CN105699368B - A kind of preparation method and application of the difunctional hydrogen peroxide without enzyme sensor based on Two-dimensional Composites structure - Google Patents

Abstract

The invention discloses a kind of preparation methods for having difunctional no enzyme hydrogen peroxide sensor based on Two-dimensional Composites structure, prepared sensor operations are simple, easy to carry, fast, at low cost, quick, the Sensitive Detection to hydrogen peroxide available for fields such as daily production and lifes of detection.

Description

A dual-functional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials Preparation method and application

technical field

The invention relates to a preparation method of a sensor for detecting hydrogen peroxide, and the sensor integrates dual functions of electrochemiluminescence and photoelectrochemistry. It belongs to the field of new nano functional materials and electrochemical biosensing analysis technology.

Background technique

Hydrogen peroxide is an oxidizing agent, which can be decomposed into water and oxygen under normal circumstances, but it is relatively slow. When a catalyst (or biological enzyme) is added, the reaction speed is accelerated, so that the amount of hydrogen peroxide or the catalyst (or The amount of biological enzymes), and hydrogen peroxide often exists in the form of reaction intermediates in organisms. Therefore, hydrogen peroxide plays an important role in the fields of medical diagnosis, clinical treatment, environmental testing and food production. Research The development of hydrogen peroxide detection method also has very important application value. Due to the advantages of simple operation and fast detection speed, electrochemical biosensing analysis technology has been paid more and more attention by people. At present, the electrochemical biosensing analysis technology used to detect hydrogen peroxide mainly includes three types: electrochemical sensor, electrochemiluminescence sensor and photoelectrochemical sensor according to the detection means. Among them, compared with electrochemical sensors, electrochemical luminescence sensors and photoelectrochemical sensors have the characteristics of less background signal noise, high sensitivity, and low detection cost. In recent years, more and more researchers have paid attention to them.

Electrochemiluminescence, also known as electrochemiluminescence, refers to the generation of some special substances on the surface of electrodes by electrochemical methods, and these substances form excited states through electron transfer between them or with other components in the system, and return to to the ground state to produce luminescence. The electrochemiluminescence sensor generates electrochemiluminescence with the analyte by changing the modified material on the electrode surface. Under optimal conditions, the qualitative and quantitative analysis of the analyte is realized according to the correlation between the concentration of the analyte and the intensity of the electrochemiluminescence.

The photoelectrochemical sensor is based on the excitation of photosensitive materials by an external light source, resulting in the separation of electron-hole pairs. Under appropriate bias conditions, the rapid transfer of electrons on electrodes, semiconductors, modifiers, and analytes is realized, and photocurrents are formed. Under optimal conditions, the change of analyte concentration will directly affect the size of the photocurrent, and the qualitative and quantitative analysis of the analyte can be realized according to the change of photocurrent.

However, since the electrochemiluminescence sensor requires external light signal capture devices such as photodiodes, and the photoelectrochemical sensor requires an external light source to excite the photosensitive material, this affects the convenience of the operation of the two to a certain extent and limits them. It is more widely used in actual production and life. Therefore, it is of great practical value to design and prepare a simpler and faster electrochemical biosensing analysis technology for detecting hydrogen peroxide.

Contents of the invention

The object of the present invention is to provide a method for preparing a hydrogen peroxide sensor that is simple to operate, easy to carry, fast to detect, and low in cost. The prepared sensor can be used for rapid and sensitive detection of hydrogen peroxide in the fields of daily production and life detection. Based on this purpose, the present invention adopts a four-electrode system in the same electrolytic cell, i.e. two working electrodes, a counter electrode and a reference electrode, wherein the working electrode 1 adopts zinc-doped molybdenum disulfide composite material Zn-MoS ₂ Loaded gold@platinum nanorods Au@Pt and electropolymerized luminol are jointly modified as the electrochemiluminescent working electrode W1, and the working electrode 2 is made of reduced graphene loaded titanium dioxide nanosheet sol rGO/TiO ₂ and hemin Hemin solution Modified together, as the photoelectrochemical working electrode W2. When performing detection, after adding hydrogen peroxide in the electrolytic cell, a step voltage is applied to W1, because Zn-MoS ₂ has a large specific surface area and good conductivity, it can better support and maintain the catalyst activity, and Au Compared with pure platinum catalyst, @Pt has more active sites, which makes luminol react with hydrogen peroxide more fully and effectively, and produces electrochemiluminescence with sufficient intensity, which is equivalent to "turning on the light" , when the step voltage is 0, the electrochemiluminescence disappears, which is equivalent to "turning off the light _" . - The hole pairs are separated, and Hemin catalyzes hydrogen peroxide to generate oxygen, making hydrogen peroxide a hole "donor", thereby obtaining a photocurrent on W2. It disappears immediately, and the magnitude of the generated photocurrent is positively correlated with the concentration of hydrogen peroxide, so the detection of hydrogen peroxide can be realized by recording the magnitude of the photocurrent.

Based on above invention principle, the concrete technical scheme that the present invention adopts is as follows:

1. A method for preparing a bifunctional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials, characterized in that the preparation steps are:

(1) The preparation method of the electrochemiluminescent working electrode W1. The W1 is an ITO conductive glass modified by Zn-MoS ₂ loaded Au@Pt and electropolymerized luminol. The specific preparation steps are as follows:

1) Using ITO conductive glass as the working electrode, drop-coat Zn-MoS ₂ on the surface of the electrode, covering an area of 1 cm × 1 cm, and dry it at room temperature;

2) The working electrode obtained in 1) was drop-coated with Au@Pt on the surface of Zn-MoS ₂ with a coverage area of 1 cm × 1 cm, and dried at room temperature;

3) Immerse the working electrode obtained in 2) into the electrolyte, and the immersion area is the area covered by Zn-MoS ₂ loaded with Au@Pt. The working electrode is electrochemically deposited using a three-electrode system, and the working electrode is taken out after deposition. Wash with ultrapure water and dry at 4 °C in the dark to prepare the electrochemiluminescent working electrode W1;

The Zn-MoS ₂ is a molybdenum disulfide two-dimensional nanomaterial doped with zinc ions, and the two-dimensional nanomaterial is in the form of a paper sheet with a thickness of about 10-20 nm; the Zn-MoS ₂ The preparation method is as follows: 0.005~0.01 g zinc chloride ZnCl ₂ , 2~6 mL of 0.1 mol/L ascorbic acid solution, 0.5~1.5 mL of sodium molybdate Na ₂ MoO ₄ solution and 0.01~0.03 g of sodium sulfide Na ₂ S , after mixing and stirring for 15 minutes, put it into the reaction kettle, and react for 12-16 hours at 150-220°C; after cooling to room temperature, use deionized water to wash centrifugally, and vacuum-dry at 40°C to obtain Zn-MoS ₂ , which is dissolved in deionized water to obtain a Zn-MoS ₂ solution;

The Au@Pt is a rod-shaped nanomaterial with a core-shell structure. The rod-shaped nanomaterial with a core-shell structure is a rod-shaped nanomaterial with gold nanorods as the core and platinum nanoparticles as the shell. The gold nanorods are rod-shaped Gold nanoparticles with a length of 20-40 nm;

Described electrolytic solution is the sulfuric acid solution containing luminol, and the concentration of luminol in described electrolytic solution is 1～10mmol/L, and sulfuric acid concentration is 0.1～1.0 mol/L;

The three-electrode system includes a working electrode, a reference electrode and a counter electrode, the reference electrode is a saturated calomel electrode, and the counter electrode is a platinum wire electrode;

In the electrochemical deposition process, the electrochemical method adopted is cyclic voltammetry, the initial voltage is -0.2 V, the final voltage is 1.5 V, the scan rate is 100 mv/s, and the cycle is 20 to 30 cycles;

(2) The preparation method of the photoelectrochemical working electrode W2. The W2 is an ITO conductive glass modified by rGO/TiO ₂ and Hemin. It is characterized in that the specific preparation steps are:

1) Use ITO conductive glass as the working electrode, drop-coat 8~12 µL rGO/TiO ₂ on the surface of the electrode, and dry it at room temperature;

2) Put the working electrode obtained in 1) into a muffle furnace, perform annealing treatment at 450 °C, and cool to room temperature after treatment;

3) Apply 8-12 µL Hemin on the surface of the working electrode obtained in 2), dry at 4 °C, wash with ultrapure water after drying, and dry at 4 °C to prepare the photoelectrochemical working electrode W2;

The rGO/ _TiO2 is an aqueous solution of reduced graphene-loaded titanium dioxide nanosheets, and the titanium dioxide nanosheets are square sheet-shaped titanium dioxide nanoparticles with a side length of 60-80 nm;

Described Hemin is the hemin aqueous solution of 5 μ mol/L;

(3) Preparation method of bifunctional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials:

1) Insert the conductive sides of W1 and W2 into the electrolytic cell, and the distance between W1 and W2 is 0.5 cm~1.5 cm;

2) Take Ag/AgCl as the reference electrode RE and platinum wire electrode as the counter electrode CE, insert it into the electrolytic cell, and form a four-electrode system together with W1 and W2;

3) Add 10 mL of NaOH solution with a pH value of 11~13 into the electrolytic cell;

4) Put the four-electrode system and the electrolytic cell prepared in 1) to 3) in a cassette to prepare a bifunctional hydrogen peroxide enzyme-free sensor based on a two-dimensional composite material.

2. The application of the bifunctional hydrogen peroxide enzyme-free sensor based on the two-dimensional composite material of the present invention to the detection of hydrogen peroxide is characterized in that the specific detection method is:

(1) Use the electrochemical workstation to apply a step voltage to W1 by using a step voltage method. The initial voltage is 0 v, the step voltage is 0.7-0.9 v, and the step time is 10-30 s; at the same time, Apply a constant voltage to W2 using the time-current method, and the voltage is 0~0.6 v;

(2) Add standard solutions of hydrogen peroxide with different concentrations in the electrolytic cell, the current on W2 will increase correspondingly with the increase of hydrogen peroxide concentration, according to the difference between the obtained current increase value and the concentration of hydrogen peroxide relationship, draw the working curve;

(3) Replace the standard solution of hydrogen peroxide with the hydrogen peroxide solution to be tested, and perform detection according to the hydrogen peroxide detection method described in (1) and (2). According to the obtained current increase value and the drawn work The curve yields the concentration of the hydrogen peroxide solution to be tested.

Beneficial results of the present invention

(1) The dual-functional hydrogen peroxide enzyme-free sensor based on the two-dimensional composite material of the present invention is simple to prepare, easy to operate, does not require external auxiliary equipment, utilizes the miniaturization and portability of detection equipment, and realizes the detection of peroxidation The rapid, sensitive and highly selective detection of hydrogen has broad market development prospects;

(2) The present invention uses a four-electrode system to detect hydrogen peroxide in the same electrolytic cell for the first time, and realizes a dual-function signal amplification strategy of electrochemiluminescence and photoelectrochemistry. In the electrolytic cell, as the concentration of hydrogen peroxide increases, on the one hand, the intensity of electrochemiluminescence increases linearly, and the excited photocurrent increases linearly; on the other hand, hydrogen peroxide acts as an electron donor, making the The photocurrent increases linearly. Therefore, the two methods of electrochemiluminescence and photoelectrochemistry react and interact together in the same electrolytic cell and under the same electrochemical workstation, realizing the double amplification of the electrical signal for hydrogen peroxide detection, which greatly improves the detection sensitivity and detection efficiency. At the same time, because no biological enzymes are used, the requirements for the detection environment are more relaxed, which has important scientific significance and market application value.

Detailed ways

Example 1 A dual-functional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials, the specific preparation steps are:

(1) Preparation of Zn- _MoS2 :

Mix 0.005 g of zinc chloride ZnCl ₂ , 2 mL of 0.1 mol/L ascorbic acid solution, 0.5 mL of sodium molybdate Na ₂ MoO ₄ solution and 0.01 g of sodium sulfide Na ₂ S, mix and stir for 15 minutes, then put into the reaction kettle In the reaction at 150°C for 16 hours; after cooling to room temperature, centrifugal washing with deionized water and vacuum drying at 40°C to obtain Zn-MoS ₂ , which was dissolved in deionized water to obtain Zn- _MoS2 solution.

(2) Preparation of ECL working electrode W1:

1) Using ITO conductive glass as the working electrode, drop-coat the Zn- _MoS2 solution prepared in (1) on the surface of the electrode, covering an area of 1 cm × 1 cm, and dry it at room temperature;

2) The working electrode obtained in 1) was drop-coated with Au@Pt on the surface of Zn-MoS ₂ with a coverage area of 1 cm × 1 cm, and dried at room temperature;

3) Immerse the working electrode obtained in 2) into the electrolyte, and the immersion area is the area covered by Zn-MoS ₂ loaded with Au@Pt. The working electrode is electrochemically deposited using a three-electrode system, and the working electrode is taken out after deposition. Wash with ultrapure water, and dry at 4°C in the dark to prepare the electrochemiluminescent working electrode W1;

The Au@Pt is a rod-shaped nanomaterial with a core-shell structure. The rod-shaped nanomaterial with a core-shell structure is a rod-shaped nanomaterial with gold nanorods as the core and platinum nanoparticles as the shell. The gold nanorods are rod-shaped Gold nanoparticles, 20 nm in length;

Described electrolytic solution is the sulfuric acid solution containing luminol, and the concentration of luminol in described electrolytic solution is 1mmol/L, and sulfuric acid concentration is 0.1 mol/L;

The three-electrode system includes a working electrode, a reference electrode and a counter electrode, the reference electrode is a saturated calomel electrode, and the counter electrode is a platinum wire electrode;

In the electrochemical deposition process, the electrochemical method adopted is cyclic voltammetry, the initial voltage is -0.2V, the final voltage is 1.5V, the scan rate is 100mv/s, and the cycle is 20 cycles.

(3) Preparation of photoelectrochemical working electrode W2:

1) Use ITO conductive glass as the working electrode, drop-coat 8 µL rGO/TiO ₂ on the surface of the electrode, and dry it at room temperature;

2) Put the working electrode obtained in 1) into a muffle furnace, perform annealing treatment at 450 °C, and cool to room temperature after treatment;

3) The surface of the working electrode obtained in 2) was drip-coated with 8 µL Hemin, dried at 4 °C, washed with ultrapure water after drying, and dried at 4 °C to prepare the photoelectrochemical working electrode W2;

The rGO/ _TiO2 is an aqueous solution of reduced graphene-loaded titanium dioxide nanosheets, and the titanium dioxide nanosheets are square sheet-shaped titanium dioxide nanoparticles with a side length of 60-80 nm;

Described Hemin is the hemin aqueous solution of 5 μ mol/L.

(4) Preparation method of bifunctional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials:

1) Insert W1 prepared in (2) and W2 prepared in (3) face to face into the electrolytic cell, and the distance between W1 and W2 is 0.5cm;

2) Take Ag/AgCl as the reference electrode RE and platinum wire electrode as the counter electrode CE, insert it into the electrolytic cell, and form a four-electrode system together with W1 and W2;

3) Add 10 mL of NaOH solution with a pH value of 11 into the electrolytic cell;

4) Put the four-electrode system and the electrolytic cell prepared in 1) to 3) in a cassette to prepare a bifunctional hydrogen peroxide enzyme-free sensor based on a two-dimensional composite material.

Example 2 A dual-functional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials, the specific preparation steps are:

(1) Preparation of Zn- _MoS2 :

The preparation steps are the same as the preparation method of the Zn-MoS solution in Example 1, except that the addition amount of ZnCl ₂ is 0.008 g, the _addition amount of ascorbic acid solution is 4 mL, and the addition amount of Na ₂ MoO ₄ solution is 1.0 mL and Na ₂ S in an amount of 0.02 g, and reacted at 220° C. for 12 hours.

(2) Preparation of ECL working electrode W1:

The preparation steps are the same as those of W1 in Example 1, except that the Zn-MoS ₂ modified electrode prepared in (1) in this example is used; the length of the gold nanorods is 30 nm; the luminol in the electrolyte is The concentration of sulfuric acid is 5 mmol/L, and the concentration of sulfuric acid is 0.5 mol/L. When electrochemical deposition is carried out by cyclic voltammetry, the cycle is 25 cycles.

(3) Preparation of photoelectrochemical working electrode W2:

1) Use ITO conductive glass as the working electrode, drop-coat 10 µL rGO/TiO ₂ on the surface of the electrode, and dry it at room temperature;

2) Put the working electrode obtained in 1) into a muffle furnace, perform annealing treatment at 450 °C, and cool to room temperature after treatment;

3) Drop-coat 10 µL Hemin on the surface of the working electrode obtained in 2), dry it at 4 °C, wash it with ultrapure water after drying, and dry it at 4 °C to prepare the photoelectrochemical working electrode W2;

The rest are the same as the preparation steps of W2 in Example 1.

(4) Preparation method of bifunctional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials:

The preparation steps are the same as in Example 1, except that the distance between W1 and W2 is 1.0 cm, and the pH value of the NaOH solution added to the electrolytic cell is 12.

Example 3 A dual-functional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials, the specific preparation steps are:

(1) Preparation of Zn- _MoS2 :

The preparation steps are the same as the preparation method of Zn-MoS solution in Example 1, except that the addition amount of Zn Cl ₂ is 0.01 g, _the addition amount of ascorbic acid solution is 6 mL, and the addition amount of Na ₂ MoO ₄ solution is 1.5 The addition amount of mL and Na ₂ S was 0.03 g, and the reaction was carried out at 220° C. for 12 hours.

(2) Preparation of ECL working electrode W1:

The preparation steps are the same as those of W1 in Example 1, except that the Zn-MoS ₂ modified electrode prepared in (1) in this example is used; the length of the gold nanorods is 40 nm; the luminol in the electrolyte is The concentration of sulfuric acid is 10 mmol/L, and the concentration of sulfuric acid is 1.0 mol/L. When electrochemical deposition is performed by cyclic voltammetry, the cycle is 30 cycles.

(3) Preparation of photoelectrochemical working electrode W2:

1) Use ITO conductive glass as the working electrode, drop-coat 12 µL rGO/TiO ₂ on the surface of the electrode, and dry it at room temperature;

2) Put the working electrode obtained in 1) into a muffle furnace, perform annealing treatment at 450 °C, and cool to room temperature after treatment;

3) The surface of the working electrode obtained in 2) was drip-coated with 12 µL Hemin, dried at 4 °C, washed with ultrapure water after drying, and dried at 4 °C to prepare the photoelectrochemical working electrode W2;

The rest are the same as the preparation steps of W2 in Example 1.

(4) Preparation method of bifunctional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials:

The preparation steps are the same as in Example 1, except that the distance between W1 and W2 is 1.5 cm, and the pH value of the NaOH solution added to the electrolytic cell is 13.

Example 4 Application of a dual-functional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials

The bifunctional hydrogen peroxide enzyme-free sensor based on the two-dimensional composite material prepared in Example 1 is applied to the detection of hydrogen peroxide, and the detection steps are:

(1) Use the electrochemical workstation to apply a step voltage to W1 by using a step voltage method. The initial voltage is 0 v, the step voltage is 0.7 v, and the step time is 10 s; at the same time, the step voltage is used on W2 The time-current method applies a constant voltage to W2, and the voltage is 0 v;

(2) Add standard solutions of hydrogen peroxide with different concentrations in the electrolytic cell, the current on W2 will increase correspondingly with the increase of hydrogen peroxide concentration, according to the difference between the obtained current increase value and the concentration of hydrogen peroxide relationship, draw the working curve;

(3) Replace the standard solution of hydrogen peroxide with the hydrogen peroxide solution to be tested, and perform detection according to the hydrogen peroxide detection method described in (1) and (2). According to the obtained current increase value and the drawn work The curve yields the concentration of the hydrogen peroxide solution to be tested.

Example 5 Application of a dual-functional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials

The bifunctional hydrogen peroxide enzyme-free sensor based on the two-dimensional composite material prepared in Example 2 is applied to the detection of hydrogen peroxide, and the detection steps are:

(1) Use the electrochemical workstation to apply a step voltage to W1 by using a step voltage method. The initial voltage is 0 v, the step voltage is 0.8 v, and the step time is 20 s; at the same time, the step voltage is used on W2 The time-current method applies a constant voltage to W2, and the voltage is 0.3 v;

(2) and (3) are the same as embodiment 4.

Example 6 Application of a dual-functional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials

The bifunctional hydrogen peroxide enzyme-free sensor based on the two-dimensional composite material prepared in Example 3 is applied to the detection of hydrogen peroxide, and the detection steps are:

(1) Use the electrochemical workstation to apply a step voltage to W1 by using a step voltage method, the initial voltage is 0 v, the step voltage is 0.9 v, and the step time is 30 s; at the same time, the step voltage is used on W2 The time-current method applies a constant voltage to W2, and the voltage is 0.6 v;

(2) and (3) are the same as embodiment 4.

Example 7 The dual-functional hydrogen peroxide enzyme-free sensor based on the two-dimensional composite material prepared in Examples 1-3 is applied to the detection of hydrogen peroxide, and has excellent detection effect, with a detection limit of 5 μmol/L.

Example 8 Detection of Hydrogen Peroxide in Human Serum

Accurately pipette the human serum sample, add a certain molar concentration of hydrogen peroxide standard solution, take the human serum without adding hydrogen peroxide as a blank, carry out the standard addition recovery experiment, and detect according to the steps of Examples 4-6, and measure the The recovery rate of hydrogen peroxide, test result is shown in Table 1.

Table 1 Detection results of hydrogen peroxide in human serum

As can be seen from the test results in Table 1, the relative standard deviation (RSD) of the result is less than 3.0%, and the recovery rate is 96 ~ 102%, showing that the present invention can be used for the detection of hydrogen peroxide in human serum, and the method has high sensitivity and strong specificity, and the results Accurate and reliable.

Claims (6)

1. A preparation method of a dual-functional hydrogen peroxide enzyme-free sensor based on a two-dimensional composite material, characterized in that the zinc-doped molybdenum disulfide composite material Zn-MoS ₂ supports gold@platinum nanorods Au@Pt The ITO conductive glass co-modified with electropolymerized luminol was used as the electrochemiluminescent working electrode W1, and the ITO conductive glass co-modified with reduced graphene-loaded titanium dioxide nanosheet sol rGO/TiO ₂ and hemin Hemin solution was used as the photoelectrochemical working electrode W2, the Ag/AgCl electrode is used as the reference electrode RE, and the platinum wire electrode is used as the counter electrode CE. The four electrodes are inserted into the same electrolytic cell to form a four-electrode system, and the prepared four-electrode system is placed in a cassette to obtain A bifunctional hydrogen peroxide enzyme-free sensor based on two-dimensional composite materials. 2. preparation method according to claim 1, is characterized in that, the molybdenum disulfide composite material Zn- _MoS2 of described zinc doping is the molybdenum disulfide two-dimensional nanomaterial that is doped with zinc ion, and described Two-dimensional nanomaterials are paper sheets with a thickness of 10-20 nm. 3. The preparation method according to claim 1, wherein the gold@platinum nanorod Au@Pt is a rod-shaped nanomaterial with a core-shell structure, and the rod-shaped nanomaterial with a core-shell structure is a gold nanorod is the core, platinum nanoparticles are rod-shaped nanomaterials of the shell, and the gold nanorods are rod-shaped gold nanoparticles with a length of 20-40 nm. 4. preparation method according to claim 1, is characterized in that, described reduced graphene supports titanium dioxide nanosheet sol rGO/TiO ₂ is the aqueous solution of reduced graphene supported titanium dioxide nanosheet, and described titanium dioxide nanosheet is a square sheet Shaped titanium dioxide nanoparticles with a side length of 60–80 nm. 5. The preparation method according to claim 1, characterized in that the conductive sides of W1 and W2 are inserted into the electrolytic cell oppositely, and the distance between W1 and W2 is 0.5 cm~1.5 cm. 6. the application method of the hydrogen peroxide enzyme-free sensor that preparation method prepares according to claim 1 is characterized in that, the step that described hydrogen peroxide enzyme-free sensor is applied to hydrogen peroxide detection is: utilize electrochemical workstation , apply a step voltage to W1 by using a step voltage method on W1, the initial voltage is 0 v, the step voltage is 0.7~0.9 v, and the step time is 10~30 s; at the same time, a time-current Method Apply a constant voltage to W2, the voltage is 0~0.6 v; add the hydrogen peroxide solution to be tested in the electrolytic cell, the current on W2 will increase with the increase of the concentration of hydrogen peroxide, according to the obtained current increase The value gives the concentration of the hydrogen peroxide solution to be tested.