KR20170138268A - Method for sensing explosive using cadmium selenide quantum dot - Google Patents

Abstract

The present invention relates to a method of detecting an explosive including a nitro aromatic compound, a nitro amine-based compound, and a nitrate ester-based compound using an optical property of a cadmium selenide quantum dot. The method of detecting the explosive using the cadmium selenide quantum dot comprises: a step of manufacturing the cadmium selenide quantum dot solution; a step of emitting light of a prescribed wavelength range to the quantum dot solution, and measuring a spectrum of light emitted from the quantum dot solution; a step of mixing a sample solution and the quantum dot solution to cause extinction of quantum dots included in the quantum dot solution; a step of emitting light of a prescribed wavelength range to a mixed solution of the sample solution and the quantum dot solution, and measuring a spectrum of light emitted from the mixed solution; and a step of comparing a spectrum of light emitted from the quantum dot solution and the light emitted from the mixed solution to detect whether a target compound exists in the sample solution. A very small amount of a nitro aromatic compound, a nitro amine-based compound, and a nitrate ester-based compound is able to be detected at high sensitivity.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for detecting an explosive using cadmium selenide quantum dots,

The present invention relates to a method for detecting an explosive comprising a nitroaromatic compound, a nitroamine compound and a nitrate ester compound using optical properties of a cadmium selenide quantum dot.

The International Committee of the Red Cross (ICRC) has revealed that more than 110 million anti-personnel mines are installed in 64 countries around the world including the Korean peninsula, threatening human lives. Since plastic mines are buried in the ground and are effective until 50-70 years, it is essential to develop a chemical detection method that accurately detects explosives without malfunction.

In addition, suicide terrorist attacks by international terrorist organizations are widespread internationally, and the 9.11 US terrorist attack is a comprehensive definitive version of suicide terrorism. Afghanistan's counterterrorism war, and Iraq war, suicide terrorism is a form of typical terrorism. have. The United States has developed a military robot Fido equipped with explosives detection sensors and deployed more than 5,000 units in Iraq and Afghanistan.

Numerous studies have been conducted on nanosensors capable of applying multimode platforms using nano materials, electronic nose, E-nose arrays, and NEMS (Nanoelectromechanical systems) devices to develop high-sensitivity and high-performance explosive detectors in many advanced countries. .

Therefore, the development of new sensors capable of detecting ultra-minute explosives with high sensitivity and high performance is an indispensable field in home defense security systems and a global requirement.

There are three broad categories of explosives: nitroaromatics compounds, nitroamines compounds and nitrate ester compounds. Among them, explosives of nitromethane compound and nitrate ester compound are extremely low in vapor pressure due to explosives used by terrorists.

Existing explosives detection methods include detection dogs, and the exact detection limit of explosives in trained dogs is several tens ppb (parts per billion) in the case of nitroglycerin, and the explosive identification taggant DMNB (Dimethyl dinitrobutane) (additive)) is reported to be 500 ppt. In the case of Ion mobility spectrometry (IMS), the detection limit does not detect the analyte vapor and has a limit of 2-10 ng (nanogram). In the field of explosive detection chemical sensors, metal detectors are most widely used at airports, but the false signal rate is high. In addition, mass spectrometers equipped with gas chromatography, surface-enhanced Raman spectroscopy, Nuclear quadrupole resonance (NQR), Energy-dispersive X-ray diffraction, Neutron activation analysis (NAA), Electron capture detection (ECD) and Cyclic voltammetry On the other hand, the apparatus is expensive, bulky, and poorly portable, which is suitable for laboratory analysis but has a disadvantage of being unsuitable for anti-terrorism purposes.

Semiconductor quantum dots (QD) or nanocrystals (NC) have attracted much attention as a key material in nanoelectronics and nanoscale optics.

Over the last decade, semiconductor nanoparticles have been actively studied due to their unique physical properties. The development of quantum dots can be applied to electronics, optics, and catalysts, and is expected to lead the next generation of core growth engines. Semiconductor nanoparticles or quantum dots can be said to have intermediate physical properties between macroscopic and molecular compounds. Recently, studies on II-VI semiconductor quantum dots, especially cadmium-selenide (CdSe) quantum dots have been conducted intensively. Studies on InP and InAs quantum dots among III-V quantum dots have been extensively carried out, PbS, Ag ₂ S, and TiO ₂ have been developed as quantum dots, and a lot of research is underway. II-VI quantum dots have been studied extensively in mass production methods for obtaining quantum dots having a relatively uniform distribution, or as fluorescent probes for quantum dot array technology, light emitting diodes, and biosensors. Has come.

 Xiaogang Peng, J. Am. Chem. Soc. 2001, 123, 183-184  Dmitri V. Talapin, Nano Lett. 2001, Vol. 1, No. 4, 207-211  Celso de Mello Donega, J. Phys. Chem. B 2003, 107, 489-496  Philippe Guyot-Sionnest, J. Phys. Chem. 1996, 100, 468-471

 An object of the present invention is to provide a detection method capable of detecting an extremely small amount of explosive using a cadmium selenide (CdSe) quantum dot.

Specifically, the present invention can detect a nitroaromatic compound, a nitromethane compound, or a nitrate ester compound present at a concentration of a level of ppb (Part per billion) or ppt (Part per trillion) using cadmium selenide quantum dots And to provide a detection method using the same.

The method includes the steps of preparing a cadmium selenide quantum dot solution, irradiating light of a predetermined wavelength band to the quantum dot solution, measuring a spectrum of light emitted from the quantum dot solution, mixing the sample solution and the quantum dot solution, Measuring a spectrum of light emitted from the mixed solution by irradiating the mixed solution of the sample solution and the quantum dot solution with the light of the predetermined wavelength band and measuring the light emitted from the quantum dot solution and the mixed solution of the mixed solution And detecting whether or not a target compound is present in the sample solution. The present invention also provides a method for detecting explosives using cadmium selenide quantum dots.

In one embodiment, the target compound may comprise at least one of a nitroaromatic compound, a nitroamine compound, or a nitrate ester compound.

In one embodiment, the nitroaromatic compound may be Picric acid or Trinitro toluene.

In one embodiment, the nitroamine-based compound may be Trinitroperhydrotriazine.

In one embodiment, the nitrate ester compound may be Pentaerythritol tetranitrate.

In one embodiment, the size of the cadmium selenide quantum dot may be between 2 nm and 10 nm.

In one embodiment, the cadmium selenide quantum dots may have an extinction wavelength of 380 nm to 563 nm and an emission wavelength of 460 nm to 630 nm.

In one embodiment, the quantum dot solution may have a Stern-Bolmer constant (Ksv) of between 20,000 M ^-1 and 180,000 M ^-1 .

In one embodiment, the stern of the quantum dot solution - if Vollmer constant (Ksv) is, wherein the target compound is an aromatic nitro compound, and to 180,000M 70,000M ^{-1 -1,} if the nitro compound, the target amine compound , From 20,000 M ^-1 to 60,000 M ^-1 , and when the target compound is a nitrate ester-based compound, it may be from 34,000 M ^-1 to 77,000 M ^-1 .

The present invention can detect very small amounts of nitroaromatic compounds, nitroamine compounds and nitrate ester compounds at high sensitivity. Specifically, the present invention can detect a target compound with sensitivity four times or more higher than that of the prior art.

1 is a flowchart showing an explosive detection method according to the present invention.
2 is a graph illustrating absorption and emission spectra of a cadmium selenide quantum dot solution according to an embodiment of the present invention.
3A and 3B are graphs showing the results of detection of Picric acid using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm, and 630 nm.
4A and 4B are graphs showing the results of detection of Trinitro toluene using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm, and 630 nm.
5A and 5B are graphs showing the results of detection of Trinitroperhydrotriazine using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm, and 630 nm.
6A and 6B are graphs showing the results of detection of pentaerythritol tetranitrate using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm and 630 nm.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be obscured. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

Hereinafter, the explosive detection method according to the present invention will be described in detail.

1 is a flowchart showing an explosive detection method according to the present invention.

First, in the explosive detection method according to the present invention, the step of producing a cadmium selenide quantum dot solution (S110) is performed.

The cadmium selenide quantum dots can be prepared by the method described in Non-Patent Documents 0001 to 0005.

In one embodiment, the cadmium selenide quantum dots are selected from the group consisting of Cadmium oxide, Selenium, Trioctylphosphine oxide (TOPO) Oleic acid (OA) and 1-Octadecene , ODE).

Specifically, Schlenk line techniques can be used to react these compounds under an argon gas atmosphere. Because the Schlenk line blocks both oxygen and moisture in the air, it provides the optimum reaction environment for producing nanoparticles such as cadmium selenide quantum dots.

Cadmium oxide, oleic acid and 1-octadecene can be mixed in a three-necked flask and heated to initiate the reaction. When all of the reactants are mixed during heating, the selenium solution containing tributyl phosphine as a solvent is added.

Here, the size of the cadmium-selenide quantum dots may vary depending on the heating temperature, and the heating temperature condition may be 230 to 310 ° C, and the size of the cadmium-selenide quantum dots may be 2 nm to 10 nm.

A cadmium selenide quantum dot solution can be prepared by the above-described method.

Next, in the present invention, a step of irradiating light of a predetermined wavelength band to the quantum dot solution and measuring a spectrum of light emitted from the quantum dot solution is performed (S120).

When light of a predetermined wavelength band is emitted to the quantum dots, the quantum dots are excited to emit light.

The cadmium selenide quantum dot can emit light in a wavelength range of 460 nm to 630 nm, and specifically, can emit blue, green, yellow, orange, and red light by absorbing light in a wavelength range of 380 nm to 563 nm.

On the other hand, the emission wavelength band can be variously formed depending on the size of the quantum dots.

When the spectral measurement of the light emitted from the quantum dot solution is completed, a step S130 is performed in which the sample solution and the quantum dot solution are mixed to quench the quantum dots contained in the quantum dot solution.

Here, the sample solution is a solution in which an unknown compound is dissolved. In the explosive detection method according to the present invention, whether or not the target compound is dissolved in the sample solution is detected.

Specifically, when the target compound is mixed with the quantum dot solution, a quenching phenomenon occurs at the quantum dots contained in the quantum dot solution. Thus, the emission intensity of the quantum dot solution is reduced.

Here, the target compound may be at least one of a nitroaromatic compound, a nitroamine compound, and a nitrate ester compound.

In one embodiment, the nitroaromatic compound may be Picric acid or Trinitro toluene, the nitroamine compound may be Trinitroperhydrotriazine, and the nitrate ester compound may be Pentaerythritol tetranitrate.

In the explosive detection method according to the present invention, the presence or absence of the target compound is detected using the emission spectrum of the quantum dot solution before and after the sample solution is mixed into the quantum dot solution.

That is, in the present invention, the step (S140) of irradiating light of the predetermined wavelength band to the mixed solution of the sample solution and the quantum dot solution and measuring the spectrum of light emitted from the mixed solution, (S150) of comparing whether the target compound is present in the sample solution by comparing the spectrum of the emitted light.

Here, in order to detect the presence or absence of the target compound, a Stern-volmer equation can be used. Specifically, the degree of extinction can be quantified by plotting the light emission intensity of the curve measured from the photoluminescence and linearly converting the intensity.

When the cadmium selenide quantum dots are quenched using each of the nitroaromatic compound, the nitroamine compound and the nitrate ester compound, the quenching degree of the quantum dot is converted into the Stern-Kolmer equation, and the Ksv is 20,000 ^-1 to 180,000 M ^-1 .

Specifically, the Ksv value is from 70,000 ^-1 to 180,000 M ^-1 when the cadmium selenide quantum dots are quenched with a nitroaromatic compound, and from 20,000 ^-1 to 60,000 M ^-1 when the cadmium selenide quantum dots are quenched with a nitrate ester compound ^-1 , and when cadmium selenide quantum dots were quenched with a nitrate ester compound, it was 34,000 ^-1 to 77,000 M ^-1 .

Generally, when Ksv is 5,000 M < ^-1 >, it has a detection limit of about 200 ppt to 50 ppb. Therefore, the explosive detection method using the cadmium selenide quantum dot of the present invention can detect explosives with a sensitivity of about four times or more have.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the scope and contents of the present invention are not construed to be limited or limited by the following Examples and Experimental Examples.

Example 1. Cadmium selenide Of the quantum dot solution  Produce

Materials such as Cadmium oxide (99.99%), Selenium (99.5%, 100 mesh), Trioctylphosphine oxide (90%), Oleic acid (99% Decane (1-octadecene, 97%) was used.

Using Schlenk line techiques, cadmium selenide quantum dots were grown under an argon gas atmosphere , And 0.1 mmol of Cadmium oxide, 1.9 mmol of oleic acid and 4 g of 1-octadecene were mixed in a three-necked flask and heated to 230 ° C.

When the mixed solvent becomes a transparent solution while heating, the prepared selenium solution is injected at 230 ° C. The selenium solution was prepared by dissolving 2 mmol of selenium in 0.472 g of trioctylphosphine oxide solution and 1.37 g of 1-octadecene in a mixed solution.

After selenium solution was injected, carded selenide quantum dots of different wavelengths were extracted at different temperatures.

Experimental Example 1 By size Cadmium selenide Quantum dot Photoluminescence (PL), light absorption (UV-Vis)  Characterization for

The optical characteristics of cadmium selenide quantum dots prepared in Example 1 were analyzed by PL and UV-Vis spectroscopy.

2 is a graph illustrating absorption and emission spectra of a cadmium selenide quantum dot solution according to an embodiment of the present invention.

UV-vis spectrometer (UV-2401 pc shimazu) was used to investigate the light absorption characteristics of the quantum dot solution, and a Perkin-Elmer Luminescenece Spestra LS 55 was used to investigate the luminescence properties. As shown in FIG. 2, absorption bands were observed at 380, 410, 511, 540 and 563 nm. The center emission wavelengths of the cadmium selenide quantum dots were 460, 520, 571, 600 and 630 nm. At this time, the emission band was in a highly symmetrical form with a half width value of 50 nm to 60 nm.

Example 2. Cadmium selenide Quantum dot  Used Picric acid  detection

0.1 g of picric acid was dissolved in 100 mL of toluene for HPLC to make a 100 ppm solution. 10 mL of a 100 ppm solution was taken, and then 90 mL of toluene was added to prepare a 10 ppm solution.

10 ppm of Picric acid solution was added to the quartz cell containing cadmium selenide QD solution. At this time, 5 times 30 μL of the picric acid solution was added using the microsyringe.

3A and 3B are graphs showing the results of detection of Picric acid using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm, and 630 nm.

The picric acid solution was mixed with a quantum dot solution having central light emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm and 630 nm, followed by extinction spectroscopy. Stern-Volmer graphs for extinction were obtained and quantified.

As a result of analyzing the degree of quenching for each emission wavelength of the cadmium selenide quantum dots, a degree of quenching of different degrees was obtained according to the size of the quantum dots as shown in FIGS. 3A and 3B.

The Ksv value calculated through Example 2 is shown in Table 1 below.

CdSe PA λem (nm) Ksv (M ^-1 ) 460 nm 191,000 520 nm 177,810 571 nm 143,910 600 nm 115,580 630 nm 95,444

As a result of the detection, the explosive detection method according to the present invention was able to detect a target compound even if the target compound contained in the sample solution in terms of ppt (Part per trillion).

Example 3 Cadmium selenide Quantum dot  Used Trinitro toluene  detection

0.1 g of Trinitro toluene was dissolved in 100 mL of toluene for HPLC to make a 100 ppm solution. 10 mL of a 100 ppm solution was taken, and then 90 mL of toluene was added to prepare a 10 ppm solution.

A 10 ppm solution of Trinitro toluene was added to the quartz cell containing the cadmium selenide QD solution. At this time, 5 times 30 μL of Trinitro toluene solution was added using a microsyringe.

4A and 4B are graphs showing the results of detection of Trinitro toluene using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm, and 630 nm.

Trinitro toluene solution was mixed with a quantum dot solution having central light emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm and 630 nm, and then a quenching spectrum was obtained and a Stern-Volmer graph for extinction was obtained and quantified.

As a result of analyzing the degree of quenching for the respective emission wavelengths of the cadmium selenide quantum dots, quenching degrees of different degrees were obtained according to the sizes of the quantum dots as shown in FIGS. 4A and 4B.

The Ksv value calculated through Example 3 is shown in Table 2 below.

CdSe TNT λem (nm) Ksv (M ^-1 ) 460 nm 151,410 520 nm 128,520 571 nm 94,640 600 nm 82,334 630 nm 74,315

 As a result of the detection, the explosive detection method according to the present invention was able to detect a target compound even if the target compound contained in the sample solution in terms of ppt (Part per trillion).

Example 4. By size Cadmium selenide Quantum dot  Trinitroperhydrotriazine detection using

Trinitroperhydrotriazine (0.1 g) was dissolved in 100 mL of toluene for HPLC to make a 100 ppm solution. 10 mL of a 100 ppm solution was taken, and then 90 mL of toluene was added to prepare a 10 ppm solution.

10 ppm of Trinitroperhydrotriazine solution was added to the quartz cell containing cadmium selenide QD solution. At this time, 30 μL of Trinitroperhydrotriazine solution was added 5 times using a microsyringe.

5A and 5B are graphs showing the results of detection of Trinitroperhydrotriazine using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm, and 630 nm.

A Trinitroperhydrotriazine solution was mixed with a quantum dot solution having central light emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm and 630 nm, and then a quenching spectrum was obtained and a Stern-Volmer graph for extinction was obtained and quantified.

As a result of analyzing the degree of quenching of the cadmium selenide quantum dots with respect to the respective emission wavelengths, quenching degrees of different degrees were obtained depending on the quantum dots size as shown in FIGS. 5A and 5B.

The Ksv value calculated through Example 4 is shown in Table 3 below.

CdSe PETN λem (nm) Ksv (M ^-1 ) 460 nm 99,606 520 nm 77,988 571 nm 51,231 600 nm 42,894 630 nm 33,573

As a result of the detection, the explosive detection method according to the present invention was able to detect a target compound even if the target compound contained in the sample solution in terms of ppt (Part per trillion).

Example 5. By size Cadmium selenide Quantum dot  Used Pentaerythritol  tetranitrate detection

Pentaerythritol tetranitrate (0.1 g) was dissolved in 100 mL of toluene for HPLC to make a 100 ppm solution. 10 mL of a 100 ppm solution was taken, and then 90 mL of toluene was added to prepare a 10 ppm solution.

10 ppm of Pentaerythritol tetranitrate solution was added to the quartz cell containing cadmium selenide QD solution. At this time, 5 times 30 μL of pentaerythritol tetranitrate solution was added using a microsyringe.

6A and 6B are graphs showing the results of detection of pentaerythritol tetranitrate using a quantum dot solution having center emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm and 630 nm.

Pentaerythritol tetranitrate solution was mixed with a quantum dot solution having central light emission wavelengths of 460 nm, 520 nm, 571 nm, 600 nm and 630 nm, followed by extinction spectroscopy. Stern-Volmer graphs for quenching were obtained and quantified.

As a result of analyzing the degree of extinction of each of the cadmium selenide quantum dots with respect to the emission wavelength, a degree of extinction of a different degree can be obtained according to the sizes of the quantum dots as shown in FIGS. 6A and 6B.

The Ksv value calculated through Example 5 is shown in Table 4 below.

CdSe RDX λem (nm) Ksv (M ^-1 ) 460 nm 85,477 520 nm 54,875 571 nm 33,566 600 nm 25,886 630 nm 15,148

As a result of the detection, the explosive detection method according to the present invention was able to detect a target compound even if the target compound contained in the sample solution in terms of ppt (Part per trillion).

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

In addition, the above detailed description should not be construed in all aspects as limiting and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (9)

Preparing a cadmium selenide quantum dot solution;
Measuring a spectrum of light emitted from the quantum dot solution by irradiating light of a predetermined wavelength band to the quantum dot solution;
Mixing the sample solution and the quantum dot solution to quench the quantum dots contained in the quantum dot solution;
Measuring a spectrum of light emitted from the mixed solution by irradiating the mixed solution of the sample solution and the quantum dot solution with light of the predetermined wavelength range; And
And comparing the spectrum of light emitted from the quantum dot solution and light emitted from the mixed solution to detect whether a target compound exists in the sample solution. The method according to claim 1,
Wherein the target compound comprises at least one of a nitroaromatic compound, a nitroamine compound, or a nitrate ester compound. 3. The method of claim 2,
Wherein the nitroaromatic compound is picric acid or trinitro toluene. 3. The method of claim 2,
Wherein the nitroamine-based compound is Trinitroperhydrotriazine. 3. The method of claim 2,
Wherein the nitrate ester compound is Pentaerythritol tetranitrate. The method according to claim 1,
Wherein the cadmium selenide quantum dot has a size of 2 nm to 10 nm. The method according to claim 6,
The cadmium selenide quantum dots have an absorption wavelength of 380 nm to 563 nm,
Wherein the emission wavelength is from 460 nm to 630 nm. The method according to claim 1,
The quantum dot solution Stern-Vollmer constant explosive detection method (Ksv) is using a cadmium selenide quantum dots, characterized in that 20,000M ^-1 to 180,000M ^-1. 9. The method of claim 8,
The Stern-Bolmer constant (Ksv) of the quantum-
When the target compound is an aromatic nitro compound, and to 180,000M 70,000M ^{-1 -1,}
If the target nitro compounds of the amine-based compound, and 20,000M ^-1 to 60,000M ^-1,
And when the target compound is a nitrate ester compound, the amount of the cadmium selenide quantum dot is 34,000 M ^-1 to 77,000 M ^-1 .

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