Search Results (57)

Chemical warfare agents (CWAs), including hydrogen cyanide (AC), 2-[fluoro(methyl)phosphoryl]oxypropane (GB), 3-[fluoro(methyl)phosphoryl]oxy-2,2-dimethylbutane (GD), ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate (VX), and di-2-chloroethyl sulfide (HD), pose a great threat to public safety; therefore, it is important to develop sensing technology for CWAs. Herein, a sensor array consisting of 24 metal oxide semiconductor (MOS)-based MEMS sensors with good gas sensing performance, a simple device structure (0.9 mm × 0.9 mm), and low power consumption (<10 mW on average) was developed. The experimental results show that there are always several sensors among the 24 sensors that show good sensing performance in relation to each CWA, such as a relatively significant response, a broad detection range (AC: 5.8–89 ppm; GB: 0.04–0.47 ppm; GD: 0.06–4.7 ppm; VX: 9.978 × 10⁻⁴–1.101 × 10⁻³; HD: 0.61–4.9 ppm), and a low detection limit that is lower than the immediately dangerous for life and health (IDLH) level of the five CWAs. This indicates that these sensors can meet the needs for qualitative detection and can provide an early warning regarding low concentrations of CWAs. In addition, features were extracted from the initial kinetic characteristics and dynamic change characteristics of the sensing response. Finally, principal component analysis (PCA) and machine learning algorithms were applied for CWA classification. The obtained PCA plots showed significant differences between groups, and the narrow neural network among the machine learning algorithms achieves a prediction accuracy of nearly 100.0%. In summary, the proposed MOS-based MEMS sensor array driven by pattern recognition algorithms can be integrated into portable devices, showing great potential and practical applications in the rapid, in situ, and on-site detection and identification of CWAs. Full article

This is a broad look at the history of phosphorus—from the element through its inorganic and organic compounds to the applications of organophosphates. In addition to commercial and peaceful applications, they were used as chemical warfare agents (CWA), both in military operations and for terrorist purposes. This article attempts to provide a concise history of their development and application in this shameful role. The origin of the chemistry of phosphorus compounds to obtain precursors for the production of CWA is presented. Rapid progress in organophosphorus chemistry in the second half of the 20th century is also described. A broad overview of chemical structures is presented, including lesser-known representatives. The mode of action and the associated toxicity of organophosphorus compounds are briefly mentioned. The Chemical Weapons Convention (CWC) schedules and their changes during their validity are indicated. They are also demonstrated to be used in proficiency tests organised by the Organization for the Prohibition of Chemical Weapons (OPCW). Organophosphates called “Novichok agents”, classified as fourth-generation chemical warfare agents, are also briefly discussed. Full article

The decontamination of chemical warfare agents (CWAs) from contaminated surfaces is of critical importance due to the severe threats posed by CWAs to human health and the environment, particularly given the persistent threat of chemical weapons since World War I. In this study, a novel UiO-66-NH₂ crosslinked hyaluronic acid (HA) hydrogel was developed in the presence of polyvinyl alcohol under ambient conditions, leveraging the dual functionality of the amino-substituted zirconium-based metal–organic framework (Zr-MOF) as both a crosslinker and a catalytic site. The hydrogel demonstrated exceptional catalytic performance, achieving a degradation efficiency of over 90% for the chemical warfare agent simulant dimethyl 4-nitrophenyl phosphate (DMNP) within 1 h. Furthermore, the hydrogel demonstrated adequate mechanical and tensile strength for practical use, enabling easy peel-off from various contaminated surfaces without leaving residues. This peelable property, combined with its decontamination capabilities, highlights its significant potential for practical applications in the field of CWA decontamination. Full article

This review summarizes the application of two-dimensional metal–organic framework (2D MOF) nanostructures and their composites in the detoxification of chemical warfare agents (CWAs). Two-dimensional MOFs, characterized by their high specific surface area, abundant active sites, and structural tunability, exhibit promising catalytic performance in CWA detoxification. Various preparation methods, including top–down exfoliation and bottom–up assembly, are discussed for the synthesis of 2D MOF nanosheets. The catalytic performance of 2D MOFs and their composites in detoxifying CWAs is evaluated, highlighting their advantages in terms of reaction kinetics and ease of recycling. Additionally, the advances and challenges in this field are discussed, aiming to promote further research into and development of 2D MOF-based materials for CWA detoxification. Full article

Di-isopropyl methyl phosphonate (DIMP) has no major commercial uses but is a by-product or a precursor in the synthesis of the nerve agent sarin (GB). Also, DIMP is utilized as a simulant compound for the chemical warfare agents sarin and soman in order to test and calibrate sensitive IMS instrumentation that warns against the deadly chemical weapons. DIMP was measured from 2 ppb_v (15 μg m⁻³) to 500 ppb_v in the air using a pocket-held ToF ion mobility spectrometer, model LCD-3.2E, with a non-radioactive ionization source and ammonia doping in positive ion mode. Excellent sensitivity (LoD of 0.24 ppb_v and LoQ of 0.80 ppb_v) was noticed; the linear response was up to 10 ppb_v, while saturation occurred at >500 ppb_v. DIMP identification by IMS relies on the formation of two distinct peaks: the monomer M·NH₄⁺, with a reduced ion mobility K₀ = 1.41 cm² V⁻¹ s⁻¹, and the dimer M₂·NH₄⁺, with K₀ = 1.04 cm² V⁻¹ s⁻¹ (where M is the DIMP molecule); positive reactant ions (Pos RIP) have K₀ = 2.31 cm² V⁻¹ s⁻¹. Quantification of DIMP at trace levels was also achieved by GC-MS over the concentration range of 1.5 to 150 μg mL⁻¹; using a capillary column (30 m × 0.25 mm × 0.25 μm) with a TG-5 SilMS stationary phase and temperature programming from 60 to 110 °C, DIMP retention time (RT) was ca. 8.5 min. The lowest amount of DIMP measured by GC-MS was 1.5 ng, with an LoD of 0.21 μg mL⁻¹ and an LoQ of 0.62 μg mL⁻¹ DIMP. Our results demonstrate that these methods provide robust tools for both on-site and off-site detection and quantification of DIMP at trace levels, a finding which has significant implications for forensic investigations of chemical agent use and for environmental monitoring of contamination by organophosphorus compounds. Full article

Mustard gas (HD) is a well-known chemical warfare agent, recognized for its extreme toxicity and severe hazards. Metal–organic frameworks (MOFs), with their unique structural properties, show significant potential for HD adsorption applications. Due to the extreme hazards of HD, most experimental studies focus on its simulants, but molecular simulation research on these simulants remains limited. Simulation analyses of simulants can uncover structure–performance relationships and enable experimental validation, optimizing methods, and improving material design and performance predictions. This study integrates molecular simulations, machine learning (ML), and molecular fingerprinting (MFs) to identify MOFs with high adsorption performance for the HD simulant diethyl sulfide (DES), followed by in-depth structural analysis and comparison. First, MOFs are categorized into Top, Middle, and Bottom materials based on their adsorption efficiency. Univariate analysis, machine learning, and molecular fingerprinting are then used to identify and compare the distinguishing features and fingerprints of each category. Univariate analysis helps identify the optimal structural ranges of Top and Bottom materials, providing a reference for initial material screening. Machine learning feature importance analysis, combined with SHAP methods, identifies the key features that most significantly influence model predictions across categories, offering valuable insights for future material design. Molecular fingerprint analysis reveals critical fingerprint combinations, showing that adsorption performance is optimized when features such as metal oxides, nitrogen-containing heterocycles, six-membered rings, and C=C double bonds co-exist. The integrated analysis using HTCS, ML, and MFs provides new perspectives for designing high-performance MOFs and demonstrates significant potential for developing materials for the adsorption of CWAs and their simulants. Full article

The increasing incidence of organophosphate (OP) pesticide poisoning and the use of OP chemical warfare agents (CWA) in conflicts and terrorist acts need sustainable methods for sensing, decontamination, and detoxification of OP compounds. Enzymes can serve as specific, cost-effective biosensors for OPs. We will report on recent advancements in the use of carboxylesterases from the Hormone-Sensitive Lipase for the detection of OP compounds. In addition, enzymatic-based OP detoxification and decontamination offer long-term, environmentally friendly benefits compared to conventional methods such as chemical treatment, incineration, neutralization, and volatilization. Enzymatic detoxification has gained attention as an alternative to traditional OP-detoxification methods. This review provides an overview of the latest research on enzymatic sensing and detoxification of OPs, by exploiting enzymes, isolated from thermophilic/extremophilic Bacteria and Archaea that show exceptional thermal stability and stability in other harsh conditions. Finally, we will make examples of integration between sensing and decontamination systems, including protein engineering to enhance OP-degrading activities and detailed characterization of the best variants. Full article

We report the exfoliation of ultrathin gallium oxide (Ga₂O₃) films from liquid metal balloons, formed by injecting air into droplets of eutectic gallium–indium alloy (eGaIn). These Ga₂O₃ films enable the selective adsorption of carbon nanotubes (CNTs) dispersed in water, resulting in the formation of a dense, percolating CNT network on their surface. The self-assembled CNT network on Ga₂O₃ provides a versatile platform for device fabrication. As an example application, we fabricated a chemiresistive gas sensor for detecting simulants of chemical warfare agents (CWAs), including diisopropyl methylphosphonate (DIMP), dimethyl methylphosphonate (DMMP), and triethyl phosphate (TEP). The sensor exhibited reversible responses, high sensitivity, and low limits of detection (13 ppb for DIMP, 28 ppb for DMMP, and 53 ppb for TEP). These findings highlight the potential of Ga₂O₃ films derived from liquid metal balloons for integrating CNTs into functional electronic devices. Full article

Chemical warfare agents (CWAs) are known as poor man’s bombs because of their small lethal dose, cheapness, and ease of production. Therefore, the highly sensitive and rapid detection of CWAs at room temperature (RT = 25 °C) is essential. In this paper, we have developed a resistive semiconductor sensor for the highly sensitive detection of CWAs at RT. The gas-sensing material is SnS₂/rGO nanosheets (NSs) prepared by hydrothermal synthesis. The lower detection limits of the SnS₂/rGO NSs-based gas sensor were 0.05 mg/m³ and 0.1 mg/m³ for the typical chemical weapons sarin (GB) and sulfur mustard (HD), respectively. The responsivity can reach −3.54% and −10.2% in 95 s for 1.0 mg/m³ GB, and in 47 s for 1.0 mg/m³ HD. They are 1.17 and 2.71 times higher than the previously reported Nb-MoS₂ NSs-based gas sensors, respectively. In addition, it has better repeatability (RSD = 6.77%) and stability for up to 10 weeks (RSD = 20.99%). Furthermore, to simplify the work of later researchers based on the detection of CWAs by two-dimensional transition metal sulfur compounds (2D-TMDCs), we carried out calculations of the SnS₂ NSs-based and SnS₂/rGO NSs-based gas sensor-adsorbing CWAs. Detailed comparisons are made in conjunction with experimental results. For different materials, it was found that the SnS₂/rGO NSs-based gas sensor performed better in all aspects of adsorbing CWAs in the experimental results. Adsorbed CWAs at a distance smaller than that of the SnS₂ NSs-based gas sensor in the theoretical calculations, as well as its adsorption energy and transferred charge, were larger than those of the SnS₂ NSs-based gas sensor. For different CWAs, the experimental results show that the sensitivity of the SnS₂/rGO NSs-based gas sensor for the adsorption of GB is higher than that of HD, and accordingly, the theoretical calculations show that the adsorption distance of the SnS₂/rGO NSs-based gas sensor for the adsorption of GB is smaller than that of HD, and the adsorption energy and the amount of transferred charge are larger than that of HD. This regularity conclusion proves the feasibility of adsorption of CWAs by gas sensors based on SnS₂ NSs, as well as the feasibility and reliability of theoretical prediction experiments. This work lays a good theoretical foundation for subsequent rapid screenings of gas sensors with gas-sensitive materials for detecting CWAs. Full article

The determination of chemical warfare agents (CWAs) and their toxic degradation products (DPs) has become increasingly important for public and military safety in recent years. We focused on assessing the possibility of the HPLC-ICP-MS analytical technique to verify the provisions of the Chemical Weapons Convention. This technique enables the identification and determination of minimal concentrations (ppt range) of elements in various matrices. This fact is important for the determination of CWAs and other highly harmful compounds, even small amounts of which can have serious consequences for living organisms. We have critically analysed the results of scientific research on the identification and quantitative determination of extremely toxic organophosphorus, organosulfur and organoarsenic CWAs, their derivatives and their degradation products using high-performance liquid chromatography (HPLC) coupled with inductively coupled plasma–mass spectrometry (ICP-MS). Full article

In this manuscript, we present in detail the design and implementation of the hardware and software to produce a standalone wireless sensor node, called SensorQ system, for the detection of a toxic chemical agent. The proposed wireless sensor node prototype is composed of a micro-controller unit (MCU), a radio frequency (RF) transceiver, a dual-band antenna, a rechargeable battery, a voltage regulator, and four integrated sensing devices, all of them integrated in a package with final dimensions and weight of 200 × 80 × 60 mm and 0.422 kg, respectively. The proposed SensorQ prototype operates using the Long-Range (LoRa) wireless communication protocol at 2.4 GHz, with a sensor head implemented on a hetero-core fiber optic structure supporting the surface plasmon resonance (SPR) phenomenon with a sensing section (L = 10 mm) coated with titanium/gold/titanium and a chemically sensitive material (zinc oxide) for the detection of Di-Methyl Methyl Phosphonate (DMMP) vapor in the air, a simulant of the toxic nerve agent Sarin. The transmitted spectra with respect to different concentrations of DMMP vapor in the air were recorded, and then the transmitted power for these concentrations was calculated at a wavelength of 750 nm. The experimental results indicate the feasibility of detecting DMMP vapor in air using the proposed optical sensor head, with DMMP concentrations in the air of 10, 150, and 150 ppm in this proof of concept. We expect that the sensor and wireless sensor node presented herein are promising candidates for integration into a wireless sensor network (WSN) for chemical warfare agent (CWA) detection and contaminated site monitoring without exposure of armed forces. Full article

In this work, we test metal–organic frameworks (MOFs) as sorbents in the solid-phase extraction (SPE) technique to determine chemical warfare agents (CWAs) and their related compounds in water samples. During this study, we used 13 target compounds to test the selectivity of MOFs thoroughly. Three MOFs were used: MIL-100(Fe), ZIF-8(Zn), and UiO-66(Zr). The obtained materials were characterized using FT-IR/ATR, SEM, and XRD. CWA’s and related compounds were analyzed using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The effect of the type of elution solvent and the amount of sorbent (MOFs) in the column on the efficiency of the conducted extraction were verified. The LOD ranged from 0.04 to 7.54 ng mL⁻¹, and the linearity range for the analytes tested extended from 0.11/22.62 (depending on the compound) to 1000 ng mL⁻¹. It was found that MOFs showed the most excellent selectivity to compounds having aromatic rings in their structure or a “spread” spatial structure. The best recoveries were obtained for DPAA, CAP, and malathion. Environmental water samples collected from the Baltic Sea were analyzed using an optimized procedure to verify the developed method’s usefulness. Full article

This study describes the development of hydrogel formulations with ionic crosslinking capacity and photocatalytic characteristics. The objective of this research is to provide an effective, accessible, “green”, and facile route for the decontamination of chemical warfare agents (CWAs, namely the blistering agent—mustard gas/sulfur mustard (HD)) from contaminated surfaces, by decomposition and entrapment of CWAs and their degradation products inside the hydrogel films generated “on-site”. The decontamination of the notorious warfare agent HD was successfully achieved through a dual hydrolytic–photocatalytic degradation process. Subsequently, the post-decontamination residues were encapsulated within a hydrogel membrane film produced via an ionic crosslinking mechanism. Polyvinyl alcohol (PVA) and sodium alginate (ALG) are the primary constituents of the decontaminating formulations. These polymeric components were chosen for this application due to their cost-effectiveness, versatility, and their ability to form hydrogen bonds, facilitating hydrogel formation. In the presence of divalent metallic ions, ALG undergoes ionic crosslinking, resulting in rapid gelation. This facilitated prompt PVA-ALG film curing and allowed for immediate decontamination of targeted surfaces. Additionally, bentonite nanoclay, titanium nanoparticles, and a tetrasulfonated nickel phthalocyanine (NiPc) derivative were incorporated into the formulations to enhance absorption capacity, improve mechanical properties, and confer photocatalytic activity to the hydrogels obtained via Zn²⁺—mediated ionic crosslinking. The resulting hydrogels underwent characterization using a variety of analytical techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), viscometry, and mechanical analysis (shear, tensile, and compression tests), as well as swelling investigations, to establish the optimal formulations for CWA decontamination applications. The introduction of the fillers led to an increase in the maximum strain up to 0.14 MPa (maximum tensile resistance) and 0.39 MPa (maximum compressive stress). The UV-Vis characterization of the hydrogels allowed the determination of the band-gap value and absorption domain. A gas chromatography–mass spectrometry assay was employed to evaluate the decontamination efficacy for a chemical warfare agent (sulfur mustard—HD) and confirmed that the ionic crosslinked hydrogel films achieved decontamination efficiencies of up to 92.3%. Furthermore, the presence of the photocatalytic species can facilitate the degradation of up to 90% of the HD removed from the surface and entrapped inside the hydrogel matrix, which renders the post-decontamination residue significantly less dangerous. Full article

Chemical warfare agents primarily comprise organophosphorus nerve agents, saliva alkaloids, cyanides, and mustard gas. Exposure to these agents can result in severe respiratory effects, including spasms, edema, and increased secretions leading to breathing difficulties and suffocation. Protecting public safety and national security from such threats has become an urgent priority. Porous metal–organic framework (MOF) materials have emerged as promising candidates for the degradation of chemical warfare agents due to their large surface area, tunable pore size distribution, and excellent catalytic performance. Furthermore, combining MOFs with polymers can enhance their elasticity and processability and improve their degradation performance. In this review, we summarize the literature of the past five years on MOF-based composite materials and their effectiveness in degrading chemical warfare agents. Moreover, we discuss key factors influencing their degradation efficiency, such as MOF structure, pore size, and functionalization strategies. Furthermore, we highlight recent developments in the design of MOF–polymer composites, which offer enhanced degradation performance and stability for practical applications in CWA degradation. These composite materials exhibit good performance in degrading chemical warfare agents, playing a crucial role in protecting public safety and maintaining national security. We can expect to see more breakthroughs in the application of metal–organic framework porous materials for degrading chemical warfare agents. It is hoped that these innovative materials will play a positive role in achieving social stability and security. Full article

Simple and efficient sample pretreatment methods are important for analysis and detection of chemical warfare agents (CWAs) in environmental and biological samples. Despite many commercial materials or reagents that have been already applied in sample preparation, such as SPE columns, few materials with specificity have been utilized for purification or enrichment. In this study, ionic magnetic mesoporous nanomaterials such as poly(4-VB)@M-MSNs (magnetic mesoporous silicon nanoparticles modified by 4-vinyl benzene sulfonic acid) and Co²⁺@M-MSNs (magnetic mesoporous silicon nanoparticles modified by cobalt ions) with high absorptivity for ethanol amines (EAs, nitrogen mustard degradation products) and cyanide were successfully synthesized. The special nanomaterials were obtained by modification of magnetic mesoporous particles prepared based on co-precipitation using -SO₃H and Co²⁺. The materials were fully characterized in terms of their composition and structure. The results indicated that poly(4-VB)@M-MSNs or Co²⁺@M-MSNs had an unambiguous core-shell structure with a BET of 341.7 m²·g⁻¹ and a saturation magnetization intensity of 60.66 emu·g⁻¹ which indicated the good thermal stability. Poly(4-VB)@M-MSNs showed selective adsorption for EAs while the Co²⁺@M-MSNs were for cyanide, respectively. The adsorption capacity quickly reached the adsorption equilibrium within the 90 s. The saturated adsorption amounts were MDEA = 35.83 mg·g⁻¹, EDEA = 35.00 mg·g⁻¹, TEA = 17.90 mg·g⁻¹ and CN⁻= 31.48 mg·g⁻¹, respectively. Meanwhile, the adsorption capacities could be maintained at 50–70% after three adsorption–desorption cycles. The adsorption isotherms were confirmed as the Langmuir equation and the Freundlich equation, respectively, and the adsorption mechanism was determined by DFT calculation. The adsorbents were applied for enrichment of targets in actual samples, which showed great potential for the verification of chemical weapons and the destruction of toxic chemicals. Full article