1
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Noh D, Oh E. Estimation of Environmental Effects and Response Time in Gas-Phase Explosives Detection Using Photoluminescence Quenching Method. Polymers (Basel) 2024; 16:908. [PMID: 38611166 PMCID: PMC11013195 DOI: 10.3390/polym16070908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/13/2024] [Accepted: 03/22/2024] [Indexed: 04/14/2024] Open
Abstract
Detecting the presence of explosives is important to protect human lives during military conflicts and peacetime. Gas-phase detection of explosives can make use of the change of material properties, which can be sensitive to environmental conditions such as temperature and humidity. This paper describes a remote-controlled automatic shutter method for the environmental impact assessment of photoluminescence (PL) sensors under near-open conditions. Utilizing the remote-sensing method, we obtained environmental effects without being exposed to sensing vapor molecules and explained how PL intensity was influenced by the temperature, humidity, and exposure time. We also developed a theoretical model including the effect of exciton diffusion for PL quenching, which worked well under limited molecular diffusions. Incomplete recovery of PL intensity or the degradation effect was considered as an additional factor in the model.
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Affiliation(s)
- Daegwon Noh
- Department of Physics, Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon 34134, Republic of Korea;
- Institute of Quantum Systems (IQS), Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon 34134, Republic of Korea
| | - Eunsoon Oh
- Department of Physics, Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon 34134, Republic of Korea;
- Institute of Quantum Systems (IQS), Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon 34134, Republic of Korea
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2
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Filippov T, Vervitski E, Kofler H, Birkan L, Levy S, Zimmerman S, Bulatov V, Schechter I, Schuetz R. Sub-PPB Detection with Gas-Phase Multiphoton Electron Extraction Spectroscopy under Ambient Conditions. Sensors (Basel) 2024; 24:2040. [PMID: 38610252 PMCID: PMC11014131 DOI: 10.3390/s24072040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/12/2024] [Accepted: 03/18/2024] [Indexed: 04/14/2024]
Abstract
Multiphoton electron extraction spectroscopy (MEES) is an advanced analytical technique that has demonstrated exceptional sensitivity and specificity for detecting molecular traces on solid and liquid surfaces. Building upon the solid-state MEES foundations, this study introduces the first application of MEES in the gas phase (gas-phase MEES), specifically designed for quantitative detection of gas traces at sub-part per billion (sub-PPB) concentrations under ambient atmospheric conditions. Our experimental setup utilizes resonant multiphoton ionization processes using ns laser pulses under a high electrical field. The generated photoelectron charges are recorded as a function of the laser's wavelength. This research showcases the high sensitivity of gas-phase MEES, achieving high spectral resolution with resonant peak widths less than 0.02 nm FWHM. We present results from quantitative analysis of benzene and aniline, two industrially and environmentally significant compounds, demonstrating linear responses in the sub-PPM and sub-PPB ranges. The enhanced sensitivity and resolution of gas-phase MEES offer a powerful approach to trace gas analysis, with potential applications in environmental monitoring, industrial safety, security screening, and medical diagnostics. This study confirms the advantages of gas-phase MEES over many traditional optical spectroscopic methods and demonstrates its potential in direct gas-trace sensing in ambient atmosphere.
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3
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Katilie CJ, DeGreeff LE, Sharpes CE, Best EM, Buckley PE, Gadberry JD, Maughan MN. Evaluation of canine training aids containment for homemade explosive and components by headspace analysis and canine testing. J Forensic Sci 2023; 68:2021-2036. [PMID: 37691017 DOI: 10.1111/1556-4029.15368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/12/2023] [Accepted: 08/15/2023] [Indexed: 09/12/2023]
Abstract
While canines are most commonly trained to detect traditional explosives, such as nitroaromatics and smokeless powders, homemade explosives (HMEs), such as fuel-oxidizer mixtures, are arguably a greater threat. As such, it is imperative that canines are sufficiently trained in the detection of such HMEs. The training aid delivery device (TADD) is a primary containment device that has been used to house HMEs and HME components for canine detection training purposes. This research assesses the odor release from HME components, ammonium nitrate (AN), urea nitrate (UN), and potassium chlorate (PC), housed in TADDs. Canine odor recognition tests (ORTs) were used with analytical data to determine the detectability of TADDs containing AN, UN, or PC. Headspace analysis by gas chromatography/mass spectrometry (GC/MS) with solid-phase microextraction (SPME) or online cryotrapping were used to measure ammonia or chlorine, as well as other unwanted odorants, emanating from bulk AN, UN, and PC in TADDs over 28 weeks. The analytical data showed variation in the amount of ammonia and chlorine over time, with ammonia from AN and UN decreasing slowly over time and the abundance of chlorine from PC TADDs dependent on the frequency of exposure to ambient air. Even with these variations in odor abundance, canines previously trained to detect bulk explosive HME components were able to detect all three targets in glass and plastic TADDs for at least 18 months after loading. Detection proficiency ranged from 64% to 100% and was not found to be dependent on either age of material.
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Affiliation(s)
| | - Lauryn E DeGreeff
- Formerly of the U.S. Naval Research Laboratory, Washington, District of Columbia, USA
| | | | - Eric M Best
- College of Emergency Preparedness, Homeland Security and Cybersecurity, University of Albany, Albany, New York, USA
| | - Patricia E Buckley
- US Army DEVCOM Chemical Biological Center, Aberdeen Proving Ground, Maryland, USA
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4
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Szyposzyńska M, Spławska A, Ceremuga M, Kot P, Maziejuk M. Stationary Explosive Trace Detection System Using Differential Ion Mobility Spectrometry (DMS). Sensors (Basel) 2023; 23:8586. [PMID: 37896679 PMCID: PMC10610698 DOI: 10.3390/s23208586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023]
Abstract
Detecting trace amounts of explosives is important for maintaining national security due to the growing threat of terror attacks. Particularly challenging is the increasing use of homemade explosives. Therefore, there is a constant need to improve existing technologies for detecting trace amounts of explosives. This paper describes the design of a stationary device (a gate) for detecting trace amounts of explosives and explosive taggants and the design of differential ion mobility spectrometers with a focus on the gas system. Nitromethane (NM), trimeric acetone peroxide (TATP), hexamine peroxide (HMTD), and explosive taggants 2,3-dimethyl-2,3-dinitrobutane (DMDNB) and 4-nitrotoluene (4NT) were used in this study. Gate measurements were carried out by taking air from the hands, pocket area, and shoes of the tested person. Two differential ion mobility spectrometers operating in two different modes were used as explosive detectors: a mode with a semi-permeable membrane to detect explosives with high vapor pressures (such as TATP) and a mode without a semi-permeable membrane (using direct introduction of the sample into the measuring chamber) to detect explosives with low vapor pressures (such as HMTD). The device was able to detect trace amounts of selected explosives/explosive taggants in 5 s.
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Affiliation(s)
- Monika Szyposzyńska
- Military Institute of Chemistry and Radiometry, al. gen. A. Chruściela “Montera” 105, 00-910 Warsaw, Poland; (A.S.); (P.K.); (M.M.)
| | - Aleksandra Spławska
- Military Institute of Chemistry and Radiometry, al. gen. A. Chruściela “Montera” 105, 00-910 Warsaw, Poland; (A.S.); (P.K.); (M.M.)
| | - Michał Ceremuga
- Military Institute of Armoured and Automotive Technology, Okuniewska 1, 05-070 Sulejówek, Poland;
| | - Piotr Kot
- Military Institute of Chemistry and Radiometry, al. gen. A. Chruściela “Montera” 105, 00-910 Warsaw, Poland; (A.S.); (P.K.); (M.M.)
| | - Mirosław Maziejuk
- Military Institute of Chemistry and Radiometry, al. gen. A. Chruściela “Montera” 105, 00-910 Warsaw, Poland; (A.S.); (P.K.); (M.M.)
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5
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Li S, Ouyang T, Guo X, Dong W, Ma Z, Fei T. Tetraphenylethene-Based Cross-Linked Conjugated Polymer Nanoparticles for Efficient Detection of 2,4,6-Trinitrophenol in Aqueous Phase. Materials (Basel) 2023; 16:6458. [PMID: 37834593 PMCID: PMC10573890 DOI: 10.3390/ma16196458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/20/2023] [Accepted: 09/26/2023] [Indexed: 10/15/2023]
Abstract
The cross-linked conjugated polymer poly(tetraphenylethene-co-biphenyl) (PTPEBP) nanoparticles were prepared by Suzuki-miniemulsion polymerization. The structure, morphology, and pore characteristics of PTPEBP nanoparticles were characterized by FTIR, NMR, SEM, and nitrogen adsorption and desorption measurements. PTPEBP presents a spherical nanoparticle morphology with a particle size of 56 nm; the specific surface area is 69.1 m2/g, and the distribution of the pore size is centered at about 2.5 nm. Due to the introduction of the tetraphenylethene unit, the fluorescence quantum yield of the PTPEBP nanoparticles reaches 8.14% in aqueous dispersion. Combining the porosity and nanoparticle morphology, the fluorescence sensing detection toward nitroaromatic explosives in the pure aqueous phase has been realized. The Stern-Volmer quenching constant for 2,4,6-trinitrophenol (TNP) detection is 2.50 × 104 M-1, the limit of detection is 1.07 μM, and the limit of quantification is 3.57 μM. Importantly, the detection effect of PTPEBP nanoparticles toward TNP did not change significantly after adding other nitroaromatic compounds, indicating that the anti-interference and selectivity for TNP detection in aqueous media is remarkable. In addition, the spike recovery test demonstrates the potential of PTPEBP nanoparticles for detecting TNP in natural environmental water samples.
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Affiliation(s)
- Shengjie Li
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, China
| | - Tianwen Ouyang
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, China
| | - Xue Guo
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, China
| | - Wenyue Dong
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, China
- Chongqing Research Institute, Changchun University of Science and Technology, Chongqing 401135, China
| | - Zhihua Ma
- Chongqing Research Institute, Changchun University of Science and Technology, Chongqing 401135, China
| | - Teng Fei
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
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6
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Ennis D, Golden D, Curtin MC, Cooper A, Sun C, Riegner K, Johnson CC, Nolletti JL, Wallace KB, Chacon JA, Bethune H, Ritchie TS, Schnee V, DeNeve DR, Riegner DE. Quantum Dot-Doped Electrospun Polymer Fibers for Explosive Vapor Sensors. ACS Appl Nano Mater 2023; 6:9315-9321. [PMID: 37325013 PMCID: PMC10262150 DOI: 10.1021/acsanm.3c00370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/04/2023] [Indexed: 06/17/2023]
Abstract
This research seeks to support reconnaissance efforts against homemade explosives (HMEs) and improvised explosive devices (IEDs), which are leading causes of combat casualties in recent conflicts. The successful deployment of a passive sensor to be developed for first responders and military must take expense, training requirements, and physical burden all into consideration. By harnessing the size-dependent luminescence of quantum dots (QDs) being electrospun into polymer fibers, the authors of this work hope to progress toward the development of lightweight, multivariable, inexpensive, easy to use and interpret, field-applicable sensors capable of detecting explosive vapors. The data demonstrate that poly(methyl methacrylate) (PMMA), polystyrene (PS), and polyvinyl chloride (PVC) fibers doped with Fort Orange cadmium selenide (CdSe) QDs, Birch Yellow CdSe QDs, or carbon (C) QDs will quench in the presence of explosive vapors (DNT, TNT, TATP, and RDX). In all cases, the fluorescent signal of the doped fiber continuously quenched upon sustained exposure to the headspace vapors. The simple method for the integration of QDs into the fibers' structure combined with their straightforward visual response, reusability, and durability all present characteristics desired for a field-operable and multimodal sensor with the ability to detect explosive threats.
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Affiliation(s)
- Dalton Ennis
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Dylan Golden
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Mackenzie C. Curtin
- U.S.
Army, Combined Arms Support Command, Fort Lee, Virginia 23801 United States
| | - Alma Cooper
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Cynthia Sun
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Kathleen Riegner
- Department
of Chemical Engineering & Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030 United States
| | - Caleb C. Johnson
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Julia L. Nolletti
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Kingsley B. Wallace
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Jose A. Chacon
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
| | - Haven Bethune
- Fires
Center of Excellence, United States Army, Fort Sill, Oklahoma 73503 United States
| | - Tessy S. Ritchie
- Center
for Devices and Radiological Health, U.S.
Food and Drug Administration, Silver
Spring, Maryland 20993 United States
| | - Vincent Schnee
- C5ISR
Center Night Vision and Electronic Sensors Directorate, U.S. Army Combat Capabilities Development Command, Aberdeen Proving Ground, Maryland 21005 United States
| | - Daniel R. DeNeve
- U.S.
Army, 3rd Infantry Division, Fort
Stewart, Georgia 31314 United States
| | - Dawn E. Riegner
- Department
of Chemistry and Life Science, United States
Military Academy, West Point, New York 10996 United States
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7
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Liu W, Wang Z, Liu Z, Chen J, Shi L, Huang L, Liu Y, Cui S, He X. Utilizing an Automated SERS-Digital Microfluidic System for High-Throughput Detection of Explosives. ACS Sens 2023; 8:1733-1741. [PMID: 36950737 DOI: 10.1021/acssensors.3c00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
The surface-enhanced Raman scattering (SERS) technique is a promising method for the detection of explosives such as 2,4,6-trinitrotoluene (TNT) and 3-nitro-1,2,4-triazol-5-one (NTO) because of its high sensitivity to trace substances. However, most SERS detection processes are often nonautomated as well as exhibit low efficiency and toxic exposure, which often poses potential danger to operators. Herein, we propose the integration of SERS with digital microfluidics (SERS-DMF) for automated, high-throughput, and high-sensitivity detection of explosives. First, we carefully designed a DMF chip comprising 40 drive electrodes and 8 storage electrodes to achieve a high-throughput process. And different concentrations of target molecules, silver nanoparticles (Ag NPs), and salts were loaded into the DMF chip. Then, the droplet aggregation, incubation, and detection processes were automatically controlled using the SERS-DMF platform. In addition, Ag NPs were efficiently aggregated by screening different types and concentrations of salts, resulting in "hotspots" and the SERS effect. With the help of the SERS-DMF platform, two explosive samples were automatically detected with high throughput and high sensitivity. The detection limits of TNT and NTO were 10-7 and 10-8 M, respectively. In addition, compared with nonautomatic operations, the SERS-DMF platform exhibited better reproducibility and higher efficiency for the detection of explosives. The proposed SERS-DMF thus has considerable potential as an analytical technique for detecting hazardous substances.
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Affiliation(s)
- Wei Liu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Material Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Zihan Wang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Material Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Zhongping Liu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Junxue Chen
- College of Science, Guilin University of Technology, Guilin 541004, China
| | - Lingyan Shi
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Material Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Longjin Huang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Material Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Yu Liu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Sheng Cui
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Material Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Xuan He
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
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8
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Tanwar A, Parui R, Garai R, Chanu MA, Iyer PK. Dual "Static and Dynamic" Fluorescence Quenching Mechanisms Based Detection of TNT via a Cationic Conjugated Polymer. ACS Meas Sci Au 2022; 2:23-30. [PMID: 36785591 PMCID: PMC9838727 DOI: 10.1021/acsmeasuresciau.1c00023] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A rare combination of dual static and dynamic fluorescence quenching mechanisms is reported, while sensing the nitroexplosive trinitrotoluene (TNT) in water by a cationic conjugated copolymer PFPy. Since the fluorophore PFPy interacts with TNT in both ground state as well as the excited states, a greater extent of interaction is facilitated between PFPy and the TNT, as a result of which the magnitude of the signal is amplified remarkably. The existence of these collective sensing mechanisms provides additional advantages to the sensing process and enhances the sensing parameters, such as LoD and highly competitive sensing processes in natural water bodies irrespective of the pH and at ambient conditions. These outcomes involving dual sensing mechanistic pathways expand the scope of developing efficient sensing probes for toxic chemical analyte and biomarker detection, preventing environmental pollution and strengthening security at sensitive locations while assisting in early diagnosis of disease biomarkers.
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Affiliation(s)
- Arvin
Sain Tanwar
- Department
of Chemistry, Indian Institute of Technology
Guwahati, Guwahati-781039, Assam, India
| | - Retwik Parui
- Department
of Chemistry, Indian Institute of Technology
Guwahati, Guwahati-781039, Assam, India
| | - Rabindranath Garai
- Department
of Chemistry, Indian Institute of Technology
Guwahati, Guwahati-781039, Assam, India
| | - Moirangthem Anita Chanu
- Department
of Chemistry, Indian Institute of Technology
Guwahati, Guwahati-781039, Assam, India
| | - Parameswar Krishnan Iyer
- Department
of Chemistry, Indian Institute of Technology
Guwahati, Guwahati-781039, Assam, India
- Centre
for Nanotechnology, Indian Institute of
Technology Guwahati, Guwahati-781039, Assam, India
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9
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Abstract
Spin current based sensing methods offer a new approach to the development of selective detection devices for explosive molecules. Employing a combination of bias voltages and transverse electric fields to vary the chemiresistive properties of a zigzag graphene nanoribbon, dual-input dual-output sensors of this kind offer major advantages: tuning the electrical properties of a single nanoribbon is equivalent to deploying a sensor array, and measuring two outputs (spin-up and spin-down currents, total current and spin current difference, etc.) offers improved selectivity. Ab initio modeling suggests that the magnetic properties of the analyte, charge transfer effects, current transmission pathways, and analyte molecule size all influence sensor signatures. Analysis of the sensing cause-effect physics relies upon the calculation of energy averaged bond currents, which visualize the global spin current transport. Principal component analysis of the proposed sensing scheme suggests that it can distinguish between common background gases, nitroaromatic explosives, and nitramine explosives and will offer far better selectivity than carbon nanotube based explosive sensing devices.
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Affiliation(s)
- Jie Zhang
- Department of Mechanical Engineering, University of Texas, Austin, Texas 78712, United States
| | - Eric P Fahrenthold
- Department of Mechanical Engineering, University of Texas, Austin, Texas 78712, United States
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10
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Adhikari S, Ampadu EK, Kim M, Noh D, Oh E, Lee D. Detection of Explosives by SERS Platform Using Metal Nanogap Substrates. Sensors (Basel) 2021; 21:5567. [PMID: 34451009 DOI: 10.3390/s21165567] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 01/13/2023]
Abstract
Detecting trace amounts of explosives to ensure personal safety is important, and this is possible by using laser-based spectroscopy techniques. We performed surface-enhanced Raman scattering (SERS) using plasmonic nanogap substrates for the solution phase detection of some nitro-based compounds, taking advantage of the hot spot at the nanogap. An excitation wavelength of 785 nm with an incident power of as low as ≈0.1 mW was used to excite the nanogap substrates. Since both RDX and PETN cannot be dissolved in water, acetone was used as a solvent. TNT was dissolved in water as well as in hexane. The main SERS peaks of TNT, RDX, and PETN were clearly observed down to the order of picomolar concentration. The variations in SERS spectra observed from different explosives can be useful in distinguishing and identifying different nitro-based compounds. This result indicates that our nanogap substrates offer an effective approach for explosives identification.
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11
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Vahčič M, Anderson D, Seghers J, Leys H, Ruiz Oses M, Rarata G, Fernández García M, Prados Román R, Pellico Escudero D. A Powdered Simulant of Triacetone Triperoxide (TATP) for Safe Testing of X-ray Transmission Screening Equipment. Molecules 2020; 25:E1473. [PMID: 32214034 DOI: 10.3390/molecules25061473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 11/16/2022] Open
Abstract
Explosives detection systems (EDS) based on X-ray are used at airports to screen baggage for the presence of explosives. Once EDS are installed in airports, however, it can be challenging to test the EDS equipment and verify that it continues to perform at the highest level, because of the impracticality of introducing bulk explosives into civil aviation airports. The problem is particularly acute for sensitive homemade explosives, such as triacetone triperoxide (TATP). This paper describes our work to develop a safe, accurate and stable simulant for TATP for EDS based on X-ray transmission. Bulk quantities of TATP were synthesised and characterised especially for this project, and we describe the unique challenges and safety considerations of collecting this data. Our calculations show that the expanded measurement uncertainty with a coverage factor of k = 2 is 5.7% for bulk density and 1.0% for Zeff at 24 months.
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12
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Vahčič M, Anderson D, Ruiz Osés M, Rarata G, Diaconu G. Development of Inert, Polymer-Bonded Simulants for Explosives Detection Systems Based on Transmission X-ray. Molecules 2019; 24:E4330. [PMID: 31783515 DOI: 10.3390/molecules24234330] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/13/2019] [Accepted: 11/16/2019] [Indexed: 11/16/2022] Open
Abstract
Explosives detection systems (EDS) based on X-ray are used at airports to screen baggage for the presence of explosives. In Europe and the United States, EDS equipment is tested extensively by specialist test centres prior to approval for operational use in airports. Once EDS are installed in airports, however, it can be challenging to test the EDS equipment and verify that it continues to perform at the highest level, because of the impracticality of introducing bulk explosives into civil aviation airports. We have developed inert, non-toxic polymer-bonded simulants and validated them against real explosives using EDS equipment. The accuracy of our simulants is within 1% of the target bulk density, and within 2% of the target effective atomic number, and the materials have a stability of at least 4 years, with an uncertainty of 0.5%. The simulants generate alarms in almost 100% of cases on a wide range of commercial EDS models, and we consider the simulants fit for purpose for use during testing of EDS equipment at airports.
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13
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Novotný F, Urbanová V, Plutnar J, Pumera M. Preserving Fine Structure Details and Dramatically Enhancing Electron Transfer Rates in Graphene 3D-Printed Electrodes via Thermal Annealing: Toward Nitroaromatic Explosives Sensing. ACS Appl Mater Interfaces 2019; 11:35371-35375. [PMID: 31525017 DOI: 10.1021/acsami.9b06683] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Additive manufacturing (AM) represents one of the nine pillars of the new industrial revolution. Owing to the enthusiastic utilization of this technology by the wider professional and amateur communities, AM is becoming a driving force in the manufacturing sector due to its fast expansion and the availability of cheap and robust 3D printers. The 3D printing, especially the fused deposition modeling (FDM) method, has previously been utilized to fabricate carbon/polylactic acid (PLA) electrodes for electrochemical setups. Such electrodes require activation from their pristine state for improved conductivity, so far achieved by chemical treatment. Herein, a new simple physical thermal annealing method to activate graphene-based PLA electrodes is presented. The graphene/PLA electrodes are fabricated via FDM 3D printing using a commercial graphene-polymer composite conductive filament and subjected to thermal and chemical activation with a subsequent electrochemical pre-treatment. The thermally annealed electrodes exhibit faster electron transfer than the chemically activated or non-treated electrodes in the inner sphere redox probe ferro/ferricyanide. The thermally activated graphene/PLA electrodes are also successfully employed as a low-cost alternative to nitroaromatic explosive sensors. This chemical-free activation method is a facile, fast, and simple route to activate conductive carbon/PLA 3D prints, which increases the electric conductivity and preserves the fine details of the printed objects, making this activation method relevant to a broad range of applied fields utilizing conductive polymer composites.
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Affiliation(s)
- Filip Novotný
- Center for Advanced Functional Nanorobots, Dept. of Inorganic Chemistry, Faculty of Chemical Technology , University of Chemistry and Technology in Prague , Technická 5 , Prague CZ-166 28 Czech Republic
| | - Veronika Urbanová
- Center for Advanced Functional Nanorobots, Dept. of Inorganic Chemistry, Faculty of Chemical Technology , University of Chemistry and Technology in Prague , Technická 5 , Prague CZ-166 28 Czech Republic
| | - Jan Plutnar
- Center for Advanced Functional Nanorobots, Dept. of Inorganic Chemistry, Faculty of Chemical Technology , University of Chemistry and Technology in Prague , Technická 5 , Prague CZ-166 28 Czech Republic
| | - Martin Pumera
- Center for Advanced Functional Nanorobots, Dept. of Inorganic Chemistry, Faculty of Chemical Technology , University of Chemistry and Technology in Prague , Technická 5 , Prague CZ-166 28 Czech Republic
- Department of Chemical and Biomolecular Engineering , Yonsei University , 50 Yonsei-ro , Seodaemun-gu, Seoul 03722 , Korea
- Future Energy and Innovation Laboratory, Central European Institute of Technology , Brno University of Technology , Purkyňova 656/123 , Brno CZ-616 00 , Czech Republic
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14
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Hikal WM, Weeks BL. Non-Isothermal Sublimation Kinetics of 2,4,6-Trinitrotoluene (TNT) Nanofilms. Molecules 2019; 24:molecules24061163. [PMID: 30909608 PMCID: PMC6471548 DOI: 10.3390/molecules24061163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/17/2019] [Accepted: 03/20/2019] [Indexed: 11/16/2022] Open
Abstract
Non-isothermal sublimation kinetics of low-volatile materials is more favorable over isothermal data when time is a crucial factor to be considered, especially in the subject of detecting explosives. In this article, we report on the in-situ measurements of the sublimation activation energy for 2,4,6-trinitrotoluene (TNT) continuous nanofilms in air using rising-temperature UV-Vis absorbance spectroscopy at different heating rates. The TNT films were prepared by the spin coating deposition technique. For the first time, the most widely used procedure to determine sublimation rates using thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) was followed in this work using UV-Vis absorbance spectroscopy. The sublimation kinetics were analyzed using three well-established calculating techniques. The non-isothermal based activation energy values using the Ozawa, Flynn–Wall, and Kissinger models were 105.9 ± 1.4 kJ mol−1, 102.1 ± 2.7 kJ mol−1, and 105.8 ± 1.6 kJ mol−1, respectively. The calculated activation energy agreed well with our previously reported isothermally-measured value for TNT nanofilms using UV-Vis absorbance spectroscopy. The results show that the well-established non-isothermal analytical techniques can be successfully applied at a nanoscale to determine sublimation kinetics using absorbance spectroscopy.
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Affiliation(s)
- Walid M Hikal
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA.
- Department of Mathematics, Australian College of Kuwait, Safat 13015, Kuwait.
- Department of Physics, Faculty of science, Assiut University, Assiut 71516, Egypt.
| | - Brandon L Weeks
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA.
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15
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Abstract
Ambient mass spectrometry has evolved rapidly over the past decade, yielding a plethora of platforms and demonstrating scientific advancements across a range of fields from biological imaging to rapid quality control. These techniques have enabled real-time detection of target analytes in an open environment with no sample preparation and can be coupled to any mass analyzer with an atmospheric pressure interface; capabilities of clear interest to the defense, customs and border control, transportation security, and forensic science communities. This review aims to showcase and critically discuss advances in ambient mass spectrometry for the trace detection of explosives.
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Affiliation(s)
- Thomas P Forbes
- National Institute of Standards and Technology, Materials Measurement Science Division, Gaithersburg, MD, USA.
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16
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Schlur L, Hofer M, Ahmad A, Bonnot K, Holz M, Spitzer D. Cu(OH)₂ and CuO Nanorod Synthesis on Piezoresistive Cantilevers for the Selective Detection of Nitrogen Dioxide. Sensors (Basel) 2018; 18:E1108. [PMID: 29621172 DOI: 10.3390/s18041108] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/23/2018] [Accepted: 04/03/2018] [Indexed: 11/17/2022]
Abstract
Self-controlled active oscillating microcantilevers with a piezoresistive readout are very promising sensitive sensors, despite their small surface. In order to increase this surface and consequently their sensitivity, we nanostructured them with copper hydroxide (Cu(OH)2) or with copper oxide (CuO) nanorods. The Cu(OH)2 rods were grown, on a homogeneous copper layer previously evaporated on the top of the cantilever. The CuO nanorods were further obtained by the annealing of the copper hydroxide nanostructures. Then, these copper based nanorods were used to detect several molecules vapors. The results showed no chemical affinity (no formation of a chemical bond) between the CuO cantilevers and the tested molecules. The cantilever with Cu(OH)2 nanorods is selective to nitrogen dioxide (NO2) in presence of humidity. Indeed, among all the tested analytes, copper hydroxide has only an affinity with NO2. Despite the absence of affinity, the cantilevers could even so condensate explosives (1,3,5-trinitro-1,3,5-triazinane (RDX) and pentaerythritol tetranitrate (PETN) on their surface when the cantilever temperature was lower than the explosives source, allowing their detection. We proved that in condensation conditions, the cantilever surface material has no importance and that the nanostructuration is useless because a raw silicon cantilever detects as well as the nanostructured ones.
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17
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Martelo LM, das Neves TFP, Figueiredo J, Marques L, Fedorov A, Charas A, Berberan-Santos MN, Burrows HD. Towards the Development of a Low-Cost Device for the Detection of Explosives Vapors by Fluorescence Quenching of Conjugated Polymers in Solid Matrices. Sensors (Basel) 2017; 17:s17112532. [PMID: 29099776 PMCID: PMC5712976 DOI: 10.3390/s17112532] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/25/2017] [Accepted: 10/30/2017] [Indexed: 12/04/2022]
Abstract
Conjugated polymers (CPs) have proved to be promising chemosensory materials for detecting nitroaromatic explosives vapors, as they quickly convert a chemical interaction into an easily-measured high-sensitivity optical output. The nitroaromatic analytes are strongly electron-deficient, whereas the conjugated polymer sensing materials are electron-rich. As a result, the photoexcitation of the CP is followed by electron transfer to the nitroaromatic analyte, resulting in a quenching of the light-emission from the conjugated polymer. The best CP in our studies was found to be poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophene] (F8T2). It is photostable, has a good absorption between 400 and 450 nm, and a strong and structured fluorescence around 550 nm. Our studies indicate up to 96% quenching of light-emission, accompanied by a marked decrease in the fluorescence lifetime, upon exposure of the films of F8T2 in ethyl cellulose to nitrobenzene (NB) and 1,3-dinitrobenzene (DNB) vapors at room temperature. The effects of the polymeric matrix, plasticizer, and temperature have been studied, and the morphology of films determined by scanning electron microscopy (SEM) and confocal fluorescence microscopy. We have used ink jet printing to produce sensor films containing both sensor element and a fluorescence reference. In addition, a high dynamic range, intensity-based fluorometer, using a laser diode and a filtered photodiode was developed for use with this system.
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Affiliation(s)
- Liliana M Martelo
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
- Centro de Química-Física Molecular (CQFM) and the Institute of Nanoscience and Nanotechnology (IN), Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal.
| | | | - João Figueiredo
- Institute of Systems and Robotics (ISR), University of Coimbra, 3030-290 Coimbra, Portugal.
| | - Lino Marques
- Institute of Systems and Robotics (ISR), University of Coimbra, 3030-290 Coimbra, Portugal.
| | - Alexander Fedorov
- Institute of Systems and Robotics (ISR), University of Coimbra, 3030-290 Coimbra, Portugal.
| | - Ana Charas
- Instituto de Telecomunicações, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
| | - Mário N Berberan-Santos
- Centro de Química-Física Molecular (CQFM) and the Institute of Nanoscience and Nanotechnology (IN), Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal.
| | - Hugh D Burrows
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
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18
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Erickson JS, Shriver-Lake LC, Zabetakis D, Stenger DA, Trammell SA. A Simple and Inexpensive Electrochemical Assay for the Identification of Nitrogen Containing Explosives in the Field. Sensors (Basel) 2017; 17:s17081769. [PMID: 28767088 PMCID: PMC5579490 DOI: 10.3390/s17081769] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 07/27/2017] [Accepted: 07/31/2017] [Indexed: 01/27/2023]
Abstract
We report a simple and inexpensive electrochemical assay using a custom built hand-held potentiostat for the identification of explosives. The assay is based on a wipe test and is specifically designed for use in the field. The prototype instrument designed to run the assay is capable of performing time-resolved electrochemical measurements including cyclic square wave voltammetry using an embedded microcontroller with parts costing roughly $250 USD. We generated an example library of cyclic square wave voltammograms of 12 compounds including 10 nitroaromatics, a nitramine (RDX), and a nitrate ester (nitroglycine), and designed a simple discrimination algorithm based on this library data for identification.
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Affiliation(s)
- Jeffrey S Erickson
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | - Lisa C Shriver-Lake
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | - Daniel Zabetakis
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | - David A Stenger
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | - Scott A Trammell
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
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19
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Abstract
Detection and identification of unknown and possibly hazardous materials is a vital area of research to which infrared (IR) spectroscopy is ideally suited. Infrared absorption spectra can be measured with many sensing paradigms of which photoacoustic spectroscopy (PAS) is a sensitive and flexible variant. The flexibility of PAS allows for the construction of narrowly tailored spectroscopic sensors that are designed for specific tasks. We discuss the evaluation of an interferometric PAS sensor by the measurement of common explosive hazards from a standoff distance of 1 m. Reproduction of IR absorption spectra for 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), pentaerythritol tetranitrate (PETN), and 2,4,6-trinitrotoluene (TNT) demonstrate the capabilities of the interferometric sensor for standoff explosives detection.
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Affiliation(s)
- Logan S Marcus
- U.S. Army Research Laboratory, RDRL-SEE-E, Adelphi, MD, USA
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20
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Cao A, Zhu W, Shang J, Klootwijk JH, Sudhölter EJR, Huskens J, de Smet LCPM. Metal-Organic Polyhedra-Coated Si Nanowires for the Sensitive Detection of Trace Explosives. Nano Lett 2017; 17:1-7. [PMID: 28073264 DOI: 10.1021/acs.nanolett.6b02360] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Surface-modified silicon nanowire-based field-effect transistors (SiNW-FETs) have proven to be a promising platform for molecular recognition in miniature sensors. In this work, we present a novel nanoFET device for the sensitive and selective detection of explosives based on affinity layers of metal-organic polyhedra (MOPs). The judicious selection of the geometric and electronic characteristics of the assembly units (organic ligands and unsaturated metal site) embedded within the MOP cage allowed for the formation of multiple charge-transfer (CT) interactions to facilitate the selective explosive inclusion. Meanwhile, the host-stabilized CT complex inside the cage acted as an effective molecular gating element to strongly modulate the electrical conductance of the silicon nanowires. By grafting the MOP cages onto a SiNW-FET device, the resulting sensor showed a good electrical sensing capability to various explosives, especially 2,4,6-trinitrotoluene (TNT), with a detection limit below the nanomolar level. Importantly, coupling MOPs-which have tunable structures and properties-to SiNW-based devices may open up new avenues for a wide range of sensing applications, addressing various target analytes.
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Affiliation(s)
- Anping Cao
- Department of Chemical Engineering, Delft University of Technology , Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Wei Zhu
- Molecular NanoFabrication Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Jin Shang
- School of Energy and Environment, City University of Hong Kong , Kowloon, Hong Kong SAR
- Department of Chemical and Biomolecular Engineering, University of Melbourne , Parkville, Victoria 3010, Australia
| | - Johan H Klootwijk
- Philips Research Laboratories, High Tech Campus 4, 5656 AE Eindhoven, The Netherlands
| | - Ernst J R Sudhölter
- Department of Chemical Engineering, Delft University of Technology , Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jurriaan Huskens
- Molecular NanoFabrication Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Louis C P M de Smet
- Department of Chemical Engineering, Delft University of Technology , Van der Maasweg 9, 2629 HZ Delft, The Netherlands
- Laboratory of Organic Chemistry, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
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21
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Li Q, Yang Z, Ren Z, Yan S. Polysiloxane-Modified Tetraphenylethene: Synthesis, AIE Properties, and Sensor for Detecting Explosives. Macromol Rapid Commun 2016; 37:1772-1779. [PMID: 27611625 DOI: 10.1002/marc.201600378] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/12/2016] [Indexed: 11/09/2022]
Abstract
Polysiloxane-modified tetraphenylethene (PTPESi) is successfully synthesized by attaching tetraphenylethene (TPE) units onto methylvinyldiethoxylsiloxane and subsequent polycondensation. Introducing polysiloxane into TPE has minimal effect on the photophysical properties and aggregation-induced emission behavior of TPE. The highest occupied and lowest unoccupied molecular orbital (HOMO and LUMO) energy levels of PTPESi are located mainly on the tetraphenylethene moieties. The fluorescence intensity and the half width of the emission peak of PTPESi before and after annealing at 120 °C for 12 h are nearly the same, indicating high thermal stability and morphological stability. In addition, use of PTPESi film as a sensor toward the vapor-phase detection of explosives is also studied and it displays quite high fluorescence quenching efficiency and good reversibility.
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Affiliation(s)
- Qiaosheng Li
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhaomin Yang
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhongjie Ren
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Shouke Yan
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
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22
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Hopkins AJ, Cooper JL, Profeta LTM, Ford AR. Portable Deep-Ultraviolet (DUV) Raman for Standoff Detection. Appl Spectrosc 2016; 70:861-73. [PMID: 27059445 DOI: 10.1177/0003702816638285] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/22/2016] [Indexed: 05/25/2023]
Abstract
Alakai Defense Systems has recently developed a man-portable ultraviolet Raman spectrometer system. The portable Raman improvised explosives detector was designed to provide rapid, standoff detection of chemicals of interest to the end user, including, but not limited to explosives, narcotics, toxic industrial chemicals, and toxic industrial materials. In this paper, we discuss general aspects of the system design and user interface. Spectral and instrument performance data are shown for several common materials involved in narcotics manufacture, as well as cocaine and heroin, with comparisons to currently marketed handheld Raman instruments.
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Affiliation(s)
| | | | | | - Alan R Ford
- Alakai Defense Systems, Inc., Largo, FL, USA
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23
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Qu J, Ge Y, Zu B, Li Y, Dou X. Transition-Metal-Doped p-Type ZnO Nanoparticle-Based Sensory Array for Instant Discrimination of Explosive Vapors. Small 2016; 12:1369-77. [PMID: 26763156 DOI: 10.1002/smll.201503131] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/28/2015] [Indexed: 05/26/2023]
Abstract
The development of portable, real-time, and cheap platforms to monitor ultratrace levels of explosives is of great urgence and importance due to the threat of terrorism attacks and the need for homeland security. However, most of the previous chemiresistor sensors for explosive detection are suffering from limited responses and long response time. Here, a transition-metal-doping method is presented to remarkably promote the quantity of the surface defect states and to significantly reduce the charge transfer distance by creating a local charge reservoir layer. Thus, the sensor response is greatly enhanced and the response time is remarkably shortened. The resulting sensory array can not only detect military explosives, such as, TNT, DNT, PNT, PA, and RDX with high response, but also can fully distinguish some of the improvised explosive vapors, such as AN and urea, due to the huge response reaching to 100%. Furthermore, this sensory array can discriminate ppb-level TNT and ppt-level RDX from structurally similar and high-concentration interfering aromatic gases in less than 12 s. Through comparison with the previously reported chemiresistor or Schottky sensors for explosive detection, the present transition-metal-doping method resulting ZnO sensor stands out and undoubtedly challenges the best.
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Affiliation(s)
- Jiang Qu
- Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics & Chemistry;, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi, 830011, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuru Ge
- Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics & Chemistry;, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi, 830011, China
| | - Baiyi Zu
- Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics & Chemistry;, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi, 830011, China
| | - Yuxiang Li
- Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics & Chemistry;, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi, 830011, China
| | - Xincun Dou
- Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics & Chemistry;, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi, 830011, China
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24
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Baldassarre L, Sakat E, Frigerio J, Samarelli A, Gallacher K, Calandrini E, Isella G, Paul DJ, Ortolani M, Biagioni P. Midinfrared Plasmon-Enhanced Spectroscopy with Germanium Antennas on Silicon Substrates. Nano Lett 2015; 15:7225-7231. [PMID: 26457387 DOI: 10.1021/acs.nanolett.5b03247] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Midinfrared plasmonic sensing allows the direct targeting of unique vibrational fingerprints of molecules. While gold has been used almost exclusively so far, recent research has focused on semiconductors with the potential to revolutionize plasmonic devices. We fabricate antennas out of heavily doped Ge films epitaxially grown on Si wafers and demonstrate up to 2 orders of magnitude signal enhancement for the molecules located in the antenna hot spots compared to those located on a bare silicon substrate. Our results set a new path toward integration of plasmonic sensors with the ubiquitous CMOS platform.
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Affiliation(s)
- Leonetta Baldassarre
- Dipartimento di Fisica, Università di Roma "La Sapienza" , Piazzale Aldo Moro 5, I-00185 Roma, Italy
- Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia , Viale Regina Elena 291, I-00161 Roma, Italy
| | - Emilie Sakat
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Jacopo Frigerio
- LNESS, Dipartimento di Fisica del Politecnico di Milano, polo di Como , via Anzani 42, I-22100 Como, Italy
| | - Antonio Samarelli
- School of Engineering, University of Glasgow , Rankine Building, Oakfield Avenue, Glasgow G12 8LT, U.K
| | - Kevin Gallacher
- School of Engineering, University of Glasgow , Rankine Building, Oakfield Avenue, Glasgow G12 8LT, U.K
| | - Eugenio Calandrini
- Dipartimento di Fisica, Università di Roma "La Sapienza" , Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Giovanni Isella
- LNESS, Dipartimento di Fisica del Politecnico di Milano, polo di Como , via Anzani 42, I-22100 Como, Italy
| | - Douglas J Paul
- School of Engineering, University of Glasgow , Rankine Building, Oakfield Avenue, Glasgow G12 8LT, U.K
| | - Michele Ortolani
- Dipartimento di Fisica, Università di Roma "La Sapienza" , Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Paolo Biagioni
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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Sun X, Liu Y, Shaw G, Carrier A, Dey S, Zhao J, Lei Y. Fundamental Study of Electrospun Pyrene-Polyethersulfone Nanofibers Using Mixed Solvents for Sensitive and Selective Explosives Detection in Aqueous Solution. ACS Appl Mater Interfaces 2015; 7:13189-97. [PMID: 26030223 DOI: 10.1021/acsami.5b03655] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Fluorescent pyrene-polyethersulfone (Py-PES) nanofibers were prepared through electrospinning technique using mixed solvents. The effects of mixed solvent ratio and polymer/fluorophore concentrations on electrospun nanofiber's morphology and its sensing performance were systematically investigated and optimized. The Py-PES nanofibers prepared under optimized conditions were further applied for highly sensitive detection of explosives, such as picric acid (PA), 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) in aqueous phase with limits of detection (S/N = 3) of 23, 160, 400, and 980 nM, respectively. The Stern-Volmer (S-V) plot for Py excimer fluorescence quenching by PA shows two linear regions at low (0-1 μM) and high concentration range (>1 μM) with a quenching constant of 1.263 × 10(6) M(-1) and 5.08 × 10(4) M(-1), respectively. On the contrary, S-V plots for Py excimer fluorescence quenching by TNT, DNT, and RDX display an overall linearity in the entire tested concentration range. The fluorescence quenching by PA can be attributed to the fact that both photoinduced electron transfer and energy transfer are involved in the quenching process. In addition, pyrene monomer fluorescence is also quenched and exhibits different trends for different explosives. Fluorescence lifetime studies have revealed a dominant static quenching mechanism of the current fluorescent sensors for explosives in aqueous solution. Selectivity study demonstrates that common interferents have an insignificant effect on the emission intensity of the fluorescent nanofibers in aqueous phase, while reusability study indicates that the fluorescent nanofibers can be regenerated. Spiked real river water sample was also tested, and negligible matrix effect on explosives detection was observed. This research provides new insights into the development of fluorescent explosive sensor with high performance.
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Affiliation(s)
- Xiangcheng Sun
- †Department of Chemical and Biomoleclular Engineering, and ‡Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yixin Liu
- †Department of Chemical and Biomoleclular Engineering, and ‡Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - George Shaw
- †Department of Chemical and Biomoleclular Engineering, and ‡Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Andrew Carrier
- †Department of Chemical and Biomoleclular Engineering, and ‡Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Swayandipta Dey
- †Department of Chemical and Biomoleclular Engineering, and ‡Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Jing Zhao
- †Department of Chemical and Biomoleclular Engineering, and ‡Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yu Lei
- †Department of Chemical and Biomoleclular Engineering, and ‡Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
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Wojtas J, Mikolajczyk J, Bielecki Z. Aspects of the application of cavity enhanced spectroscopy to nitrogen oxides detection. Sensors (Basel) 2013; 13:7570-98. [PMID: 23752566 PMCID: PMC3715239 DOI: 10.3390/s130607570] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/02/2013] [Accepted: 05/27/2013] [Indexed: 11/17/2022]
Abstract
This article presents design issues of high-sensitive laser absorption spectroscopy systems for nitrogen oxides (NO(x)) detection. Examples of our systems and their investigation results are also described. The constructed systems use one of the most sensitive methods, cavity enhanced absorption spectroscopy (CEAS). They operate at different wavelength ranges using a blue--violet laser diode (410 nm) as well as quantum cascade lasers (5.27 µm and 4.53 µm). Each of them is configured as a one or two channel measurement device using, e.g., time division multiplexing and averaging. During the testing procedure, the main performance features such as detection limits and measurements uncertainties have been determined. The obtained results are 1 ppb NO(2), 75 ppb NO and 45 ppb N(2)O. For all systems, the uncertainty of concentration measurements does not exceed a value of 13%. Some experiments with explosives are also discussed. A setup equipped with a concentrator of explosives vapours was used. The detection method is based either on the reaction of the sensors to the nitrogen oxides directly emitted by the explosives or on the reaction to the nitrogen oxides produced during thermal decomposition of explosive vapours. For TNT, PETN, RDX and HMX a detection limit better than 1 ng has been achieved.
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Affiliation(s)
- Jacek Wojtas
- Institute of Optoelectronics, Military University of Technology, 2 Gen. S. Kaliskiego St., Warsaw 00-908, Poland; E-Mails: (J.M.); (Z.B.)
| | - Janusz Mikolajczyk
- Institute of Optoelectronics, Military University of Technology, 2 Gen. S. Kaliskiego St., Warsaw 00-908, Poland; E-Mails: (J.M.); (Z.B.)
| | - Zbigniew Bielecki
- Institute of Optoelectronics, Military University of Technology, 2 Gen. S. Kaliskiego St., Warsaw 00-908, Poland; E-Mails: (J.M.); (Z.B.)
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Li R, Yuan YP, Qiu LG, Zhang W, Zhu JF. A rational self-sacrificing template route to metal-organic framework nanotubes and reversible vapor-phase detection of nitroaromatic explosives. Small 2012; 8:225-30. [PMID: 22114057 DOI: 10.1002/smll.201101699] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Indexed: 05/24/2023]
Abstract
Metal-organic framework nanotubes (MOFNTs) are achieved by a strategy in which MOF nanorods formed initially act as a self-sacrificing template for the formation of the final MOFNTs. The fluorescent MOFNTs obtained exhibit high sensitivity, significant selectivity, and a fast response rate for the reversible vapor-phase detection of nitroaromatic explosives.
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Affiliation(s)
- Rui Li
- Laboratory of Advanced Porous Materials, School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, P.R. China
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Mäkinen M, Nousiainen M, Sillanpää M. Ion spectrometric detection technologies for ultra-traces of explosives: a review. Mass Spectrom Rev 2011; 30:940-973. [PMID: 21294149 DOI: 10.1002/mas.20308] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In recent years, explosive materials have been widely employed for various military applications and civilian conflicts; their use for hostile purposes has increased considerably. The detection of different kind of explosive agents has become crucially important for protection of human lives, infrastructures, and properties. Moreover, both the environmental aspects such as the risk of soil and water contamination and health risks related to the release of explosive particles need to be taken into account. For these reasons, there is a growing need to develop analyzing methods which are faster and more sensitive for detecting explosives. The detection techniques of the explosive materials should ideally serve fast real-time analysis in high accuracy and resolution from a minimal quantity of explosive without involving complicated sample preparation. The performance of the in-field analysis of extremely hazardous material has to be user-friendly and safe for operators. The two closely related ion spectrometric methods used in explosive analyses include mass spectrometry (MS) and ion mobility spectrometry (IMS). The four requirements-speed, selectivity, sensitivity, and sampling-are fulfilled with both of these methods.
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Affiliation(s)
- Marko Mäkinen
- Laboratory of Applied Environmental Chemistry, Department of Environmental Science, University of Eastern Finland, Patteristonkatu 1, 50100 Mikkeli, Finland.
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Holthoff EL, Stratis-Cullum DN, Hankus ME. A nanosensor for TNT detection based on molecularly imprinted polymers and surface enhanced Raman scattering. Sensors (Basel) 2011; 11:2700-14. [PMID: 22163761 DOI: 10.3390/s110302700] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 02/08/2011] [Accepted: 02/22/2011] [Indexed: 12/30/2022]
Abstract
We report on a new sensor strategy that integrates molecularly imprinted polymers (MIPs) with surface enhanced Raman scattering (SERS). The sensor was developed to detect the explosive, 2,4,6-trinitrotoluene (TNT). Micron thick films of sol gel-derived xerogels were deposited on a SERS-active surface as the sensing layer. Xerogels were molecularly imprinted for TNT using non-covalent interactions with the polymer matrix. Binding of the TNT within the polymer matrix results in unique SERS bands, which allow for detection and identification of the molecule in the MIP. This MIP-SERS sensor exhibits an apparent dissociation constant of (2.3 ± 0.3) × 10(-5) M for TNT and a 3 μM detection limit. The response to TNT is reversible and the sensor is stable for at least 6 months. Key challenges, including developing a MIP formulation that is stable and integrated with the SERS substrate, and ensuring the MIP does not mask the spectral features of the target analyte through SERS polymer background, were successfully met. The results also suggest the MIP-SERS protocol can be extended to other target analytes of interest.
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