer and transferred to the flexible film substrate;

10) The counter electrode and the working electrode are respectively connected to the electrochemical workstation or the measurement circuit through wires;

11) The chitosan film immobilized with glucose oxidase is pasted on the skin surface, and the glucose on the skin surface is oxidized

Under the action of enzymes, hydrogen peroxide is produced, and hydrogen peroxide reacts with the accumulated Prussian blue film to generate water and free electricity.

The number of free electrons generated is proportional to the concentration of glucose, and the free electrons are transferred to the electrode through the Prussian blue film.

The ChemStation either uses the measurement circuit to form a reaction current, the Electrochemical Workstation is in the measurement mode or uses the measurement

The circuit measures the current generated by the reaction, which gives the concentration of glucose.

Wherein, in step 1), the substrate is cleaned with a cleaning agent, heated and dried on a heating plate to obtain the substrate.

In step 6), the surface etching conductive layer forms the pattern of counter electrode and working electrode, specifically comprises the following steps:

a) spin-coating photoresist on the conductive layer;

b) using a mask to expose the photoresist under a photolithography machine;

c) developing in a developing solution;

d) Etching the conductive layer in an etchant to form the pattern of the counter electrode and the pattern of the working electrode.

In step 7), a Prussian blue film is formed on the pattern of the working electrode by electrochemical deposition; or the Prussian blue is made into an ink solution, and the ink is dropped on the surface of the electrode by printing, printing, spin coating or drop coating , to obtain a Prussian blue film after the ink dries.

The Prussian blue thin film is formed by electrochemical deposition, which specifically includes the following steps:

a) Connect the pattern of the working electrode to the electrochemical workstation through wires;

b) immersing the pattern of the working electrode in the electrochemical deposition solution;

c) Obtaining a nanoscale Prussian blue film by means of constant potential deposition;

d) The Prussian blue thin film obtained after electrochemical deposition is scanned by cyclic voltammetry in an electrochemical workstation;

e) be heated to the dryness of Prussian blue film;

f) After potentiostatic activation at low potential, the cyclic voltammetry scan was performed again.

In step 8), the preparation method of the chitosan solution that has fixed glucose oxidase comprises the following steps:

a) Dissolving chitosan powder and acetic acid in deionized water, and adding a certain amount of glycerol to form a chitosan solution, the volume concentration of glycerol is 3% to 10%;

b) dissolving glucose oxidase in chitosan solution;

c) dissolving the glucose oxidase powder extracted from Aspergillus niger in deionized water to form an aqueous enzyme solution;

d) uniformly mixing the chitosan solution and the enzyme aqueous solution according to a certain ratio to form a chitosan solution immobilized with glucose oxidase, and the volume ratio of the chitosan solution to the enzyme aqueous solution is 0.5:1˜2:1.

Advantages of the present invention:

The invention prepares the pattern of nanoscale counter electrode and working electrode on the ultra-thin and flexible insulating support layer and bonding layer, forms a Prussian blue film on the pattern of the working electrode, and forms a glucose oxidase-fixed Prussian blue film on the Prussian blue film. Chitosan film, pasted on the skin surface, glucose produces hydrogen peroxide under the action of glucose oxidase, hydrogen peroxide catalyzes reaction with accumulated Prussian blue film, generates water and free electrons, and measures the reaction current to obtain the concentration of glucose The sensor of the present invention has the characteristics of ultra-thin and flexible, and can be attached to any position on the surface of the human skin, without affecting the movement of the human body and normal life, it can non-invasively and accurately measure the concentration of glucose present on the surface of the skin, and realize the anti-diabetes Non-invasive monitoring of blood glucose in patients.

Description of drawings

Fig. 1 is the sectional view of an embodiment of the skin-like ultra-thin flexible glucose measurement sensor of the present invention;

Fig. 2 is a schematic diagram of the counter electrode and the working electrode of the skin-like ultra-thin flexible glucose measurement sensor of the present invention.

detailed description

The present invention will be further elaborated below through specific embodiments in conjunction with the accompanying drawings.

As shown in Figure 1, the skin-like ultra-thin flexible glucose measurement sensor of this embodiment includes: a flexible film substrate, an insulating support layer 1, an adhesive layer 2, a counter electrode 4, a working electrode, and chitosan with glucose oxidase fixed. Sugar film 6; wherein, a transfer layer is formed on the substrate, an insulating support layer 1 is formed on the transfer layer, an adhesive layer 2 is formed on the insulating support layer, and a conductive layer is formed on the adhesive layer 2; the surface is etched conductive The pattern of the counter electrode and the pattern 3 of the working electrode are formed layer by layer, and the Prussian blue film 5 is formed on the pattern 3 of the working electrode. 4; form a chitosan film immobilized with glucose oxidase on the working electrode; The structure is peeled from the transfer layer and transferred onto a flexible film substrate.

As shown in Figure 2, the counter and working electrodes have various shapes, rectangular, interdigitated, and filamentary.

In this embodiment, the substrate is a silicon wafer, the transfer layer is PMMA, the insulating support layer is PI, the adhesive layer is Pt, and the conductive layer is gold.

The preparation method of the skin-like ultra-thin flexible glucose measurement sensor of this embodiment comprises the following steps:

1) Clean the silicon wafer with acetone, isopropanol and deionized water, heat and dry it on a heating plate, and use it as a substrate;

2) Spin coating PMMA on the silicon wafer to form a transfer layer;

3) forming an insulating support layer by spin-coating PI on the transfer layer, and curing;

4) sputtering chromium on the insulating support layer to form a bonding layer;

5) sputtering gold on the bonding layer to form a conductive layer;

6) Etch the conductive layer on the surface to form the pattern of the counter electrode and the working electrode:

a) spin-coating photoresist on the conductive layer;

b) using a mask to expose the photoresist under a photolithography machine;

c) developing in a developing solution;

d) etching the conductive layer in the etchant to form the pattern of the counter electrode and the working electrode;

7) Form a Prussian blue film on the pattern of the working electrode, the pattern of the working electrode and the Prussian blue film formed on it constitute the working electrode, and the pattern of the counter electrode is used as the counter electrode:

a) Connect the pattern of the working electrode to the electrochemical workstation through wires;

b) Immerse the pattern of the working electrode in a mixed solution of KCl, K ₃ [Fe(CN) ₆ ], FeCl ₃ and HCl;

c) Obtaining a nanoscale Prussian blue film by means of constant potential deposition;

d) The Prussian blue thin film obtained after electrochemical deposition is scanned by cyclic voltammetry in an electrochemical workstation;

e) be heated to the dryness of Prussian blue film;

f) After constant potential activation at low potential, perform cyclic voltammetry scan again;

8) drip the chitosan solution that has fixed glucose oxidase on the working electrode, form the chitosan film that has fixed glucose oxidase after the solution is evaporated to dryness:

a) dissolving chitosan powder and acetic acid in deionized water, and adding glycerol with a volume concentration of 8% to form a chitosan solution;

b) dissolving glucose oxidase in chitosan solution;

c) dissolving the glucose oxidase powder extracted from Aspergillus niger in deionized water to form an aqueous enzyme solution;

d) mix the chitosan solution and the aqueous solution of the enzyme according to the volume ratio of 1:1 to form a chitosan solution immobilized by glucose oxidase;

9) The insulating support layer, the bonding layer, the counter electrode, the working electrode and the chitosan film immobilized with glucose oxidase form a multi-layer structure, and the multi-layer structure is peeled off from the transfer layer and transferred to the flexible film substrate;

10) The counter electrode and the working electrode are respectively connected to the electrochemical workstation or the measurement circuit through wires.

Finally, it should be noted that the purpose of the disclosed embodiments is to help further understand the present invention, but those skilled in the art can understand that various replacements and modifications can be made without departing from the spirit and scope of the present invention and the appended claims. It is possible. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the protection scope of the present invention is subject to the scope defined in the claims.

Claims (10)

1. the ultrathin flexible glucose measuring sensor of a species skin, it is characterised in that the glucose measuring sensor bag Include：Flexible film substrate, insulating support layer, tack coat, to electrode, working electrode and the chitosan for securing glucose oxidase Film；Wherein, transfer printing layer is formed on substrate, insulating support layer is formed on transfer printing layer, tack coat is formed on insulating support layer, Conductive layer is formed on tack coat；Surface etch conductive layer is to the upper surface of insulating support layer, in conductive layer shape paired electrode The pattern of pattern and working electrode, pattern to electrode and insulate between the pattern of working electrode, on the pattern of working electrode Prussian blue film is formed, the pattern of working electrode and the Prussian blue film formed thereon form working electrode, to electrode Pattern is used as to electrode；The chitosan film for securing glucose oxidase is formed on the working electrode (s；Insulating support layer, bonding Layer, to electrode, working electrode and secure glucose oxidase chitosan film form sandwich construction；Sandwich construction is from transfer printing layer Upper stripping, is transferred in flexible film substrate；To electrode and working electrode respectively by wire be connected to electrochemical workstation or Person's measuring circuit；The chitosan film for securing glucose oxidase is pasted onto skin surface, and the glucose of skin surface is in grape Produce hydrogen peroxide in the presence of carbohydrate oxidase, with product Prussian blue film catalytic reaction occurs for hydrogen peroxide, generate water and from By electronics, quantity caused by free electron is directly proportional to the concentration of glucose, and free electron is arrived by Prussian blue film transfer Electrochemical workstation or measuring circuit form kinetic current, and electrochemical workstation is in measurement mode or using measuring circuit Electric current caused by measurement reaction, so as to obtain the concentration of glucose.

2. glucose measuring sensor as claimed in claim 1, it is characterised in that described to electrode and the thickness of working electrode For 100nm~1cm；Working electrode and electrode is shaped as by plane electrode, is inserted and refers to electrode or wire electrode.

3. glucose measuring sensor as claimed in claim 1, it is characterised in that the insulating support layer is sub- using polyamides One kind in amine, polyethylene terephthalate and polyvinyl alcohol；The tack coat uses Cr or Pt.

4. glucose measuring sensor as claimed in claim 1, it is characterised in that the working electrode is led by anisotropy Conductive film ACF flexible wires are connected with electrochemical workstation or measuring circuit.

5. the preparation method of the ultrathin flexible glucose measuring sensor of a species skin, it is characterised in that the preparation method Comprise the following steps：

1) substrate of clean dried is provided；

2) the spin coating transfer printing layer on substrate；

3) on transfer printing layer by way of spin coating either knifing or using ready-made thin film dielectric material be pasted and fixed on turn The surface of layer is printed, prepares insulating support layer；

4) tack coat is sputtered on insulating support layer；

5) plating, electrochemical deposition, the mode of vapour deposition or magnetron sputtering prepare conductive layer on tack coat；

6) surface etch conductive layer is to the upper surface of insulating support layer, in the pattern and working electrode of conductive layer shape paired electrode Pattern, pattern to electrode and insulate between the pattern of working electrode；

7) form Prussian blue film on the pattern of working electrode, the pattern of working electrode and formed thereon Prussian blue thin Film forms working electrode, and the pattern of electrode is used as to electrode；

8) chitosan solution for securing glucose oxidase is added dropwise on the working electrode (s, solution forms after being evaporated and secures grape The chitosan film of carbohydrate oxidase；

9) insulating support layer, tack coat, to electrode, working electrode and secure glucose oxidase chitosan film form multilayer Structure, sandwich construction is peeled off from transfer printing layer, is transferred in flexible film substrate；

10) electrochemical workstation or measuring circuit are connected to by wire respectively to electrode and working electrode；

11) chitosan film for securing glucose oxidase is pasted onto skin surface, and the glucose of skin surface is in grape glycosyloxy Hydrogen peroxide is produced in the presence of change enzyme, with product Prussian blue film catalytic reaction, generation water and freely electricity occur for hydrogen peroxide Son, quantity caused by free electron is directly proportional to the concentration of glucose, and free electron passes through Prussian blue film transfer to electrification Learn work station or kinetic current is formed using measuring circuit, electrochemical workstation is in measurement mode or using measuring circuit Electric current caused by measurement reaction, so as to obtain the concentration of glucose.

6. preparation method as claimed in claim 5, it is characterised in that in step 6), surface etch conductive layer is formed to electricity Pole and the pattern of working electrode, specifically include following steps：

A) spin coating photoresist on the electrically conductive；

B) photoresist is exposed under litho machine using mask；

C) develop in developer solution；

D) the etching conductive layer in etching liquid, so as to the pattern of shape paired electrode and the pattern of working electrode.

7. preparation method as claimed in claim 5, it is characterised in that in step 7), by the way of electrochemical deposition, Prussian blue film is formed on the pattern of working electrode；Or using ink solution is made by Prussian blue, utilize printing, print Ink droplet in electrode surface, is obtained Prussian blue film by brush, spin coating, drop coating after ink dried.

8. preparation method as claimed in claim 7, it is characterised in that formed by the way of electrochemical deposition Prussian blue thin Film, specifically include following steps：

A) pattern of working electrode is connected to electrochemical workstation by wire；

B) pattern of working electrode is immersed in electrochemical deposition solution；

C) nano level Prussian blue film is obtained using the mode of potentiostatic electrodeposition；

D) the Prussian blue film obtained after electrochemical deposition carries out cyclic voltammetry scan in electrochemical workstation；

E) it is heated to Prussian blue film drying；

F) after carrying out constant potential activation under low potential, cyclic voltammetry scan is carried out again.

9. preparation method as claimed in claim 5, it is characterised in that in step 8), secure the shell of glucose oxidase The preparation method of glycan solution, comprises the following steps：

A) by Chitosan powder and acetate dissolution in deionized water, and add glycerine formed chitosan solution；

B) glucose oxidase is dissolved in chitosan solution；

C) the glucose oxidase powder dissolving for refining to obtain from aspergillus niger is formed to the aqueous solution of enzyme in deionized water；

D) aqueous solution of chitosan solution and enzyme is well mixed and forms the chitosan solution for securing glucose oxidase.

10. preparation method as claimed in claim 9, it is characterised in that the volumetric concentration of glycerine is 3%~10%；Shell gathers The volume ratio of the aqueous solution of sugar juice and enzyme is 0.5:1~2:1.