KR101905317B1 - Sensor for detecting hydrogen peroxidase and method of detecting hydrogen peroxidase using thesame - Google Patents

Abstract

The present invention relates to a nano-composite including transition metal dichalcogenide encapsulated to carbonaceous materials, a manufacturing method of the nano-composite, a sensor for detecting peroxide including the nano-composite, and a method for detecting peroxide using the sensor for detecting peroxide. Since the nano-composite has a remarkably improved electrochemical signal and long lasting stability, the nano-composite can be effectively used for detecting peroxide.

Description

TECHNICAL FIELD The present invention relates to a sensor for detecting hydrogen peroxide and a method for detecting hydrogen peroxide using the same,

The present invention relates to a nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material, a method for producing the nanocomposite, a sensor for detecting hydrogen peroxide including the nanocomposite, and a method for detecting the hydrogen peroxide And a method for detecting hydrogen peroxide using the sensor.

Biosensor based biosensors have received great attention because of their wide applicability in disease diagnosis and medical applications. Biomaterials such as protein and DNA are used in the production of biosensor based biosensors because of their high reaction rate and high selective reactivity with target materials. Among them, metalloprotein possesses inherent redox potential and is considered suitable for signal detection for the measurement of specific substances.

However, such biosensor-based biosensors have some limitations. For example, non-uniform immobilization of biomaterials on a widely used substrate, low electrochemical signals in measurement, and electron transfer characteristics that appear slowly in layers above a double phase show limitations in ensuring accuracy and practicality of measurement.

Numerous types of nanomaterials have been used to overcome the problems of bio-based biosensors, and the excellent conductivity, electron transfer capability and biocompatibility of carbon-based nanomaterials such as carbon nanotubes and graphene Based biosensors and bioelectronic devices by combining them with biomaterials.

In recent years, Transition metal dichalcogenide (TMD) has been attracting attention as a new material that has been evaluated as superior to graphene. Molybdenum disulfide or bismuth selenide belong to the TMD. However, until now, studies using TMD materials have mostly been confined to the study of synthesis in sheet form.

Hydrogen peroxide is a substance that plays an important role in research on cellular mechanisms and therapeutics in biological and medical fields. Hydrogen peroxide is a reactive oxygen species (ROS) that can cause cell and tissue damage, and is more active and unstable than normal oxygen, making it one of the major causes of cancer and other diseases and aging. It is a substance which is attracted to many researchers for accurate measurement and elimination because it often adversely affects the cell mechanism.

For this reason, sensors for measuring hydrogen-peroxide in the market are being developed and distributed. The biosensor for measuring hydrogen peroxide can be used mainly for the measurement of hydrogen peroxide in an industrial purification apparatus including a wastewater treatment facility and also for sterilization or purification of landfill, various water and ground water.

In particular, the direct redox property of a metal protein is suitable for the purpose of rapidly detecting a specific molecule. The electrochemical signals generated by the metal proteins can be obtained simply by using electrochemical techniques, and thus, a variety of metal protein-based biosensors have been studied.

However, in the conventional electrode, in the interaction between the metal protein and the target molecule, the biomolecule on the electrode has an unintended orientation, the electrochemical signal derived from the biomolecule is weak, the electron transfer rate is slow, There was a limit in not being constant.

To improve this, new types of electrodes, such as gold nanoparticles and dendritic polymer based electrodes, have been used to develop bioelectronic devices and biosensors with amplified electrochemical signals and sensitivities, Promoting transmission of the disease. However, the biosensor manufactured by such a study has a complicated manufacturing process and a limited possibility of improving the sensitivity.

Numerous papers and patent documents are referenced and cited throughout this specification. The disclosures of the cited papers and patent documents are incorporated herein by reference in their entirety to better understand the state of the art to which the present invention pertains and the content of the present invention.

The present inventors have anticipated that if transition metal dichalcogenide (TMD) materials are synthesized as nanoparticles, it would be possible to maximize the effect according to the enlargement of the surface area. In addition, by binding with biocompatible materials such as graphene It was judged that it would be useful for bonding with a biomaterial by maximizing the electron transfer effect by improving the mobility.

The present inventors have tried to develop a sensor for detecting hydrogen peroxide which is excellent in sensitivity and stability. As a result, the present inventors have completed the present invention by confirming that electrochemical signals are greatly improved and stability is sustained when a biosensor based on MoS ₂ nanoparticle-oxide graphene complex is used.

It is therefore an object of the present invention to provide a nanocomposite comprising a transition metal chalcogenide encapsulated with a carbonaceous material.

Another object of the present invention is to provide a method for producing the nanocomposite.

It is still another object of the present invention to provide a sensor for detecting hydrogen peroxide comprising the nanocomposite.

It is still another object of the present invention to provide a method for detecting hydrogen peroxide using the sensor for detecting hydrogen peroxide.

In the present invention, MoS ₂ nanoparticle-graphene complexes were prepared by synthesizing MoS ₂ nanoparticles after surface modification with amine groups and encapsulating them with oxidized graphene in order to maintain the electrochemical signals and biomaterial stability of the biosensor.

The complex can be used as a platform of a biosensor, and it can improve the electrochemical signal and maintain the stability of myoglobin for a long time when measuring hydrogen peroxide by myoglobin. The MoS ₂ nanoparticle-oxidized graphene composite-based biosensor developed through the present invention can be used in a variety of bio-medical field development and biopharmaceutical fields including a sophisticated biosensor that can be practically used.

One aspect of the invention is a nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material.

The transition metal chalcogenide is one which is surface-modified with at least one functional group selected from the group consisting of an amine group (-NH ₂ ), a carboxyl (-COOH) group, a cyan (-SH) group and a hydroxy And may be, for example, surface-modified with an amine group, but is not limited thereto.

The carbonaceous material may be graphene, carbon nanofiber, carbon nanotube, or graphite, and may be, for example, oxidized graphene, but is not limited thereto.

In addition, the carbonaceous material may include an oxide of a carbonaceous material, but is not limited thereto.

In one embodiment of the present invention, the transition metal is selected from the group consisting of Mo, Bi, Ti, V, Nb, Ta and W And may be, for example, molybdenum, but is not limited thereto.

In one embodiment of the present invention, the transition metal chalcogenide is one wherein the transition metal is chalcogenated with at least one chalcogen element selected from the group consisting of sulfur (S), selenium (Se) and tellurium (Te) For example, the transition metal may be chalcogenated with sulfur, but is not limited thereto.

Another aspect of the present invention is directed to a method of making a nanocomposite comprising the steps of:

A step of modifying the surface of the transition metal dichalcogenide; And

An encapsulation step of encapsulating the transition metal chalcogenide with a carbonaceous material.

In one embodiment of the invention, the encapsulation step may be to encapsulate the transition metal chalcogenide with the carbonaceous material by electrostatic attraction.

As used herein, the term " encapsulation " means that the transition metal chalcogenide nanoparticles are surrounded by a carbonaceous material having a regular structure through electrostatic attraction.

The surface modification may be surface modification with at least one functional group selected from the group consisting of an amine group, a carboxyl group, a seed group and a hydroxyl group, and may be, for example, an amine group, but is not limited thereto.

An organic material that can be used for surface modification of the transition metal chalcogenide may be introduced and surface modified with an amine group to induce it to be encapsulated by graphene oxide due to electrostatic attraction.

The surface modification and encapsulation may each independently be performed at a reaction time of 6 to 24 hours. For example, the reaction time may be 6 to 12 hours, but is not limited thereto. In order to sufficiently react, the reaction time can be set to 6 hours or more, and it is unnecessary to exceed 24 hours.

Also, the surface modification and encapsulation may be performed independently at a reaction temperature of 0 to 10 ° C, for example, the reaction temperature may be 0 to 4 ° C, but is not limited thereto.

Another aspect of the present invention relates to a sensor for detecting hydrogen peroxide comprising a nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material.

The sensor for detecting hydrogen peroxide may be one in which a carbonaceous substance is bound to a metal protein.

The metal protein may be selected from the group consisting of myoglobin, azurine, hemoglobin, hemerythrin, cytochrome, iron-sulfur protein, rubredoxin, flasks Toshima not (plastocyanine), ferritin (ferritin), PRA jasmine Cellulofine (ceruloplasmin), carbonic anhydrase (carbonic anhydrase), vitamin B ₁₂ - dependent enzymes (vitamin B ₁₂ -dependent enzyme), nitro dehydrogenase kinase (nitrogenase), The proteins of the present invention include superoxide dismutase, chlorohyll-binding protein, calmodulin, glucose-6-phosphate, hexokinase, DNA polymerase A DNA polymerase, a vanabin, an arginase, a catalase, a hydrogenase, an iron-responsive element binding protein, an aconitase, Urease, cytochrome oxidase (a), laccase, alcohol dehydrogenase, carboxypeptidase, aminopeptidase,? -amyloid protein, nitrate reductase, glutathione May be one or more selected from the group consisting of glutathione peroxidase, metallothionein and phosphatase, and may be, for example, myoglobin, but is not limited thereto.

The binding of the metal protein to the carbonaceous substance may be performed at a reaction temperature of 0 to 10 ° C, for example, the reaction temperature may be 0 to 4 ° C, but is not limited thereto. A method for maintaining the activity of the metal protein in an optimal state can be performed by setting conditions at the same temperature as that for preparation or storage of the metal protein before the reaction.

The myoglobin is a redox enzyme containing a heme group in which a redox reaction can take place, and a redox reaction of Fe ^{3 +} and Fe ^{2 +} occurs due to peroxide. The myoglobin may form one or more layers on the surface of the carbonaceous substance.

The nanocomposite may be immobilized on a substrate by a chemical linker.

The nanocomposite contained in the sensor for detecting hydrogen peroxide of the present invention may be immobilized on a substrate. For example, a solid substrate made of an organic polymer or inorganic materials may be used, , Any of the substrates usable in the present invention can be used regardless of the surface characteristics.

The metal which can be used as a solid substrate in the present invention may include all of the metals, metal oxides and alloys, and examples thereof include alloys of gold, silver, copper, platinum, copper, For example, an alloy of gold and copper) or a metal oxide substrate, but is not limited thereto, and any metal used in the art can be used.

In addition, the solid substrate may include not only a solid substrate made of a metal but also a substrate coated with a metal.

In the solid substrate used in the present invention, the shape, size and chemical composition of the surface are not particularly limited.

The chemical linker may be one containing at least one functional group selected from the group consisting of a cyan (-SH) group, an amine (-NH ₂ ) group and a carboxyl (-COOH) group bonded to the substrate at a first end, For example, it may be a seed, but is not limited thereto.

In addition, the chemical linker may contain at least one functional group selected from the group consisting of a silyl group, an amine group and a carboxyl group bonded to the nanocomposite at the second terminal. For example, the chemical linker may be an amine group, It is not.

As described above, the nanocomposite can be immobilized on a substrate using a chemical linker. By immobilizing myoglobin, which is a metal protein capable of measuring hydrogen peroxide, in the graphene oxide portion of the nanocomposite, electrochemical signals are greatly improved and the stability of myoglobin It can be confirmed as shown in FIG. 1 that there is a long-lasting effect.

The sensor for detecting hydrogen peroxide may additionally include three electrodes including a working electrode, a reference electrode, and a counter electrode, but the present invention is not limited thereto. In the sensor for detecting hydrogen peroxide of the present invention, it is possible to use a previous electrode system, but in the three electrode system, a reference electrode which is a comparative electrode is used, so that an accurate current value can be measured.

Another aspect of the present invention relates to a method for detecting hydrogen peroxide comprising the steps of:

(a) contacting a sample to a sensor for detecting hydrogen peroxide comprising a nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material; And

(b) measuring an electrical signal generated by the sensor for detecting hydrogen peroxide.

The present invention relates to a nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material, a method for producing the nanocomposite, a sensor for detecting hydrogen peroxide including the nanocomposite, and a method for detecting the hydrogen peroxide The sensor for detecting hydrogen peroxide of the present invention can be effectively used for the detection of hydrogen peroxide because the electrochemical signal is greatly improved and the stability is maintained for a long time.

1 is a schematic diagram of a sensor for detecting hydrogen peroxide according to an embodiment of the present invention.
2A shows X-ray diffraction (XRD) analysis results of molybdenum disulfide (hereinafter referred to as MoS ₂ ) nanoparticles synthesized according to an embodiment of the present invention.
FIG. 2B shows a transmission electron microscope (TEM) image of GO @ MoS ₂ synthesized according to an embodiment of the present invention.
2C shows a TEM image of the oxidized graphene.
FIG. 2D shows a TEM image of GO @ MoS ₂ synthesized according to an embodiment of the present invention.
FIG. 2E shows UV-vis (ultraviolet-visible spectroscopy) spectroscopic results of MoS ₂ nanoparticles according to surface modification.
FIG. 2F shows the result of UV-vis analysis of MoS ₂ nanoparticles according to encapsulation.
3A shows the results of an atomic force microscope (AFM) analysis of a gold substrate on which nothing is processed.
3B shows the AFM analysis result of the gold substrate on which the MoS ₂ nanoparticles are immobilized.
FIG. 3C shows the AFM analysis result of a gold substrate on which graphene oxide (hereinafter referred to as GO) is immobilized.
FIG. 3D shows an AFM analysis result of a gold substrate on which GO @ MoS ₂ is immobilized.
3E shows an SEM image of a gold substrate on which GO @ MoS ₂ is immobilized.
Figure 3f is a GO @ MoS ₂ is immobilized against a gold substrate GO @ MoS ₂ myoglobin (myoglobin, less Mb) current measurement method is a sensor for a complete detection (Mb / GO @ MoS ₂₎ immobilized on (cyclic voltammetry, hereinafter CV ) Analysis graph.
FIG. 4 shows energy dispersive X-ray spectroscopy (EDX) analysis results of a gold substrate on which GO @ MoS ₂ is immobilized.
FIG. 5A shows a result of surface analysis of a gold substrate on which only cysteamine, which is a chemical linker, was immobilized on a gold substrate not subjected to any treatment.
FIG. 5B shows the surface analysis result of the gold substrate on which GO @ MoS ₂ is immobilized.
FIG. 5C shows a surface analysis result of a gold substrate immobilized with Mb / GO @ MoS ₂ bonded with myoglobin.
6A is a cyclic voltammetry (CV) graph of Mb / GO @ MoS ₂ versus a gold substrate on which only myoglobin is immobilized.
6B shows a CV graph of Mb / GO @ MoS ₂ versus a gold substrate immobilized with only oxidized graphene and myoglobin (Mb / GO).
6C shows a CV graph of Mb / GO @ MoS ₂ versus a gold substrate immobilized with only MoS ₂ nanoparticles and myoglobin (Mb / MoS ₂ NP).
6D shows a graph of the oxidation current peak value of Mb / GO @ MoS ₂ over time.
FIG. 6E shows the average value of redox current peaks ((r): reduction current peak value, (o): oxidation current peak value) of Mb / GO @ MoS ₂ relative to a gold substrate immobilized with only myoglobin.
FIG. 7A shows the result of confirming Mb / GO @ MoS ₂ according to the hydrogen peroxide input using an amperometric it curve.
FIG. 7B shows the result of current measurement analysis of Mb / GO @ MoS ₂ versus gold substrate immobilized with only myoglobin (Mb).
Figure 7c shows a graph showing selective hydrogen peroxide detection of Mb / GO @ MoS ₂ .
Figure 7d shows a graph showing the hydrogen peroxide detection limit of Mb / GO @ MoS ₂ .

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these examples are for illustrative purposes only and that the scope of the present invention is not construed as being limited by these examples.

Example 1: Experimental material

Myoglobin (Sigma-Aldrich, USA) was buffered with phosphate buffered saline (PBS) solution (Sigma-Aldrich, USA). Gold electrodes were prepared at the National Nanofab Center (Korea). 6-Mercaptohexanoic acid (hereinafter referred to as 6-MHA) and cysteamine were purchased from Sigma-Aldrich and H ₂ O ₂ and H ₂ SO ₄ were purchased from Daejung Chemical Korea . Graphene oxide (GO) was purchased from Graphene Supermarket (USA). Distilled water was purified through a Milli-Q system (Millipore, USA). Sodium molybdate, hydrazine hydrate and Aliquat HTA-1 (Sigma-Aldrich, USA) were used for the synthesis of molybdenum disulfide (MoS ₂ ) nanoparticles. L-Homocysteine thiolactone hydrochloride (L-hth) from Sigma-Aldrich was used for surface modification of MoS ₂ NP. A transmission electron microscopy grid was obtained from Ted Pella Inc (USA). The sensor for detecting hydrogen peroxide prepared according to one embodiment of the present invention using L-ascorbic acid (AA), sodium bicarbonate (NaHCO ₃ ) and sodium nitrite (NaNO ₂ ) solution (all Sigma-Aldrich) Were evaluated.

Example 2: Synthesis of nanoparticles and preparation of nanoparticle-oxidized graphene complexes

MoS ₂ nanoparticles were synthesized and then reacted with chemical functional groups for surface modification to modify the surface to an amine group (-NH ₂ ). Followed by electrostatic attraction with oxidized graphene to form MoS ₂ nanoparticle-oxide graphene complex (GO @ MoS ₂ ).

2-1. Nanoparticle synthesis

To synthesize MoS ₂ nanoparticles, 1 g of sodium molybdate was dissolved in 25 mL of distilled water (DI water), and then 2 mL of Aliquat HTA-1 (1.98 g) and 8.24 mM of sodium sulfide sodium sulfide) in a nitrogen gas atmosphere for 30 minutes. After the addition of 2 mL of hydrazine hydrate, an additional reaction was performed for 30 minutes. 5 mL of 1 M hydrochloric acid was added and reacted for 5 hours at 373 K. The reaction solution was purified using filter paper and washed with distilled water and ethanol to obtain the synthesis of MoS ₂ nanoparticles . And finally dried at 70 캜 for 3 hours to obtain synthesized MoS ₂ nanoparticles.

2-2. Manufacture of nanoparticle-oxide graphene complex

In order to modify the surface of the nanoparticles to an amine group, the synthesized MoS ₂ nanoparticles were mixed with L-homocysteine thiolactone hydrochloride (L-hth) at a reaction ratio of 1:10, For a period of time to obtain surface-modified MoS ₂ nanoparticles. Subsequently, GO @ MoS ₂ was finally obtained by reacting the surface modified MoS ₂ nanoparticles and the oxidized graphene (GO) at a ratio of 10: 1 at room temperature for 6 hours.

2-3. Structure verification

XRD (X-ray diffraction) was performed to confirm the crystal structure of the synthesized MoS ₂ nanoparticles.

As can be seen from FIG. 2A, it was confirmed that the peaks at 2θ values of 14, 16, 24, 42 and 59 corresponding to the hexagonal phase of the MoS ₂ nanoparticles were broad. In addition, broad peaks were observed at 2? Values of 42-45 mainly due to the amorphous nature of MoS ₂ nanoparticles. The XRD pattern of the MoS ₂ nanoparticles not surface modified shows no sharp peaks and therefore poor crystallinity. Therefore, it was confirmed that the entire spectrum shows the typical characteristics of amorphous MoS ₂ .

Then, the structure of the synthesized MoS ₂ nanoparticles, the graphene oxide and the GO @ MoS ₂ complex was confirmed by scanning electron microscopy (SEM) and transmission electron microscope (TEM) images , And the results are shown in Figs. 2B to 2D.

As can be seen in FIG. 2B, TEM micrographs of the synthesized MoS ₂ nanoparticles show their morphological and nanostructural characteristics. MoS ₂ nanoparticles have an average diameter of about 10 nm, are well dispersed, stable, and uniform. TEM images also show a well-dispersed cubic morphology of MoS ₂ nanoparticles.

The TEM image of the GO can be seen in FIG. 2c, but the particle size of the GO exceeds 200 nm to 500 nm (not shown in FIG. 2c). The aggregated form of GO was also confirmed.

As can be seen in FIG. 2d, there was a structural characteristic in which small MOS ₂ nanoparticles were closely packed in the shape of the GO, and thus it was confirmed that the image shown in FIG. 2d is a composite composed of GO and MOS ₂ nanoparticles .

UV-vis (ultraviolet-visible spectroscopy) analysis of the surface modification of the MoS ₂ nanoparticles and the difference in encapsulation results is shown in FIGS. 2E and 2F. For UV-vis analysis, UV-vis spectrophotometer (Nanodrop 2000, Thermo scientific) was used.

FIG. 2E shows the UV spectrum of MoS ₂ nanoparticles, L-hth and L-hth surface-modified MoS ₂ nanoparticles. The UV peaks for MoS ₂ nanoparticles are located at 240 nm, the relatively small for L-hth and the large UV peaks at 250 and 220 nm, respectively. The UV results for L-hth surface-modified MoS ₂ nanoparticles show peaks at 240 nm and 220 nm, respectively, which correspond to the results for MoS ₂ nanoparticles and L-hth, respectively.

In Figure 2f, the UV peaks of the surface modified MoS ₂ nanoparticles, GO and GO @ MoS ₂ are shown. The UV result of GO shows only the peak appearing at 230 nm. The UV peak of GO @ MoS ₂ is similar to the UV peak measured on surface modified MoS ₂ nanoparticles, but it is deformed. They overlap the UV peak of the surface modified MoS ₂ nanoparticles at about 290 nm. UV peak at 290 nm of the GO @ MoS ₂ is present in a higher position than the MoS ₂ The surface modification. These results may be due to the encapsulation of MoS ₂ surface modified by GO.

Since the UV peak value of GO is longer at 250 nm than the UV peak value of the surface modified MoS ₂ nanoparticles, encapsulation of the MoS ₂ nanoparticles by the GO results in a UV peak having the shape of the UV peak of GO @ MoS ₂ .

Example 3: Nanoparticle-oxidized graphene complex and myoglobin immobilization

MoS ₂ nanoparticle-oxide graphene complex (GO @ MoS ₂ ) and myoglobin (Mb) were immobilized on a gold substrate for the production of a sensor for detecting hydrogen peroxide.

Specifically, 10 mM cysteamine was immobilized on a gold substrate at 4 캜 for 3 hours. The thiol group (-SH) of cysteamine reacted with the gold of the substrate and immobilized by a self-assembly method so that the amine group is located in the opposite direction to the substrate. Thereafter, the fabricated nanoparticle-oxidized graphene composite was immobilized at a temperature of 4 캜 for 3 hours. The carboxyl group (-COOH) of the GO located on the surface of the nanoparticle-graphene complex reacted with the amine group of cysteamine and electrostatically attracted and immobilized. Finally, the biosensor was fabricated by immobilizing myoglobin at 4 ° C for 3 hours.

The immobilization of the nanoparticle-oxidized graphene composite of the prepared biosensor for the detection of hydrogen peroxide on a gold substrate was performed using a scanning tunneling microscope (STM), a scanning electron microscope (SEM) and an energy dispersive spectroscopy (Energy Dispersive X-ray Spectroscopy, hereinafter referred to as EDX), and the results are shown in FIGS. 3A to 3C, respectively.

As can be seen in Figure 3a, the STM image of the gold substrate without any treatment shows a regular pattern with a height of 2.98 nm.

As it can be found at 3b, according to the STM image of a Au substrate fixing the MOS ₂ nanoparticles MOS ₂ nanoparticles was found to be 7.95 nm to increase a size of about 10 nm.

As can be seen in FIG. 3C, according to the STM image of the gold substrate on which the GO particles are fixed, the diameter of the GO particles is 250 nm and the height is 11.75 nm.

As can be seen in FIG. 3D, according to the image confirmed by STM after immobilizing a composite composed of G0 and MOS ₂ nanoparticles on a gold substrate, G0 is surrounded by MOS ₂ , so the total diameter is reduced compared to GO It can be confirmed that the height increases in comparison with FIGS. 3B and 3C.

As can be seen in FIG. 3E, it can be confirmed that MoS ₂ nanoparticles (about 10 nm in size) are encapsulated by GO through a SEM image of a gold substrate immobilized with GO @ MoS ₂ .

As shown in FIG. 3F, when the myoglobin immobilized on the gold substrate was analyzed by cyclic voltammetry (CV), it was confirmed that the redox peak inherent to myoglobin was fixed by immobilizing myoglobin on the complex, Respectively.

Next, the gold substrate immobilized with GO @ MoS ₂ analyzed by the SEM image in FIG. 3C was subjected to EDX analysis, and the results of the analysis were subjected to compositional analysis according to ratios.

Element Unn. [wt.%] C norm. [wt.%] Catom. [at.%] C Error [at.%] Carbon 5.66 8.12 40.72 2.13 Gold 51.31 73.62 22.51 5.82 Silicon 4.83 6.93 14.86 0.68 Nitrogen 0.75 1.08 4.64 0.45 Chlorine 1.44 2.06 3.51 0.22 Oxygen 0.55 0.79 2.98 0.33 Sodium 0.04 0.06 0.16 0.09 Sulfur 3.36 4.82 9.05 0.43 Molybdenum 1.75 2.51 1.58 0.26 Total 69.69 100.00 100.00

As can be seen from FIG. 4, Mo, S, and C, which are components of the composite, were analyzed. As a result, it was confirmed that GO @ MoS ₂ identified by the SEM image is a composite composed of GO and MoS ₂ .

In addition, the immobilization process at each step was confirmed by surface roughness change and average height change using a surface profiler, and the results are shown in Table 2 and FIG. 5.

Ra Rq Bare gold 1.92 nm 2.6 nm Cysteamine 1.96 nm 2.78 nm GO @ MoS ₂ 18.57 nm 26.36 nm Mb / GO @ MoS ₂ 53.26 nm 70.44 nm

Table 2 shows that the surface roughness value increases as the linker (cysteamine), GO @ MoS ₂ complex, and myoglobin are layered on the gold substrate in order. As a result, the atomic force microscope (AFM) Likewise, it means a result of confirming immobilization of the biosensor and corresponds to FIGS. 5A to 5C.

As can be seen from FIG. 5A, the surface roughness value was increased by the presence of cysteamine, and the surface roughness value was further increased as the GO @ MoS ₂ complex was bonded after cysteamine bonding as shown in FIG. 5B. Likewise, the surface roughness value was further increased by the binding of myoglobin after the binding of the GO @ MoS ₂ complex.

Example 4: Electrochemical characterization of biosensor

 The electrochemical characteristics of the fabricated sensor for the detection of hydrogen peroxide were analyzed to confirm the improvement of the electrochemical signal and the stability of the biomaterial.

Specifically, for the electrochemical analysis, a three electrode system composed of Ag / AgCl reference electrode, working electrode and platinum wire counter electrode was constructed, and electrochemical analysis was conducted using the electrode system Respectively.

CV (cyclic voltammetry) analysis was performed to confirm the electrochemical property and sensing performance of the biosensor in detecting H ₂ O ₂ by using the manufactured biosensor. Particularly, the effect due to the immobilization of GO @ MoS ₂ For confirmation, GO @ MoS ₂ was used to identify electrochemical signals from non-immobilized myoglobin-based biosensors.

CV analysis was performed between 600 mV and -200 mV, and PBS solution was used as an electrolyte. The electrochemical signal enhancement was confirmed through the results of the CV analysis. The prepared substrate was stored at room temperature. The CV was measured from the day of manufacture to the 9th day as the date passed. The results are shown in Tables 3, 6A to 6E Respectively.

Day One 3 5 7 9 Current (μA) 1.87 1.85 1.82 1.75 1.71

As can be seen from FIG. 6A, the electrochemical signals of the Mb / GO @ MoS ₂ composite were compared with those of the gold substrate on which nothing was treated and the gold substrate on which the myoglobin was immobilized.

As shown in FIG. 6B, the electrochemical signal was improved by comparing the CV analysis result of the Mb / GO @ MoS ₂ complex with the Mb / Go without MoS ₂ nanoparticles.

As can be seen from FIG. 6C, the electrochemical signals of the Mb / GO @ MoS ₂ composite were improved by comparing the CV analysis results with the Mb / MoS ₂ nanoparticles having no GO.

As shown in FIG. 6D, the biosensor immobilized with Mb / GO @ MoS ₂ maintained the redox property at room temperature for 9 days, and the redox peak current slightly decreased from 1.87 μA on the first day to 1.71 μA on the ninth day. On the 9th day, the biosensor showed that the electrochemical redox peak was improved compared to the result on the gold substrate immobilized with myoglobin. The graph of FIG. 6D reflects the standard deviation (SD) after 5 measurements, and the biocompatibility of GO affects the stability of the biosensor for 9 days at room temperature.

As can be seen from FIG. 6E, the reproducibility of the fabricated biosensor is shown as redox peak and compared. It was further confirmed that the peak value was also significantly increased when the Mb / GO @ MoS ₂ complexes were compared to those measured only for myoglobin.

Example 5: Measurement of hydrogen peroxide using a biosensor

Electrode system composed of a platinum counter electrode and an Ag / AgCl reference electrode was constructed using the prepared biosensor as a working electrode in order to confirm the hydrogen peroxide detection effect of the biosensor manufactured using the Mb / GO @ MoS ₂ complex. A PBS solution (pH = 7.4) was used as a buffer for electrochemical measurements.

Specifically, 10 μL of a 10 mM hydrogen peroxide solution was continuously added to 3 mL of an electrolytic solution of PBS to confirm the reaction of the biosensor, thereby obtaining data by an amperometric i-t curve. The initial potential before the reaction was set to -0.2 V to completely reduce myoglobin.

As can be seen from FIG. 7A, the manufactured biosensor responded to the continuous input of hydrogen peroxide stably, and the current value was continuously increased according to the analysis by the current measurement method.

As shown in FIG. 7B, it was confirmed that the electrochemical signal in the hydrogen peroxide measurement was improved by comparing hydrogen peroxide to the biosensor (Mb) immobilized with only myoglobin and comparing the data by the current measurement method.

As shown in FIG. 7C, in order to confirm the selective measuring ability of Mb / GO @ MoS ₂ , the same amounts of L-ascorbic acid (AA), NaNO ₂ and NaHCO ₃ were added continuously with hydrogen peroxide and hydrogen peroxide Only the results of selective measurements could be obtained.

As shown in FIG. 7D, the detection limit of the detection sensor can be confirmed by measuring the current value by measuring the current by varying the concentration of hydrogen peroxide from 100 nM to 10 nM to obtain the final detection limit value . At 100, 50, and 20 nM, the measured current value increased, but at 10 nM level, there was almost no change. As a result, the detection limit was found to be 20 nM.

Having described specific portions of the present invention in detail, those skilled in the art will appreciate that these specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (16)

A nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material. The method according to claim 1, wherein the transition metal chalcogenide is at least one selected from the group consisting of an amine group (-NH ₂ ), a carboxyl (-COOH) group, a cyan (-SH) group and a hydroxy Wherein the nanocomposite is surface modified with functional groups. The nanocomposite according to claim 1, wherein the carbonaceous material is graphene, carbon nanofiber, carbon nanotube or graphite. The nanocomposite according to claim 1, wherein the carbonaceous material comprises an oxide of a carbonaceous material. The method of claim 1, wherein the transition metal is selected from the group consisting of Mo, Bi, Ti, V, Nb, Ta, Nanocomposites that are more than species. The method of claim 1, wherein the transition metal chalcogenide is one wherein the transition metal is chalcogenated with one or more chalcogen elements selected from the group consisting of sulfur (S), selenium (Se), and tellurium (Te) Complex. A process for preparing a nanocomposite comprising the steps of:
A step of modifying the surface of the transition metal dichalcogenide; And
An encapsulation step of encapsulating the transition metal chalcogenide with a carbonaceous material. 8. The method of claim 7, wherein the encapsulating step is encapsulating the transition metal chalcogenide with the carbonaceous material by electrostatic attraction. The method according to claim 7, wherein the surface modification is performed by using at least one functional group selected from the group consisting of an amine group (-NH ₂ ), a carboxyl (-COOH) group, a cyan (-SH) group, and a hydroxy Wherein the nanocomposite is reformed. A sensor for detecting hydrogen peroxide comprising a nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material. 11. The sensor for detecting hydrogen peroxide according to claim 10, wherein the sensor for detecting hydrogen peroxide is a metal protein bonded to a carbonaceous substance. 12. The method of claim 11, wherein the metal protein is selected from the group consisting of myoglobin, azurine, hemoglobin, hemerythrin, cytochrome, iron-sulfur protein, BRAY single (rubredoxin), plasminogen Toshima not (plastocyanine), ferritin (ferritin), cellulite in plastic jasmine (ceruloplasmin), carbonic anhydrase (carbonic anhydrase), vitamin B ₁₂ - dependent enzymes (vitamin B12-dependent enzyme), nitro dehydrogenase (Eg, nitrogenase, superoxide dismutase, chlorohyll-binding protein, calmodulin, glucose-6-phosphate, hexokinase, , DNA polymerase, vanabin, arginase, catalase, hydrogenase, iron-responsive element binding protein, (Aconitase), urease (urease), cytochrome acid It is also possible to use enzymes such as cytochrome oxidase, laccase, alcohol dehydrogenase, carboxypeptidase, aminopeptidase, β-amyloid protein, nitrate reductase Wherein the sensor is one or more selected from the group consisting of glutathione peroxidase, metallothionein, and phosphatase. 11. The sensor for detecting hydrogen peroxide according to claim 10, wherein the nanocomposite is immobilized on a substrate by a chemical linker. The chemical linker according to claim 13, wherein the chemical linker has at least one functional group selected from the group consisting of a cyan (-SH) group, an amine (-NH ₂ ) group, and a carboxyl (-COOH) And at least one functional group selected from the group consisting of a silanol group, an amine group, and a carboxyl group bonded to the nanocomposite at the second terminal. 11. The sensor for detecting hydrogen peroxide according to claim 10, wherein the sensor further comprises three electrodes consisting of a working electrode, a reference electrode and a counter electrode. A hydrogen peroxide detection method comprising the steps of:
(a) contacting a sample to a sensor for detecting hydrogen peroxide comprising a nanocomposite comprising a transition metal dichalcogenide encapsulated with a carbonaceous material; And
(b) measuring an electrical signal generated by the sensor for detecting hydrogen peroxide.

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