KR101035352B1 - Method for detecting target molecule using selective aggregation of quantum dots - Google Patents

Abstract

The present invention relates to a method for detecting a target substance using selective aggregation of quantum dots. According to the present invention, by using the phenomenon that the quantum dots selectively aggregate when the target material is present, the target material is detected by reducing the fluorescence even without pretreatment such as tagging the fluorescent material to the target material or the detection material or surface treatment of the nanoparticles. The existence can be easily identified with the naked eye. Therefore, the method of the present invention is very efficient because the target material can be easily and quickly detected at low cost without any special analytical device. In particular, when the method of the present invention is used for the analysis of monobasic polymorphism in DNA, it is possible to quickly and efficiently discriminate the presence of monobasic polymorphism by confirming that aggregation of quantum dots does not occur, so as to diagnose and treat genetic diseases, And it can be very useful in biological and medical research.

Quantum dots, flocculation, target substance, detection

Description

Method for detecting target molecule using selective aggregation of quantum dots}

The present invention relates to a method for detecting a target material using selective agglomeration of quantum dots, wherein the selective aggregation of the quantum dots by electrostatic attraction due to the combination of the target material and the detection material, or the combination of the detection material and the target material on the surface of the quantum dot The present invention relates to a method of detecting a target substance using selective aggregation of quantum dots, which can easily detect the presence of the target substance by analyzing the decrease in luminescence intensity due to selective aggregation of quantum dots such as cross-linking aggregation.

Nanoparticles of 1 to 100nm size are one of the major research materials of nanotechnology, and show various applications in various fields such as physics, chemistry, biology and medicine, and various kinds of metal, nonmetal, and semiconductor nanoparticles are manufactured for this purpose. It is becoming.

In particular, nanoparticles are attracting attention in various applications including biotechnology because they exhibit unique physical, chemical or optical properties depending on their type and size. For example, gold nanoparticles of several tens to tens of nanometers exhibit surface plasmon resonance bands around 520 nm, and have wavelengths that vary depending on the surrounding environment or attachment of other materials. The semiconductor nanoparticles are excited by UV when they are within 10 nm in size, and exhibit quantum dot characteristics that emit wavelengths in various visible light regions depending on the size and shape of the nanoparticles. Fluorescence Resonance Energy Transfer (FRET) is known to occur in quantum dots and gold nanoparticles. Thus using these properties they can be used as imaging probes, biosensors, catalysts, display materials and biological tagging materials in the chemical, material science, biology and medicine fields.

For example, a method of tagging the surface of a metal nanoparticle with a probe DNA modified with a thiol group to detect a target DNA through a change in optical properties according to aggregation of metal particles has been reported (K. Sato, K. Hosokawa, M. Maeda, J. Am. Chem. Soc. 2003, 125, 8102-8103; CA Mirkin, RL Letsinger, RC Mucic, JJ Storhoff, Nature 1996, 382, 607-609). However, for the surface treatment of metal nanoparticles using thiol-modified probes, a separate and complicated process is required for this, and sensing is performed only under specific conditions (temperature, etc.), and the tagging reaction is inefficient and expensive. It has the disadvantage of being.

Most of conventional sensors using quantum dots have used fluorescence resonance energy transfer (FRET). FRET phenomenon refers to a phenomenon in which the fluorescence intensity decreases as the quantum dot acts as an electron donor when the distance between the quantum dot and another material (gold nanoparticles, glucose, etc.) becomes close. It was bound to a substance or a detection substance, and the FRET phenomenon was caused by the direct binding between the target substance and the detection substance, and a method of detecting the presence of the target substance was used. However, the method of tagging a quantum dot to a target material or a detection material has a problem that the tagging reaction is inefficient and time-consuming and costly as with the surface treatment of metal nanoparticles.

On the other hand, the genetic codes included in the genomes of organisms belonging to the same species do not coincide with each other, and there are differences in nucleotide sequences called polymorphisms. Polymorphisms are known in which one or more bases have been deleted or inserted, and certain base sequences have been duplicated. Substitution of one base with another is called single nucleotide polymorphism (hereinafter abbreviated as "SNP").

SNP is a single base-pair variation in DNA between individuals and is the most common form of DNA sequence polymorphism (about 1 kb). Since SNPs cause a difference in sensitivity to individual diseases, they can be effectively used for diagnosis, treatment and prevention of genetic diseases. Therefore, there has been a need for a quick and easy way to find SNPs, which are parts of genes that bring about individual differences, race differences, and "sensitivity" differences to diseases.

So far, SNP analysis methods include TaqMan PCR, Matassis assisted laser desorption-time of flight / mass spectrometry (MALDI-TOF / MS), PCR-restriction fragment length polymorphism analysis, and single- Single-strand conformation polymorphism detection, dideoxy minisequencing, oligonucleotide tigation assays, allele-specific polymerase chains reactions, abbreviated as "AS PCR"), ligase chain reactions, primer-required nucleotide incorporation assays and fluorescence energy transfer-based assays. -based assays) (Landegren, U, M Nilsson, and PY Kwok., 1998, Genome Res , 8: 769-776; Gut, IG, 2001, Hum Mutat , 17: 475-492; Shi, MM, 2001, Clin Chem , 47: 164-172). In addition, mass spectrometry (Ross P et al., 2000, BioTechniques , 29: 620-629) and oligonucleotide microarray-based analysis can be used to directly and accurately determine the mass of a single short DNA fragment. analysis (Wang, DG et al ., 1998, Science , 280: 1077-1082) is also known. Since the methods for analyzing SNPs have relative advantages and disadvantages for specific purposes, it cannot be asserted as to which method is superior to other methods. For example, the TaqMan PCR method is an SNP assay using a PCR reaction, which has the advantage of having a small number of analysis steps and the fastest analysis (T. Morris et al ., J. Clin. Microbiol ., 1996, 34, 2933., KJ Livak et al ., Genet. Anal ., 1999, 14, 143]. However, this method has a disadvantage in that the cost of producing a labeled probe is high because two types of fluorescent labeled probes are required to analyze one type of SNP. In another example, the MALDI-TOF / MS (Matris assisted laser desorption-time of flight / mass spectrometry) method has the advantage of using one primer without requiring any labeling for one SNP analysis [see: L, A. Haff et al., Genome Res ., 1997, 7,378. P. Ross et al., Nat. Biotechnol. , 1998, 16, 1347], PCR amplification of the target region, purification of the PCR product, primer extension reaction, purification of the primer extension reaction product, spotting of the mass measurement sample, mass spectrometry, etc. has a disadvantage in that there are too many operating steps.

An object of the present invention is to provide a method for easily and quickly detecting a target material without the need for a pretreatment such as a tagging reaction or surface treatment in the detection of the target material using quantum dots.

In particular, the present invention is to provide a simple and easy method for detecting a nucleic acid having a single nucleotide polymorphism using quantum dots.

In order to achieve the above object, the present invention

Adding a sample to be examined for the presence of the target substance to a solution containing quantum dots; And

It provides a method of detecting a target material comprising analyzing the selective aggregation of the quantum dots.

The invention also

Hybridizing a sample to be examined for the presence of a nucleic acid with monobasic polymorphism with a detection agent;

Adding hybridized double stranded DNA to a solution containing quantum dots; And

Provided is a method for detecting nucleic acids with monobasic polymorphism comprising analyzing selective aggregation of quantum dots.

According to the present invention, by using the phenomenon that the quantum dots selectively aggregate in the presence of the target material, the presence of the target material can be easily visually observed by reducing the emission intensity without pretreatment such as tagging the fluorescent material to the target material or the detection material. Can be identified. Therefore, using the method of the present invention, it is very efficient to detect the target material easily and quickly at low cost without a special analyzer. In particular, when the method of the present invention is used for the analysis of monobasic polymorphism in DNA, it is possible to quickly and efficiently discriminate the presence of monobasic polymorphism by confirming that aggregation of quantum dots does not occur, so as to diagnose and treat genetic diseases, And it can be very useful in biological and medical research.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated concretely.

The present invention

Adding a sample to be examined for the presence of the target substance to a solution containing quantum dots; And

The present invention relates to a method for detecting a target substance comprising analyzing selective aggregation of quantum dots.

The present invention is characterized by detecting the target material by using the phenomenon that selective aggregation of the quantum dots occurs in the presence of the target material.

Selective aggregation of quantum dots in the presence of the target material occurs when the target material binds to the detection material (i.e., the probe), so that electrostatic stabilization occurs and does not bind to the quantum dot, while the target material does not bind to the detection material. The material is due to adsorption on quantum dots for electrostatic stabilization. If the target material binds to the detection material, there is no substance adsorbed on the quantum dot, so that selective aggregation of the quantum dots occurs. On the other hand, if the target material fails to bind to the detection material, the detection material is adsorbed on the quantum dot, causing aggregation between the quantum dots. This does not happen. Therefore, by analyzing the selective aggregation of the quantum dots it is possible to simply and easily detect the presence of the target material.

Alternatively, the surface of the quantum dot can be functionalized as a surface capping agent or a detection material to analyze the selective aggregation of the quantum dots through cross-linking aggregation of the quantum dots through binding with the target material, thereby making it simple and easy to detect the presence of the target substance. It becomes possible.

The detection method of the target substance of the present invention will be described in detail step by step.

The first step is adding a sample containing a target substance to a solution containing quantum dots.

In the present invention, the target substance is a substance to be detected in the sample, and means a substance that can specifically bind to the detection substance. On the other hand, the detection material (or probe) means a material that can selectively recognize and bind the target material.

The target material and the detection material that can be used in the present invention may be any material as long as it can induce selective aggregation of quantum dots by binding therebetween. That is, the method of the present invention may be applied to a target material and a detection material that do not cause aggregation of quantum dots in the absence of the target material and selectively cause aggregation of quantum dots only in the presence of the target material.

In one embodiment, the target agent is a nucleic acid and the detection agent can be a nucleic acid complementary thereto.

In other embodiments, the target material is a heavy metal, and the detection material can be a pair of non-complementary DNAs where hybridization can occur by such heavy metals.

The quantum dot is not particularly limited as long as it is a quantum dot dispersed in a solvent and present in a colloidal phase. In the case of the quantum dots synthesized in the organic phase, it is possible to disperse through ligand exchange (ligand exchange). For example, CdS, CdSe, CdTe, or PbS may be used alone or in combination of two or more.

The surface of the quantum dots may be modified with hydrophobic hydrophilic functional groups such as hydroxyl groups, carboxyl groups, or amine groups using surface capping agents to exclude the possibility of undesirable adsorption in addition to the target material in the sample. Can be.

As the surface stabilizer, mercaptopropionic acid (MPA), mercaptoacetic acid (MAA), mercaptosuccinic acid (MSA), dithiotriitol (DTT), glutathione, histidine, thiol-containing silane, or the like or two or more kinds Can be used.

The solution containing the quantum dots refers to a solution in which the quantum dots are dispersed in water or an organic solvent. Cyclohexane, toluene, or the like may be used alone or in combination of the above organic solvents.

In addition, the solution containing the quantum dots may include a detection material. More specifically, the detection material may be coupled to the surface of the quantum dot, but is not limited thereto. This is because if the binding between the detection material and the target material works well under certain conditions, the target material may be contacted before being exposed to the quantum dots. In this case, the coupling between the target material and the detection material may cause selective aggregation of quantum dots due to electrostatic stabilization. In addition, if the detection material is bound to the surface of the quantum dots, the combination of the detection material and the target material may cause cross-linking aggregation of the quantum dots.

Accordingly, the detection method of the target material of the present invention has the feature that the presence or absence of the target material can be detected through the selective aggregation of the quantum dots without limitation, even if the detection material is bound to the quantum dot surface.

In one embodiment, the target agent is a nucleic acid and the detection agent can be a nucleic acid complementary thereto. The nucleic acid and the nucleic acid complementary thereto may be hybridized prior to exposure to the quantum dots to analyze whether the quantum dots are aggregated to easily detect the presence of a target substance.

In other embodiments, the target material is a heavy metal, and the detection material can be a pair of non-complementary DNAs where hybridization can occur by such heavy metals. Pair that is not complementary to each other are coupled to the quantum dot surface DNA can be hybridized by the presence of Hg ^{2+ Hg 2+ (J.-S. Lee, MS Han} , CA Mirkin, Angew. Chem. Int. Ed. 2007, 46, 4093-4096). Therefore, when heavy metals are present, non-complementary pairs of DNA hybridize to induce selective aggregation of quantum dots, and thus analysis of selective aggregation of quantum dots enables the detection of heavy metals.

As described above, the detection material is not particularly limited to a material that selectively recognizes and binds a target material.

The second step is to analyze the selective aggregation of the quantum dots according to the combination of the target material and the detection material.

Selective aggregation of the quantum dots can be analyzed by investigating a decrease in the emission intensity of the solution containing the quantum dots. Quantum dots emit particles when exposed to UV light. The luminescence of the quantum dots is due to quantum confinement, and when the aggregation of the quantum dots occurs, the quantum dots are eliminated and the emission intensity decreases, and eventually, the particles form a precipitate, so that the solution containing the quantum dots Becomes transparent. Therefore, using the method of the present invention, it is possible to easily identify the presence of the target material without a special analyzer.

 In addition, selective aggregation of quantum dots can be analyzed by using known methods by investigating changes in the size or shape of the quantum dots, the change in the diameter of the crystal grains of the quantum dots, the change in zeta potential, or UV-visible absorption spectroscopy. The following example shows a specific method for this example.

The invention also

Hybridizing a sample to be examined for the presence of a nucleic acid with monobasic polymorphism with a detection agent;

Adding hybridized double stranded DNA to a solution containing quantum dots; And

The present invention relates to a method for detecting a nucleic acid having a monobasic polymorphism comprising analyzing selective aggregation of quantum dots.

In one embodiment, the nucleic acid having a single nucleotide polymorphism may be hybridized with the detection material to form a double strand, but when exposed to the quantum dots, dehybridized and not electrostatically stabilized, thereby adsorbing to the surface of the quantum dots. Accordingly, selective aggregation of quantum dots does not occur in the presence of a nucleic acid having a single nucleotide polymorphism, whereas selective aggregation of quantum dots occurs when only completely matched double stranded DNA is present. Thus, by using the above described method where the selective aggregation of quantum dots occurs in the presence of a target substance, detection of nucleic acids with monobasic polymorphism can be performed by confirming that aggregation of quantum dots does not occur.

The following examples specifically illustrate a method for detecting a nucleic acid having a monobasic polymorphism with a nucleic acid as a target material when the target material is a nucleic acid and the detection material is a probe nucleic acid complementary thereto.

The following examples are only intended to illustrate the invention, and it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Example 1 Detection of BRCA2 Gene Monobasic Polymorphism

1 is a schematic diagram showing an overview of an experiment according to an embodiment of the present invention.

First, Mao et al. (J. Mao, J.-N. Yao, L.-N. Wang, W.-S. Liu, J. Colloid Interface Sci. 2007, 319, 353-356) to prepare mercaptoacetic acid stabilized soluble CdS quantum dots.

To detect single nucleotide polymorphisms of the BRCA2 gene, which is known to be associated with prenatal viability and breast cancer risk, single stranded oligonucleotide probes based on BRCA2 (GenBank number: NM_000059), sequences completely complementary to Oligonucleotides with oligonucleotides having a single mismatched base substituted with guanine instead of thymine for the formation of oligonucleotides and monobasic polymorphism mutations were designed as shown in Table 1 (Bioneer Inc.)

The target DNA or SNP DNA (0.2 mM, 2 μl) and the probe (0.2 mM, 2 μl) were respectively hybridized in 0.15 M NaCl / 0.1M phosphate buffer at pH 7, followed by hybridization of the dsDNA (0.1 mM, 4 μl). ) Was added to a suspension containing 1.3 mL of CdS quantum dots. Thereafter, 0.59 mL of sterile water and 0.1 mL of the same buffer solution were added to prevent sudden aggregation. The amount of NaCl was adjusted to find the optimal salt concentration where dsDNA with a fully matched pair causes selective aggregation. Finally, a NaCl solution having a concentration of 8 × 10 ⁻⁴ M, 1.2 × 10 ⁻³ M, and 1.6 × 10 ⁻³ M was added.

Aggregation of quantum dots with double-stranded DNA is visually determined by irradiation with UV lamps and through transmission electron microscopy (TEM), quasi-elastic light scattering (QELS), zeta potential and luminescence measurements. Observed. The shape of CdS quantum dots was observed using TEM (JEOL JEM-2100), and the hydrodynamic radius and surface potential of the particles were observed with a Malvern Nano-ZS instrument for QELS and zeta potential measurements. Emission spectra of CdS quantum dots were obtained using a PerkinElmer LS 50 emission spectrometer.

Figure 2 shows a photograph of the solution before and after addition of dsDNA in 1.2 × 10 ⁻³ M NaCl under UV lamp (excitation wavelength of 365 nm) [a) 10 minutes, b) 20 minutes, c) 30 minutes after DNA addition; i) ssDNA (probe), ii) dsDNA (SNP), iii) dsDNA (target DNA)]. After the addition of the DNA, the color change was not negligible for the first 30 minutes in all cases. Interestingly, after 30 minutes of dsDNA addition, significant bleaching of color occurred substantially only in suspensions containing dsDNA with perfectly matched pairs, resulting in reduced luminescence intensity, which appears to be due to large scale quantum dot aggregation.

3 shows TEM images of quantum dots after addition of dsDNA in 1.2 × 10 ⁻³ M NaCl. The embedded image in each TEM photograph shows the lattice structure of CdS quantum dots. As can be seen in FIG. 3A, in the case of dsDNA with a single base mismatched pair, no significant change in size and shape was observed. However, as can be seen in Figure 3b, after addition of dsDNA with a fully matched sequence, the size and shape of the CdS quantum dots showed a significant change. This indicates that addition of dsDNA with a perfectly matched sequence causes aggregation of CdS quantum dots.

To investigate the selective aggregation behavior of quantum dots, QELS was used to monitor the aggregation process. As can be seen in FIG. 4, in 8 × 10 ⁻⁴ M NaCl, the average diameter of the nanocrystals did not show any significant increase in all cases [a) 8 × 10 ⁻⁴ M; b) 1.2 × 10 ⁻³ M; c) 1.6 × 10 ⁻³ M]. This indicates that the increase in ionic strength of the suspension caused by the addition of 8 × 10 ⁻⁴ M NaCl is insufficient to block the electrostatic repulsion and induce aggregation of CdS nanocrystals. A significant increase in mean diameter was found in all cases at NaCl concentrations of 1.6 × 10 ⁻³ M, suggesting that high ionic strength caused destabilization and aggregation of CdS nanocrystals. Significant aggregation was observed exclusively for fully matched dsDNA at 1.2 × 10 ⁻³ M. This indicates that dsDNA has a stable double helix structure with a negatively charged phosphate backbone that acts as an electrolyte to prevent electrostatic repulsion, whereas dsDNA with a single base mismatch exhibits dehybridization and the surface of the quantum dots for electrostatic stabilization It is because it is adsorbed on. The results illustrate the colloidal stability of the suspension with probe and SNP DNA at 1.2 × 10 ⁻³ M, which is confirmed by zeta potential measurement.

5 shows the change in zeta potential as a function of time at three different NaCl concentrations. The value of the zeta potential of the unmodified CdS quantum dots was determined to be -51.6 mV. At 8 × 10 ⁻⁴ M NaCl, all samples showed negligible changes in zeta potential, indicating that the stability of the CdS suspension was not affected by the addition of electrolytes or ssDNA. At 1.6 × 10 ⁻³ M NaCl, a significant increase (ca. −30 mV) of zeta potential was observed in all samples leading to reduced electrostatic repulsion and aggregation of CdS quantum dots. At 1.2 × 10 ⁻³ M NaCl, an increase in zeta potential was seen in samples with only fully matched dsDNA, because the dsDNA did not adsorb to the particle surface and acted as an electrolyte to block electrostatic repulsion. Measurement of zeta potential confirms selective aggregation of fully matched dsDNA due to low colloidal stability.

6 shows the emission spectra of CdS quantum dots after addition of oligonucleotides at different NaCl concentrations of 8 × 10 ⁻⁴ M, 1.2 × 10 ⁻³ M, and 1.6 × 10 ⁻³ M. After addition of DNA, in all cases the decrease in luminescence intensity at 8 × 10 ⁻⁴ M was negligible, while at 1.6 × 10 ⁻³ M a significant decrease in luminescence intensity was observed in all cases. Thus, it was not possible to identify fully matched sequences from dsDNA with ssDNA or single base mismatched pairs at these concentrations. However, at 1.2 × 10 ⁻³ M, a significant decrease in luminescence after 30 minutes was observed only for dsDNAs with fully matched sequences, due to the selective aggregation of CdS quantum dots. In addition, the emission peak maximum shifted to longer wavelengths (from 530 to 570 nm) as the particle size increased.

Example 2 Monobasic Polymorphism Detection of Sipa1

In order to reconfirm in another gene from the above results, a similar experiment was carried out using Sipa1 (signal-induced proliferation-associated gene 1) related to the transfer process.

Based on the mouse Sipa1 sequence (GenBank number: NM_011379), a single-stranded oligonucleotide probe, an oligonucleotide having a sequence completely complementary thereto, and an oligonucleotide having a single mismatch base substituted with adenine instead of guanine for a monobasic polymorphic mutation Was designed as shown in Table 2 (Bioneer Inc.). Since the process was the same as above.

The results shown in FIGS. 7-10 confirm that SNP detection based on selective aggregation of CdS quantum dots can be well applied to other types of DNA sequences.

1 is a schematic diagram showing an overview of an experiment according to an embodiment of the present invention.

FIG. 2 shows photographs of solutions before and after addition of dsDNA in 1.2 × 10 ⁻³ M NaCl under UV lamp (excitation wavelength of 365 nm) with respect to SNP detection of BRCA2.

3 shows TEM images of quantum dots after addition of dsDNA in 1.2 × 10 ⁻³ M NaCl with respect to SNP detection of BRCA2.

FIG. 4 shows the change in mean diameter of quantum dots over time at NaCl concentrations of 8 × 10 ⁻⁴ M, 1.2 × 10 ⁻³ M, and 1.6 × 10 ⁻³ M with respect to SNP detection of BRCA2.

5 shows the change in zeta potential as a function of time at NaCl concentrations of 8 × 10 ⁻⁴ M, 1.2 × 10 ⁻³ M, and 1.6 × 10 ⁻³ M with respect to SNP detection of BRCA2.

FIG. 6 shows the emission spectra of CdS quantum dots after addition of oligonucleotides at NaCl concentrations of 8 × 10 ⁻⁴ M, 1.2 × 10 ⁻³ M, and 1.6 × 10 ⁻³ M with respect to SNP detection of BRCA2.

FIG. 7 shows photographs of solutions before and after addition of dsDNA in 1.2 × 10 ⁻³ M NaCl under UV lamp (excitation wavelength of 365 nm) with respect to SNP detection of Sipa1.

FIG. 8 shows the change in average diameter of quantum dots over time at NaCl concentrations of 4 × 10 ⁻⁴ M, 8 × 10 ⁻⁴ M, and 1.2 × 10 ⁻³ M with respect to SNP detection of Sipa1.

FIG. 9 shows the change in zeta potential as a function of time at NaCl concentrations of 4 × 10 ⁻⁴ M, 8 × 10 ⁻⁴ M, and 1.2 × 10 ⁻³ M with respect to SNP detection of Sipa1.

FIG. 10 shows the emission spectra of CdS quantum dots after addition of oligonucleotides at NaCl concentrations of 4 × 10 ⁻⁴ M, 8 × 10 ⁻⁴ M, and 1.2 × 10 ⁻³ M with respect to SNP detection of Sipa1.

Claims (15)

Adding a sample to be examined for the presence of the target substance to a solution containing quantum dots; And A method of detection of a target material comprising analyzing selective aggregation of quantum dots. The method of claim 1, A method for detecting a target substance, wherein the target substance is a nucleic acid or heavy metal ion. The method of claim 1, A quantum dot is at least one selected from the group consisting of CdS, CdSe, CdTe and PbS. The method of claim 1, The surface of the quantum dot is a detection method of a target substance modified by one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group and an amine group. The method of claim 1, A solution containing a quantum dot is a method for detecting a target material, wherein the quantum dot is dispersed in water or an organic solvent. The method of claim 1, A method of detecting a target substance, wherein the solution containing quantum dots comprises a detection substance. The method of claim 6, A detection method of a target substance, wherein the detection substance is bound to the surface of the quantum dot. The method of claim 1, The analysis of selective aggregation of quantum dots is a method of detecting a target substance which investigates the decrease in the luminescence intensity of a solution containing quantum dots. The method of claim 1, The analysis of selective aggregation of quantum dots is a method of detecting a target substance by examining the change in the size or shape of the quantum dots, the change in the diameter of the crystal grains of the quantum dots, the change in the zeta potential, or UV-visible absorption spectroscopy. Hybridizing a sample to be examined for the presence of a nucleic acid with monobasic polymorphism with a detection agent; Adding hybridized double stranded DNA to a solution containing quantum dots; And A method for detecting nucleic acids with monobasic polymorphism comprising analyzing selective aggregation of quantum dots. The method of claim 10, A quantum dot is a method for detecting a nucleic acid having a monobasic polymorphism is at least one selected from the group consisting of CdS, CdSe, CdTe and PbS. The method of claim 10, The surface of the quantum dot is a method for detecting a nucleic acid having a monobasic polymorphism modified by one or more functional groups selected from the group consisting of hydroxyl, carboxyl and amine groups. The method of claim 10, A solution containing a quantum dot is a method for detecting a nucleic acid having a monobasic polymorphism wherein the quantum dot is dispersed in water or an organic solvent. The method of claim 10, The analysis of selective aggregation of quantum dots confirms that no aggregation of quantum dots is observed. The method of claim 10, Analysis of selective aggregation of quantum dots is a method for detecting nucleic acids with monobasic polymorphism by examining changes in the size or shape of the quantum dots, changes in the diameter of the crystal grains of the quantum dots, changes in zeta potential, or UV-visible absorption spectroscopy.

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