CN109211863B

CN109211863B - Using Eu2+Method for detecting explosive TNP (trinitrotoluene) by f-f transition spectrum

Info

Publication number: CN109211863B
Application number: CN201811258092.8A
Authority: CN
Inventors: 华瑞年; 张璇; 刘力涛; 那立艳; 张伟
Original assignee: Dalian Minzu University
Current assignee: Dalian Minzu University
Priority date: 2018-10-26
Filing date: 2018-10-26
Publication date: 2021-04-20
Anticipated expiration: 2038-10-26
Also published as: CN109211863A

Abstract

The invention provides a method for utilizing Eu²⁺The method for detecting explosive TNP by f-f transition spectrum is characterized by that it uses amino modified rare earth Eu²⁺Application of the down-conversion nano material doped with nano particles in explosive detection. Exciting with 258nm ultraviolet light, and using Eu²⁺F-f transition fluorescence intensity generated in the matrix material at 360nm and energy resonance transfer formed by TNP at 360nm for Eu²⁺Measurement of fluorescence intensity at 360nm enables quantitative detection of the concentration of the explosive TNP. Eu (Eu)²⁺The f-f transition spectrum can show a stable and good detection result in explosive TNP detection, can quickly and efficiently judge the concentration of the explosive in real time, and is simple and easy to popularize.

Description

Using Eu2+Method for detecting explosive TNP (trinitrotoluene) by f-f transition spectrum

Technical Field

The invention relates to the utilization of Eu²⁺f-f transition spectroscopy detects the explosive TNP.

Background

Trinitrophenol (TNP) is a dangerous explosive and has negative influence on the environment, so that the Trinitrophenol (TNP) is particularly important for detecting and analyzing trace explosives, and at present, the method for detecting the explosives mainly comprises a chromatography method, an ion migration method, a Raman spectroscopy method and a biosensing technology method, wherein the chromatography method has the defects of expensive and heavy equipment and complex operation. The ion migration method has the defects of complex operation, large error and low detection limit. The spectrum of the Raman spectrum method is weak, the Raman spectrum method is easily interfered by the outside, and the detection result is unstable. The biosensing technique is greatly interfered by the outside and has high error. Therefore, a fast, convenient and stable method for detecting explosives is receiving more and more attention from those skilled in the art.

The rare earth down-conversion luminescent nano material refers to a process of splitting a high-energy photon into a plurality of low-energy photons. Generally speaking, the process can realize efficient energy transfer and conversion by doping rare earth elements and utilizing the abundant energy level structure of the rare earth elements. Rare earth down-conversion luminescent nano materials are widely applied to the field of biomarkers, but are rarely reported in the field of explosive detection.

Disclosure of Invention

In order to make up the blank of the prior art, the invention provides a rare earth Eu modified by amino²⁺The application of the doped down-conversion nano material in the detection of explosive TNP.

The technical scheme of the invention is as follows: eu under excitation of 258nm ultraviolet light²⁺The f-f transition fluorescence intensity at 360nm generated in the matrix material is combined with the absorption of TNP at 360nm to form energy resonance transfer, and the concentration of TNP and Eu are combined²⁺The fluorescence intensity at 360nm has a linear relationship with Eu²⁺Measurement of fluorescence intensity at 360nm enables quantitative detection of the concentration of the explosive TNP. Wherein the matrix material is amino-modified rare earth Eu²⁺Doping the down-converting nanomaterial. Such as BaAlF₅、SrAlF₅、BaSiF₆、 KMgF₃、KZnF₃、LiBaF₃One kind of (1).

The detection method specifically comprises the following steps: dissolving nanoparticles and PEI in deionized water, uniformly mixing by magnetic stirring, centrifuging for 3-4 times by using ethanol and the deionized water to obtain nanoparticles connected with PEI, dissolving the nanoparticles connected with PEI in the deionized water, adding TNP with concentration to be measured after magnetic stirring for 4 hours, performing spectral measurement on mixed liquid after stirring for 10 minutes, detecting the intensity of emitted light under the excitation of 258nm ultraviolet light, and detecting the intensity of the emitted light by the TNP with the Eu concentration²⁺The intensity of the f-f transition emission (at 360 nm) shows a linear relationship, and the explosive is quantitatively detected. The mass ratio of the nano particles to the PEI is 1: 10.

wherein BaAlF₅：Eu²⁺F-f transition emission of nanoparticles: (⁶P_7/2→⁸S_7/2) Can detect nanogram-grade TNP, Eu²⁺The f-f transition emission intensity of (A) and the TNP concentration satisfy the linear relation of y being 108341.3c-1012.5, R²0.997. The detection limit is 1 ng/ml.

BaSiF₆：Eu²⁺F-f transition emission of nanoparticles: (⁶P_7/2→⁸S_7/2) Can detect nanogram-grade TNP, Eu²⁺The f-f transition emission intensity of (A) and the TNP concentration satisfy a linear relation of y-104623.4 c-265.3, R²0.997. The detection limit is 3 ng/ml.

In the above linear relation, y represents the corresponding integrated intensity of the spectrum, and c represents the corresponding concentration of the analyte. R²Representing the accuracy of the fit for the linear relationship.

Has the advantages that:

the invention provides rare earth Eu modified by amino²⁺Application of the down-conversion nano material doped with nano particles in explosive detection. Using Eu²⁺The f-f transition spectrum can show a stable and good detection result in explosive TNP detection, can quickly and efficiently judge the concentration of the explosive in real time, and is simple and easy to popularize.

Drawings

FIG. 1(a) shows BaAlF₅：Eu²⁺Nanoparticles of (b) BaSiF₆：Eu²⁺Scanning electron microscope images of the nanoparticles.

FIG. 2 Eu before and after coating PEI²⁺The infrared spectrum of the doped nano-particle, wherein (a) is the BaAlF before and after coating PEI₅/BaSiF₆：Eu²⁺Infrared spectrum of the nanoparticles. (b) Is BaAlF₅/BaSiF₆：Eu²⁺Emission spectrum of the nanoparticles and absorption spectrum of TNP.

FIG. 3 Eu before and after coating PEI²⁺XRD pattern of doped nanoparticles, wherein (a) BaAlF before and after coating PEI₅：Eu²⁺XRD pattern of nanoparticles. (b) BaSiF before and after coating PEI₆：Eu²⁺XRD patterns of nanoparticlesSpectra.

FIG. 4 PEI-BaAlF after addition of different concentrations of TNP₅：Eu²⁺The fluorescence intensity of the nanoparticles at 360nm is corrected.

FIG. 5 PEI-BaSiF after addition of different concentrations of TNP₆：Eu²⁺The fluorescence intensity of the nanoparticles at 360nm is corrected.

Detailed Description

The invention is described in more detail below with reference to specific examples, without limiting the scope of the invention. Unless otherwise stated, the experimental methods adopted by the invention are all conventional methods, and experimental equipment, materials, reagents and the like used in the experimental method can be purchased from chemical companies.

Example 1

BaAlF₅：Eu²⁺Preparation of nanoparticles

1. Weighing 2mmol AlCl₃·6H₂O、1.92mmol BaCl₂·6H₂O、0.08mol EuCl₂Dissolving 10mL of distilled water in a 50mL beaker, adding a rotor into the beaker, and putting the beaker on a magnetic stirrer to stir for 20min so as to fully dissolve the beaker, thereby obtaining a mixed solution I.

2. Weighing 2mmol of NH₄HF₂Dissolving the mixture in 5mL of distilled water, slowly dropping the mixture into the mixed solution I after the mixture is fully dissolved, and stirring for 20min to obtain a mixed solution II.

3. The mixed solution is transferred to a 25mL reaction kettle and heated for 24h at 200 ℃.

4. After the reaction kettle is taken out, the reaction kettle is cooled to room temperature and then is centrifuged for 10 minutes at the rotating speed of 5000rpm/min, the supernatant is discarded, and the precipitate is washed by distilled water for 4 times. After drying, the composition was analyzed, and it was found from the XRD pattern 3(a) that pure phase BaAlF was obtained₅：Eu² ⁺Nanoparticles.

BaAlF₅：Eu²⁺Preparation of @ PEI nanoparticles

1. 0.2g of BaAlF₅：Eu²⁺The nanoparticles and 2g PEI were added to a 50mL beaker and dissolved by magnetic stirring at room temperature for 4h with 10mL distilled water.

2. The centrifugation was repeated 3 times with distilled water. Drying to obtain the surface modificationPost-sexual PEI-BaAlF₅：Eu²⁺And (3) nano particles.

Example 2

BaSiF₆:Eu²⁺Preparation of nanoparticles

1. Weighing 2g CTAB, dissolving in a mixed solution of 50mL cyclohexane and 2mL n-butanol, and magnetically stirring in a water bath at 60 ℃ for 30min to obtain a light yellow transparent solution, and preparing two identical solutions.

2. Respectively adding 1mLBaCl₂A mixed solution of (1mol/L) and Citric Acid (CA) and 1mLH₂SiF₆(10%) and CA were added to the two solutions obtained in step 1 and stirring was continued for 30 min.

3. The two solutions were mixed and stirred vigorously at room temperature for 1h, then transferred to a 100mL reaction vessel and heated at 120 ℃ for 12 h.

4. After the reaction kettle is taken out, the reaction kettle is cooled to room temperature and then is centrifuged at 9000rpm/min for 10 minutes, the supernatant is discarded, and the precipitate is washed with ethanol and distilled water for 4 times. Drying, performing component analysis, and obtaining pure phase BaSiF from XRD pattern 3 (b)₆:Eu²⁺Nanoparticles.

BaSiF₆:Eu²⁺Preparation of @ PEI nanoparticles

1. 0.2g of BaSiF₆：Eu²⁺The nanoparticles and 2g PEI were added to a 50mL beaker and dissolved by magnetic stirring at room temperature for 4h with 10mL distilled water.

2. The centrifugation was repeated 3 times with distilled water. Drying to obtain the surface modified PEI-BaSiF₆：Eu²⁺And (3) nanoparticles.

As shown in FIG. 2(b), BaAlF₅/BaSiF₆:Eu²⁺The emission peak of the nanoparticle coincides with the absorption peak of TNP. Because the amino has redundant electron pairs and the benzene ring in TNP has electron holes, the amino and the benzene ring can be connected together and energy resonance transfer can occur. The relation between the concentration of the explosive and the fluorescence concentration of the sample can be analyzed according to the method, so that the aim of accurately detecting the concentration of the explosive is fulfilled.

Application example 1

BaAlF₅:Eu²⁺Method for detecting TNP by using nanoparticles

1. Taking 5mgBaAlF₅:Eu²⁺@ PEI, the nanoparticles were down-converted and added to a vial containing 4ml of deionized water and stirred for 4 h.

2. Adding TNP (original solution concentration 400ng/ml) with concentration to be measured, performing gradient experiment, respectively adding TNP 10ul, 20ul, 30ul, 40ul and 50ul, stirring for 10min, and respectively performing spectrum measurement.

As shown in fig. 4, when different concentrations of TNP were added, the intensity of the spectrum decreased linearly with increasing TNP concentration.

Wherein BaAlF₅：Eu²⁺F-f transition emission of nanoparticles: (⁶P_7/2→⁸S_7/2) Can detect nanogram-grade TNP, Eu²⁺The f-f transition emission intensity of (A) and the TNP concentration satisfy the linear relation of y being 108341.3c-1012.5, R²0.997; in the linear relation, y represents the corresponding spectrum integral intensity, and c represents the corresponding concentration of the object to be detected. R²Representing the accuracy of the fit for the linear relationship. As is clear from the experimental results, BaAlF after surface modification₅:Eu²⁺The detection limit of the down-conversion nanoparticles on TNP is 1 ng/ml.

Application example 2

BaSiF₆:Eu²⁺Method for detecting TNP by using nanoparticles

1. Taking 5mgBaAlF₅：Eu²⁺@ PEI, the nanoparticles were down-converted and added to a vial containing 4ml of deionized water and stirred for 4 h.

2. Adding TNP (original solution concentration 400ng/ml) with concentration to be measured, performing gradient experiment, respectively adding 30ul, 40ul, 50ul and 150ul TNP, stirring for 10min, and respectively performing spectrum measurement.

As shown in fig. 5, when different concentrations of TNP were added, the intensity of the spectrum decreased linearly with increasing TNP concentration. BaSiF₆：Eu²⁺F-f transition emission of nanoparticles: (⁶P_7/2→⁸S_7/2) Can detect nanogram-grade TNP, Eu²⁺The f-f transition emission intensity of (A) and the TNP concentration satisfy a linear relationship of y to 104623.4c-265.3，R²0.997. In the linear relation, y represents the corresponding spectrum integral intensity, and c represents the corresponding concentration of the substance to be detected. R²Representing the accuracy of the fit for the linear relationship. From the experimental results, it is clear that the surface-modified BaSiF₆：Eu²⁺The detection limit of the down-conversion nanoparticles on TNP is 3 ng/ml.

The above description is only for the purpose of creating a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the technical scope of the present invention.

Claims

1. By using Eu²⁺A method for detecting explosive TNP is characterized in that Eu is excited by ultraviolet light with the wavelength of 258nm²⁺The f-f transition fluorescence intensity at 360nm generated in the matrix material is combined with the absorption of TNP at 360nm to form energy resonance transfer for Eu²⁺The measurement of fluorescence intensity at 360nm enables the quantitative detection of the concentration of explosive TNP;

the matrix material is BaAlF₅Or BaSiF₆；

The specific method comprises the following steps: mixing BaAlF₅：Eu²⁺Or BaSiF₆：Eu²⁺Dissolving the nano particles and PEI in deionized water, stirring and mixing uniformly by magnetic force, centrifuging for 3-4 times by using ethanol and the deionized water to obtain the nano particles connected with the PEI, dissolving the nano particles connected with the PEI in the deionized water, stirring for 4 hours by magnetic force, adding TNP with the concentration to be measured, stirring for 10 minutes, performing spectral measurement on the mixed liquid, detecting the intensity of emitted light under the excitation of 258nm ultraviolet light, and measuring the intensity of emitted light by the TNP with the Eu according to the concentration of the TNP²⁺Quantitatively detecting the explosives by using a linear relation presented between f-f transition emission intensities at 360 nm;

BaAlF₅：Eu²⁺nano particle f-f transition emission can detect nanogram level TNP, Eu²⁺The f-f transition emission intensity and the TNP concentration satisfy a linear relationy=108341.3c-1012.5，R²=0.997；

BaSiF₆：Eu²⁺Nano particle f-f transition emission can detect nanogram level TNP, Eu²⁺The linear relation y =104623.4c-265.3 is satisfied between the f-f transition emission intensity and the TNP concentration, and R²=0.997；

Wherein y represents the corresponding spectral integrated intensity, c is the corresponding concentration of the substance to be detected, and R²Representing the accuracy of the fit for the linear relationship.