Detection Of Hazardous Chemicals Research Articles

Drone-Based Localization of Hazardous Chemicals by Passive Smart Dust

The distribution of tiny sensors over a specific area was first proposed in the late 1990s as a concept known as smart dust. Several efforts focused primarily on computing and networking capabilities, but quickly ran into problems related to power supply, cost, data transmission, and environmental pollution. To overcome these limitations, we propose using paper-based (confetti-like) chemosensors that exploit the inherent selectivity of chemical reagents, such as colorimetric indicators. In this work, cheap and biodegradable passive sensors made from cellulose could successfully indicate the presence of hazardous chemicals, e.g., strong acids, by a significant color change. A conventional color digital camera attached to a drone could easily detect this from a safe distance. The collected data were processed to define the hazardous area. Our work presents a combination of the smart dust concept, chemosensing, paper-based sensor technology, and low-cost drones for flexible, sensitive, economical, and rapid detection of hazardous chemicals in high-risk scenarios.

Prediction of Endocrine-Disrupting Chemicals Related to Estrogen, Androgen, and Thyroid Hormone (EAT) Modalities Using Transcriptomics Data and Machine Learning.

Endocrine-disrupting chemicals (EDCs) are chemicals that can interfere with homeostatic processes. They are a major concern for public health, and they can cause adverse long-term effects such as cancer, intellectual impairment, obesity, diabetes, and male infertility. The endocrine system is a complex machinery, with the estrogen (E), androgen (A), and thyroid hormone (T) modes of action being of major importance. In this context, the availability of in silico models for the rapid detection of hazardous chemicals is an effective contribution to toxicological assessments. We developed Qualitative Gene expression Activity Relationship (QGexAR) models to predict the propensities of chemically induced disruption of EAT modalities. We gathered gene expression profiles from the LINCS database tested on two cell lines, i.e., MCF7 (breast cancer) and A549 (adenocarcinomic human alveolar basal epithelial). We optimized our prediction protocol by testing different feature selection methods and classification algorithms, including CATBoost, XGBoost, Random Forest, SVM, Logistic regression, AutoKeras, TPOT, and deep learning models. For each EAT endpoint, the final prediction was made according to a consensus prediction as a function of the best model obtained for each cell line. With the available data, we were able to develop a predictive model for estrogen receptor and androgen receptor binding and thyroid hormone receptor antagonistic effects with a consensus balanced accuracy on a validation set ranging from 0.725 to 0.840. The importance of each predictive feature was further assessed to identify known genes and suggest new genes potentially involved in the mechanisms of action of EAT perturbation.

Hazardous Chemicals Detection and Classification Through Millimeter Wave and Machine Learning

Hazardous Chemicals Detection and Classification Through Millimeter Wave and Machine Learning

Hydrothermal Synthesis of a Novel One-dimensional Cadmium-based Coordination Polymer for Effective Detection of Hazardous Chemicals

Hydrothermal Synthesis of a Novel One-dimensional Cadmium-based Coordination Polymer for Effective Detection of Hazardous Chemicals

Effect‐based methods in cultured cells—Valuable tools for detection of chemical hazards in drinking water

AbstractChemical contamination of drinking water is of great concern for public health. Chemical analyses are used for monitoring of selected chemicals, however, no information on unknown chemicals or potential toxicity of the mixture of chemicals in a water sample is obtained. Effect‐based methods in cells are new high throughput tools, to evaluate the hazard of the whole mixture of chemicals present in drinking water. These methods can be used together with chemical analysis for assessment of the chemical safety of drinking water. This article will review the principle of effect‐based methods in cells and how they compare to traditionally used chemical analysis and effect‐based methods in whole organisms. Further, this article will give examples from the literature, highlighting how cellular effect‐based methods can be used in different practical applications to improve drinking water safety; for example, for monitoring of drinking water quality and evaluation of treatment efficiency in drinking water processing. Finally, this article will review the current regulatory and water sector acceptance of these methods and discuss future expectations on the role of effect‐based methods for improved drinking water safety.This article is categorized under: Engineering Water > Water, Health, and Sanitation Science of Water > Water Quality

Development of novel nanocomposites based on SrSnO3-conjugated coconut-shell activated carbon with conducting polymers towards 4-nitrophenol detection by electrochemical approach

To simplify the synthesis process for developing a sensor for 4-nitrophenol (4-NP), an in-situ chemical oxidation method was applied by composite of coconut shell-activated carbon (CSAC) and SrSnO3 coated with conducting polymers (CPs) such as Polypyrrole (PPy), Polyindole (PIn), and Polycarbazole (PCz), resulting in the formation of ternary nanocomposites (NCs) consisting of CSAC/SrSnO3/PPy, CSAC/SrSnO3/PIn, and CSAC/SrSnO3/PCz. To facilitate their application as a sensing platform, the synthesized NCs were successfully modified onto a glassy carbon electrode (GCE), enabling their effective use in the detection of 4-NP. Despite utilizing the same fillers, the composites displayed distinct thermal and structural characteristics, suggesting the formation of fundamentally different composites that interact with the 4-NP analyte in unique ways. Furthermore, the detection effectiveness of all the NCs was compared in this study. It was found that the ternary CSAC/SrSnO3/PPy NCs exhibited higher sensitivity compared to sensors composed of either CSAC/SrSnO3/PIn or CSAC/SrSnO3/PCz NCs. These findings highlight the potential of CSAC/SrSnO3/PPy ternary NCs as promising sensors for 4-NP detection, attributed to their high sensitivity (6.329 µAmM−1cm−2), exceptionally lower detection limit (LOD; 0.15 nM), and limit of quantity (LOQ; 0.45 nM) with a linear dynamic range (LDR) from 1.0 nM to 10.0 mM for 4-NP concentrations. Additionally, the proposed 4-NP sensor improved electrical interactions and demonstrated rapid response times and satisfactory reproducibility in its performance. The proposed sensor was employed for the environmental samples analysis and highly satisfactory results were obtained. Thus, the study presents a novel approach for the detection of hazardous chemicals in the environment by utilizing newly developed NCs based on an electrochemical method.

Triboelectric Nanosensor Integrated with Robotic Platform for Self-Powered Detection of Chemical Analytes

Rapid on-site detection of hazardous chemicals is imperative for remote security and environmental monitoring applications. However, the implementation of current sensing technologies in real environments is limited due to an external high-power requirement, poor selectivity and sensitivity. Recent progress in triboelectric nanosensors and nanogenerators presents tremendous opportunities to address these issues. Here, we report an innovative self-powered triboelectric nanosensor for detection of Hg2+ ions, a harmful chemical pollutant, in a rapid single step on-site detection mechanism. Based on the mechanism of solid-liquid contact electrification, tellurium nanowire (Te NW) arrays serving as a solid triboelectric material as well as the sensing probe underwent periodic contact and separation with the Hg2+ solution, leading to the in situ formation of mercury telluride nanowire (HgTe NWs) owing to the selective binding affinity of Te NWs toward Hg2+ ions. To realize the on-site sensing potential, Te NW arrays were mounted onto the robotic hands equipped with additional wireless transmission functionality for rapid detection of Hg2+ ions in resource-limited settings by employing a simple "touch and sense" mechanism. Such a demonstration of direct integration of self-powered sensors with robotics would lead to the development of low-cost, automated chemical sensing machinery for the on-field detection of harmful analytes.

Ketamine plasmonic sensor using polyaniline-rGO-Fe3O4 nanocomposite thin layer

Ketamine is a narcotic and palliative substance and the measurement of the low concentration of ketamine is a great intense interest matter in biotechnology and medicine. The surface plasmon resonance imaging method can monitor the low concentration of bio-substance such as ketamine and dopamine. The reduced graphene oxide-Fe 3 O 4 nanoparticles and polyaniline-reduced graphene oxide-Fe 3 O 4 nanocomposite layers as the sensing layer were prepared using sonication and electro-deposition methods, respectively. The average particle size of Fe 3 O 4 was 38.53 nm, and the sensing layer thickness was in the range of 19–24.5 nm. The morphology, functional group, and contribution of chemical elements were investigated using field emission electron microscopy; Fourier transforms infrared spectroscopy, and energy-dispersive X-ray spectroscopy, respectively. The surface plasmon resonance imaging pattern confirmed that the minimum concentration for detecting ketamine, the sensitivity of the sensor, and the response time were about 0.1 mg/L, 0.044, and 220 s, respectively. The affinity constant is 11.19 for the detection of ketamine, and the tendency of the sensing layer to bind the ketamine is higher than dopamine and glucose. • Hazardous chemical detection using surface plasmon resonance image sensor. • Detection of ketmine using surafce plasmon resonance image sensor. • Nanocomposite based on reduced graphene oxide and magnetic nanoparticles for biosensor application. • The effect of low concentration of Ketamine, dopamine, and glucose on the intensity pattern of SPR image.

Selection and development strategy of sample preparation methods for the detection of chemical hazards in food

Selection and development strategy of sample preparation methods for the detection of chemical hazards in food

A multifunctional piperazine-modified tetraphenylethene derivative: Hazardous chemical detection and lysosome-targeted cell imaging

We report the synthesis and the investigation on the multi-functional property of a piperazine-modified tetraphenylethene (TPE-Pz). After acidification, the cationic TPE-Pz+ molecules can form stable suspensions in tetrahydrofuran/water mixture solutions and the molecular aggregates are highly emissive due to the aggregation-induced emission property of the tetraphenylethene unit. The experimental results showed that the suspension can be directly used as fluorescent probe for the detection of hazardous chemicals such as aldehydes and picric acid. For aldehydes, the probe exhibited high quenching efficiency (up to 80.90%), high sensitivity and low detection limit (0.05–0.97 μM). The piperazine group allows TPE-Pz to possesses high specificity for lysosome with low cytotoxicity and high contrast in comparison with LysoTracker Red.

Application of Electrochemical Biosensors for Chemical Hazards Detection

Electrochemical biosensor is a subject that has received the most attention from scientists in recent years. It is not only related to human life but also natural environment. Research on electrochemical biosensors is also cross-linked with many other scientific fields, such as nanomaterials and hazardous chemical detection. In this research, electrochemical biosensor is discussed by divided into three types, including potentiometric, amperometric, and voltammetric biosensors. The unique mechanism, advantages and application of these electrochemical biosensors is also introduced in this article. Potentiometric biosensor is frequently used for phosphate, toxicity and heavy metal detection. Amperometric biosensors are usually combined with enzymes for the identification of additives in products and contaminants in water. Voltammetric biosensors are most commonly used for blood glucose testing, but can also detect many tastes.

Sensitivity enhancement of microelectromechanical sensors using femtosecond laser for biological and chemical applications

Rapid, selective, and highly sensitive microelectromechanical sensors are a promising technology for biosensing, medical recognition, and the detection of chemical hazards. At the same time, the surfaces of silicon microcantilevers cannot bond with thiols and cannot be functionalized without a bonding layer, such as gold. Therefore, in past literature, the surfaces of silicon microcantilevers have been coated with gold to facilitate their bonding with the thiol functional groups on the probe layers. However, gold coating produces thermal noise in the results owing to the metallic effect. Accordingly, this study aimed to modify the surface of silicon microcantilevers by patterning it using femtosecond laser (FSL) micromachining so that it could bond with the thiol functional groups with high sensitivity. The surface patterning of silicon microcantilevers enhances their physical, micromechanical, and chemical properties, increasing sensitivity by increasing the quality factor, specific surface area, and creating trapping areas on the microcantilever surfaces. The surfaces of the silicon microcantilever were patterned by microgrooves aligned from the free end to the bounded end, with each microgroove comprising submicrogrooves. To demonstrate their use in a biosensing applications, the modified microcantilevers were functionalized to detect severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2; COVID‐19) by immobilizing thiolated oligonucleotides on the surfaces, which worked as the probe layer. The modified biosensor was used to detect low concentrations of SSDNA sequence targets ranging from 300 nM down to 100 pM. The modified silicon‐microcantilever sensors were directly functionalized without a joining layer, such as a gold layer. The results revealed a selective response to SARS‐CoV‐2 SSDNA down to a 9‐nM concentration. To detect hazardous chemicals, the modified microcantilever was functionalized using reduced L‐cysteine to detect Pb2+ at low concentrations down to 100 pM. The results revealed enhanced sensitivity and selectivity and demonstrated that the FSL patterning activated the microcantilevers to bond with probe layers through the interaction of the silanol created on the surface with the functional groups, such as the thiols, on the probe layers. The microcantilevers patterned with 10 microgrooves exhibited higher responses than those patterned with seven microgrooves.

A molecularly imprinted electrochemical sensor based on a MoS2/peanut shell carbon complex coated with AuNPs and nitrogen‐doped carbon dots for selective and rapid detection of benzo(a)pyrene

SummaryIn this study, a new electrochemical strategy based on the fabrication of a molecularly imprinted sensor onto a MoS2‐loaded peanut shell carbon complex with gold nanoparticles (AuNPs) and nitrogen‐doped carbon dots (N‐CDs) was proposed for the detection of benzo(a)pyrene (BaP). Molecularly imprinted polymer (MIP) films were prepared by cyclic voltammetry (CV) using 2‐mercaptobenzimidazole (2‐MBI) as a functional monomer in the presence of BaP. The surface morphologies, structural characteristics and electrochemical properties of the obtained MIP/AuNPs/N‐CDs/PSBC/MoS2/GCE were investigated via scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy‐dispersive spectrometry (EDS), Fourier transform infrared spectrometry (FTIR), X‐ray diffraction (XRD), UV–Vis spectrometry, fluorescence spectrometry, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimised conditions, the detection range of the electrode towards BaP varied from 5 nM to 20 μM with a detection limit of 1.5 nM. The prepared electrochemical sensor also exhibited good stability, relevant reproducibility and high selectivity. The application of the sensor in the actual analysis of edible oil samples showed promising results, thereby being relevant as a biomimetic sensing platform for the detection of chemical hazards in food and environment.

Experimental Study on the Detection of Hazardous Chemicals Using Alternative Sensors in the Water Environment

Chemical accidents in rivers may be triggered by natural or anthropogenic causes and refer to the flow of large quantities of hazardous chemicals into rivers. In South Korea, domestic water is sourced from large rivers, such as the Nakdong River. However, owing to rapid industrialization, industrial facilities have become heavily concentrated in the middle and upper reaches of the Nakdong River. Therefore, severe problems could arise if harmful chemicals are leaked from industrial facilities into the river, and this contaminated river water is supplied to cities. Quantitative evaluation based on instrumental analysis during chemical accidents and prediction research based on modeling is actively being conducted however, research on the initial response is insufficient. Therefore, in this study, the variations in pH and EC were analyzed according to their chemical concentrations for seven chemicals. These seven chemicals are designated accident-preparedness substances that frequently cause chemical spills in South Korea. Additionally, we evaluated the possibility of identifying unknown substances by comparing the variations in pH and EC and statistics while diluting unknown substances. Thus, the potential of pH and EC as alternative indicators for detecting and identifying chemicals was evaluated in this study. NaF, NH4HF2, NaCN, and NH4OH were classified by comparing their spatial distributions in a pH-EC relation curve. However, H2SO4, HCl, and SOCl2 showed similar spatial distributions in the pH-EC curves and were difficult to identify. The results of this study provide information for chemical detection and identification using alternative sensors that permit easy and rapid field measurements in the event of a chemical spill and could be used as preliminary data for rapidly responding to accidents.

Smartphone-integrated multi-color ratiometric fluorescence portable optical device based on deep learning for visual monitoring of Cu2+ and thiram

Dual emission ratiometric fluorescence probes have been widely used for naked visual individual detection of hazardous chemicals, but it is still limited to simultaneously detecting multiple targets in a complex system. In this work, a deep learning-assisted smartphone-integrated tricolor ratiometric fluorescence optical device has been designed for visual monitoring of Cu2+ and thiram. The tricolor sensing probes are consist of blue-emission carbon quantum dots (B-QDs), green-emission cadmium telluride quantum dots (G-QDs), and red-emission cadmium telluride quantum dots (R-QDs). The sensing system presents a three emission response to Cu2+ and thiram based on electron transfer effect, complexing effect, and inner filter effect (IFE), respectively. The reaction mechanisms were verified by density functional theory (DFT). Interestingly, the G-QDs and R-QDs’ fluorescence intensity are simultaneously quenched by Cu2+, whereas the fluorescence intensity of B-QDs remained unchanged and used as the internal reference, resulting in a distinct color shift from orange-red to blue with a detection limit (LOD) of 0.05 μM. Subsequently, the addition of thiram restored the G-QDs and R-QDs’ intensity while the fluorescence intensity of B-QDs was quenched accompanied by a distinguishable color transition from blue to red with LOD of 0.073 μM. Moreover, colorimetric detection of thiram is realized based on the variation of UV absorption intensity with LOD of 0.142 μM. Besides, deep learning-YOLO v3 algorithm-assisted smartphone-integrated tricolor portable optical device for in-situ monitoring of Cu2+ and thiram with ultralow LOD of 0.344 μM and 1.840 μM, respectively. In conclusion, the sensing system shows excellent stability, sensitivity, and specificity, which provides a great capacity for the convenient evaluation of Cu2+ concentration and thiram residue.

Excellent visible-light photocatalytic activity towards the degradation of tetracycline antibiotic and electrochemical sensing of hydrazine by SnO2–CdS nanostructures

The present study investigated a tin oxide/cadmium sulfide (SnO2–CdS) nanostructure for enhancing the photocatalytic efficiency of CdS nanoparticles. Herein, the desired nanostructure was fabricated through a straightforward and cost-effective approach. The physicochemical properties of the fabricated nanostructure were analyzed by various characterization techniques. The SnO2–CdS shows an excellent band-gap of 2.14 eV, a high surface area of 29 m2/g, and favorable photoluminescence properties. The examination of the degradation capabilities of SnO2–CdS nanostructures (SOCdS) with visible light was conducted using tetracycline hydrochloride (TC), methylene blue (MB), and Congo red (CR) as models of antibiotic and dye pollutants. The photocatalyst possessed a TC removal efficiency of 94.5 ± 0.02% in 60 minutes under visible-light irradiation with over 60 ± 0.06% adsorption of TC under equilibrium conditions. Further, the photocatalysts exhibited excellent performance for MB and CR degradation with degradation effectiveness of 99.08 ± 0.01% in 120 min and 83 ± 0.06% in 40 min, respectively. In addition, the glassy carbon electrode (GCE) was modified with SOCdS (SOCdS/GCE) and was employed for the efficient and precise detection of hydrazine at room temperature. The SOCdS/GCE showed first-rate response for the recognition of hydrazine: CV: LOD of 0.18 μM, 8 μM–50 μM linear range, and 25.7 μA μM−1 cm−2 of sensitivity; and LSV: LOD of 0.19 μM, 5 μM–50 μM linear range, and 23.6 μA μM−1 cm−2 of sensitivity. Results suggest that the SnO2–CdS nanostructure showed excellent photocatalytic activity than bare-CdS NPs and has the ability to detect the analyte viz. hydrazine. The role of CdS nanoparticles is interesting to enhance the photocatalytic and electrochemical properties. We report a straightforward and cost-effective fabrication approach for SnO2–CdS nanostructure and provide a robust platform for the utilization of chalcogenides-based systems for environmental remediation and detection of hazardous chemicals.

Fabrication of Electrochemical Sensor Using SnO2-Modified-TiO2 Nanocomposite for Detection of Hydrazine

In this paper, we report the preparation of an SnO2/TiO2 nanocomposite (SnO2/TiO2 NC) for modifying a glassy carbon electrode (GCE) via a self-assembly approach; the SnO2/TiO2/GCE thus prepared was employed as a working electrode for the electrochemical detection of hydrazine (Hz) at room temperature. The detection of Hz as a model analyte was efficiently monitored by the dual approaches of linear sweep voltammetry and cyclic voltammetry under different optimization conditions. The SnO2/TiO2/GCE sensor showed a low limit of detection (LoD), and high sensitivity and selectivity with good linearity. The sensitivity and LoD of the proposed sensor were obtained using CV as 23.14 μA μM−1 cm−2 and 0.160 μM, respectively. A linear calibration plot was obtained (R2 = 0.974) for varying concentrations of Hz (5 to 45 μM). However, the sensitivity and LoD using LSV were obtained as 32.92 μA μM−1 cm−2 and 0.143 μM, respectively with linear range of 1 to 40 μM (R2 = 0.984). The present work provides a method of fabrication of an SnO2/TiO2 NC-based electrochemical sensor that is effective in the detection of hazardous chemicals.

Ag-modified SnO2-graphitic-carbon nitride nanostructures for electrochemical sensor applications

Hydrazine is a well-known carcinogen and can cause several other adverse effects on human health such as respiratory issues, irritation of the eyes, liver and kidney problems, and dermal corrosion. An effective method is needed to detect the carcinogenic reagent like hydrazine. Tin oxide (SnO2)-modified graphitic carbon nitride (g-C3N4) decorated with well-crystallized silver (Ag) nanoparticles (denoted as Ag@SO-gCN) was fabricated by a biogenic/green approach and characterized by standard techniques. A fluorine-doped tin oxide (FTO) support/substrate was coated with Ag@SO-gCN by the doctor-blade technique, and employed as the working electrode (denoted as Ag@SO-gCN/FTO) for the electrochemical detection of carcinogenic hydrazine (Hz) as a model analyte at room temperature. The dual electrochemical techniques of linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were used for the detection of hydrazine (denoted as Hz). The Ag@SO-gCN/FTO sensor shows an effective current response in the detection of Hz in solutions. The concentration of Hz was very efficiently monitored using LSV and CV under different conditions. The sensor shows a low limit of detection (LOD), high sensitivity and selectivity, and good linear range. The sensitivity and LOD of this sensor using LSV are 2.01 μA μM−1 cm−2 and 0.164 ± 0.013 μM, respectively. However, the fabricated Hz sensor using CV showed a sensitivity of 2.305 μA μM−1 cm−2 and LOD of 0.143 ± 0.011 μM. This study thus provides an innovative Ag@SnO2-g-C3N4-based electrochemical sensor as an effective device for the successful detection of hazardous chemicals.

Fast, Miniaturized, Real-Time Unit for Sampling, Modulation, and Separation in Detection of Hazardous Chemicals.

A sampling, modulation, and separation (SMS) unit was tested for detection of hazardous chemicals. The SMS unit, designed and developed for on-site sampling and analysis, consists of a dynamic inlet system coupled with a fast, miniaturized gas chromatograph (GC). Feasibility of the SMS unit was evaluated together with a hazardous chemical vapor generator. The performance of the SMS unit was tested with automated thermal desorption after SMS to collect samples for GC-mass spectrometry (GC-MS) measurements. Detection of sarin nerve agent was verified. Additionally, the vapor generator was connected to the SMS unit, which was hyphenated with a photoionization detector (PID), thus creating a fast GC-PID system. This system gave a positive response for degradation products of sulfur mustard, thereby indicating suitability of the SMS-PID unit for field drone applications.

Standoff pump-probe photothermal detection of hazardous chemicals

A novel pump-probe Photothermal methodology using Quartz Tuning Fork (QTF) detector has been demonstrated for the first time. A tunable mid-IR Quantum Cascade Laser (QCL) and a CW fixed wavelength visible laser have been used as the pump and probe beam respectively. The developed Photothermal (PT) technique is based on Quartz Tuning Fork (QTF) detector for the detection of hazardous/explosive molecules adsorbed on plastic surface and also in aerosols form. PT spectra of various trace molecules in the fingerprinting mid- infrared spectral band 7–9 µm from distance of 25 m have been recorded. The PT spectra of explosives RDX, TNT and Acetone have been recorded at very low quantities. Acetone is the precursor of explosive Tri-Acetone Tri-Phosphate (TATP). The experimentations using pump and probe lasers, exhibit detection sensitivity of less than 5 μg/cm2 for RDX, TNT powders and of ~ 200 nl quantity for Nitrobenzene (NB) and Acetone (in liquid form) adsorbed on surfaces, from a distance of ~ 25 m. The sensitivity of the same order achieved from a distance of 15 m by using only a mid-IR tunable pump laser coupled to QTF detector. Thus the pump-probe PT technique is more sensitive in comparison to single tunable QCL pump beam technique and it is better suited for standoff detection of hazardous chemicals for homeland security as well as for forensic applications.