CN103913493B - Keggin-type heteropolyacid functionalized graphene-loaded copper nanoparticles modified electrode and its application - Google Patents

Abstract

The invention discloses the preparation and application of a Keggin-type heteropolyacid functionalized graphene-loaded copper nanoparticle modified electrode; it includes preparing Keggin-type heteropolyacid-functionalized graphene, pretreating a glassy carbon electrode, and then utilizing layer-by-layer self-assembly. Keggin-type heteropolyacid-functionalized graphene film was prepared as an ideal platform for loading copper nanoparticles. A Cu/Keggin-type heteropolyacid-GR biosensor was constructed and used for sensitive quantification of glucose through current-time curve method. Analysis and determination; the beneficial effect of the present invention is that the new sensor constructed by this method has good catalytic performance for glucose, and has the advantages of good selectivity and stability, high sensitivity, and wide detection range.

Description

Keggin-type heteropolyacid functionalized graphene-loaded copper nanoparticles modified electrode and its application

technical field

The invention relates to the technical field of electrochemical analysis and detection, in particular to the preparation of a Keggin-type heteropolyacid functionalized graphene-loaded copper nanoparticle modified electrode and its application in enzyme-free determination of glucose.

Background technique

Glucose detection has been extensively studied because of its clinical importance, especially in diabetic patients. The traditional method for detecting glucose is spectrophotometry, but due to the lack of chromophore and fluorophore ligands for glucose, qualitative and quantitative detection cannot be performed. Electrochemistry is currently the most effective method for detecting glucose due to its simple equipment and operation methods. Glucose amperometric sensors are divided into amperometric glucose oxidase biosensors and enzyme-free sensors. Since Clark and Lyons first reported about glucose oxidase electrodes in 1962, in the past 50 years, glucose oxidase biosensors have been used because of their high sensitivity and selectivity. Good performance is favored by international researchers, but the glucose oxidase sensor still has some defects due to the instability and low reproducibility of the natural enzyme. In order to solve the above problems, more research has turned to enzyme-free sensors, which have been developed rapidly. The main principle of most enzyme-free sensors is based on the direct current response of glucose oxide on the electrode surface.

Noble metals and transition metals are widely used to construct electrodes for enzyme-free determination of glucose. Precious metals are commonly used for pulse electrochemical detection of glucose. Although this method has high sensitivity and stability, the surface of the electrode absorbs intermediate products and the electrode surface easily loses electrical activity; another method uses transition metals, such as copper, nickel, and alloys, as electrodes. Modified materials construct amperometric sensors, and the main reaction mechanism is that glucose participates in the regulation of multivalent metal redox electron pair transfer on the transition metal modified electrode surface. Because of copper's electrocatalytic properties, wide response range, low detection limit, and better stability than other materials, the current research on the use of copper nanomaterials to modify electrodes for the determination of glucose has attracted attention.

Recent studies have shown that changing the size, texture, and surface morphology of catalyst particles can change their catalyst characteristics, so nanoscale catalysts are currently a hot research topic. Current reports focus on the preparation of highly dispersed copper nanoparticles to modify its catalytic performance towards glucose, but few literatures report the dispersion of copper nanoparticles on the surface of graphene functionalized by heteropolyacids.

Graphene (GR) is a two-dimensional material, and the two planes of graphene can support metal nanoparticles, which is an ideal carrier. The unique properties of graphene are reflected in its single-layer form, but the van der Waals force between graphene layers can easily lead to its irreversible agglomeration, so avoiding the irreversible agglomeration of graphene is to be solved by using the special properties of graphene The key issue.

Contents of the invention

Aiming at the above-mentioned prior art, the present invention provides a Keggin-type heteropolyacid functionalized graphene-supported copper nanoparticle modified electrode and its use method as an electrochemical glucose sensor in enzyme-free determination of glucose.

The present invention is achieved through the following technical solutions:

A preparation method of Keggin type heteropolyacid functionalized graphene-loaded copper nanoparticles modified electrode, the steps are as follows:

1) Preparation of Keggin-type heteropolyacid-functionalized graphene: put 10mg GR into 10ml of 0.05-0.1M Keggin-type heteropolyacid solution, ultrasonically disperse for 24h, and centrifuge until Keggin-type heteropolyacid is added. The color does not change, and Keggin type heteropolyacid functionalized graphene is obtained;

2) Pretreatment of the glassy carbon electrode: Polish the bare glassy carbon electrode to a mirror surface with 0.3 μm and 0.05 μm alumina powder in sequence, then rinse with double distilled water, then ultrasonically wash with nitric acid, acetone, and double distilled water, and finally dry at room temperature;

2) A Keggin-type heteropolyacid-functionalized graphene-loaded copper nanoparticle-modified electrode: first, place the pretreated glassy carbon electrode in PDDA solution for 10-20 minutes, and place it in the Keggin-type heteropolyacid after the electrode is dried. Polyacid-functionalized graphene solution for 10-20min, repeat the same process to prepare graphene membrane-modified electrodes with different layers; Keggin-type heteropolyacid-functionalized graphene is adsorbed by electrostatic attraction between Keggin-type heteropolyacid and PDDA to the surface of the glassy carbon electrode to obtain a Keggin-type heteropolyacid-GR/GCE modified electrode; the Keggin-type heteropolyacid-GR/GCE modified electrode is used as a working electrode to form a three-electrode system with a saturated calomel electrode and a platinum wire electrode. In the CuSO ₄ solution of M, pass through N ₂ for 15min, and then electrodeposit at -0.4V for 480s to obtain a Cu/Keggin type heteropolyacid-GR modified electrode; immerse the Cu/Keggin type heteropolyacid-GR modified electrode into In 0.1M NaOH solution, use cyclic voltammetry under the potential window of –0.50～+0.30V, set the scan rate to 100mV s ^–1 , and scan repeatedly until it is stable.

The Keggin type heteropoly acid is phosphomolybdic acid, phosphotungstic acid or silicotungstic acid.

The present invention also provides a Keggin type heteropolyacid functionalized graphene-supported copper nanoparticle modified electrode prepared according to the above method.

A Keggin-type heteropolyacid-functionalized graphene-loaded copper nanoparticle-modified electrode is used as an electrochemical glucose sensor in the enzyme-free determination of glucose. The Cu/Keggin-type heteropolyacid-GR modified glassy carbon electrode is used as a working electrode. The calomel electrode was used as the reference electrode, and the platinum wire electrode was used as the auxiliary electrode to form a three-electrode system; when measuring glucose, the three-electrode system was placed in 10 mL of 0.1M NaOH solution; then a certain anode potential was applied to the working electrode, when After the background current reaches a steady state, add a certain concentration of glucose standard solution to the 0.1M NaOH solution sequentially with stirring, and record the current-time curve; A linear relationship curve between current and glucose concentration was obtained, the linear correlation coefficient r=0.998, and the glucose was quantitatively detected by the standard curve method.

The beneficial effects of the present invention are that the Cu/Keggin type heteropolyacid-GR/GCE biosensor is constructed by using the layer-by-layer self-assembly method to prepare the Keggin type heteropolyacid functionalized graphene film as an ideal platform for loading copper nanoparticles, and It is used for the sensitive detection of glucose; the use of Keggin-type heteropolyacid dispersed graphene significantly improves the stability and dispersion of graphene, and makes the surface negatively charged, which is conducive to the assembly of PDDA, adsorbed on the surface of the electrode, and loads Copper nanoparticles effectively improve the catalytic performance of copper nanoparticles on glucose; the new sensor constructed by this method has good catalytic performance on glucose, and has the advantages of good selectivity and stability, high sensitivity, and wide detection range.

Description of drawings

Fig. 1 is the cyclic voltammetry behavior of the embodiment of the present invention 1PMo ₁₂ on the surface of the glassy carbon electrode modified by 4, 6, 8, 10 layers of self-assembled graphene films;

Fig. 2 is the SEM figure of the embodiment of the present invention 1Cu/PMo ₁₂ -GR, wherein, the number of assembled layers of graphene is 8 layers, and the time of electrodeposition copper is 480s;

Fig. 3 is the Cu/PMo ₁₂ -GR/GCE (a), Cu/GR/GCE (b), PMo ₁₂ -GR/GCE ( c) and the cyclic voltammogram on Cu/PMo ₁₂ -GR/GCE (d) in a solution of 0.1 M NaOH without glucose solution;

Figure 4 is the optimization of the conditions for the preparation of the sensor in Example 1 of the present invention, (a) the electrochemical behavior of Cu/PMo ₁₂ -GR/GCE prepared under different deposition times in 0.1M glucose 0.1M NaOH solution, (b) Electrochemical behavior of Cu/PMo ₁₂ -GR/GCE prepared at different deposition potentials in 0.1M glucose in 0.1M NaOH solution;

Fig. 5 is the glucose time-current curve measured at different potentials by Cu/PMo ₁₂ -GR/GCE in Example 1 of the present invention;

Fig. 6 is the time-current curve of measuring glucose by Cu/PMo ₁₂ -GR/GCE in Example 1 of the present invention, wherein the inset is a linear relationship diagram between peak current and concentration of glucose oxidation;

Fig. 7 is a measurement diagram of Cu/PMo ₁₂ -GR/GCE interference experiment on glucose in Example 1 of the present invention.

Detailed ways

The present invention will be further described below in conjunction with embodiment.

Example 1:

A preparation method of Keggin type heteropolyacid functionalized graphene-loaded copper nanoparticles modified electrode, the steps are as follows:

1) Preparation of Keggin-type heteropolyacid-functionalized graphene: put 10 mg GR into 10 ml of 0.05-0.1 M PMo ₁₂ solution, disperse ultrasonically for 24 hours, and centrifuge until the color does not change after adding PMo ₁₂ to obtain Phosphomolybdic acid functionalized graphene;

2) Pretreatment of the glassy carbon electrode: Polish the bare glassy carbon electrode to a mirror surface with 0.3 μm and 0.05 μm alumina powder in sequence, then rinse with double distilled water, then ultrasonically wash with nitric acid, acetone, and double distilled water, and finally dry at room temperature;

3) A Keggin-type heteropolyacid-functionalized graphene-loaded copper nanoparticle-modified electrode: first, place the pretreated glassy carbon electrode in PDDA solution for 10-20 minutes, and place it in phosphomolybdic acid after the electrode is dry. In the functionalized graphene solution for 10 to 20 minutes, repeat the same process to prepare graphene membrane-modified electrodes with different layers; phosphomolybdic acid functionalized graphene is adsorbed to the surface of the glassy carbon electrode by the electrostatic attraction between phosphomolybdic acid and PDDA, The PMo ₁₂ -GR/GCE modified electrode was obtained; the PMo ₁₂ -GR/GCE modified electrode was used as the working electrode, and a three-electrode system was formed with a saturated calomel electrode and a platinum wire electrode. In 0.04M CuSO ₄ solution, after passing N ₂ for 15min , Electrodeposited at -0.4V for 480s, the Cu/PMo ₁₂ -GR modified electrode can be obtained; the Cu/PMo ₁₂ -GR modified electrode was immersed in 0.1M NaOH solution, using cyclic voltammetry at –0.50～+0.30 Under the potential window of V, set the scan rate to 100mV _s ^-1 , and scan repeatedly until it is stable.

A Keggin-type heteropolyacid functionalized graphene-loaded copper nanoparticles modified electrode as an electrochemical glucose sensor in the enzyme-free determination of glucose, using Cu/PMo ₁₂ -GR modified glassy carbon electrode as working electrode, saturated calomel electrode As a reference electrode and a platinum wire electrode as an auxiliary electrode, a three-electrode system is formed; when glucose is measured, the three-electrode system is placed in 10mL of 0.1M NaOH solution; then a certain anode potential is applied to the working electrode, when the background current reaches After the steady state, add a certain concentration of glucose standard solution to the 0.1M NaOH solution sequentially with stirring, and record the current-time curve; in the range of glucose concentration of 0.01-0.10mM, the current and glucose The linear relationship curve of the concentration has a linear correlation coefficient of r=0.998, and the glucose is analyzed and detected by the standard curve method.

(1) Characterization of self-assembled graphene film modified electrodes

The characteristics of the graphene film on the electrode surface were studied by cyclic voltammetry in 0.1M H ₂ SO ₄ solution with a scan rate of 100mV/s. As shown in Figure 1, with the increase of the number of assembled layers, the _three pairs of oxidation The reduction peak current increased, which indicated that the graphene functionalized by phosphomolybdic acid was successfully adsorbed on the electrode surface. When 8 layers were assembled, the PMo ₁₂ current no longer increased, which was the optimal number of layers. PMo ₁₂ is used to chemically modify graphene, mainly based on the spontaneous and strong chemical adsorption between the graphene surface and PMo _12. The negatively charged single-layer PMo ₁₂ can make graphene uniformly dispersed and stable _. The buried graphene utilizes the electrostatic attraction between negatively charged _PMo12 and positively charged PDDA to self-assemble to form ordered graphene films on the electrode surface.

After using JSM-7001F for SEM scanning, the results are shown in Figure 2. The morphology of electrodeposited copper nanoparticles on the self-assembled graphene surface under the optimal conditions (deposition potential is -0.4V, deposition time is 480s), with a diameter of about Copper nanoparticles with a spherical shape of 100 nm are uniformly dispersed on the surface of self-assembled graphene.

(2) Optimization of conditions for preparing Cu/PMo ₁₂ -GR modified electrodes

During the electrodeposition of copper nanoparticles, the deposition potential and deposition time have a great influence on the catalytic activity of copper nanoparticles. From Figure 4(a), it can be concluded that when the deposition potential is -0.4V and the electrodeposition time is 480s, the modified electrode has the best catalytic performance for glucose. The possible reason is that the deposition potential and deposition time affect the Particle size and morphology characteristics of copper nanoparticles. The optimum deposition potential of copper nanoparticles is -0.4V. As the deposition time increases, the peak oxidation current of glucose increases. When the deposition time is 480s, the peak oxidation current of glucose If the time is too long and the film is too thick, the transfer rate of electrons will be slowed down.

(3) Electrocatalysis of glucose on Cu/PMo ₁₂ -GR/GCE

As shown in Figure 3, it can be seen from the comparison of (a) and (d) that after adding glucose, there is an irreversible oxidation peak current in the (a) curve, which is the peak current caused by the catalytic oxidation of glucose by the modified electrode. Variety. Comparing (a), (b), and (c), it can be seen that the oxidation peak current of glucose on the surface of Cu/PMo ₁₂ -GR/GCE is the largest, mainly due to the synergistic effect of GR, PMo ₁₂ and PDDA on the dispersed graphene In the process, on the one hand, PMo ₁₂ prevents the agglomeration of graphene and increases the specific surface area of graphene; On the electrode surface, the graphene film prepared by this self-assembly method can immobilize more copper nanoparticles. Graphene provides a porous framework with a larger specific surface area, and the negatively charged film can absorb more copper nanoparticles.

(4) Optimization of detection conditions

The detection potential is the most important factor affecting the ampere response. As shown in Figure 5, in 0.1M NaOH solution, 40μM glucose is continuously added at intervals of 50s, and the detection potential is between 0.3 and 0.55V. Increase, the response current also increases rapidly, when the potential is 0.5V, the response current reaches the maximum value, so 0.5V is the best response potential.

(5) Electrochemical detection of glucose

Under the best experimental conditions, glucose was detected by amperometric method, as shown in Figure 6, when 0.03mM and 0.1mM glucose solutions were continuously added, it showed a stable current-time response, and Cu/PMo ₁₂ -GR modified within 5s The electrode reaches 95% of the steady-state current, which shows that the modified electrode has a fast catalytic rate for glucose and can detect glucose sensitively; it also reflects the reproducibility and stability of the Cu/PMo ₁₂ -GR modified electrode. In the solution, under the condition of +0.5V, the parallel experiments were carried out on 0.01mM and 0.10mM glucose solutions, and the relative standard deviations were 5.2% and 3.6% respectively. The inner illustration in Fig. 6 is the graph of the linear relationship between the glucose oxidation peak current and the concentration, the linear equation is I=0.57+0.21c (μM), R is 0.998, and the detection can reach 3.0×10 ^-8 M.

The anti-interference ability of the glucose biosensor is evaluated by studying the interfering substances that coexist with glucose in people's serum and other samples. In human blood, the normal concentration of glucose is other interfering substances, such as dopamine (DA), urea (UA) and ascorbic acid (AA) etc. 30 times. As shown in Figure 7, when 30μM glucose was added to 0.1M NaOH solution, there was an obvious current response. When 100μM DA, UA and AA were continuously added, there was almost no electrode current response, but when the glucose solution was added again, the same The current response of the star indicates that the sensor has strong anti-interference ability and good selectivity.

Among them, glucose was purchased from Tianjin Guangfu Technology Development Co., Ltd., phosphomolybdic acid was purchased from Tianjin Ruijinte Chemical Co., Ltd., expanded graphite was provided by Qingdao Fujin Graphite Co., Ltd., and copper sulfate was purchased from Tianjin Kemiou Chemical Reagent Co., Ltd. , sodium hydroxide was purchased from Jiangsu Qiangsheng Functional Chemical Co., Ltd., dopamine was purchased from Aldrich Company, uric acid was purchased from Sinopharm Chemical Reagent Co., Ltd., ascorbic acid AA was purchased from Shanghai Aibi Chemical Co., Ltd., diethylene glycol diphthalate Acrylic acid PDDA was purchased from Aldrich Company, all reagents were of analytical grade, and experimental water was double distilled water. The CHI660C electrochemical workstation of Haichenhua Instrument Company was operated, the glassy carbon electrode (GCE) was used as the working electrode, the saturated calomel electrode (SCE) was used as the reference electrode, and the platinum wire electrode was used as the counter electrode. All electrochemical experiments were carried out at room temperature.

Example 2:

A preparation method of Keggin type heteropolyacid functionalized graphene-loaded copper nanoparticles modified electrode, the steps are as follows:

1) Preparation of Keggin-type heteropolyacid-functionalized graphene: put 10mg GR into 10ml of 0.05-0.1M phosphotungstic acid solution, ultrasonically disperse for 24 hours, and centrifuge until the color does not change after adding phosphotungstic acid , to obtain phosphotungstic acid functionalized graphene;

2) Pretreatment of the glassy carbon electrode: Polish the bare glassy carbon electrode to a mirror surface with 0.3 μm and 0.05 μm alumina powder in sequence, then rinse with double distilled water, then ultrasonically wash with nitric acid, acetone, and double distilled water, and finally dry at room temperature;

3) A Keggin-type heteropolyacid-functionalized graphene-loaded copper nanoparticle-modified electrode: first, place the pretreated glassy carbon electrode in PDDA solution for 10-20 minutes, and place it in phosphotungstic acid after the electrode is dry. In the functionalized graphene solution for 10 to 20 minutes, repeat the same process to prepare graphene membrane-modified electrodes with different layers; phosphotungstic acid functionalized graphene is adsorbed to the surface of the glassy carbon electrode by the electrostatic attraction between phosphotungstic acid and PDDA, Phosphotungstic acid-GR/GCE modified electrode was obtained; the phosphotungstic acid-GR/GCE modified electrode was used as a working electrode, and a _three- electrode system was formed with a saturated calomel electrode and a platinum wire electrode _. After 15 minutes, electrodeposit at -0.4V for 480s to obtain the Cu/phosphotungstic acid-GR modified electrode; immerse the Cu/phosphotungstic acid-GR modified electrode in 0.1M NaOH solution, and use cyclic voltammetry Under the potential window of 0.50～+0.30V, set the scan rate to 100mV _s ^–1 , and scan repeatedly until it is stable.

A Keggin-type heteropolyacid-functionalized graphene-loaded copper nanoparticle-modified electrode is used as an electrochemical glucose sensor in the enzyme-free determination of glucose. The Cu/phosphotungstic acid-GR modified glassy carbon electrode is used as the working electrode, saturated calomel The electrode was used as a reference electrode, and the platinum wire electrode was used as an auxiliary electrode to form a three-electrode system; when measuring glucose, the three-electrode system was placed in 10 mL of 0.1M NaOH solution; then a certain anode potential was applied to the working electrode, when the background current After reaching a steady state, add a certain concentration of glucose standard solution to the 0.1M NaOH solution sequentially with a micro-injector under stirring, and record the current-time curve; The linear relation curve of glucose concentration, its linear correlation coefficient r=0.998, utilizes standard curve method to analyze and detect glucose.

Example 3:

A preparation method of Keggin type heteropolyacid functionalized graphene-loaded copper nanoparticles modified electrode, the steps are as follows:

1) Preparation of Keggin-type heteropolyacid-functionalized graphene: put 10mg GR into 10ml of 0.05-0.1M silicotungstic acid solution, ultrasonically disperse for 24 hours, and centrifuge until the color does not change after adding silicotungstic acid , to obtain silicotungstic acid functionalized graphene;

2) Pretreatment of the glassy carbon electrode: Polish the bare glassy carbon electrode to a mirror surface with 0.3 μm and 0.05 μm alumina powder in sequence, then rinse with double distilled water, then ultrasonically wash with nitric acid, acetone, and double distilled water, and finally dry at room temperature;

3) A Keggin-type heteropoly acid functionalized graphene-loaded copper nanoparticle modified electrode: first place the pretreated glassy carbon electrode in PDDA solution for 10-20 minutes, after the electrode is dry, place it in silicotungstic acid In the functionalized graphene solution for 10 to 20 minutes, repeat the same process to prepare graphene film-modified electrodes with different layers; silicotungstic acid functionalized graphene is adsorbed to the surface of the glassy carbon electrode by the electrostatic attraction between silicotungstic acid and PDDA, Obtain a silicotungstic acid-GR/GCE modified electrode; the silicotungstic acid-GR/GCE modified electrode is used as a working electrode to form a three-electrode system with a saturated calomel electrode and a platinum wire electrode. In a 0.04M CuSO ₄ solution, pass N ₂ After 15 minutes, electrodeposit at -0.4V for 480s to obtain a Cu/silicotungstic acid-GR modified electrode; immerse the Cu/silicotungstic acid-GR modified electrode in 0.1M NaOH solution, and use cyclic voltammetry to obtain the modified electrode in – Under the potential window of 0.50～+0.30V, set the scan rate to 100mV _s ^–1 , and scan repeatedly until it is stable.

A Keggin-type heteropolyacid-functionalized graphene-loaded copper nanoparticle-modified electrode is used as an electrochemical glucose sensor in the enzyme-free determination of glucose. The Cu/silicotungstic acid-GR modified glassy carbon electrode is used as the working electrode, saturated calomel The electrode was used as a reference electrode, and the platinum wire electrode was used as an auxiliary electrode to form a three-electrode system; when measuring glucose, the three-electrode system was placed in 10 mL of 0.1M NaOH solution; then a certain anode potential was applied to the working electrode, when the background current After reaching a steady state, add a certain concentration of glucose standard solution to the 0.1M NaOH solution sequentially with a micro-injector under stirring, and record the current-time curve; The linear relation curve of glucose concentration, its linear correlation coefficient r=0.998, utilizes standard curve method to analyze and detect glucose.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (3)

1. a preparation method for Keggin-type heteropoly acid functionalization graphene supported copper Nanoparticle Modified electrode, it is characterized in that, step is as follows:

1) preparation of Keggin-type heteropoly acid functionalization graphene: Keggin-type heteropoly acid solution 10mg GR being put into 10ml 0.05 ~ 0.1M, ultrasonic disperse 24h, do not change to its color after adding Keggin-type heteropoly acid through centrifuging, obtain Keggin-type heteropoly acid functionalization graphene;

2) pre-service of glass-carbon electrode: with the alumina powder of 0.3 μm, 0.05 μm, naked glass-carbon electrode is polished to minute surface successively, then rinses with redistilled water, then uses nitric acid, acetone, redistilled water supersound washing successively, finally at room temperature dry;

3) a kind of Keggin-type heteropoly acid functionalization graphene supported copper Nanoparticle Modified electrode: first pretreated glass-carbon electrode is placed in PDDA solution 10 ~ 20min, after pole drying, be placed on 10 ~ 20min in Keggin-type heteropoly acid functionalization graphene solution, repeat same process, prepare different number of plies graphene film modified electrode; Keggin-type heteropoly acid functionalization graphene is adsorbed onto glassy carbon electrode surface by the electrostatic attraction between Keggin-type heteropoly acid and PDDA, obtains Keggin-type heteropoly acid-GR/GCE modified electrode; Keggin-type heteropoly acid-GR/GCE modified electrode, as working electrode, forms three-electrode system, at the CuSO of 0.04M with saturated calomel electrode, platinum electrode ₄in solution, pass through N ₂after 15min, electro-deposition 480s under-0.4V, can obtain Cu/Keggin type heteropoly acid-GR modified electrode; Cu/Keggin type heteropoly acid-GR modified electrode is immersed in 0.1M NaOH solution, under utilizing the electrochemical window of cyclic voltammetry – 0.50 ~+0.30V, arranges and sweep fast 100mV s ^{– 1}, be repeatedly scanned up to stable;

Described Keggin-type heteropoly acid is phosphomolybdic acid, phosphotungstic acid or silico-tungstic acid.

2. a kind of Keggin-type heteropoly acid functionalization graphene supported copper Nanoparticle Modified electrode of preparing of the method for claim 1.

3. a kind of Keggin-type heteropoly acid functionalization graphene supported copper Nanoparticle Modified electrode as claimed in claim 2 as electrochemical glucose sensor without the application in enzymatic determination glucose, it is characterized in that, using Cu/Keggin type heteropoly acid-GR modified glassy carbon electrode as working electrode, saturated calomel electrode as contrast electrode, platinum electrode as auxiliary electrode, composition three-electrode system; During mensuration glucose, three-electrode system is placed in the NaOH solution of the 0.1M of 10mL; Then apply certain anode potential on the working electrode (s, after background current reaches stable state, under agitation in the NaOH solution of 0.1M, add certain density Glucose standards solution successively with microsyringe, record electricity Liu – time curve; Be within the scope of 0.01 ~ 0.10mM at concentration of glucose, obtain the linear relationship curve of electric current and concentration of glucose, its linearly dependent coefficient r=0.998, utilizes calibration curve method quantitatively to detect glucose.