KR20150083701A - Surface modified-nanoparticles, its preparation and the colorimetric detection method of ions of nitric oxide - Google Patents

Abstract

The present invention relates to a surface-modified nanoparticle which includes a nanoparticle having the diameter of 100 nm or smaller and a modifier bound to the surface of the nanoparticle. Therefore, the nanoparticle has high selectivity and sensitivity with respect to ion nitrogen oxide and exhibits a surface plasmon resonance phenomenon which can be seen by naked eyes. In addition, a chromogenic detection method of nitrogen oxide ions includes: an insertion step of inserting a sample for detection in a chromogenic sensor including the modified-nanoparticles; and a detection step of detecting whether 1 ppm or greater of the nitorgen oxide ion is included in the sample by using color change of the chromogenic sensor caused as nitrogen oxide ions, included in the sample, are bound with the modifier bound to the surface of the surface-modified nanoparticle. Therefore, the chromogenic method is simple and easy, is capable of direct detection at a site, uses a threshold detection concentration in accordance with a value of regulations, and is capable of rapid and accurate calibration.

Description

TECHNICAL FIELD The present invention relates to a surface modification-nanoparticle, a method for producing the same, and a method for detecting colorimetry of nitrogen oxide ions using the same. BACKGROUND ART [0002]

TECHNICAL FIELD The present invention relates to a surface modification-nanoparticle, a method for producing the same, and a method for detecting colorimetry of nitrogen oxide ions using the same. More particularly, the present invention relates to a surface modification- To a method for selectively detecting nitrogen oxide ions using a surface plasmon resonance phenomenon, and also to a method for producing the nanoparticles.

Research on colorimetric sensor utilization technology for environmental monitoring is underway in four areas using nanoparticles, organic dyes, vesicles, and arrays. Specifically, it has been utilized in various fields such as detecting harmful substances such as heavy metals including Hg and Cd, chemical substances including pesticides, and biomaterials such as amino acids and proteins, and research is underway . Researchers such as Gwanmanbok have developed gold nanoparticle colorimetric sensors using oxytetracycline as an infectious agent [Biosensors and bioelectronics 26 (2010) 1644-1649], researchers at Lee Hiebing and others [ And developed as a sensor for detecting pesticide components [nanotechnology 19 (2008) 1-6]. In addition, a colorimetric sensor capable of detecting melamine in milk has been developed by the Ryuhei Research Group and can be easily detected at less than 2.5 ppb without using expensive analytical equipment [J. AM. CHEM. SOC. 131 (2009) 9496-9497.

In addition, many researchers in the United States, Europe, Japan, and China have used colorimetric sensors to produce high performance receptors such as aromatic isomers (Acsnano, 4 (2010) 6387-6394), epotherms, antibodies, dendrimers, And supports research and development. We are also conducting research to acquire source technology using various nanoparticles that can detect food harmful substances, hazardous chemical substances, and the like.

The sensor technology for measuring harmful substances quickly analyzes and detects the various harmful substances to be detected in the vicinity of the contaminated accident site or the environment contaminated by the harmful substances, It is a key element technology that enables the removal of harmful substances by monitoring and real time measurement and continuous management of harmful substances.

Nitrite ion (NO ₂ ^- ) is an imperfect state of the intermediate phase of the nitrogen circulation that occurs when ammonia is oxidized or nitrate is reduced. Generally, the water containing nitrite ions indicates that the ammonia component such as manure, domestic wastewater, livestock wastewater has recently been introduced and is actively oxidized, or industrial wastewater has been introduced.

Nitric acid ions (NO ₂ ^- ) strongly stimulate the airways, stimulate the eyes and neck, cause tensions in the chest, headache, nausea and gradual weakness, and severe symptoms occur after 5-7 hours with hemoglobin in combination with methemoglobin Methemoglobin is a substance that can cause cyanosis. Excessive absorption of such nitrite ions can cause dyspnea, irregular breathing, lethargy, and death from lung diseases if not treated.

The method of quantifying nitrite ions is to measure the absorbance in a UV spectrometer and to analyze it by using ion chromatography. However, all of these methods require the analysis equipment required for the measurement, need. Accordingly, there is a demand for the development of a colorimetric sensor which can be easily carried and real-time analyzed so as to be able to perform on-site analysis of environmental pollutants, which is deviated from device-oriented technology, in detecting environmental harmful factors.

It is an object of the present invention to provide a surface modification-nanoparticle in which a modifier having high selectivity and sensitivity to nitrogen oxide ions is connected to nanoparticles. In addition, it is possible to carry out a simple portability and selectively detect a specific pollutant on the spot in the field, and it is superior in performance compared with the ion chromatographic detection method which has limitations in place and equipment, and a colorimetric sensor To provide a method for detecting colorimetry of nitrogen oxide ions.

The surface modification-nanoparticle according to an embodiment of the present invention includes nanoparticles having a diameter of 100 nm or less and a modifier connected to the surface of the nanoparticle.

The nanoparticles may be any one of nanoparticles selected from the group consisting of gold, silver, titanium oxide, cadmium telluride, copper, and combinations thereof, and the modifier may include a compound of the following formula (1).

[Chemical Formula 1]

Wherein R < 1 > is any one selected from the group consisting of C1 to C3 mercaptoalkyl, aminoalkyl, hydroxyalkyl, halogenalkyl and carboxyalkyl.

The modifier may be 1- (2-mercaptomethyl) -1,3,5-triazinane-2 , 4,6-trione), 1- (2-mercaptoethyl) -1,3,5-triazinene-2,4,6-trione 2-mercaptopropyl) -triazinane-2,4,6-trione (MTT), 1- (2-mercaptopropyl) -1,3,5-triazinene- -1,3,5-triazinane-2,4,6-trione), and combinations thereof.

The surface modifying-nanoparticle may have an absorbance ratio (A ₇₉₀ / A ₅₃₅ ) at 790 nm and 535 nm of 0.05 to 0.2.

According to another embodiment of the present invention, there is provided a method for preparing a surface modification-nanoparticle, comprising: preparing a first solution in which nanoparticles are dispersed; And a functionalization step of mixing the second solution containing the modifier with the first solution to form functionalized surface modification-nanoparticles by connecting the modifier to the surface of the nanoparticles.

The nanoparticles may be any one of nanoparticles selected from the group consisting of gold, silver, titanium oxide, cadmium telluride, copper, and combinations thereof, and the modifier may include a compound of the following formula (1).

[Chemical Formula 1]

Wherein R < 1 > is any one selected from the group consisting of C1 to C3 mercaptoalkyl, aminoalkyl, hydroxyalkyl, halogenalkyl and carboxyalkyl.

In the functionalization step, mixing of the first solution and the second solution may be carried out by mixing 30 to 90% by volume of the first solution and 10 to 70% by volume of the second solution.

The modifier may be 1- (2-mercaptomethyl) -1,3,5-triazinane-2 , 4,6-trione), 1- (2-mercaptoethyl) -1,3,5-triazinene-2,4,6-trione 2-mercaptopropyl) -triazinane-2,4,6-trione (MTT), 1- (2-mercaptopropyl) -1,3,5-triazinene- -1,3,5-triazinane-2,4,6-trione), and combinations thereof.

According to another embodiment of the present invention, there is provided a colorimetric detection method of nitrogen oxide ions comprising the steps of: inputting a sample to be detected to a colorimetric sensor including surface modification-nanoparticles; And the color change of the colorimetric sensor caused by the combination of the nitrogen oxide ion contained in the sample to be detected and the modifying agent connected to the surface of the surface modifying-nanoparticle is used to determine whether or not the nitrogen oxide ion is contained in 1 ppm or more And a detecting step of detecting a signal.

The surface modification-nanoparticle may include nanoparticles having a diameter of 100 nm or less and a modifier connected to the surface of the nanoparticle, wherein the nanoparticle is selected from the group consisting of gold, silver, titanium oxide, cadmium telluride, Or a combination thereof, and the modifier may include a compound represented by the following formula (1).

[Chemical Formula 1]

Wherein R < 1 > is any one selected from the group consisting of C1 to C3 mercaptoalkyl, aminoalkyl, hydroxyalkyl, halogenalkyl and carboxyalkyl.

The method may further include a concentration measuring step of measuring a change in color of the colorimetric sensor in the sensing step using the spectrometer or a colorimeter to check the concentration of nitrogen oxide ions in the sample to be detected after the sensing step.

The color change of the colorimetric sensor in the sensing step may be such that the surface modification-nanoparticles are aggregated by hydrogen bonding of the nitrogen oxide ion and the compound of formula 1, The color of the colorimetric sensor may be changed to a color that is lighter or more colorless than the color of the previous colorimetric sensor.

The nitrogen oxide ion may be any one selected from the group consisting of nitrite ions (NO ₂ ^- ), nitrate ions (NO ₃ ^- ), and combinations thereof, and the modifier is 1- (2-mercaptomethyl) (2-mercaptomethyl) -1,3,5-triazinane-2,4,6-trione, 1- (2- (2-mercaptoethyl) -1,3,5-triazinane-2,4,6-trione (MTT) , 1- (2-mercaptopropyl) -1,3,5-triazinane-2,4,6-triazine, 6-trione, and combinations thereof. The color of the colorimetric sensor in the applying step may be dark red, and the color of the colorimetric sensor in the sensing step may be transparent or purple .

As used herein, the terms "comprise", "having", and the like are used to specify that there is a stated feature, number, step, component, or combination thereof, Does not preclude the presence or addition of one or more other features, steps, components, or combinations thereof.

When an element is referred to herein as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, but there may be other elements in between And it is to be understood that any component connected to or coupled to another component may be a physical connection or a combination or a chemical connection or combination.

As used herein, the singular and plural representations are not to be construed as limiting the number of materials for a particular material, but may refer to one particular material or to a group of specific materials.

The compound of the formula used in the present specification means that the compound of the formula contains all of the compounds in which resonance, tautomerization or isomerization occurs, Is not limited to a compound having a structure of the formula when reacted, or to a compound in a state of the corresponding formula structure.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The present invention provides a method for detecting colorimetric detection of nitrogen oxide ions using surface modification-nanoparticles whose surface is modified with a highly selective modifier to specific ions, a method for producing the surface modification-nanoparticles and the surface modification-nanoparticles Hereinafter, the present invention will be described in more detail.

The colorimetric detection method of nitrogen oxide ions according to an embodiment of the present invention includes the steps of: inputting a sample to be detected to a colorimetric sensor including surface modification-nanoparticles; And the color change of the colorimetric sensor caused by the combination of the nitrogen oxide ion contained in the sample to be detected and the modifying agent connected to the surface of the surface modifying-nanoparticle is used to determine whether or not the nitrogen oxide ion is contained in 1 ppm or more And a detecting step of detecting a signal.

Also, the surface modification-nanoparticle according to another embodiment of the present invention includes nanoparticles having a diameter of 100 nm or less and a modifier connected to the surface of the nanoparticle.

In the colorimetric detection method, it is important that the size of the nanoparticles is in the range, the shape of the prepared nanoparticles is uniform, and the kind of the modifier that is connected to the surface of the nanoparticles is important. Surface plasmon resonance phenomenon of the surface modification-nanoparticles used in the present invention.

In the surface plasmon resonance phenomenon, nanoparticles having a size of 100 nm or more exhibit the same characteristics as those of a common metal. However, nanoparticles of a size smaller than that of the ordinary nanoparticles have a free electron cloud moving in a direction opposite to the electric field of the electromagnetic wave due to light, All the objects emit light of a certain wavelength according to the definition of the mexwell that emits an electromagnetic wave (light) according to the vibration, and represents the phenomenon that the nanoparticles exhibit color within the wavelength range of visible light {Chem. Eur. J., 10, 5570-5580 (2004)] and Kor. Chem. Eng. Res., 49 (4), p.393-399 (2011)].

Prior to a description of a method for detecting colorimetry of nitrogen oxide ions using a surface plasmon resonance phenomenon, the surface modification-nanoparticles according to another embodiment of the present invention will be described as nanoparticles used in the colorimetric detection method.

The nanoparticles of the surface modification-nanoparticles may have a size of 100 nm or less, and preferably 10 to 100 nm or less. When the size of the nanoparticles is 100 nm or less, the surface plasmon resonance phenomenon is different from the surface plasmon resonance phenomenon of nanoparticles having a size exceeding 100 nm It is possible to detect nitrogen oxide ions using the resonance phenomenon. When the nanoparticles having a size of 100 nm or less are applied to a colorimetric detection method, nitrogen oxide ions can be detected easily and quickly with the naked eye And further, it may be possible to measure up to the concentration of nitrogen oxide ions.

The nanoparticles may be in the form of spherical, ellipsoidal, or spherical analogs and are substantially uniform. Any kind of nanoparticles may be used without limitations as long as they are nanoparticles whose color changes by surface plasmon resonance. Nanoparticles, or metal oxides. The metal nanoparticles may be, for example, nanoparticles such as gold, silver or copper. As the metal oxide nanoparticles, for example, titanium oxide or the like may be used. Further, cadmium telluride or the like may be applied to other nanoparticles . Furthermore, it may be a combination of the above metals, preferably gold nanoparticles. The modifying agent for the surface modification-nanoparticle may include a compound represented by the following formula (1).

[Chemical Formula 1]

Wherein R < 1 > is any one selected from the group consisting of C1 to C3 mercaptoalkyl, aminoalkyl, hydroxyalkyl, halogenalkyl and carboxyalkyl.

The modifier is generally a derivative of a substance called cyanuric acid, and the official name (IUPAC name) of cyanuric acid is 1,3,5-triazinein-2,4,6-trione . The cyanuric acid derivative may be a compound in which the organic group corresponding to R1 is bonded to the nitrogen atom at the first nitrogen atom, and the compound of the formula (1), which is the ketone type, is converted to an alcohol form by the tautomerization.

The modifier may be, for example, 1- (2-mercaptomethyl) -1,3,5-triazinane- 2,4,6-trione, 1- (2-mercaptoethyl) -1,3,5-triazine, 5-triazinane-2,4,6-trione (MTT) or 1- (2-mercaptopropyl) -1,3,5-triazinene- ) -1,3,5-triazinane-2,4,6-trione), and the like.

Such a modifier can improve the sensitivity by inducing selective bonding with nitrogen oxide ions and by using hydrogen bonds for aggregation, and is thus suitable as a surface modifier for nanoparticles used in the method for detecting colorimetry of nitrogen oxide ions.

The surface modification-nanoparticle may have an absorbance ratio (A ₇₉₀ / A ₅₃₅ ) at 790 nm and 535 nm of 0.05 to 0.2. The absorbance ratio is an index indicating that the connection between the nanoparticles and the modifier is very stable and that the surface modification-aggregation between the nanoparticles does not occur. The surface modification-nanoparticle of the present invention having the above- useful.

Wherein the color of the colorimetric sensor in the applying step is dark red, the color of the colorimetric sensor in the sensing step may be transparent or purple, 1, the color of the colorimetric sensor changes to be less than or less than the color of the colorimetric sensor before the detection target sample is introduced.

That is, the principle of the color change of the color sensor in the sensing step is as follows. First, the surface modification-nanoparticles (specifically, the modifier bound to the surface of the nanoparticles) contained in the colorimetric sensor and the nitrogen oxide ions contained in the detection target sample are hydrogen bonded. Here, the hydrogen bond may be a bond between oxygen bonded to the nitrogen oxide ion and nitrogen bonded to the hydrogen atoms bonded to the 3 and 5 of the modifier of the above formula (1). If the above formula (1) is tautomerized, And may be a bond between oxygen and nitrogen of oxide ions.

Subsequently, the surface modification-nanoparticles aggregate with each other due to the hydrogen bonding, and the external size of the nanoparticles existing as a single particle by the aggregation increases. Thus, when the size of agglomerated nanoparticles exceeds 100 nm, the agglomerated nanoparticles exhibit colors different from those initially exhibited by the surface plasmon resonance phenomenon.

Specifically, the surface modification-nanoparticles dispersed in the solution during the Brownian motion overcome the repulsive force between particles due to the strong hydrogen bonding force between the modifier and the nitrogen oxide ion connected thereto, crosslinking bond is progressed, so that agglomeration of particles occurs. As a result of such agglomeration, light scattering or degree of light absorption of a single particle changes, and the color represented thereby changes.

According to this principle, it is possible to detect whether or not the nitrogen oxide ion is contained in 1 ppm or more due to the color change and the color change, and the regulation value by the water pollution process test method is 1 ppm and the nitrogen oxide ion Is the same as the detection limit concentration. This indicates that the colorimetric detection method is useful for the detection of nitrogen oxide ions, and the colorimetric detection method can detect the concentration of nitrogen oxide ions as well as the detection of nitrogen oxide ions.

The calibration may further include a concentration measurement step of measuring the color change of the colorimetric sensor in the sensing step after the sensing step with a spectrometer or a colorimeter to calibrate the concentration of nitrogen oxide ions in the sample to be detected. That is, in the concentration measurement step, a change in color by the spectrometer or a colorimeter, that is, the wavelength of the light emitted by the surface plasmon resonance phenomenon of the coagulated surface modification-nanoparticles, or the color represented by the surface plasmon resonance phenomenon By measuring the position of the color coordinates clearly and comparing it with the color of the light emitted by the nanoparticles before the agglomeration, it is possible to measure the concentration of the nitrogen oxide ion have.

The nitrogen oxide ions that can be detected by the colorimetric detection method may be any one selected from the group consisting of nitrite ions (NO ₂ ^- ), nitrate ions (NO ₃ ^- ), and combinations thereof. As described above, the nitrogen oxide ion is a dangerous harmful substance that can cause airway irritation, headache, nausea, cyanosis or pulmonary edema. It is contained in domestic sewage, livestock wastewater or industrial wastewater, and therefore, rapid detection and follow- By using the colorimetric detection method, it is possible to selectively detect the nitrogen oxide ions in real time, and it can be detected quickly and easily with high sensitivity, which is a promising technology for environmentally friendly green technology.

According to another embodiment of the present invention, there is provided a method for preparing a surface modification-nanoparticle, comprising: preparing a first solution in which nanoparticles are dispersed; And a functionalization step of mixing the second solution containing the modifier with the first solution to form functionalized surface modification-nanoparticles by connecting the modifier to the surface of the nanoparticles.

The description of the nanoparticles of the surface modification-nanoparticles and the modifier is the same as that described above, and hence the description thereof will be omitted.

In the functionalization step, mixing of the first solution and the second solution may be carried out by mixing 30 to 90% by volume of the first solution and 10 to 70% by volume of the second solution.

When the second solution is added in an excess amount exceeding 70 vol%, when attempting to detect nitrogen oxide ions by the naked eye without using a spectrometer or a colorimeter, the color due to the surface plasmon resonance phenomenon represented by the nanoparticles in the first solution If the second solution is added in a smaller amount than 10 vol.%, The sensitivity to nitrogen oxide ions is lowered, so that the detection step on the colorimetric detection method The color change may be insignificant. Therefore, surface modification-nanoparticles with high selectivity and sensitivity to nitrogen oxide ions can be produced when mixing is carried out in an appropriate volume ratio.

The surface modification-nanoparticles of the present invention have a particle size of 100 nm or less and the shape is substantially uniform, so that the surface plasmon resonance phenomenon can be remarkably expressed. Therefore, the present invention is suitable for a method for detecting colorimetry of nitrogen oxide ions because of its sensitivity to nitrogen oxide ions and selectivity for nitrogen oxide ions by a modifier bound to the surface of nanoparticles. In the method for detecting colorimetry of nitrogen oxide ions, Detection of oxide ions enables detection in a short time and in real time, and it is easy to carry and can be directly detected in the field.

In addition, it has a detection limit concentration suitable for the regulated value and has a performance which is not inferior to the ion chromatography detection method. In addition to the detection of nitrogen oxide ions, a method capable of achieving calibration by a spectrometer or the like is provided.

FIG. 1 shows, by way of example, (a) a state in which a modifier (MTT) is functionalized in nanoparticles and a state in which surface modification-nanoparticles are hydrogen bonded with a nitrite ion, Modification - This is a conceptual diagram showing the color change caused by aggregation of nanoparticles and nitrite ions.
FIG. 2 is a graph showing, for example, (a) a distribution diagram of the particle size of the surface modification-nanoparticles, (b) a surface modification- dispersion (left) of the nanoparticles and a surface modification- (C) Surface Modification - An image of nanoparticles dispersed in a dispersion liquid is photographed by transmission electron microscope (TEM) (phase) and atomic force microscope (AFM) (bottom) (d) Surface Modification - An image of the coagulated states of nanoparticles and nitrite bound to each other by transmission electron microscopy (TEM) and atomic force microscopy (AFM).
FIG. 3 is an image of a color change observed in (a) when various ions are added to a dispersion of surface-modified nanoparticles as an example, (b) 400 to 800 nm using a spectrophotometer (C) a graph showing absorbance ratios at 790 nm and 535 nm. FIG.
FIG. 4 is an image of a color change observed when (a) an increasing amount of a modifier solution (second solution) is added to a nanoparticle solution (first solution), (b) a spectrophotometer -vis spectrometer in the range of 400 to 800 nm, and (c) a graph showing the absorbance ratios at 790 nm and 535 nm.
FIG. 5 is an image of (a) color change photographed when (b) a UV-vis spectrometer is used as an example, when the amount of the nitrite ion added to the surface modification- (C) Scanning curves of absorbance at 790 nm and 535 nm, respectively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Manufacturing example  1 to 7: Surface modification - Preparation of nanoparticles

The gold nanoparticle colloid was used as the first solution, and 1- (2-mercaptoethyl) -1,3,5-triazine-2,4,6-trione (1- mercaptoethyl) -1,3,5-triazinance-2,4,6-trione (MTT). (MTT) was added to the surface of gold nanoparticles by adding 0.08, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.1 ml of the second solution to 0.5 ml of the first solution, Modified nanoparticles were prepared.

FIG. 2A shows the particle size distribution of the nanoparticles prepared in Preparation Example 5. FIG. The particle size was 10 to 100 nm, and the average particle size was about 35 nm, which confirmed that the particle size was uniform.

4A shows the color change due to the surface plasmon resonance of the surface modification-nanoparticles prepared in Preparation Examples 1 to 7. In FIG. 4B, the color change of the surface modification- (A ₇₉₀ / A ₅₃₅ ) at 790 nm and 535 nm in FIG. 4C. In addition, FIG. 4C shows the absorbance ratio at 790 nm and 535 nm (A ₇₉₀ / A ₅₃₅ ).

As a result, as the addition amount of the modifier solution (second solution) was increased, the nanoparticle solution (first solution) was thinned due to the effect of dilution, but the color change due to agglomeration of the nanoparticles was not exhibited. Regardless of the amount of solution added, the form of the spectra was identical and the absorbance ratio was linear. That is, it was confirmed that the connection states of the nanoparticles and the modifier were very stable to each other, and that the coagulation phenomenon did not occur.

Example  1: Detection experiment of nitrogen oxide ion

Surface Modification - In order to confirm whether or not nitrogen oxide ions could be detected with nanoparticles, a sample to be detected containing a nitrite ion was added to a colorimetric sensor including the surface modification-nanoparticles prepared in Production Example 5. Next, the color change of the color gamut sensor was visually observed, and the surface modification-nanoparticles before and after the reaction were photographed by a transmission electron microscopy (TEM) and an atomic force microscopy (AFM) Respectively.

FIGS. 1A and 1B schematically illustrate the principle of detecting nitrite ions as surface modification-nanoparticles. When surface modification-nanoparticles and nitrite ions meet, hydrogen bonded to the nitrogen on the modifier surface connected to the surface of the nanoparticles reacts with nitrite ions The surface modification nanoparticles aggregate to form an aggregate, thereby increasing the particle size. Therefore, the surface plasmon resonance phenomenon of the nanoparticles causes color change. The color of the time changes from red wine to violet.

Referring to FIG. 2C, it can be seen that all of the particles are uniformly distributed without agglomeration, and that the size of the particles is equal to the average particle size of 35 nm as shown in FIG. 2A. Referring to FIG. 2d, Surface modification - It can be seen that the nanoparticles are enlarged due to the aggregation of the nanoparticles due to the binding of the nitrite ions to the nanoparticles. Plasmon resonance phenomenon of the nanoparticles occurs due to the enlargement of the size, and the corresponding color change This can be confirmed by the naked eye observation of the surface modification-nanoparticles showing red wine in FIG. 2b and the surface modification-nanoparticles aggregated in association with the nitrite ions showing violet .

Example  2: Calibration of nitrogen oxide ions

To confirm whether quantitative detection of nitrogen oxide ions was possible, the colorimetric sensor comprising the surface modification-nanoparticles prepared in Production Example 5 was subjected to the detection target containing nitrite ions at 1, 2, 3, 4 and 5 ppm, respectively The samples were put in the same manner as in Examples 2-1 to 2-5, and the changes in the wavelengths emitted to the color change of the color gamut sensor were measured using a spectrophotometer (UV-vis spectrometer).

Referring to FIG. 5A, it can be seen that the color changes gradually from dark red to purple as the amount of nitrite ions increases, and then the color changes transparently due to agglomeration of the nanoparticles. The reaction time according to the concentration was about 100 minutes for Example 2-1 (1 ppm of nitrite ion), about 30 minutes for Example 2-5 (nitrite ion 5 ppm), and about 16 minutes for higher concentrations The higher the concentration, the shorter the reaction time and the faster the aggregation.

Referring to FIG. 5B, as the amount of the nitrite ions increases, the spectrum of 400 to 800 nm gradually increases to show that the absorbance of visible light increases, and the same phenomenon occurs at a wavelength of 800 nm or more Can be confirmed.

FIG. 5C shows a quantitative curve using the ratio of absorbance (A ₇₉₀ / A ₅₃₅ ), which is represented by the regression linear equation Y = 0.2329X + 0.0517 and the correlation coefficient R ² is 0.9736. It can be seen that there is a high correlation between the amount and the absorbance ratio. That is, it was confirmed that the concentration of the nitrite ion can be measured by using the absorbance ratio measured by the spectrophotometer.

Example  3: Surface modification - Selectivity test for nitrogen oxide ion of nanoparticles

Surface Modification-To confirm ion selectivity for selectively detecting nitrogen oxide ions as compared with other ions as nanoparticles, a colorimetric sensor including the surface modification-nanoparticles prepared in Production Example 5 3 ppm of fluoride ion (F ^-), chloride ion (Cl ^-), bromide ion (Br ^-), phosphate ion (PO ₄ ^{2 -),} sulfate ion (SO ₄ ^{2 -),} nitrite ion (NO ₂ ^-) and Nitrate ion (NO ₃ ^- ) was added. Each of Examples 3-1 to 3-7 was checked visually for color change, and the degree of change in wavelength was measured using a spectrophotometer (UV-vis spectrometer).

Referring to FIG. 3A, the control group includes only the surface modification-nanoparticles as a reference material. When compared with the reference, the change in color due to the addition of each ion indicates that nitrite ions (NO ₂ ^- ) and nitrate (NO _{3 <} ^- >) was added in Examples 3-6 and 3-7. In Example 3-6, it was confirmed that the color change was observed from dark red to violet when viewed from the naked eye. In the case of Example 3-7, however, the change of color was slight, There was difficulty.

FIG. 3B is a result of scanning the above Examples 3-1 to 3-7 within the range of 400 to 800 nm using a spectrophotometer, and all the anions including the control group had the maximum absorbance at 535 nm, It can be seen that the absorbance increases to 800 nm. It can also be seen that, except for Examples 3-6 and 3-7, there is almost no change in absorbance due to the plasmon resonance phenomenon.

Figure 3c shows A ₇₉₀ / A ₅₃₅ , the absorbance ratio at 790 nm and 535 nm, indicating the selectivity and sensitivity of the subject material. The control group and Examples 3-1 to 3-5 show values of 0.14 which are almost the same as those of A ₇₉₀ / A ₅₃₅ , but the nitrite ion (NO ₂ ^- ) of Example 3-6 and the 3-7 The absorbance ratio of A ₇₉₀ / A ₅₃₅ of nitrate ion (NO ₃ ^- ) was 0.86 and 0.25, respectively. It was confirmed that nitrate ion has 1.5 times selectivity and sensitivity compared to other ions, and nitrite ion has 6 times selectivity and sensitivity.

That is, in the detection system of the present invention, the sensitivity to nitrite ions was higher than that of other ions so that they could be discriminated by the naked eye, and the sensitivity to nitrate ions was difficult to be distinguished from the naked eye. However, It can be seen that the nanoparticles modified with surface modifier (MTT) are excellent and suitable for the detection of nitrite ions, and it is possible to detect not only nitrite ions but also nitrate ions.

Example  4: Surface modification - Evaluation of effectiveness of detection system containing nanoparticles

1. Evaluation of detection limit concentration of nitrite ion

Surface Modification for Hazardous Substances-Prior to evaluating the effectiveness of nanoparticles, in order to confirm the detection limit concentration of the method for detecting colorimetry of nitrogen oxide ions of the present invention using tap water and pond water as detection target samples, The above samples were injected into a colorimetric sensor including particles and ion chromatography, and the concentration measured by the colorimetric sensor of the above detection system and the concentration measured by ion chromatography were compared and the results are shown in Table 1 below.

sample The amount of ions of nitrite (μg / ml) The colorimetric sensor Ion chromatography tap water <1 <0.01 Pond water <1 <0.01

As shown in Table 1, the detection limit concentration of nitrite ions by ion chromatography was 10 ppb or less, which was much lower than the detection limit concentration 1 ppm by the colorimetric sensor of the present invention. The detection limit concentration 1 ppm of the colorimetric sensor is suitable for 1 ppm which is the regulation value by the water pollution process test method, and the surface modification-nanoparticle of the present invention It is confirmed that the colorimetric sensor can be applied to the detection of nitrogen oxide ion which is a harmful substance in the environment.

2. For nitrite ions Surface modification - Evaluation of the effectiveness of nanoparticles

First, tap water containing 3 ppm of nitrite ions and 5 ppm of pond water were added to the sample to be detected, and the sample to be detected was introduced into a colorimetric sensor including ionic surface-modified nanoparticles and ion chromatography. The error values of the concentration and concentration of the nitrite ions measured by the spectrophotometer and the colorimetric sensor were compared with the error values of the concentration and concentration of the nitrite ions measured by the ion chromatography. Respectively.

sample
(Nitrite ion concentration) The amount of ions of nitrite (μg / ml) The colorimetric sensor Ion chromatography Tap water (3 ppm) 2.63 ± 0.31 2.99 ± 0.33 Pond water (5 ppm) 4.77 ± 0.37 4.97 ± 0.60

2.99 ± 0.33 ppm and 4.97 ± 0.60 ppm were detected in the tap water and the pond water by the ion chromatography detection method, respectively, and the values of 2.63 ± 0.31 ppm and 4.77 ± 0.37 ppm were measured for the colorimetric sensor of the present invention, respectively Respectively. As a result of confirming that the detection system can detect the nitrite ions contained in the actual harmful substances, the error range is also narrow compared with the result of ion chromatography, It was confirmed that the performance was not lowered compared with the ion chromatography method with limitation.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (10)

A nanoparticle having a diameter of 100 nm or less and a modifier connected to the surface of the nanoparticle,
Wherein the nanoparticles are nanoparticles selected from the group consisting of gold, silver, titanium oxide, cadmium telluride, copper, and combinations thereof,
Wherein the modifier comprises a compound of formula (I): &lt; EMI ID = 6.1 &gt;
[Chemical Formula 1]

Wherein R &lt; 1 &gt; is any one selected from the group consisting of C1 to C3 mercaptoalkyl, aminoalkyl, hydroxyalkyl, halogenalkyl and carboxyalkyl. The method according to claim 1,
The modifier may be 1- (2-mercaptomethyl) -1,3,5-triazinane-2 , 4,6-trione), 1- (2-mercaptoethyl) -1,3,5-triazinene-2,4,6-trione 2-mercaptopropyl) -triazinane-2,4,6-trione (MTT), 1- (2-mercaptopropyl) -1,3,5-triazinene- -1,3,5-triazinane-2,4,6-trione), and combinations thereof. The method according to claim 1,
Wherein the surface modifying-nanoparticle has an absorbance ratio (A ₇₉₀ / A ₅₃₅ ) value at 790 nm and 535 nm of 0.05 to 0.2. Preparing a first solution in which nanoparticles are dispersed; And
And a functionalizing step of mixing the first solution with a second solution containing a modifier to prepare functionalized surface modification-nanoparticles by connecting the modifier to the surface of the nanoparticles,
Wherein the nanoparticles are any one selected from the group consisting of gold, silver, titanium oxide, cadmium telluride, copper, and combinations thereof,
Wherein the modifier comprises a compound represented by the following formula (1).
[Chemical Formula 1]

Wherein R &lt; 1 &gt; is any one selected from the group consisting of C1 to C3 mercaptoalkyl, aminoalkyl, hydroxyalkyl, halogenalkyl and carboxyalkyl. 5. The method of claim 4,
Mixing the first solution and the second solution in the functionalization step comprises mixing the first solution and the second solution in an amount of 30 to 90% by volume and the second solution in an amount of 10 to 70% Gt; 5. The method of claim 4,
The modifier may be 1- (2-mercaptomethyl) -1,3,5-triazinane-2 , 4,6-trione), 1- (2-mercaptoethyl) -1,3,5-triazinene-2,4,6-trione 2-mercaptopropyl) -triazinane-2,4,6-trione (MTT), 1- (2-mercaptopropyl) -1,3,5-triazinene- -1,3,5-triazinane-2,4,6-trione), and a combination thereof. A step of injecting a sample to be detected into a colorimetric sensor including surface modification-nanoparticles; And
Using the color change of the colorimetric sensor caused by the combination of the nitrogen oxide ions contained in the sample to be detected and the modifying agent connected to the surface of the surface modifying-nanoparticle, to determine whether or not the nitrogen oxide ion is contained in 1 ppm or more in the sample to be detected And a detecting step of detecting the signal,
Wherein the surface modification-nanoparticle comprises nanoparticles having a diameter of 100 nm or less and a modifier connected to a surface of the nanoparticle,
Wherein the nanoparticles are any one selected from the group consisting of gold, silver, titanium oxide, cadmium telluride, copper, and combinations thereof,
Wherein the modifier comprises a compound represented by the following formula (1).
[Chemical Formula 1]

Wherein R &lt; 1 &gt; is any one selected from the group consisting of C1 to C3 mercaptoalkyl, aminoalkyl, hydroxyalkyl, halogenalkyl and carboxyalkyl. 8. The method of claim 7,
Further comprising a concentration measuring step of measuring the color change of the colorimetric sensor in the sensing step with a spectrometer or a colorimeter in the sensing step and then measuring the concentration of nitrogen oxide ions in the sample to be detected, . 8. The method of claim 7,
The color change of the colorimetric sensor in the sensing step may be such that the surface modification-nanoparticles are aggregated by hydrogen bonding of the nitrogen oxide ion and the compound of formula 1, Wherein the color of the colorimetric sensor is changed to a color that is lighter or more colorless than the color of the previous colorimetric sensor. 9. The method according to claim 7 or 8,
The nitrogen oxide ion is any one selected from the group consisting of nitrite ions (NO ₂ ^- ), nitrate ions (NO ₃ ^- ), and combinations thereof,
The modifier may be 1- (2-mercaptomethyl) -1,3,5-triazinane-2 , 4,6-trione), 1- (2-mercaptoethyl) -1,3,5-triazinene-2,4,6-trione 2-mercaptopropyl) -triazinane-2,4,6-trione (MTT), 1- (2-mercaptopropyl) -1,3,5-triazinene- -1,3,5-triazinane-2,4,6-trione), and combinations thereof.
Wherein the color of the colorimetric sensor in the applying step is dark red and the color of the colorimetric sensor in the sensing step is transparent or violet.

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