Detection Of Toxic Chemicals Research Articles

On-spot detection of diethylchlorophosphate through device fabrication, pen and spray method based on intramolecular charge transfer modulated sensor molecule extending application to cell imaging

BackgroundDetecting diethyl chlorophosphate (DCP), a highly toxic chemical simulant for nerve agents like Sarin, Soman, and Tabun, is crucial due to its prevalence in warfare scenarios, as well as its presence in contaminated soil and air. Traditional detection methods often struggle with sensitivity and versatility, limiting their effectiveness in real-time, on-the-spot applications. Effective detection is vital for safety, environmental monitoring, and mitigating the risks associated with these hazardous substances. There is a pressing need for advanced sensors that can offer high sensitivity, specificity, and practicality in various environments. ResultsIn our study, we developed and introduced two ICT-based fluorocolorimetric sensors, TPAHY and TPAPD, designed for the detection of DCP. These sensors exhibit remarkable sensitivity, with limits of detection (LOD) at 23.31 nM for TPAHY and 28.42 nM for TPAPD. TPAHY proves to be an efficient sensor for the on-spot DCP detection, showcasing practical applications such as fluorescent sprays, pens, and detection devices. Upon addition of DCP, TPAHY undergoes a distinct colorimetric shift from yellow to orange, coupled with an enhancement of orange fluorescence. Conversely, TPAPD demonstrates a colorimetric transition from colourless to yellow and experiences fluorescence quenching from blue emission. To understand the underlying mechanisms, we conducted studies using density functional theory (DFT) and lifetime measurements, providing deeper insights into the sensor behaviours. SignificanceThe development of TPAHY and TPAPD provides reliable, sensitive, and versatile solutions for monitoring DCP. TPAHY not only serves as a useful tool for detecting DCP in various field applications but also extends its utility to biological imaging, as demonstrated in HeLa cell studies. This dual functionality enhances its relevance for both environmental monitoring and broader scientific investigations. These sensors represent a significant advancement in the detection of toxic chemicals, offering improved safety and research capabilities.

Bi-functional NiFe2O4/SrTiO3 S-scheme heterojunction for eminent performance photocatalytic treatment of sewage effluent and electrochemical hydrazine determination

Devising of materials that afforded dual applicability in decontamination and pollutant detection were still a towering challenge owing to the increasing flux of discharge toxic contaminants over the years. Herein, the NiFe2O4 nanoparticles-loaded on cube-like SrTiO3 (NiFe2O4/SrTiO3) composite was fabricated by a two-step hydrothermal approach providing remarkable photocatalytic treatment and electrochemical sensing of noxious pollutants in wastewater. The material traits of the fabricated composite were scrutinized by myriad characterization approaches. The NiFe2O4/SrTiO3 hybrid material demonstrated high surface area of 19.81 m2/g, adequate band gap energy of 2.75 eV, and prominent photoluminescence characteristics. In the presence of visible light, the NiFe2O4/SrTiO3 exhibited profound photocatalysis capability to eliminate sewage effluent-bearing chlortetracycline hydrochloride (CTCH) with 88.6% COD removal in 120 min, outperforming other pure materials. Meanwhile, the toxicity examination of effluent, the possible degradation pathway of CTCH and the proposed photocatalysis mechanism were also divulged. More importantly, the glassy carbon electrode was modified with synergized NiFe2O4/SrTiO3 (NiFe2O4/SrTiO3−GCE) was adopted for the precise quantification of Hydrazine (Hz). The NiFe2O4/SrTiO3−GCE obeyed first-order response for the Hz detection within the range of 1–10 mM: cyclic voltametric: limit of detection (LOD) of 0.119 μM with sensitivity of 18.9 μA μM−1 cm−2, and linear sweep voltametric: LOD of 0.222 μM with a sensitivity of 12.05 μA μM−1 cm−2. The stability and interference of modified electrode were also inspected. This work furnished valuable insights to yield a composite with the prominent S-scheme heterojunction system for quenching of charge carrier recombination and consequently contributing to the future realization into the domains of environmental clean-up and toxic chemical detection.

Development of a sensitive immunoassay for detecting persistent contaminant dichlorodiphenyltrichloroethane (DDT) in food samples using a monoclonal antibody

Although gas chromatography is the gold standard for detecting the persistent organic pollutant dichlorodiphenyltrichloroethane (DDT), a quick and easy alternative is needed to detect this highly toxic pesticide in food and household products. Therefore, we developed a monoclonal antibody (mAb)-based assay for the sensitive detection of DDT. The mAb used in our assay demonstrated favourable binding affinity in the nanomolar range against 2,2-bis(4-chlorophenyl)acetic acid (DDA), a DDT analogue, which is considered higher than commercially developed antibodies. By optimizing the assay conditions, we were able to detect DDT and its closely related compounds, including dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), and isomeric impurities. Our dot blotting assay demonstrated a detection limit of 0.9 ng/mL for DDT. Using computational modelling, we predicted the structure of the mAb and its interaction with DDT. Overall, this study provides insights for engineering mAb with improved sensitivity, facilitates point-of-care detection of toxic chemicals, including DDT, and offers a vital method for food safety monitoring and environmental protection.

High sensitivity of graphdiyne nanoflake toward detection of phosgene, thiophosgene and phosogenoxime; a first-principles study

The sensing properties of 2D carbon materials are well explored for various gaseous analytes, however, the detection of toxic chemicals e.g., phosgene (Ph), thiophosgene (ThP) and phosogenoxime (PhO) are rarely studied. To the best of our literature survey, only a single study is found for the adsorption of phosgene on 2D carbon nanoflake (graphyne). This motivated us to explore the sensitivity of graphdiyne (GDY) nanoflake for the detection of phosgene and couple of its derivatives. Therefore, we have performed a density functional analysis to simulate the comparative interaction between phosgene, thiophosgene and phosogenoxime with graphdiyne nanoflake. The interaction behaviours are estimated by interaction energies, (symmetry adopted perturbation) SAPT0 analysis, (noncovalent interaction index) NCI analysis, molecular orbital analysis, natural bond orbital (NBO) charge transfer and UV–Vis absorption analysis. The obtained results demonstrate the trend in sensitivity of graphdiyne for analytes is PhO@GDY > ThP@GDY > Ph@GDY. The sensible justification for the particular observation is provided by the energy gaps between HOMO and LUMO orbitals in term of %sensitivity. The %sensitivity is in complete accord with the aforementioned trend. In addition, results suggest that graphdiyne based sensor for detecting phosgene and derivatives are better in sensitivity in comparison with already reported graphyne sensor.

A Compact Circular Multipass Cell for Millimeter-Wave/Terahertz Gas Spectroscopy

Millimeter-wave/terahertz (mmW/THz) spectros-copy is a promising tool for gas sensing applications, such as breath analysis or the detection of toxic chemicals, which require compact portable systems. Long gas cells that are needed for high sensitivities are often bulky and limit the portability of the system. We present a compact mmW/THz circular multipass gas cell with an optical path length of 1.9 m and an outer diameter of only 21.5 cm. The beam is refocused at each internal reflection as a consequence of the large divergence of the mmW/THz beams. We determined the losses of the cell to about 3 dB around 250 GHz and demonstrated sensitive gas spectroscopy with a detection limit of 14 ppm/√Hz for acetaldehyde in a mixture with methanol.

Recent advances in film-based fluorescence sensing

<p indent=0mm>The film-based fluorescence sensor is recognized as one of the most promising micro-trace substance detection technologies after ion mobility spectrometry. Due to its sensitivity, portability, real-time detection, fast response, easy manufacture, and no pollution to the system to be tested, it has attracted extensive research attention in the fields of food testing, environmental monitoring, quality control and biomedical analysis. This review mainly discusses the research progress of film-based fluorescence sensing in the fields of volatile gas detection, toxic chemical detection, hidden explosive detection, solution phase ion detection and biological monitoring in the past five years. Moreover, the challenges and future development directions of film-based fluorescence sensing are proposed.

Microbial fuel cells as a sustainable platform technology for bioenergy, biosensing, environmental monitoring, and other low power device applications

Microbial Fuel Cell (MFC) technology is a promising sustainable energy alternative to combat issues pertaining to non-renewable energy consumption, climate change, and environmental pollution. MFC technology employs anaerobic microorganisms, which convert biodegradable substances into simpler substances and produce bioelectricity. MFCs show promise for low-cost energy yielding wastewater treatment. Recent research efforts have shown that the technological know-how of MFC technology has evolved beyond the primary applications of wastewater treatment and energy generation. Hence, research attention has shifted towards other specific value-added applications of MFCs such as small implantable health devices, robotics, and environmental quality monitoring sensors, etc. This article concisely addresses the potential applications of MFC technology past power production and wastewater treatment for biofuels such as biogas, and hydrogen production, and in the fields of medical implantable devices, robotics, and as biosensors for heavy metals and detection of toxic chemicals among others.

Detection of Toxic Chemicals on Ground by Stand‐off Raman Spectroscopy

Detection of Toxic Chemicals on Ground by Stand‐off Raman Spectroscopy

NANITIES THE NANO-PIEZO ROBOTS

A nanomachine, also called a nanite, is a mechanical or electromechanical device whose dimensions are measured in nanometers The first useful applications of nanomachines will likely be in medical technology, where they could be used to identify pathogens and toxins from samples of body fluid. Another potential application is the detection of toxic chemicals, and the measurement of their concentrations, in the environment.

Molecular manipulations for enhancing luminescent bioreporters performance in the detection of toxic chemicals.

Microbial whole-cell bioreporters are genetically modified microorganisms that produce a quantifiable output in response to the presence of toxic chemicals or other stress factors. These bioreporters harbor a genetic fusion between a sensing element (usually a gene regulatory element responsive to the target) and a reporter element, the product of which may be quantitatively monitored either by its presence or by its activity. In this chapter we review genetic manipulations undertaken in order to improve bioluminescent bioreporter performance by increasing luminescent output, lowering the limit of detection, and shortening the response time. We describe molecular manipulations applied to all aspects of whole-cell bioreporters: the host strain, the expression system, the sensing element, and the reporter element. The molecular construction of whole-cell luminescent bioreporters, harboring fusions of gene promoter elements to reporter genes, has been around for over three decades; in most cases, these two genetic elements are combined "as is." This chapter outlines diverse molecular manipulations for enhancing the performance of such sensors.

Integrated microring resonator biosensors for monitoring cell growth and detection of toxic chemicals in water

Integrated microring resonators fabricated on silicon wafers were used as signal transducers to detect alterations in physical traits of attached live mammalian cells. Cell adhesion and growth events could be monitored by the shift in resonance frequency of the microring resonator. Toxic chemical-induced changes in cell motility were rapidly detected based on variations in the fluctuation of resonance frequency. Microring resonators modified with an endothelial cell line (MS1) adhered onto its surface were used to detect the presence of two toxic chemicals, viz. sodium pentachlorophenate and Aldicarb at concentrations above the military exposure guideline levels within a duration of 1 h.

Piezoelectric biosensor using olfactory receptor protein expressed in Escherichia coli

An olfactory receptor protein of C. elegans, ODR-10, was expressed in Escherichia coli as a fusion protein, with GST and 6x His-tag. The expression of the target protein was analyzed by SDS-PAGE and Western blot, and was confirmed to be expressed at the membrane fraction of the host E. coli. The surface of a quartz crystal microbalance (QCM) was coated with crude membrane extracts, containing the expressed receptor protein, and the interaction between the olfactory receptor and various odorant molecules examined. Compared with other odorants, diacetyl (2,3-butanedione), known as a natural ligand for the ODR-10 receptor, interacted most strongly with the expressed protein. Various concentrations of diacetyl were applied to the expressed ODR-10 receptor, and the response of the QCM showed a linear relationship to the logarithmic value of the odorant concentration. This piezoelectric biosensor system, using olfactory receptor proteins expressed in E. coli, can be used in diagnostics, toxic chemical detection and the quality control of food.

Urban estuarine systems under stress: Environmental issues facing Louisiana's Lake pontchartrain

Lake Pontchartrain is part of a brackish coastal estuarine system which serves as an important economic and recreational resource for the New Orleans region. Seafood extraction, shell dredging and leisure time activities are the major uses occurring on Lake Pontchartrain. In the past several decades, man has severely altered this system through urbanization, industrial activity, levee construction and subsequent destruction of wetlands surrounding the lake. There is a growing awareness of the environmental crisis facing Lake Pontchartrain, advanced by recent fish kills, detection of toxic chemicals, curtailment of recreational opportunities and the report of ‘dead zones’ in the lake. This study summarizes a series of international environmental management techniques and examines the utilization of a regional structure for water resources management in the Lake Pontchartrain Basin.