KR20110026972A - Bio sensing method, apparatus and system using graphene oxide - Google Patents

Abstract

PURPOSE: A bio-sensing method using a graphene oxide and a sensor are provided to optically identify the presence of material and to ensure economic benefit. CONSTITUTION: A bio-sensor comprises a target material which is labeled with a metal particle and a probe substance which is conjugated to a graphene oxide with fluorescence characteristic. In case of binding the target material and probe, fluorescence characteristic is reduced by metal particles of the target material. The target and probe material is DNA. A bio-sensing method comprises: a step of contacting the target material labeled with a metal particle; and a step of measuring graphene oxide fluorescence intensity.

Description

Bio-sensing method, apparatus and system using graphene oxide using graphene oxide

The present invention relates to a biosensor using a graphene oxide, a sensing method and a system thereof, and more particularly, by using the inherent fluorescence properties of the graphene oxide itself without the use of a dye for dyeing the target material, The present invention relates to a biosensor using graphene oxide, a sensing method, and a system thereof, which can be optically distinguished from each other, and which is economical by avoiding the use of a complicated and expensive dye.

Graphene refers to a planar monolayer structure in which carbon atoms are filled into a two-dimensional (2D) lattice, which forms the basis for all other dimensional graphite materials. That is, the graphene may be a basic structure of graphite stacked in a fullerene, a one-dimensional nanotube, or a three-dimensional structure. In 2004, Novoselev et al reported that a free-standing graphene monolayer was obtained on top of a SiO2 / Si substrate, which was found experimentally by mechanical microfractionation. In recent years, many research groups have shown that graphene has unique physical properties due to its honeycomb crystal structure, two interpenetrating triangular sub lattice structures, and one atomic size. For example, attention is paid to the fact that it shows zero band gap). In addition, graphene has unique charge transport characteristics, which causes graphene to exhibit a unique phenomenon that has not been observed in the past. For example, the semi-integer quantum Hall effect, the bipolar supercurrent transistor effect, and the like are examples, and this is also considered to be due to the unique structure of the graphene described above.

However, a technique for practically applying graphene exhibiting such unique characteristics has not been sufficiently disclosed. In particular, the technology of applying graphene to the bio-industry tends to aggregate in a hydrophilic environment has not yet been disclosed.

Accordingly, an object of the present invention is to provide a biosensing method using graphene oxide.

Another object of the present invention is to provide a biosensor using graphene oxide.

Another object of the present invention is to provide a bio-sensing system using graphene oxide.

The present invention to solve the above problems is a target material labeled with metal particles; And a probe material bound to graphene oxide exhibiting fluorescence properties, wherein when the target material and the probe material combine, the metal particles of the target material reduce the fluorescence property of the graphene oxide. Provide a biosensor. In one embodiment of the invention the target and probe material is DNA, and in another embodiment of the invention the target and probe material are antigen and antibody, respectively.

The metal particles may be metal nanoparticles capable of reducing the fluorescence intensity of the graphene oxide, and the metal nanoparticles may be gold nanoparticles. The target DNA and the probe DNA are also single stranded DNA, and metal particles may be linked to the target DNA. The antigen and the metal particles may be linked by polymers, in particular single stranded DNA.

In order to solve the above another object, the present invention comprises the steps of contacting the target material labeled with a metal particle to the graphene oxide bonded to the probe material surface; And it provides a bio-sensing method comprising the step of measuring the graphene oxide fluorescence intensity before, after the contact. The metal particles are metal nanoparticles capable of reducing the fluorescence intensity of the graphene oxide, and the metal may be gold.

One embodiment of the present invention for solving the above problems is the step of contacting the target DNA labeled with a metal particle to the graphene oxide bonded to the probe DNA surface; And measuring the graphene oxide fluorescence intensity before and after the contact, wherein the DNA is a single strand, and the target DNA and the probe DNA are complementarily bound to each other. , The fluorescence intensity of the graphene oxide is reduced. Another embodiment of the present invention comprises the steps of contacting the antigen labeled with a metal particle to the graphene oxide antibody is bound to the surface; And measuring the graphene oxide fluorescence intensity before and after the contact, and another embodiment of the present invention provides an antigen to graphene oxide having an antibody bound to a surface thereof. Contacting; Contacting the antigen with another antibody that specifically binds to the antigen and is labeled with a metal particle; And it provides a bio-sensing method comprising the step of measuring the graphene oxide fluorescence intensity after contact with the another antibody labeled with metal particles. In one embodiment of the present invention, the metal particle and the antigen are connected by a single stranded DNA, wherein the single stranded DNA has 50 to 300 base pairs. When the antigen and the antibody bind, the fluorescence intensity of the graphene oxide decreases.

In order to solve the above another problem, the present invention is a transparent substrate; A graphene oxide array provided on the transparent substrate and having a probe material bonded to a surface thereof; A target material labeled with a metal particle capable of reducing the fluorescence intensity of the graphene oxide; When the target material is bound to the probe material, it provides a bio-sensing system including a measuring unit capable of measuring the fluorescence intensity of the graphene oxide is reduced.

Biosensing methods, sensors and systems according to the present invention can utilize the inherent fluorescence properties of graphene oxide itself without the use of dyes to dye the target material, thereby optically identifying the presence of a detection material. In addition, since the use of dyes, which are difficult to synthesize and expensive, can be avoided, the economy is excellent. That is, in the case of the conventional micro array, it is difficult to determine the presence or absence and the position of the probe material on the substrate (particularly, the glass substrate), but in the present invention, the probe material is bonded to the graphene oxide of the array type having fluorescence properties. After being used on the substrate, the binding position of the probe material on the substrate can be accurately identified through fluorescence analysis, thereby improving the reliability and reproducibility of the micro array technology for bio-sensing.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments and drawings. However, the following examples and the like are all intended to illustrate the invention, the scope of the present invention is not limited or limited thereto.

The biosensor for detecting the presence of the biomaterial may identify the type of the substance through the combination of the target substance (ie, a sensing target substance) and the probe substance (ie, a substance which can be selectively and selectively combined with a desired substance). The detection method of such a biosensor is various, for example, there is an electrical, optical method and the like.

Of these, the optical method can detect whether the desired target material is bound by an optical microscope or the like without a separate electric device, which is relatively simple and economical. However, the optical method requires a dye to induce the optical property change due to the binding of the materials, and there is a process problem in that the target material or the probe material is labeled with the dye, and the dye is difficult to synthesize. Since the price is expensive, there is a problem that the economy is relatively low.

Accordingly, the present invention recognizes the problem of the prior art, using a graphene oxide having its own fluorescence properties, a new concept of biosensing method, sensor and sensor system capable of sensing a target material without separate dye-labeling to provide.

1 is a view showing a basic concept of bio-sensing according to the present invention.

Referring to FIG. 1, the biosensor according to the present invention uses graphene oxide 110 and a probe material 120 coupled to the surface of the graphene oxide 110. The probe material may be any material that can be selectively and specifically bound to the target biomaterial according to the type of target biomaterial to be sensed. In one embodiment of the present invention, the biomaterial is DNA, and in another embodiment of the present invention, the antigen-antibody is used, but the scope of the present invention is not limited thereto.

Thereafter, the target material 130 is coupled to the probe material 120, and the target material 130 is connected to the metal particles 140 to label the target material 130. When the metal particles 140 are adjacent to the graphene oxide 110, the metal particles 140 generate a so-called quenching effect, which reduces the fluorescence intensity of the graphene oxide 110.

Therefore, the present inventors have focused on the fact that, when a bond between the probe material and the target material occurs, the flowing metal particles are fixed to the graphene oxide surface, thereby reducing the fluorescence properties of the graphene oxide, thus leading to the present invention. . The metal particles may be any metal material as long as it can reduce the fluorescent property of graphene oxide, but in one embodiment of the present invention, gold nanoparticles were used as the metal particles.

The present invention provides a biosensor for detecting DNA and a sensing method as a first application example of the biosensor. Bio sensing method and apparatus according to an embodiment of the present invention is an amine-bound single strand DNA (ssDNA, probe DNA) is graphene oxide bonded to the surface; And target DNA labeled with metal particles capable of quenching the fluorescence intensity of the graphene oxide. That is, in the biosensor and sensing method for detecting DNA according to the present invention, when target DNA is complementarily bound to probe DNA, the fluorescence intensity of graphene oxide is reduced by the FRET effect and electron transfer of metal particles. I was focused on that. Therefore, the DNA detection method and apparatus according to the present invention discloses a metal particle that can bind to the DNA complementary to the probe DNA, and can quench the fluorescent properties of the graphene. That is, the present invention is to detect the binding of the DNA, the fluorescence characteristics of the graphene and FRET (Foster resonance energy transfer) phenomenon of the metal particles that can remove or reduce the fluorescence intensity of the graphene and metal particles and graphene Electron transfer phenomenon between oxides is used.

2 is a diagram illustrating an interaction between graphene oxide-DNA-gold nanoparticles according to an embodiment of the present invention.

Referring to FIG. 2, the graphene oxide according to the present invention has a single strand of probe DNA bound to a surface thereof, and the binding of graphene oxide and probe DNA is a carbonyl group (CO) of the carboxyl group of graphene oxide and the probe DNA end. It is made of an amide group (CONH) by the amine group bonded to. As a result, a single strand of probe DNA is bound to the graphene oxide surface to which the DNA to be detected is complementarily bound, and the graphene oxide still retains its unique fluorescence property until the present stage. Thereafter, the target DNA to be detected is contacted with the graphene oxide to which DNA is bound. At this time, the metal nanoparticles are bound to the target DNA, that is, labeled state. If the target DNA is complementarily bound to the probe DNA of graphene oxide, the metal nanoparticles are connected to the graphene oxide. At this time, the fluorescence intensity of the graphene oxide is reduced by the adjacent metal nanoparticles. Conversely, if the DNA to be detected does not complementarily bind to the single stranded DNA, the metal nanoparticles to which the DNA to be detected is bound to the surface are not adjacent to or connected to graphene oxide, and as a result, the fluorescence property of the graphene oxide is It is not quenched by metal particles. That is, the present invention binds the DNA complementary to the desired target DNA to the graphene oxide, and then contacts the DNA to be detected to the graphene oxide, wherein the fluorescence characteristics of the graphene oxide are analyzed to determine the DNA. Determine if complementary combination of.

Looking in more detail the quenching effect by the metal nanoparticles according to the present invention.

In the metal nanoparticle-DNA-graphene oxide complex formed by complementary binding of a single strand of probe DNA and a target DNA, the graphene oxide and the metal nanoparticles (eg, gold nanoparticles) are fluorescence and electron donor ( It functions as a fluorescence donor and an acceptor, and as a result, the fluorescence emission effect of graphene oxide is effectively quenched by gold nanoparticles (AuNP). In other words, DNA-DNA interaction can be detected by FRET and electron transfer effects between graphene oxide and nanoparticles generated when hybridizing probe DNA bound to graphene oxide to target DNA labeled with gold nanoparticles. .

3A and 3B illustrate a concept of detecting an antigen according to another embodiment of the present invention.

Referring to FIG. 3A, an antibody, that is, a first antibody 320 is bound to the graphene oxide 310 surface. Thereafter, the antigen 330 that selectively binds to the antibody 320 is contacted, so that the antigen 330 and the antibody 320 bind to the first. Thereafter, another antibody labeled with metal particles 340 capable of reducing or quenching the fluorescence intensity of the graphene oxide 310 is contacted with the antigen 330 to bind the second antibody. If the antigen, which is a target substance, is an antigen of a desired type, that is, when the antibody labeled with the metal particle is an antigen that can selectively bind, the metal particle 340 is connected to the antigen 330. 3A, the metal particles 340 reduce the fluorescence intensity of graphene oxide.

In particular, the present invention, the antigen 330 and the metal particles 340 is connected by a single stranded DNA (350a) of a loose structure connected to the antibody and the coalescence, the synthetic method of connecting the gold nanoparticles to the antibody is shown in FIG. Shown. The inventors noted that the distance between the metal particles and the graphene oxide is not sufficiently short, especially when the length of the single stranded DNA 350a is less than 50 base pairs (bp), so that the fluorescence quenching effect by the metal particles does not occur sufficiently. (See Figure 3b). In addition, when the single stranded DNA is excessively long, for example, in excess of 300bp, there is a problem in that the antibody labeled with metal particles cannot sufficiently migrate due to entanglement between DNAs.

However, alternatively, after labeling the antigen itself with metal particles, binding it with the antibody on the graphene surface, and measuring the fluorescence intensity, it is also possible to belong to the scope of the present invention.

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples.

Example  One

DNA Sensing

Example  1-1

Synthesis of Gold Nanoparticles

Hydrogen tetrachloro O rate (HAuCl ₄₎ were synthesized by the gold nanoparticles (AuNP) reductase, 0.01% HAuCl ₄ 1% sodium citrate solution to 200ml near boiling point _{(C 6 H 5 Na 3 O} 7) It was reduced by vigorous stirring for 15 minutes with 7 ml of the solution. The gold nanoparticle concentration thus obtained was calculated according to Beer's law.

Example  1-2

single Strand Inn  Target DNA end Combined  Synthesis of Gold Nanoparticles

6 nmole single stranded target DNA was added to a 100 μL DTT solution to break the disulfide bond (S-S) to make DNA having thiol (-SH) groups as end groups. The target DNA was then purified on PD-10 column. DNA location was detected at 260 nm absorption wavelength using a UV-visible spectrophotometer and the concentration of the single stranded target DNA was calculated by Beer's law. Thereafter, the 100 μL probe DNA was added to the gold nanoparticles (1 mL) prepared in Example 1-1. The final product of the finally obtained probe DNA-gold nanoparticle solution showed red color and showed no aggregation phenomenon visually.

Example  1-3

Graphene  Oxide manufacturing

Graphene oxide was prepared by the modified Hummer method. 0.06 mg of graphene oxide was suspended in 300 μL of N, N-dimethylformamide (DMF), and 2.1 μmole of Sulfo-NHS was added to the graphene oxide DMF suspension solution. Thereafter, it was placed in the vortex and mixed and reacted for 1 hour. 3 nmole of amine-single strand DNA was then added and mixed and reacted for 2 hours on the vortex. Unreacted EDC, Sulfo-NHS and NH ₂ -DNA were removed by centrifugation three times for 30 minutes at 14,000 rpm.

Example  1-4

Graphene  Amine-single phase Strand DNA ( NH ₂ - ssDNA ) Combination

2 μL of the graphene oxide (0.2 mg / mL) solution of Example 1-3 was pipetted onto an amine-glass slide, dried at room temperature, washed three times for 10 minutes with DI water, and nitrogen. Dried over. 1 μL EDC (26 nmole) and 1 μL Sulfo-NHS (260 nmole), previously prepared in 0.1 M MES buffer, were pipetted onto a graphene film, dropped, and incubated in a wet chamber for 1 hour. Next, 1 μL of NH 2 -single strand DNA (0.17 nmole, probe DNA) was dropped on the graphene oxide film, and then placed in a wet chamber for 10 hours to proceed with graphene oxide and probe DNA binding.

Example  1-5

Target DNA Wow Graphene  Oxide Hybridization

2 μL of 15 nm diameter gold nanoparticles (0.02 pmole) bound by a single strand of target DNA were dropped onto the graphene oxide film, hybridized in a wet chamber for 10 hours, and then deionized (DI) for 3 times in 10 minutes. ) And dried with nitrogen

Example  2

antigen Sensing

The gold nanoparticles of Example 1-1 and the graphene oxide of Examples 1-3 were used to test the biosensing effect of antigen-antibody binding.

Example  2-1

Antibody binding Graphene  Oxide manufacturing

1 μg / mL solution of graphene oxide (GO) was dropped on the glass substrate pretreated with amine (NH 2) by 1 μl and dried at room temperature for 1 hour. After drying, the mixture was washed three times with 15 minutes each in distilled water. Then, 1 μl of EDC (1-ethyl-3- [3-dimethylaminopropyl] carbodiimide Hydrochloride, Pierce) at a concentration of 130 pmol / L (in 0.1 M MES (2- [morpholino] ethanesulfonic acid) buffer) was injected and moist conditions ( 1 hour incubation in a moisture condition) and washed again with distilled water for 5 minutes.

Again, inject 1 μl of Sulfo-NHS (N-hydroxysulfo succinimide, Pierce) at a concentration of 320 pmol / L (in 0.1 M MES (2- [morpholino] ethanesulfonic acid) buffer) and incubate for 1 hour under moist conditions. It was. Then, 1.5 μl of a 1.29 mg / ml antibody (Rotavirus monoclonal antibody, Fitzerald 10-R30A) was injected, incubated for at least 12 hours in a moist condition, and the antibody injected portion was washed with PBS buffer. Incubate for hours.

Example  2-2

Antigen Binding and Labeling

1.5 μl of the antigen (Rotavirus, 10 ⁵ PFU / ml) was injected only to specific spots of the antibody-bound graphene oxide and incubated for a minimum of 12 hours in a humid condition. As a result, the antigen was bound to the antibody of Example 2-1. Thereafter, 1.5 μl injection of antibody-DNA-gold nanoparticle (gold nanoparticle, 8.5 μmol / μl) polymer was incubated for at least 12 hours and washed three times with distilled water for 15 minutes.

Experimental Example  One

UV  analysis

5 is graphene oxide (GO), graphene oxide-single strand DNA (GO-ssDNA) of the present invention and the graphene oxide-hybridized DNA-gold nanoparticle complex (GO-dsDNA-AuNP) of Example 1 UV-visible absorption spectrum. Here, graphene oxide-hybridized DNA-gold nanoparticle complex (GO-dsDNA-AuNP) refers to a structure in which a probe DNA of graphene oxide and a target DNA of gold nanoparticles are complementarily bound.

Referring to FIG. 5, graphene oxide shows a typical strong absorption band at 230 nm. Graphene oxide-single strand DNA spectra, on the other hand, show peaks that overlap with the typical absorption peak (260 nm) of DNA, indicating a covalent conjugation between amine-DNA and graphene oxide. The graphene oxide-hybridized DNA-gold nanoparticles (GO-dsDNA-AuNP) of Example 1 obtained by complementary DNA binding show peaks at 519 nm, corresponding to gold nanoparticles. The results indicate that hybridization of two single stranded DNAs was successful in the present invention.

Experimental Example  2

Fluorescence intensity change measurement

6 is a graph showing the relative change in fluorescence intensity in graphene oxide (GO) and graphene oxide-hybridized DNA-gold nanoparticles of Example 1 (GO-dsDNA-AuNP).

Referring to FIG. 6, when the target DNA labeled with gold nanoparticles complementarily binds to a single stranded DNA of graphene oxide, it can be seen that the fluorescence intensity is significantly reduced. That is, conventional graphene oxide shows high fluorescence intensity, but when the target DNA labeled with 15 nm gold nanoparticles hybridizes, the graphene oxide-hybridized DNA-gold nanoparticles (GO-dsDNA-AuNP) are very It shows a low fluorescence intensity, which means that the gold nanoparticles linked to the graphene oxide by the complementary binding between the DNA in the present invention effectively quench and reduce the intrinsic fluorescence intensity of the graphene oxide.

Experimental Example  3

TEM  analysis

7A is a TEM image of a graphene oxide sheet.

Referring to Figure 7a, it can be seen that the graphene oxide film according to the present invention has a slight wrinkles on the surface, and a sharp folded structure on the edge portion. NH ₂ -single stranded DNA is added to the graphene oxide solution to induce a chemical reaction between the carboxyl group of the graphene oxide and the amine group of the single stranded DNA and form an amide group. As a result, the single stranded DNA covalently binds to the graphene oxide by amide bonding, and then hybridizes to the target DNA labeled with 15 nm AuNP. 7B is a TEM image after hybridization.

Referring to FIG. 7B, in the graphene oxide surface of the present invention, the COOH group is formed not only at the edge portion but also at the folded portion of the graphene surface. That is, the COOH group formed on the graphene surface by the conventional graphene oxidation process is also formed on the graphene oxide surface, which means that DNA hybridization can also be performed on the graphene surface.

FIG. 7C is the result of HRTEM-EDX analysis of the graphene-hybridized DNA-metal nanoparticles of Example 1 prepared on a lacey carbon-coated grid. FIG.

Referring to Figure 7c, it can be seen that the peak corresponding to the phosphorus of the DNA nucleotide base appears. However, it was very difficult to accurately detect the nitrogen peak here, which is judged to be due to the overlapping phenomenon of carbon and oxygen peaks.

Experimental Example  4

Sensing  Comparison of Systems and Their Fluorescence Intensities

The biosensing system according to the present invention senses and detects a biomaterial using metal nanoparticles capable of quenching the fluorescence intensity of graphene oxide.

8 is a schematic diagram of a bio-sensing system according to an embodiment of the present invention.

Referring to FIG. 8, the biosensing system according to the present invention includes a graphene oxide array 820 having a probe material (eg, DNA, an antibody, etc.) bonded to a surface thereof, and a target material on the graphene oxide array. Target material (not shown) for analyzing whether it can be contacted with. In this case, the graphene oxide array 820 is provided on a transparent substrate 810 such as glass, whereby the measuring unit 830 provided outside the transparent substrate 810, for example, a confocal microscope, a fluorescence analyzer Etc., the fluorescence intensity change in the graphene oxide array can be easily analyzed and compared. That is, when a change in fluorescence intensity is detected through the sensing system according to the present invention, that is, when there is a quenching effect, it may be determined that the target material is bound to the probe material, and conversely, when there is no change in fluorescence intensity, It can be determined that there is no binding between the material and the probe material.

For example, the biosensing system for DNA detection in Example 1 of the present invention includes a glass substrate, which is a transparent substrate coated with an amine, and a graphene oxide sheet is laminated on the glass substrate. That is, the group is a function strip is NH ^{3 +} and negative strip-positively charged binding graphene oxide sheets are bonded by electrostatic attraction, and thus is provided with a graphene oxide on a transparent substrate. At this time, the graphene oxide is coupled to probe DNA (ie, NH ₂ -single strand DNA), wherein the graphene oxide surface and the probe DNA are bound by an amide group, as described above. Next, the target DNA is contacted with the graphene oxide, wherein the target DNA is labeled with metal nanoparticles capable of fluorescence intensity of graphene oxide, that is, 15 nm gold nanoparticles. DNA detection apparatus according to the present invention also includes a fluorescence measuring unit for measuring the fluorescence intensity of the graphene oxide, the fluorescence intensity of the graphene oxide generated when the gold nanoparticles are connected to the graphene oxide through the measuring unit Can be detected. In one embodiment of the present invention, the measurement unit was an Axon GenePix 4000A fluorescence reader, and analyzed fluorescence intensity at an excitation wavelength of 532 nm.

FIG. 9 is an image and graph comparing the average fluorescence intensity between graphene oxide and graphene oxide-hybridized DNA-gold nanoparticles of Example 1. FIG.

Referring to FIG. 9, when the gold nanoparticles are connected to graphene oxide by complementary DNA binding, a quenching effect is observed, and in particular, in the case of green, the quenching effect is 86.8% (FIG. 9B). Reference). The results indicate that the biosensing method of the present invention using graphene oxide enables effective sensing of DNA. Furthermore, the present invention, which utilizes the fluorescent properties of graphene oxide itself, not only avoids the use of dyes that are harmful to humans and the environment, but also allows them to function as effective biosensors.

10 is an image of measuring the change in fluorescence intensity according to Example 2, wherein the left two columns of fluorescence measurement images are fluorescence images of graphene oxide, and the right two columns are fluorescence images after antigen-antibody-antigen binding. Referring to FIG. 10, it can be seen that the fluorescence intensity of the fluorescent image measured after binding of the antigen and the gold particle labeled antibody is reduced. Whether or not it can be effectively detected and sensed without the use of a separate dye. Furthermore, the fluorescence measurement images of the two left columns can accurately analyze the binding position of the antibody as the probe material on the glass substrate.

1 is a view showing a basic concept of bio-sensing according to the present invention.

2 is a diagram illustrating an interaction between graphene oxide-DNA-gold nanoparticles according to an embodiment of the present invention.

3A and 3B illustrate a concept of detecting an antigen according to another embodiment of the present invention.

4 is a schematic diagram showing a synthetic method of linking gold nanoparticles to an antibody.

5 is graphene oxide (GO), graphene oxide-single strand DNA (GO-ssDNA) of the present invention and the graphene oxide-hybridized DNA-gold nanoparticle complex (GO-dsDNA-AuNP) of Example 1 UV-visible absorption spectrum.

6 is a graph showing the relative change in fluorescence intensity in graphene oxide (GO) and graphene oxide-hybridized DNA-gold nanoparticles of Example 1 (GO-dsDNA-AuNP).

FIG. 7A is a TEM image of a graphene oxide sheet, FIG. 7B is a TEM image after hybridization, and FIG. 7C is an HRTEM-EDX of the graphene-hybridized DNA-metal nanoparticle of Example 1 prepared on a lacey carbon-coated grid. The result of the analysis.

8 is a schematic diagram of a bio-sensing system according to an embodiment of the present invention.

FIG. 9 is an image and graph comparing the average fluorescence intensity between graphene oxide and graphene oxide-hybridized DNA-gold nanoparticles of Example 1. FIG.

10 is an image of measuring the change in fluorescence intensity according to Example 2, wherein the left two columns of fluorescence measurement images are fluorescence images of graphene oxide, and the right two columns are fluorescence images after antibody-antigen-antibody binding.

Claims (20)

Target material labeled with metal particles; And And a probe material bound to graphene oxide exhibiting fluorescence properties, wherein the target particles and the probe material bind to each other, wherein the metal particles of the target material reduce the fluorescence properties of the graphene oxide. sensor. The method of claim 1, The target and probe material is a biosensor, characterized in that the DNA. The method of claim 1, And the target and probe substances are antigens and antibodies, respectively. The method of claim 1, The metal particles are biosensors, characterized in that the metal nanoparticles that can reduce the fluorescence intensity of the graphene oxide. The method of claim 4, wherein The metal nanoparticle is a biosensor, characterized in that the gold nanoparticles. 3. The method of claim 2, The target DNA and the probe DNA is a single-stranded DNA, characterized in that the biosensor for DNA detection. 3. The method of claim 2, The biosensor, characterized in that the target DNA and the metal particles are connected to each other. The method of claim 3, wherein The antigen and the metal particles are biosensor, characterized in that connected by a polymer. The method according to claim 7 or 8, The polymer is a biosensor, characterized in that the single strand DNA. Contacting a target material labeled with a metal particle with graphene oxide having a probe material bound to a surface thereof; And And measuring the graphene oxide fluorescence intensity before and after the contact. The method of claim 10, The metal particles are bio-sensing method, characterized in that the metal nanoparticles that can reduce the fluorescence intensity of the graphene oxide. The method of claim 11, And said metal is gold. Contacting a target DNA labeled with a metal particle with graphene oxide having a probe DNA bound to a surface thereof; And And measuring the graphene oxide fluorescence intensity before and after the contact. The method of claim 13, Biosensing method, characterized in that the DNA is a single strand. The method of claim 13, Bio-sensing method characterized in that when the target DNA and the probe DNA complementarily bind, the fluorescence intensity of the graphene oxide is reduced. Contacting an antigen labeled with a metal particle with graphene oxide having an antibody bound to the surface thereof; And And measuring the graphene oxide fluorescence intensity before and after the contact. First contacting the antigen with graphene oxide, to which the antibody is bound to a surface; Second contacting another antigen specifically binding to said antigen and labeled with a metal particle; And And measuring the graphene oxide fluorescence intensity after contact with the another antibody labeled with metal particles. The method of claim 17, The metal particle and the another antibody is connected by a single stranded DNA, wherein the DNA has a bio-sensing method characterized in that it has 50 to 300 base pairs. The method of claim 17, Bio-sensing method characterized in that the fluorescence intensity of the graphene oxide is reduced when the antigen and the other antibody binds. Transparent substrates; A graphene oxide array provided on the transparent substrate and having a probe material bonded to a surface thereof; A target material labeled with a metal particle capable of reducing the fluorescence intensity of the graphene oxide; And And a measurement unit capable of measuring the fluorescence intensity of the graphene oxide that is reduced when the target material binds to the probe material.

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