KR20140109714A

KR20140109714A - Method of fabricating graphene-iron oxide nanoparticle buckypaper and sensor for hydrogen peroxide detection using the same

Info

Publication number: KR20140109714A
Application number: KR1020130024053A
Authority: KR
Inventors: 박정호; 유학추
Original assignee: 고려대학교 산학협력단
Priority date: 2013-03-06
Filing date: 2013-03-06
Publication date: 2014-09-16

Abstract

Comprising the steps of mixing a solution of graphene-PDDA [poly (diallyldimethylammoniumchloride)] with a solution of iron oxide nanoparticles to form a mixed solution, followed by reduced pressure filtration and drying to obtain a free standing graphene-PDDA- iron oxide nanoparticle composite material A method for producing graphene-PDDA-iron oxide nanoparticles bucky paper is proposed. According to the present invention, a composite material for a hydrogen peroxide measurement sensor electrode having excellent reproducibility can be easily produced by complexing iron oxide nanoparticles with graphene. The hydrogen peroxide measurement sensor manufactured by this method can easily measure the concentration of hydrogen peroxide contained in the sample in an earlier time by using an electrochemical method and also can measure a small amount of hydrogen peroxide contained in the sample sensitively, It is stable because it does not use enzyme.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphene-iron oxide nanoparticle bucky paper and a hydrogen peroxide detection sensor using the same,

The present invention relates to a graphene composite material, a manufacturing method thereof, a device using the graphene composite material, and a manufacturing method thereof, and more particularly, to a composite material of graphene and metal oxide nanoparticles, And an electrochemical sensor using the same.

Graphene is a planar two-dimensional carbon structure that forms an sp2 bond, and is a material with high physical and chemical stability. At room temperature, electrons can move 100 times faster than silicon, and 100 times more current per unit area than copper. It has more than twice the thermal conductivity of diamond, 200 times more mechanical strength than steel, and transparency. In addition, carbon is stretched due to the spatial margin of the hexagonal honeycomb structure connected like a net, and it does not lose its electrical conductivity even when stretched or folded. Research for application to various fields such as electronic field, sensor, mechanical resonator, energy storage and conversion (super capacitor, battery, fuel cell, solar battery, etc.) and display using the specific structure and properties of graphene .

At present, graphene is produced by mechanical, epitaxial, thermal expansion, gas phase, CVD (chemical vapor deposition), graphene oxidation-reduction, and graphite intercalation compound method. In order to apply graphene with excellent properties to various fields, it is necessary to fabricate graphene as a composite material. In order to produce such a composite material, graphene must be mass-produced and graphene produced at a low temperature. In addition, in order to commercialize it, it must be competitive in price, and the safety of the process should be secured.

On the other hand, hydrogen peroxide (H ₂ O ₂ ) has strong oxidizing properties and is widely used in various fields due to its nature. For example, hydrogen peroxide is widely used in organic compound synthesis, food manufacturing, pulp and paper bleaching, and medical applications. Hydrogen peroxide can also be used as an oxidizing agent for fuel cells, and is widely used in various commercial products such as cosmetics and pharmaceuticals. In addition, hydrogen peroxide has attracted attention as an important by-product of enzymatic reaction in the field of biosensors in recent years because it is a chemical substance that is indispensably a chemical substance that occurs in various biological mechanisms occurring in the human body. Thus, the detection and quantification of hydrogen peroxide is very necessary in various fields.

Conventionally, most sensors for detecting hydrogen peroxide are configured to detect and detect horseradish peroxidase (HRP), which is a hydrogen peroxide oxidase, on a sensing part of an electrode. These enzymatic sensors have a disadvantage that the enzyme is expensive and that the activity of the enzyme is greatly influenced by the thermochemical factors, and the enzyme activity is deteriorated when stored for a long time.

A problem to be solved by the present invention is to provide a method for producing a graphene composite material which enables the excellent performance of graphene to be utilized in various fields.

Another object of the present invention is to provide a method for producing a hydrogen peroxide measurement sensor which does not require an enzyme by using a graphene composite material.

In order to solve the above-described problems, the present invention provides a method for preparing a mixed solution comprising mixing a solution of graphene-PDDA (poly (diallyldimethylammoniumchloride)) and a solution of iron oxide (Fe ₃ O ₄ ) nanoparticles to form a mixed solution; And a step of filtering and drying the mixed solution under reduced pressure to obtain a free standing graphene-PDDA-iron oxide nanoparticle composite material, wherein the graphene-PDDA-iron oxide nanoparticle bucky paper is produced.

Wherein the graphene-PDDA solution comprises: oxidizing graphite to form a graphite oxide; Ultrasonically dispersing the graphite oxide to form a colloidal dispersion of individual oxidized graphene sheets; And mixing the colloidal dispersion of the oxidized graphene sheet with PDDA to reduce the oxidized graphene.

The iron oxide nanoparticle solution can be obtained by dispersing the iron oxide nanoparticle powder in a TMAOH solution.

In order to solve the above-described problems, the present invention also proposes a method of manufacturing a hydrogen peroxide measurement sensor by constituting an electrode including a graphene-PDDA-iron oxide nanoparticle bucky paper manufactured by the above method.

According to the present invention, a graphene-PDDA-iron oxide nanoparticle composite material can be manufactured through a simple process such as mixing of a raw material solution. In the present invention, the plate of each graphene-PDDA-iron oxide nanoparticle is subjected to a vacuum filtration method It is assembled and manufactured as freely standing type bucky paper. This bucky paper has a laminate of plates of graphene-PDDA-iron oxide nanoparticles, which is flexible due to the interfacial lamination structure between the van der Waals force and the plate, and has excellent mechanical strength. In addition, the electrical properties of the graphene itself are excellent, and the iron oxide nanoparticles exhibit an activity similar to that of an enzyme to be applicable to an electrochemical sensor.

In this invention, by introducing the graphene-PDDA-iron oxide nanoparticle bucky paper into the electrode for measuring hydrogen peroxide, an electrode having excellent reproducibility can be easily prepared, and the concentration of hydrogen peroxide can be increased by the measurement using an electrochemical method It can be easily measured in time. It can also be sensitive to small amounts of hydrogen peroxide contained in the sample to be measured.

The hydrogen peroxide chemical sensor manufactured according to the present invention has linear correlation coefficient of about 0.986, linearity over a wide range of 10 ppm (~ 0.3 mM) to 800 ppm (~ 23 mM), and exhibits excellent electrocatalytic activity, And exhibits excellent sensitivity of up to 218 μAmM ^-1 cm ^-2 . The hydrogen peroxide measurement sensor manufactured according to the present invention is a sensor of high sensitivity that can detect hydrogen peroxide at a low concentration with a fast response speed by maximizing the working electrode area without using an enzyme.

As described above, according to the present invention, it is possible to produce a graphene composite material called graphene-PDDA-iron oxide nanoparticle bucky paper by an easy and economical method, and this bucky paper can be used for manufacturing a hydrogen peroxide measurement sensor with better performance .

FIG. 1 is a flowchart of a method for producing a graphene-PDDA-iron oxide nanoparticle bucky paper according to an embodiment of the present invention.
FIG. 2 is an overall process diagram of a method for producing a graphene-PDDA-iron oxide nanoparticle bucky paper according to an embodiment of the present invention.
FIG. 3 is a graph showing the graphene-PDDA colloid reduced by addition of oxidized graphene colloid and PDDA according to the experimental example of the present invention.
4 shows the EDX analysis results of the oxidized graphene film and the PDDA reduced graphene film according to the experimental example of the present invention.
5 is a graph showing oxidized graphene colloid, graphene-PDDA colloid, and graphene-PDDA-iron oxide nanoparticle colloid according to Experimental Example of the present invention.
6 is an AFM photograph of a PDDA-graphene film according to an experimental example of the present invention.
7 is an AFM photograph of a graphene-PDDA-iron oxide nanoparticle film according to an experimental example of the present invention.
8 is a photograph of a graphene-PDDA-iron oxide nanoparticle bucky paper according to an experimental example of the present invention.
9 is an SEM photograph of a graphene-PDDA-iron oxide nanoparticle bucky paper according to an experimental example of the present invention.
10 is an SEM photograph of the surface of the graphene-PDDA-iron oxide nanoparticle bucky paper according to the experimental example of the present invention.
11 shows the EDX analysis results of the graphene-PDDA-iron oxide nanoparticles bucky paper according to the experimental example of the present invention.
12 is an XRD pattern of a graphene-PDDA-iron oxide nanoparticle bucky paper according to an experimental example of the present invention.
13 is a graph of a cyclic voltammogram measured using an electrode of a graphene-PDDA-iron oxide nanoparticle bucky paper according to an experimental example of the present invention.
FIG. 14 is a graph showing a change in current according to the concentration of hydrogen peroxide by applying a constant potential of -0.2 V to a graphene-PDDA-iron oxide nanoparticle bucky paper according to an experimental example of the present invention.
Figure 15 is an illustration of the electrocatalytic mechanism of graphene-PDDA-iron oxide nanoparticles for hydrogen peroxide reduction.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Therefore, the shapes and the like of the elements in the drawings are exaggerated in order to emphasize a clearer explanation.

First, FIG. 1 is a flowchart of a method for manufacturing a graphene-PDDA-iron oxide nanoparticle bucky paper according to an embodiment of the present invention.

Referring to FIG. 1, a first step S100 is a step of mixing a solution of graphene-PDDA [poly (diallyldimethylammoniumchloride)] with a solution of iron oxide nanoparticles to form a mixed solution.

In a first step (SlOO), the graphen-PDA solution is prepared by oxidizing graphite to form graphite oxide; Ultrasonically dispersing the graphite oxide to form a colloidal dispersion of individual oxidized graphene sheets; And mixing the colloidal dispersion of the oxidized graphene sheet with PDDA to reduce the oxidized graphene. The iron oxide nanoparticle solution can be obtained by dispersing the iron oxide nanoparticle powder in a TMAOH solution.

FIG. 2 is an overall process diagram of a method for manufacturing a graphene-PDDA-iron oxide nanoparticle bucky paper according to an embodiment of the present invention. Referring to FIG. 2, the first step S100 will be described in detail.

2 (a) shows graphite as a raw material. FIG. 2 (b) corresponds to a step of oxidizing graphite to form graphite oxide, and ultrasonic dispersion of the graphite oxide to form a colloidal dispersion of individual oxidized graphene sheets. Next, FIG. 2 (c) corresponds to a step of mixing PDDA with the colloidal dispersion of the oxidized graphene sheet to reduce the graphene oxide.

Oxidized graphene is well dispersed in water by functional groups, but graphene loses its dispersibility and flocculates and precipitates. To solve this problem, PDDA is used in the present invention. When PDDA is added before oxidized graphene is reduced, PDDA-graphene does not aggregate.

When the mixed solution of the graphene-PDDA solution and the iron oxide nanoparticle solution is formed, the PDDA acts as a glue to attach the iron oxide nanoparticles on the graphene. As shown in FIG. 2 (d), the graphene- A nanoparticle (NP) plate is formed. The nanoparticles are negatively charged by adsorbing OH- ions from solution, and graphene is positively charged as it is functionalized by positively charged PDDA. Thus, nanoparticles can be electrostatically attached onto graphene-PDDA to form plates of nanoscale graphene-PDDA-iron oxide nanoparticles.

Referring to FIG. 1 again, the second step S200 includes a step of filtering the mixed solution of the graphene-PDDA solution and the iron oxide nanoparticle solution under reduced pressure and drying to obtain a free standing graphene-PDDA-iron oxide nanoparticle composite material to be. The composite material stripped from the filter is a freestanding bucky paper (BP).

This bucky paper can be made by itself, or by hydrogen peroxide chemical sensors attached to Au or Pt electrodes, without enzymes. Iron oxide nanoparticles in bucky papers have similar enzymatic activities as natural peroxidases. Graphene has high surface area and excellent electrical conductivity, which can improve the catalytic ability of iron oxide nanoparticles. In addition, the nanoparticles serve to increase the spacing between the graphene layers, further increasing the surface area.

The decompression filtering step may use the device configuration as shown in FIG. 2 (e). Pour the mixture over the membrane filter and vacuum it under the filter. After drying in this state, when the membrane filter is lifted, the composite material is obtained on the membrane filter as shown in (f) of FIG. 2, and if it is peeled off, it is bucky paper. The bucky paper may be transferred to another substrate, for example, an electrode, as shown in FIG. 2 (g), or used singly without use.

As described above, according to the present invention, a graphene composite material can be mass-produced in a simple, economical and low-temperature process. In addition, since the graphene composite material is free-standing bucky paper, it is very advantageous to apply it to a composite material obtained from a powder or a solution in application of a sensor or the like.

As in the experimental example to be described later, the graphene-PDDA-iron oxide nanoparticle bucky paper manufactured according to one embodiment of the present invention can be included in the electrode and can serve as a catalyst in the hydrogen peroxide measurement sensor. Hereinafter, embodiments of the present invention will be described in more detail with reference to experimental examples.

Oxidation Grapina Dispersion manufacturing

Graphite oxide can be made by pretreating graphite with a strong acid and completely oxidizing it.

In the pretreatment, 100 ml of concentrated H ₂ SO ₄ and 5 g of graphite were added to the beaker, and the mixture was heated at 90 ° C. for 30 minutes with stirring. The mixture temperature was lowered to 80 ° C, and the mixture was kept at 80 ° C for 5 hours using a hot plate and then the heating was stopped. The mixture was then diluted with 2 L of deionized water and allowed to stand overnight. The next day, the mixture was washed and filtered using a 0.2 micron Millipore filter to remove any remaining acid. The obtained solid was placed in a drying dish and dried overnight in air.

For the graphite oxidation step, 200 ml of H ₂ SO ₄ was placed in a 3 L flask and cooled to 0 ° C using an ice bath. The pretreated graphite thus prepared was placed in the flask and 30 g of KMnO ₄ , which is an oxidizing agent, was slowly added to dissolve while stirring. The mixture was reacted at 35 ° C for about 10 hours, and then 20 ml of distilled water was added to the mixture. When water was added, the temperature of the mixture rapidly increased, so that the addition of distilled water proceeded in an ice bath so that the temperature did not rise above 50 ° C. As the amount of water added increased, the reactivity of the mixture deteriorated and the last 500 ml could be added without increasing the temperature.

After the addition of 1 L of distilled water was completed, the mixture was stirred for about 2 hours. When 50 ml of 30% H ₂ O ₂ was added to the mixture, bubbling occurred in the mixture and turned yellow. After the mixture was stabilized for one day, the clear solution at the top was removed, and the remaining mixture was centrifuged, washed with 5 L of 10% HCl solution, and then washed to remove distilled water. The obtained solid was dried and diluted to prepare a 3 mg / mL dispersion, and the remaining metal was removed by dialysis for 3 days. The concentration of the dispersion can be suitably varied.

The obtained graphite oxide dispersion could be made into a graphene oxide (GO) sheet which was peeled off when the ultrasonic dispersion was continued for about 1 hour. As a result, a colloidal dispersion of individual oxidized graphene sheets was obtained.

PDDA Induced oxidation Grapina restoration

PDDA was used to reduce oxidized graphene. First, 20 mL of PDDA (20 wt%) solution was mixed with 100 mL of the oxidized graphene solution (3 mg / mL) prepared in the previous experimental step for 30 minutes while vigorously stirring. The mixture was placed in an ultrasonic water bath equipped with a temperature controllable heater, heated to 90 < 0 > C, sonicated for 5 hours and placed in a reflux condition.

FIG. 3 is a graph showing the graphene-PDDA colloid reduced by addition of the graphene oxide (0.3 mg mL ^-1 ) colloid and the PDDA according to this experimental example. As shown in FIG. 3, the color of the solution gradually changed to black in the initial tan, indicating that graphene was generated.

EDX (Energy-dispersive X-ray spectroscopy) analysis was performed to analyze the degree of reduction of oxidized graphene. 4 shows the EDX analysis results of the oxidized graphene film and the PDDA reduced graphene film. Referring to FIG. 4, the oxygen atom fraction in the graphene oxide is 46.41%, while the oxygen atom fraction in the PDDA-graphene is 25.98% It can be seen that the reduction remarkably decreased by the reduction. Reduction of the oxidized graphene is possible due to the ammonium group of PDDA.

After refluxing, the resultant was cooled to room temperature, washed with distilled water and filtered. The obtained graphene-PDDA was diluted with distilled water to a concentration of 3 mg / mL. The concentration of the graphene-PDDA dispersion can be suitably varied.

Grapina - PDDA - Iron oxide nanoparticle colloid synthesis

NH ₄ OH solution was used to coprecipitate Fe ² ⁺ and Fe ³ ⁺ to prepare an iron oxide (Fe ₃ O ₄ ) nanoparticle powder. The prepared nanoparticle powder was dispersed in a TMAOH solution. The concentration of the nanoparticle dispersion can be suitably varied. The nanoparticles adsorb OH ^- ions from the solution. As a result, the attached ions give negative charges to the nanoparticles. The zeta potential of the TMAOH-stabilized iron oxide nanoparticles was -7.9 mV. On the other hand, since graphene was functionalized by positively charged PDDA, the PDDA-graphene produced in the above procedure showed a positive zeta potential (54.7 mV).

Negatively charged nanoparticles can be easily coupled to positively charged PDDA-graphene by electrostatic interactions. The 3 mg / mL PDDA-graphene solution and the 3 mg / mL nanoparticle dispersion were uniformly mixed in a 200 ml batch to prepare the graphene-PDDA-iron oxide nanoparticle colloid. The graphene-PDDA-iron oxide nanoparticle colloid thus prepared was immediately used for vacuum filtration.

It is sufficient to use a rotary pump that can simply apply a weak force during the vacuum filtration. After the water is drained out, the membrane filter can be peeled off after removing the water until the remaining membrane filter like paper can be peeled off.

FIG. 5 is a view showing (a) peeled graphene oxide colloid, (b) graphene-PDDA colloid, and (c) graphene-PDDA-iron oxide nanoparticle colloid. As shown in FIG. 5, the black solution of graphene-PDDA turned yellowish brown due to adhesion of iron oxide nanoparticles.

FIGS. 6 and 7 are AFM-measurement results of PDDA-graphene film and PDDA-graphene-nano-particle film, respectively. The measurement was performed on the film formed by dropping the PDDA-graphene solution and the PDDA-graphene-nanoparticle solution droplets, respectively.

As a result of the height measurement, the surface of the obtained graphene is relatively smooth, and the average thickness of the graphene layer is about 0.5 nm as shown in FIG. On the other hand, the graphene-nanoparticle plate shows a very rough surface due to the nanoparticles attached to the surface, and as shown in Fig. 7, the average surface roughness of the graphene-PDDA-iron oxide nanoparticle film is about 3.8 nm do.

Grapina - PDDA - iron oxide nanoparticles Bucky paper Produce

The graphene-PDDA-iron oxide nanoparticle bucky paper was prepared by vacuum filtration of graphene-PDDA-iron oxide nanoparticle colloid using a polycarbonate membrane filter (47 mm in diameter, 0.4 μm in pore size), followed by drying and peeling from the filter . By controlling the amount of colloidal dispersion, the thickness of the graphene-PDDA-iron oxide nanoparticle bucky paper can be controlled. If the amount of the dispersion is large, the thickness of the graphene-PDDA-iron oxide nanoparticle bucky paper becomes large, and if the amount of the dispersion is small, the thickness of the graphene-PDDA-iron oxide nanoparticle bucky paper becomes small. In the experimental example, graphene-PDDA-iron oxide nanoparticle bucky paper of 1 to 30 μm could be produced. The prepared graphene-PDDA-iron oxide nanoparticle bucky paper was analyzed with a sample cut to a size of 15 mm x 10 mm.

Vacuum filtration applies a vacuum under the filter, so there is a certain downward directionality in the movement of the mixture. Thus, the graphene-nanoparticle sheet produced by reduced pressure filtration can be produced with a well-ordered macrostructure.

8 is a photograph of a graphene-PDDA-iron oxide nanoparticle bucky paper according to an experimental example of the present invention. As shown in Fig. 8 (a), the bucky paper is black and has flexibility when it is 10 mu m or more. Various applications are possible in the application of bucky paper. For example, bucky paper may be wound on a stainless steel bar coated with Pt as shown in FIG. 8 (b), or may be pasted on a glass substrate coated with Au as shown in FIG. 8 (c). At this time, conductive silver (Ag) paste can be used. Of course, because bucky paper is free standing, bucky paper alone can be utilized as an electrode material without additional information such as a stainless steel bar or glass substrate. Therefore, the composite material obtained in the form of powder or solution is formed into a film on an additional substrate and then dried, and further substrate is necessarily required. On the other hand, the bucky paper according to the present invention is brought into a desired object It can be used as a simple method of transferring or can be used without any additional description. Therefore, it is convenient for miniaturization of devices.

9 is a SEM photograph of a section of a graphite-PDDA-iron oxide nanoparticle bucky paper fracture. Referring to Fig. 9, the layered structure can be observed throughout the sample. As shown in the top view of FIG. 9, the nanoparticles are observed on the surface of the bucky paper.

10 shows an SEM top view of the surface of a graphene-PDDA-iron oxide nanoparticle bucky paper showing that the arrangement of the graphene-PDDA-iron oxide nanoparticle plate is like a naturally scattered cherry petal. This arrangement, such as a tile structure that engages the van der Waals forces between the plates, imparts flexibility and rigidity to the bucky paper.

11 shows the EDX analysis results of the graphene-PDDA-iron oxide nanoparticles bucky paper according to the experimental example of the present invention. As a result of EDX analysis to confirm the composition of the bucky paper, it was confirmed that the carbon: iron: oxygen atom fraction was 50.16: 13.74: 25.98 as shown in FIG.

The layered structure of the graphene-PDDA-iron oxide nanoparticle bucky paper is also evident from the X-ray diffraction pattern. 12 is an XRD pattern of graphene-PDDA-iron oxide nanoparticle bucky paper. The diffraction peak (G) located at 2? = 26.4 ° is due to the PDDA-graphene (002) interlayer distance. If the graphene (002) diffraction in the bucky paper is wide, it suggests that the PDDA-graphene is not aligned along the lamination direction. This shows that there is a wide PDDA-graphene sheet in free state in the bucky paper. The remaining peaks in Fig. 12 correspond to various diffraction peaks of cubic iron oxide (JCPDS 75-0033).

Grapina - PDDA - iron oxide nanoparticles Bucky paper Manufactured Hydrogen Peroxide Measurement Sensor

The PDDA-graphene-iron oxide nanoparticle bucky paper was cut to a size of 15 mm x 10 mm, and the sample was attached to a glass substrate with Au deposited thereon to prepare a working electrode for a hydrogen peroxide measurement sensor. The reference electrode used in the experiment was an Ag / AgCl electrode and the counter electrode was a platinum counter electrode.

The Au-only electrode shows a small current response to hydrogen peroxide. When the PDDA-graphene-iron oxide nanoparticle nanoparticle bucky paper is attached to the Au electrode as in the experimental example of the present invention, the reduction current rapidly increases. Since graphene has a large surface area and high charge mobility and electrical conductivity, integration of graphene and iron oxide nanoparticles can increase electrocatalytic activity. Thus, the PDDA-graphene-iron oxide nanoparticle bucky paper electrode exhibits excellent performance in hydrogen peroxide sensing.

13 is a cyclic voltammetry graph of PDDA-graphene-iron oxide nanoparticle bucky paper attached to an Au electrode for 50 ppm and 100 ppm presence in the absence of hydrogen peroxide under PBS (0.1 M, pH 7.0) Scan speed of 100 mV / s). From the tendency that the reduction current increases sharply when hydrogen peroxide is introduced, PDDA-graphene-iron oxide It can be seen that the nanoparticle bucky paper exhibits excellent electrocatalytic activity in reducing hydrogen peroxide in an air saturated environment.

Considering the sensitivity and stability of the sensor, -0.2 V was set as the applied potential. The current response increased in proportion to the increase of hydrogen peroxide concentration. Figure 14 shows the relationship between hydrogen peroxide concentration and current response. The hydrogen peroxide chemical sensor manufactured according to the present invention has a linear correlation coefficient of about 0.986 and a linearity over a wide range of 10 ppm (~ 0.3 mM) to 800 ppm (~ 23 mM), which is a conventional sensor using HRP Compared to a wider range. In addition, the hydrogen peroxide chemical sensor according to the present invention showed excellent sensitivity up to 218 μAmM ^-1 cm ^-2 .

In general, insufficient stability of the enzyme electrode is the result of loss and inactivation of the enzyme. However, since the sensor manufactured according to the present invention does not contain an enzyme, it has long stability and can be evaluated by measuring the sensitivity to hydrogen peroxide at atmospheric conditions. The sensor manufactured according to the present invention is a high sensitivity sensor that can detect hydrogen peroxide even at a low concentration because the surface area of the electrode is widened due to the use of graphene.

The electron transfer mechanism during hydrogen peroxide measurement using a graphene-PDDA-iron oxide nanoparticle bucky paper electrode is shown in FIG. For reduction of hydrogen peroxide, Fe ³ ⁺ is reduced to Fe ² ⁺ , while H ₂ O ₂ releases OH ^- . That is, it can be seen that, after the reaction of the following reaction formula 1 occurs, the reaction similar to the reaction formula 2 immediately occurs and the hydrogen peroxide is reduced.

(One)

(2)

Conventionally, sensors using enzymes have a disadvantage that the enzyme is expensive and that the activity of the enzyme is affected by the thermochemical factors, and that the activity of the enzyme decreases when stored for a long time. Since the sensor employing the graphene-PDDA-iron oxide nanoparticle bucky paper electrode manufactured according to the present invention does not use an enzyme, it is stable in the long term and the bucky paper electrode is not exposed to the reduction result, It can be repeatedly used for measurement.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications can be made by those skilled in the art within the technical scope of the present invention. Is obvious. The embodiments of the present invention are to be considered in all respects as illustrative and not restrictive, and it is intended to cover in the appended claims rather than the detailed description thereto, the scope of the invention being indicated by the appended claims, .

Claims

Mixing a solution of graphene-PDDA [poly (diallyldimethylammoniumchloride)] with an iron oxide nanoparticle solution to form a mixed solution; And
And filtering the mixed solution under reduced pressure and drying to obtain free standing graphene-PDDA-iron oxide nanoparticle composite material.

The method of claim 1, wherein the graphene-
Oxidizing the graphite to form a graphite oxide;
Ultrasonically dispersing the graphite oxide to form a colloidal dispersion of individual oxidized graphene sheets; And
And mixing the colloidal dispersion of the oxidized graphene sheet with PDDA to reduce the graphene oxide graphene. The method of producing graphene-PDDA-iron oxide nanoparticle bucky paper according to claim 1,

The method according to claim 1, wherein the iron oxide nanoparticle solution comprises:
Wherein the iron oxide nanoparticle powder is dispersed in a TMAOH solution to obtain a graphene-PDDA-iron oxide nanoparticle bucky paper.

Mixing a solution of graphene-PDDA [poly (diallyldimethylammoniumchloride)] with an iron oxide nanoparticle solution to form a mixed solution;
Filtering the heated mixed solution under reduced pressure and drying to obtain free standing graphene-PDDA-iron oxide nanoparticle composite material; And
And forming an electrode including the composite material to manufacture a hydrogen peroxide measurement sensor.