Specific Volatile Organic Compounds Research Articles

Thermal energy and electro-osmotic for biomimetic artificial olfactory cilia in tri-hybrid nanofluids: entropy-defying approaches

Biomimetic artificial olfactory cilia have demonstrated potential in identifying specific volatile organic compounds linked to various diseases, including certain cancers, metabolic disorders, and respiratory conditions. These sensors may facilitate non-invasive disease diagnosis and monitoring. Cilia Motility is the coordinated movement of cilia, which are hair-like projections present on the surface of particular cells in different species. Cilia serve an important part in several biological functions, including motility, fluid movement, and sensory reception. Cilia motility is a complicated process that requires the coordinated interaction of structural components and molecular pathways. Cilia are made up of a highly structured structure known as the axoneme, which is made up of microtubules grouped in a unique pattern. The axoneme is made up of nine outer doublet microtubules and a core pair of singlet microtubules. This arrangement offers structural support and serves as a scaffold for the proteins involved in ciliary movement. Our latest endeavors investigate these Multiphysics phenomena in ciliary beating flows that are inspired by biology, utilizing copper, gold, and titania nanoparticles. We examine their functions in biological systems such as peristaltic transport computationally. Our models give precise two- and three-dimensional velocity, temperature, and concentration solutions by integrating transverse magnetohydrodynamics with laser heating. Furthermore, at the channel wall expressions, the skin friction coefficient, Sherwood number, Nusselt number and optimization of entropy generation are acquired and analyzed. Important properties of the velocity and scalar profiles are revealed by a thorough analysis of dimensionless parameters. The simplified examination provides more insight into the trapping patterns that result from the complex interaction between nanofluid rheology and optics. These findings greatly contribute to our knowledge and improvement of nanofluidic transport technologies in a variety of fields supporting industry, sustainability, and medicine. Our combined computational and experimental methodology clarifies the complex dynamics in these systems and provides design guidance for the engineering of improved fluidic devices that make use of multifunctional nanomaterial interfaces and peristaltic motion.

Selective discrimination and accurate quantification of five target vapors among multiple vapors using 2D CuO and Co3O4 sensors

Selective and sensitive detection of volatile organic compounds (VOCs) are critically needed for various applications like environmental sustainability, industrial safety, healthcare, etc Metal oxides are one of the most explored chemiresistive sensing materials because of their high sensitivity, but they lack selectivity. This work reports synthesis of two metal oxides - CuO and Co3O4 using surfactant assisted hydrothermal method. The 2D morphologies of both the metal oxides were ensured through fielded emission scanning electron microscope. The polycrystalline nature of the materials was studied using X-ray diffractometer and bandgaps were found to be 1.72 eV (CuO) and 1.9 and 2.89 eV (Co3O4) through the Kubelka Munk plot. The two metal oxides were employed to detect four different concentrations (6–50 ppm) of five targeted VOCs (lung cancer biomarkers) - acetone, acetonitrile, isopropanol, methanol, and toluene. In addition, response of the sensors for 6–50 ppm of ethyl acetate, hexanal, ammonia, and NO2 were also recorded as these VOCs are naturally produced in the body as a result of metabolic processes. The responses were recorded for 10 min for all the gases with CuO and Co3O4. Despite the intrinsic metal oxides lacking selectivity towards a specific VOC, careful feature selection achieved a classification accuracy of 95% using random forest (RF) algorithm. Subsequent application of RF model on validation dataset yielded a 91% accuracy in identifying target VOCs. Multilinear regression (MLR) algorithm was then employed to quantify the concentrations of the VOCs and low mean absolute error (MAE) values were obtained.

Plant volatiles: Herbivores shush the chatty tree

Plant-insect interactions can be complex and elusive. A new study shows that sap-feeding herbivores reduce tree emissions of specific volatile organic compounds that attract natural enemies. Sap-feeding insects thereby provide enemy-free space for chewing herbivores living on the same tree.

Computational study of pure and Lithium decorated bismuthene for detection of VOCs

To meet the crucial need for VOC detection, we propose a nanosensor based on bismuthene, employing density functional theory calculations. This nano-sensor aims to detect specific volatile organic compounds (VOCs) present in human breath, including acetone (C3H6O), ethanol (C2H6O), methanol (CH3OH), formaldehyde (CH2O), and toluene (C7H8), which serve as potential biomarkers for identifying physiological disorders. Additionally, we investigate how carbon dioxide (CO2) and water vapor (H2O), common in exhaled breath, interact with bismuthene as likely interfering species. Notably, toluene exhibited higher adsorption energy with pure and Li-decorated bismuthene. The favorable adsorption and desorption performance of bismuthene with molecules such as formaldehyde, methanol, and acetone at near-ambient temperatures suggest its suitability as a VOCs sensor with simple operational conditions. The density of states, charge analysis, adsorption properties, sensitivity, conductivity, selectivity, and recovery time have been calculated and discussed. Our results highlight Bismuthene’s potential as an efficient nano-sensor for detecting VOCs associated with pulmonary malignancies.

Revolution in malaria detection: unveiling current breakthroughs and tomorrow’s possibilities in biomarker innovation

The ongoing battle against malaria has seen significant advancements in diagnostic methodologies, particularly through the discovery and application of novel biomarkers. Traditional diagnostic techniques, such as microscopy and rapid diagnostic tests (RDTs), have their limitations in terms of sensitivity, specificity, and the ability to detect low-level infections. Recent breakthroughs in biomarker research promise to overcome these challenges, providing more accurate, rapid, and non-invasive detection methods. These advancements are critical in enhancing early detection, guiding effective treatment, and ultimately reducing the global malaria burden. Innovative approaches in biomarker detection are leveraging cutting-edge technologies like next-generation sequencing (NGS), proteomics, and metabolomics. These techniques have led to the identification of new biomarkers that can be detected in blood, saliva, or urine, offering less invasive and more scalable options for widespread screening. For instance, the discovery of specific volatile organic compounds (VOCs) in the breath of infected individuals presents a revolutionary non-invasive diagnostic tool. Additionally, the integration of machine learning algorithms with biomarker data is enhancing the precision and predictive power of malaria diagnostics, making it possible to distinguish between different stages of infection and identify drug-resistant strains. Looking ahead, the future of malaria detection lies in the continued exploration of multi-biomarker panels and the development of portable, point-of-care diagnostic devices. The incorporation of smartphone-based technologies and wearable biosensors promises to bring real-time monitoring and remote diagnostics to even the most resource-limited settings.

Forensic significance of VOCs profiling in decayed ante- and post-mortem injuries by GC×GC-TOF/MS.

Accurately identifying and differentiating the types of injuries in decomposed corpses is a major challenge in forensic identification. Forensic investigations involving decomposed cadavers pose challenges in determining the cause of death. Traditional methods often lack conclusive evidence. However, the implementation of advanced analytical techniques, such as comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOF/MS), shows promise in overcoming these limitations, but the potential in this area remains limited. Therefore, this study aims to bridge this gap by exploring the potential of GC × GC-TOF/MS in the analysis of volatile organic compounds (VOCs) changes within decaying ante- and post-mortem injuries.The research emphasizes the forensic significance of VOCs changes in decomposed cadavers. We used GC × GC-TOF/MS analysis to identify the specific volatile compounds in putrefied corpse tissue samples from mice. The GC × GC-TOF/MS analysis results showed that under winter conditions, PC1 explained 57.16% of the variance, and PC2 explained 25.23% of the variance; while under summer conditions, PC1 explained 71.89% of the variance, and PC2 explained 24.49% of the variance. This demonstrates the potential of GC × GC-TOF/MS in identifying specific VOCs present in tissue samples that can serve as potential biomarkers for distinguishing between antemortem and postmortem injury. GC × GC-TOF/MS analysis revealed distinct VOC patterns in both conditions. Comprehensive use of GC × GC-TOF/MS analysis enhances accuracy in identifying and characterizing ante- and post-mortem injuries in decomposed cadavers. This study can significantly contribute to the field of forensic medicine and improve the accuracy of forensic investigations.

Volatilome: A Novel Tool for Risk Scoring in Ischemic Heart Disease.

Developing a novel risk score for accurate assessment of cardiovascular disease (CVD) morbidity and mortality is an urgent need in terms of early prevention and diagnosis and, thereafter, management, particularly of ischemic heart disease. The currently used scores for the evaluation of cardiovascular disease based on the classical risk factors suffer from severe limitations, including inaccurate predictive values. Therefore, we suggest adding a novel non-classical risk factor, including the level of specific exhaled volatile organic compounds that are associated with ischemic heart disease, to the SCORE2 and SCORE2-OP algorithms. Adding these nonclassical risk factors can be used together with the classical risk factors (gender, smoking, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, diabetes mellitus, arterial hypertension, ethnicity, etc.) to develop a new algorithm and further program to be used widely.

Odor-Cued Grab Air Sampling for Improved Investigative Odorant Prioritization Assessment of Transient Downwind Environmental Odor Events.

A critical prelude to any community odor assessment should be the prioritization of specific chemical odorants that are most responsible for targeted downwind odors. Unfortunately, and historically, this is a step that has often been bypassed or overlooked. However, correct understanding of the specific impactful volatile organic compounds (VOCs) can inform the follow-on sampling, analytical, and remediation strategies that are most appropriate and efficient, based upon the chemistry behind the issue. With this understanding, the techniques and sampling strategies presented herein should be viewed as a qualitative prelude rather than an addendum to a follow-up routine, automated downwind odor monitoring. Downwind odor characteristics can vary depending upon the size of the upwind source, interim topography, and wind conditions. At one extreme, the downwind odor plume from a relatively large source located on a flat open plain and under stable, near-straight line wind conditions can be rather broad, sustained, and predictable. In contrast, the plume from a small point source (e.g., a roof vent stack) located on irregular topography and under rapidly shifting wind conditions can be intermittent and fleeting ("spikes" or "bursts"). These transient odor events can be surprisingly intense and offensive, despite their fleeting occurrence and perception. This work reports on improving and optimizing an environmental sampling strategy for odorant prioritization from such transient downwind odor conditions. This optimization addresses the challenges of (1) sampling of transient odor "spikes" and (2) prioritizing odors/odorants from multiple, closely colocated point sources under transient event conditions. Prioritizing is defined as identifying the key impactful odorants downwind. Grab air sampling protocol refinement has emerged from actual community environmental odor assessment projects. The challenge of assessing transient odor events has been mitigated by utilizing (a) rapid, odor-cued whole-air grab sampling (i.e., activated by and synchronous with the perceived sensory spikes) into metalized fluorinated ethylene polymer (m-FEP) gas sampling bags; (b) immediate transfer from bags onto solid-phase microextraction (SPME) fibers or sorbent tubes; and (c) maintaining refrigerated storage and shipment conditions between field collection and in-laboratory analysis. Results demonstrated approximately 11-fold increases in target odorant yields for 900 mL air sample capture on sorbent tube transfers from 2 to 3 s "burst" odor event bag captures compared to equivalent direct collections (with sorbent tubes) at the same downwind receptor location but during perceived (stable) odor "lull" periods. An application targeting general odor sampling and point-source differentiation utilizing tracer gases is also presented.

Advances in analytical techniques for assessing volatile organic compounds in pulse crops: a comprehensive review

Pulse crops, including beans, peas, chickpeas, and lentils, are vital sources of protein, fiber, and essential nutrients worldwide. They serve not only as staple foods but also as key components of sustainable agricultural practices, contributing to soil fertility through nitrogen fixation and enhancing overall productivity. However, pulse crops face numerous abiotic and biotic stresses mainly insect pest attack and pathogen invasion, which pose significant threats to pulse crops, impacting both production and food security. To overcome these challenges, plants have evolved diverse defense mechanisms, including the emission of specific volatile organic compounds (VOCs). These volatiles play crucial roles in plant communication, protection, and real-time health status indication. Monitoring VOCs offers a promising approach for early detection of pest infestations or pathogen infections, enabling the grower to take early action and decide on the proper control measure to minimize losses. The identification of plant-emitted VOCs requires robust and sensitive analytical techniques such as gas chromatography and mass spectrometry, which are the mainly used techniques for in pulse crops studies. However, traditional methods have limitations, prompting the need for advanced, portable, and real-time detection alternatives, such as gas-sensing technologies. This paper provides a comprehensive review of VOC measuring methods, including extraction, separation, and analytical techniques, focusing on their application in pulse crops. Recent advancements in gas-sensing technologies are also discussed, highlighting their potential in enhancing crop protection and agricultural sustainability.

Characterization of the SPIRITAS: A Disposable Sampling Setup for Volatile Organic Compound Collection and Analysis

Analyzing exhaled breath for volatile organic compounds (VOCs) using thermal desorption–gas chromatography–mass spectrometry (TD-GC-MS) offers a non-invasive diagnostic approach for various diseases. Despite its promise, the method faces challenges like sampling heterogeneity and high costs. Following the European Respiratory Society’s advocacy for methodological standardization, we developed the SPIRITAS (Standardized Product for Inexpensive Respiratory InvesTigation: A breath Sampler), a low-cost, disposable breath sampler. This study evaluates the SPIRITAS’s effectiveness in detecting targeted VOCs. We tested the SPIRITAS using the Peppermint Experiment, a standardized protocol that allows for comparison between different breath sampling and analytical practices by assessing the ability to detect five peppermint-specific VOCs after ingestion of a 200-milligram peppermint oil capsule. We included ten subjects and performed six breath samples per participant, including a baseline measurement taken before ingestion. We used the Wilcoxon signed-rank test to evaluate whether baseline values were significantly lower than the peak values of the targeted VOCs. Additionally, we conducted an experiment utilizing humidified medical-grade air to identify any VOCs attributable to the SPIRITAS setup itself. Results showed successful detection of four out of five targeted “peppermint-associated” VOCs: alpha-pinene (p ≤ 0.01), beta-pinene (p ≤ 0.01), menthone (p = 0.01), and menthol (p = 0.02), indicating significant differences between the baseline and peak values in the volunteers’ breath. However, detection of eucalyptol was inconsistent. In addition, we identified 16 VOCs that were released by the SPIRITAS, one of which remains unidentified. Our findings underscore the SPIRITAS’s potential for clinical applications, paving the way for broader biomarker research. The combination of ease of use, low cost, reduced risk of contamination, and standardization makes SPIRITAS very suitable for large-scale international studies. Furthermore, we have demonstrated the SPIRITAS’s effectiveness in detecting specific VOCs and identified 16 compounds originating from the SPIRITAS, ensuring that these compounds would not be mis-qualified as potential biomarkers in future clinical studies.

The use of Tetraselmis chuii as seafood flavoring agent in a vegetable broth

The growing demand of seafood alternatives is driven by concerns on overfishing, marine pollutants and animal welfare in aquaculture and fisheries. Currently, the availability of non-animal-based seafood flavorings on the market is limited, and animal-based seafood flavorings conflict with vegetarian and vegan criteria.The aim of this study is to explore the use of Tetraselmis chuii as a seafood flavoring in a vegetable broth. The flavor of the T. chuii broth was compared with a broth containing vegan fish flavoring based on a yeast extract and two broths containing white fish and lobster flavorings. To evaluate the different broths, the study employs a combination of sensory evaluation by a trained panel, chemical flavor analysis for aroma and umami characteristics, and consumer acceptability tests.Our results indicate that T. chuii effectively imparts a fish and shellfish flavor to the broth, which is less intense compared to the white fish and lobster flavorings. Nevertheless, consumers are equally positive of the aroma and flavor of the T. chuii broth and the animal-based seafood flavorings broths. The chemical flavor analysis of the T. chuii broth identifies volatile organic compounds (VOCs) such as dimethyl sulfide, methanethiol, trimethylamine, and 4-heptenal (Z), which collectively contribute to its distinct seafood aroma.Consumer preference tests show a preference for the seafood aroma of the T. chuii broth over the vegan fish flavoring broth, attributed to the meaty-like off-odor originating from specific VOCs of the yeast extract. In contrast, the vegan fish flavoring broth exhibits a stronger umami taste which is explained by elevated levels of free glutamate and guanosine-5′-monophosphate.This study highlights the potential of T. chuii as innovative seafood flavoring agent to enhance the sensory experience of seafood alternatives, contributing to the ongoing development of sustainable and flavorful non-animal alternatives in the food industry.

Volatile Organic Compounds Mediate Host Selection of Wheat Midge, Sitodiplosis Mosellana (Géhin) (Diptera: Cecidomyiidae) between Preanthesis and Postanthesis Stages of Wheat.

The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a significant wheat pest in the Prairie Provinces of Canada and northern regions of the USA. Wheat phenology plays a critical role in wheat midge oviposition. We hypothesized that S. mosellana oviposition behaviour is influenced by volatile organic compounds (VOCs) emitted by wheat at two adjacent wheat growth stages: preanthesis and postanthesis. A higher number of S. mosellana eggs laid on preanthesis than postanthesis spikes in an oviposition choice experiment using the susceptible spring wheat cultivar 'Roblin'. In preanthesis, wheat emitted higher amounts of Z-3-hexenyl acetate (Z3-06:OAc) than at the postanthesis stage. Higher amounts of methyl ketones such as 2-tridecanone, 2-pentadecanone, and 2-undecanone were emitted by wheat in the postanthesis stage and these VOCs were sensitive to S. mosellana antennae used in the Gas Chromatography-Electroantennographic Detection. Females were attracted to synthetic Z3-06:OAc but were deterred by 2-tridecanone relative to the solvent control in the vertical Y-tube olfactometer. 2-Undecanone and 2-pentadecanone did not show any attractiveness or deterrence. In a no-choice oviposition experiment, fewer eggs were laid in preanthesis wheat exposed to a synthetic VOC blend of Z3-06:OAc, 2-undecanone, 2-tridecanone, and 2-pentadecanone at the concentrations released by postanthesis spikes. This study shows that the reduction of Z3-06:OAc, in the VOC mix, and possibly the increase in 2-tridecanone, are likely responsible for the reduction in oviposition on postanthesis wheat. These results elucidate for the first time the role of specific VOCs mediating S. mosellana oviposition in preanthesis and postanthesis wheat.

Single atom dispersed tungsten disulfide (WS2) based nanosensors for VOCs detection related to decomposed humans in disaster events

Locating and recovering the victims as a result of disaster events is extremely challenging due to vast search areas, hazardous nature of destroyed infrastructure, and large number of potential victims. An effective avenue for the victim’s detection is through the sensing of human-specific volatile organic compounds (VOCs) emitted both in life and in death. Motivated by this, we employed first principles density functional theory (DFT) calculations to study the sensing properties of pristine, vacancy-induced and single atom dispersed tungsten disulfide (WS2) monolayers towards 11 specific VOCs associated with decomposing humans. We found that pristine, and vacancy-induced WS2 weakly adsorbed the selected VOCs with adsorption energies (Eads) between −0.26 to −0.76 eV. However, the incorporation of selected single atoms of Co, Fe, Nb, and Ni in WS2 improved the sensing properties tremendously. In particular, Nb-WS2 adsorbed the incident VOCs with Eads values of −1.89, −209, −1.43, −0.94, −2.08, −1.57, −1.44, −1.47, −1.70, −1.03, and −2.14 eV for 2-Butanone, benzaldehyde, butanol, heptane, hexanal, methylamine, dimethyl disulfide, dimethyl trisulfide, pyridine, octane, and toluene, respectively, which are ideal for efficient sensing mechanism. Appropriate adsorptions were coupled with the measurable changes in the electronic properties (band gaps) of Nb-WS2, which is essential for proficient sensing. Charge transfer analysis, electro localization functions, electrostatic potentials, and work function calculations further authenticated the sensing propensities of single atom dispersed WS2. Finally, Langmuir adsorption model was employed to explore the sensing at diverse pressure and temperature settings. We believe that these results will help for the development of highly efficient nanosensors for the detection of VOCs related to decomposed humans in mass disaster events. This will increase the detection ability and the chance of locating these victims.

Optimization of volatile organic compounds sampling from dairy cow exhaled breath using polymer-based solid-phase extraction cartridges for gas chromatographic analysis

We explored appropriate technical setups for the detection of volatile organic compounds (VOCs) from exhaled cow breath by comparing six different polymer-based solid-phase extraction (SPE) cartridges currently on the market for gas chromatography/mass spectrometry (GC-MS) screening. Exhaled breath was sampled at a single timepoint from five lactating dairy cows using six different SPE cartridges (Bond Elut ENV (ENV); Chromabond HRX (HRX); Chromabond HRP (HRP); Chromabond HLB (HLB); Chromabond HR-XCW (XCW) and Chromabond HR-XAW (XAW)). The trapped VOCs were analyzed by dynamic headspace vacuum in-tube extraction GC-MS (DHS-V-ITEX-GC-MS). Depending on the SPE cartridge, we detected 1174–1312 VOCs per cartridge. Most VOCs were alkenes, alkanes, esters, ketones, alcohols, aldehydes, amines, nitriles, ethers, amides, carboxylic acids, alkynes, azoles, terpenes, pyridines, or sulfur-containing compounds. The six SPE cartridges differed in their specificity for the chemical compounds, with the XAW cartridge showing the best specificity for ketones. The greatest differences between the tested SPE cartridges appeared in the detection of specific VOCs. In total, 176 different VOCs were detected with a match factor >80%. The greatest number of specific VOCs was captured by XAW (149), followed by ENV (118), HLB (117), HRP (115), HRX (114), and XCW (114). We conclude that the tested SPE cartridges are suitable for VOC sampling from exhaled cow breath, but the SPE cartridge choice enormously affects the detected chemical groups and the number of detected VOCs. Therefore, an appropriate SPE adsorbent cartridge should be selected according to our proposed inclusion criteria. For targeted metabolomics approaches, the SPE cartridge choice depends on the VOCs or chemical compound groups of interest based on our provided VOC list. For untargeted approaches without information on the animals’ metabolic condition, we suggest using multi-sorbent SPE cartridges or multiple cartridges per animal.

Roles of photochemical consumption of VOCs on regional background O3 concentration and atmospheric reactivity over the pearl river estuary, Southern China

Understanding of the photochemical ozone (O3) pollution over the Pearl River Estuary (PRE) of southern China remains limited. We performed an in-depth analysis of volatile organic compounds (VOCs) data collected on an island (i.e., the Da Wan Shan Island, DWS) located at the downwind of Pearl River Delta (PRD) from 26 November to 15 December 2021. Abundances of O3 and its precursors were measured when the air masses originated from the inland PRD. We observed that the VOCs levels at the DWS site were lower, while the mixing ratio of O3 was higher, compared to those reported at inland PRD, indicating the occurrence of photochemical consumption of VOCs during the air masses transport, which was further confirmed by the composition and diurnal variations of VOCs, as well as ratios of specific VOCs. The simulation results from a photochemical box model showed that the O3 level in the outflow air masses of inland PRD (O3(out-flow)) was the dominant factor leading to the intensification of O3 pollution and the enhancement of atmospheric radical concentrations (ARC) over PRE, which was mainly contributed by the O3 production via photochemical consumption of VOCs during air masses transport. Overall, our findings provided direct quantitative evidence for the roles of outflow O3 and its precursors from inland PRD on O3 abundance and ARC over the PRE area, highlighting that alleviation of O3 pollution over PRE should focus on the impact of photochemical loss of VOCs in the outflow air masses from inland PRD.

Spatial distribution of volatile organic compounds in contaminated soil and distinct microbial effect driven by aerobic and anaerobic conditions

The vertical distribution of 35 volatile organic compounds (VOCs) was investigated in soil columns from two obsolete industrial sites in Eastern China. The total concentrations of ΣVOCs in surface soils (0–20 cm) were 134–1664 ng g−1. Contamination of VOCs in surface soil exhibited remarkable variability, closely related to previous production activities at the sampling sites. Additionally, the concentrations of ΣVOCs varied with increasing soil depth from 0 to 10 m. Soils at depth of 2 m showed ΣVOCs concentrations of 127–47,389 ng g−1. Among the studied VOCs, xylene was the predominant contaminant in subsoils (2 m), with concentrations ranging from n.d. to 45,400 ng g−1. Chlorinated alkanes and olefins demonstrated a greater downward migration ability compared to monoaromatic hydrocarbons, likely due to their lower hydrophobicity. As a result, this vertical distribution of VOCs led to a high ecological risk in both the surface and deep soil. Notably, the risk quotient (RQ) of xylene in subsoil (2 m, RQ up to 319) was much higher than that in surface soil. Furthermore, distinct effects of VOCs on soil microbes were observed under aerobic and anaerobic conditions. Specifically, after the 30-d incubation of xylene-contaminated soil, Ilumatobacter was enriched under aerobic condition, whereas Anaerolineaceae was enriched under anaerobic condition. Moreover, xylene contamination significantly affected methylotrophy and methanol oxidation functions for aerobic soil (t-test, p < 0.05). However, aromatic compound degradation and ammonification were significantly enhanced by xylene in anaerobic soil (t-test, p < 0.05). These findings suggest that specific VOC compound has distinct microbial ecological effects under different oxygen content conditions in soil. Therefore, when conducting soil risk assessments of VOCs, it is crucial to consider their ecological effects at different soil depths.

The role of volatile organic compounds for assessing characteristics and severity of non-cystic fibrosis bronchiectasis: an observational study.

Hypoxic conditions and Pseudomonas aeruginosa (P. aeruginosa) infection are significant factors influencing the prognosis and treatment of patients with bronchiectasis. This study aimed to explore the potential for breath analysis to detect hypoxic conditions and P. aeruginosa infection in bronchiectasis patients by analyzing of volatile organic compounds (VOCs) in exhaled breath condensate (EBC). EBC samples were collected from stable bronchiectasis patients and analyzed using solid phase microextraction-gas chromatography-mass spectrometry (SPME-GCMS). The association of VOCs with bronchiectasis patients' phenotypes including hypoxic conditions and P. aeruginosa isolation was analyzed, which may relate to the severity of bronchiectasis disease. Levels of 10-heptadecenoic acid, heptadecanoic acid, longifolene, and decanol in the hypoxia group were higher compared to the normoxia group. Additionally, the levels of 13-octadecenoic acid, octadecenoic acid, phenol, pentadecanoic acid, and myristic acid were increased in P. aeruginosa (+) group compared to the P. aeruginosa (-) group. Subgroup analysis based on the bronchiectasis severity index (BSI)reveled that the levels of 10-heptadecenoic acid, heptadecanoic acid, decanol, 13-octadecenoic acid, myristic acid, and pentadecanoic acid were higher in the severe group compared to the moderate group. Multivariate linear regression showed that 10-heptadecenoic acid and age were independent prognostic factors for bronchiectasis patients with hypoxia. Furthermore, octadecenoic acid, phenol and gender were identified as independent prognostic factors for bronchiectasis patients with P. aeruginosa isolation. The study provides evidence that specific VOCs in EBC are correlated with the severity of bronchiectasis, and 10-heptadecenoic acid is shown to be a predictive marker for hypoxia condition in bronchiectasis patients.

Efficient detection of lung cancer biomarkers using functionalized transition metal dichalcogenides (MoS2) Monolayers: DFT study

Selective sensing properties of transition metal dichalcogenides (MoX2, X = S, Se) towards specific volatile organic compounds (VOCs) associated with lung-cancer are investigated using state-of-the-art density-functional theory (DFT) methods. In the present investigation, a combination of DFT and the non-equilibrium Green’s functions (NEGF) formalism are employed to probe the sensing of four VOCs; namely: (i) Isoprene “C5H8”, (ii) Toluene “C7H8”, (iii) Cyclopropanone “C3H4O”, and (iv) Isopropanol “C3H8O”; and four interfering air molecules CO2, H2O, N2 and O2. We find that the doping of single atom of selected transition metals (TMs = Mn, Fe, Ni, Cu) can enhance both the sensitivity and the selectivity of MoX2. Our results show that the selectivity is rather distinct towards the detection of VOCs when TMs doping is targeting the chalcogenide site. Adsorption energies, charge transfers, electronic properties through density of states and band structures, and the sensor responses are obtained in all the cases, particularly for C5H8 and C3H8O, which show superior selectivities. Enhanced selectivity is attributed to the enhancement in the polarity of the substrate after the TMs doping targeting the chalcogenide sites. Our work demonstrates the potential of MoX2 based single atom catalysts as efficient biosensor towards the specific VOCs for the early diagnosis of lung cancer.PACS Numbers: 31.15.E-, 68.43.-h, 68.43.Fg, 82.33.Pt, 87.15.Aa, 87.15.Kg, 87.19.Xx, 87.19.xj.

Correlation between Volatile Organic Compounds (VOC) with Leukotriene B4 and Eosinophil Counts in Chronic Obstructive Pulmonary Disease Patients

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by increasing Leukotriene B4 (LTB4) and eosinophil counts. Volatile organic compounds (VOCs) have shown promise as non-invasive biomarkers, reflecting COPD pathophysiology. Identifying specific VOCs associated with increased LTB4 and eosinophil counts could lead to the discovery of potential biomarkers for COPD severity or progression. AIMS: This study aims to investigate the correlation between VOCs and leukotriene B4 (LTB4) levels, as well as eosinophil counts counts in COPD patients. METHOD: Using an observational-analytic method with a case-control approach, 20 COPD patients and 20 controls were enrolled from the respiratory outpatient department of Dr. Saiful Anwar General Hospital, Malang. VOC levels were measured using a breath analyzer, while LTB4 levels were determined through enzyme-linked immunosorbent assays. Spearman’s correlation tests examined associations between VOCs, LTB4, eosinophil counts, and comorbidity, with Mann-Whitney tests comparing results against the control group. Data significance was set at p &lt; 0.05. RESULT: There were 40 COPD patients and 40 controls in this study. There were significant differences between VOCs in the COPD group and the control group (p &lt; 0.05). LTB4 level significantly increased in the COPD group than in the control group (p &lt; 0.001), and there was no difference in the eosinophil level. There was a correlation between LTB4 and VOC level of C2H5OH in COPD patients (p = 0.009; r = 0.410). There was no correlation between eosinophil counts and VOCs (p = 0.939). The level of VOCs was significantly different between patients with only COPD and patients with COPD and comorbid lung cancer (p &lt; 0.05). CONCLUSION: There is a correlation between VOC and LTB4 in COPD patients.

Analysis of potential volatile organic compounds in Sitophilus zeamais (Coleoptera: Curculionidae)-infestedwheat based on lipid oxidation-a reference to early and rapid detection method.

The maize weevil, Sitophilus zeamais Motschulsky, is a hidden pest that presents serious risk to grain quality during postharvest storage. Lipid-derived volatile detection is considered a key reference for early prediction of S. zeamais infestation. However, the exact compositions of fatty acids and volatile organic compounds (VOCs) in S. zeamais-infested wheat are yet to be determined. In this study, we aimed to explore the effect of S. zeamais infestation on lipid metabolism in wheat infested with S. zeamais eggs (4 days), larvae (20 days), pupae (35 days), and adults (45 days). Compared to those in the control group, the activities of lipid oxidation enzymes, such as lipase, lipoxygenase, and alcohol dehydrogenase, increased by 82.73%, 105.12%, and 487.86%, respectively, during the storage period of 1 life cycle of S. zeamais. Additionally, the fatty acid composition of S. zeamais-infested wheat was significantly altered (palmitic acid [1.10-fold], oleic acid [1.07-fold], and linoleic acid [0.95-fold]). Furthermore, 91 VOCs were identified in all wheat samples; then, multivariate statistical analyses categorized these samples into 4 groups: uninfested, longer storage, lightly infested, and heavily infested. Moreover, 31, 26, and 45 potential VOCs were identified to distinguish uninfested wheat from those in the other 3 groups. These results demonstrated that S. zeamais infestation induces an elevation in lipid-related enzymatic activities, which potentially leads to a decrease in lipid content alongside the production of specific VOCs (undecan-4-olide, heptaldehyde, and 2-nonenal). These findings provide novel insights for rapidly identifying grains infested by hidden pests and effectively managing these pests during grain storage.