Research

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20 pages, 7187 KiB

Open AccessArticle

Influence of Water Molecules on the Detection of Volatile Organic Compounds (VOC) Cancer Biomarkers by Nanocomposite Quantum Resistive Vapor Sensors vQRS

by Abhishek Sachan, Mickaël Castro, Veena Choudhary and Jean-Francois Feller

Chemosensors 2018, 6(4), 64; https://doi.org/10.3390/chemosensors6040064 - 10 Dec 2018

Cited by 12 | Viewed by 3752

Abstract

The anticipated diagnosis of various fatal diseases from the analysis of volatile organic compounds (VOC) biomarkers of the volatolome is the object of very dynamic research. Nanocomposite-based quantum resistive vapor sensors (vQRS) exhibit strong advantages in the detection of biomarkers, as they can [...] Read more.

The anticipated diagnosis of various fatal diseases from the analysis of volatile organic compounds (VOC) biomarkers of the volatolome is the object of very dynamic research. Nanocomposite-based quantum resistive vapor sensors (vQRS) exhibit strong advantages in the detection of biomarkers, as they can operate at room temperature with low consumption and sub ppm (part per million) sensitivity. However, to meet this application they need to detect some ppm or less amounts of biomarkers in patients’ breath, skin, or urine in complex blends of numerous VOC, most of the time hindered by a huge amount of water molecules. Therefore, it is crucial to analyze the effects of moisture on the chemo-resistive sensing behavior of carbon nanotubes based vQRS. We show that in the presence of water molecules, the sensors cannot detect the right amount of VOC molecules present in their environment. These perturbations of the detection mechanism are found to depend on the chemical interactions between water and other VOC molecules, but also on their competitive absorption on sensors receptive sites, located at the nanojunctions of the conductive architecture. This complex phenomenon studied with down to 12.5 ppm of acetone, ethanol, butanone, toluene, and cyclohexane mixed with 100 ppm of water was worth to investigate in the prospect of future developments of devices analysing real breath samples in which water can reach a concentration of 6%. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

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10 pages, 1593 KiB

Open AccessArticle

Measuring Vapor and Liquid Concentrations for Binary and Ternary Systems in a Microbubble Distillation Unit via Gas Sensors

by Nada N. Abdulrazzaq, Baseem H. Al-Sabbagh, Julia M. Rees and William B. Zimmerman

Chemosensors 2018, 6(3), 31; https://doi.org/10.3390/chemosensors6030031 - 03 Aug 2018

Cited by 2 | Viewed by 4256

Abstract

A cost effective, fast, and accurate technique was needed to measure the vapor composition of a binary system (ethanol-water) and also that of a liquid composition in a ternary system (acetic acid-acetol–water) in a microbubble distillation unit. Cheap TGS-series gas sensors were used [...] Read more.

A cost effective, fast, and accurate technique was needed to measure the vapor composition of a binary system (ethanol-water) and also that of a liquid composition in a ternary system (acetic acid-acetol–water) in a microbubble distillation unit. Cheap TGS-series gas sensors were used for this purpose with both calibrations and measurements carried out in a specially designed chamber. A single parameter polynomial regression was fitted to the binary system, and a two parameter polynomial with an interaction term was fitted to the ternary system. The correlation coefficient, R-squared, was found to be greater than 0.99 for both systems, thus validating the implementation of this novel sensor. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

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Review

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36 pages, 708 KiB

Open AccessReview

Applications of Electronic-Nose Technologies for Noninvasive Early Detection of Plant, Animal and Human Diseases

by Alphus Dan Wilson

Chemosensors 2018, 6(4), 45; https://doi.org/10.3390/chemosensors6040045 - 04 Oct 2018

Cited by 75 | Viewed by 8971

Abstract

The development of electronic-nose (e-nose) technologies for disease diagnostics was initiated in the biomedical field for detection of biotic (microbial) causes of human diseases during the mid-1980s. The use of e-nose devices for disease-diagnostic applications subsequently was extended to plant and animal hosts [...] Read more.

The development of electronic-nose (e-nose) technologies for disease diagnostics was initiated in the biomedical field for detection of biotic (microbial) causes of human diseases during the mid-1980s. The use of e-nose devices for disease-diagnostic applications subsequently was extended to plant and animal hosts through the invention of new gas-sensing instrument types and disease-detection methods with sensor arrays developed and adapted for additional host types and chemical classes of volatile organic compounds (VOCs) closely associated with individual diseases. Considerable progress in animal disease detection using e-noses in combination with metabolomics has been accomplished in the field of veterinary medicine with new important discoveries of biomarker metabolites and aroma profiles for major infectious diseases of livestock, wildlife, and fish from both terrestrial and aquaculture pathology research. Progress in the discovery of new e-nose technologies developed for biomedical applications has exploded with new information and methods for diagnostic sampling and disease detection, identification of key chemical disease biomarkers, improvements in sensor designs, algorithms for discriminant analysis, and greater, more widespread testing of efficacy in clinical trials. This review summarizes progressive advancements in utilizing these specialized gas-sensing devices for numerous diagnostic applications involving noninvasive early detections of plant, animal, and human diseases. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

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20 pages, 3295 KiB

Open AccessReview

Stochastic and Temporal Models of Olfactory Perception

by Thomas P. Hettinger and Marion E. Frank

Chemosensors 2018, 6(4), 44; https://doi.org/10.3390/chemosensors6040044 - 26 Sep 2018

Cited by 3 | Viewed by 3563

Abstract

Olfactory systems typically process signals produced by mixtures composed of very many natural odors, some that can be elicited by single compounds. The several hundred different olfactory receptors aided by several dozen different taste receptors are sufficient to define our complex chemosensory world. [...] Read more.

Olfactory systems typically process signals produced by mixtures composed of very many natural odors, some that can be elicited by single compounds. The several hundred different olfactory receptors aided by several dozen different taste receptors are sufficient to define our complex chemosensory world. However, sensory processing by selective adaptation and mixture suppression leaves only a few perceptual components recognized at any time. Thresholds determined by stochastic processes are described by functions relating stimulus detection to concentration. Relative saliences of mixture components are established by relating component recognition to concentration in the presence of background components. Mathematically distinct stochastic models of perceptual component dominance in binary mixtures were developed that accommodate prediction of an appropriate range of probabilities from 0 to 1, and include errors in identifications. Prior short-term selective adaptation to some components allows temporally emergent recognition of non-adapted mixture-suppressed components. Thus, broadly tuned receptors are neutralized or suppressed by activation of other more efficacious receptors. This ‘combinatorial’ coding is more a process of subtraction than addition, with the more intense components dominating the perception. It is in this way that complex chemosensory mixtures are reduced to manageable numbers of odor notes and taste qualities. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

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16 pages, 1295 KiB

Open AccessEditor’s ChoiceReview

From Gas Sensors to Biomimetic Artificial Noses

by Paolo Pelosi, Jiao Zhu and Wolfgang Knoll

Chemosensors 2018, 6(3), 32; https://doi.org/10.3390/chemosensors6030032 - 07 Aug 2018

Cited by 44 | Viewed by 6329

Abstract

Since the first attempts to mimic the human nose with artificial devices, a variety of sensors have been developed, ranging from simple inorganic and organic gas detectors to biosensing elements incorporating proteins of the biological olfactory system. In order to design a device [...] Read more.

Since the first attempts to mimic the human nose with artificial devices, a variety of sensors have been developed, ranging from simple inorganic and organic gas detectors to biosensing elements incorporating proteins of the biological olfactory system. In order to design a device able to mimic the human nose, two major issues still need to be addressed regarding the complexity of olfactory coding and the extreme sensitivity of the biological system. So far, only 50 of the approximately 300–400 functioning olfactory receptors have been de-orphanized, still a long way from breaking the human olfactory code. On the other hand, the exceptional sensitivity of the human nose is based on amplification mechanisms difficult to reproduce with electronic circuits, and perhaps novel approaches are required to address this issue. Here, we review the recent literature on chemical sensing both in biological systems and artificial devices, and try to establish the state-of-the-art towards the design of an electronic nose. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

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20 pages, 284 KiB

Open AccessReview

Application of Fecal Volatile Organic Compound Analysis in Clinical Practice: Current State and Future Perspectives

by Sofia El Manouni el Hassani, Daniel J. C. Berkhout, Sofie Bosch, Marc A. Benninga, Nanne K. H. De Boer and Tim G. J. De Meij

Chemosensors 2018, 6(3), 29; https://doi.org/10.3390/chemosensors6030029 - 23 Jul 2018

Cited by 11 | Viewed by 5126

Abstract

Increasing interest is noticed in the potential of volatile organic compound (VOC) analysis as non-invasive diagnostic biomarker in clinical medical practice. The spectrum of VOCs, originating from (patho)physiological metabolic processes in the human body and detectable in bodily excrements, such as exhaled breath, [...] Read more.

Increasing interest is noticed in the potential of volatile organic compound (VOC) analysis as non-invasive diagnostic biomarker in clinical medical practice. The spectrum of VOCs, originating from (patho)physiological metabolic processes in the human body and detectable in bodily excrements, such as exhaled breath, urine and feces, harbors a magnificent source of information. Thus far, the majority of studies have focused on VOC analysis in exhaled breath, aiming at identification of disease-specific VOC profiles. Recently, an increasing number of studies have evaluated the usability of VOC present in the headspace of feces in the diagnostic work-up of a wide range of gastrointestinal diseases. Promising results have been demonstrated particularly in those diseases in which microbiota alterations are considered to play a significant etiological role, such as colorectal carcinoma, inflammatory bowel disease, irritable bowel syndrome, celiac disease and infectious bowel diseases. In addition, fecal VOC analysis seems to have potential as a diagnostic biomarker for extra-intestinal diseases, including bronchopulmonary dysplasia and sepsis. Different methods for VOC analysis have been used in medical studies, such as gas-chromatography mass spectrometry, selected-ion flow tube-mass spectrometry, ion-mobility spectrometry, and electronic nose devices. In this review, the available literature on the potential of fecal VOCs as diagnostic biomarker, including an overview of relevant VOC detection techniques, is discussed. In addition, future hurdles, which need to be taken prior to implementation of VOC analysis in daily clinical practice, are outlined. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

25 pages, 948 KiB

Open AccessReview

Honey Evaluation Using Electronic Tongues: An Overview

by Ana C. A. Veloso, Mara E. B. C. Sousa, Leticia Estevinho, Luís G. Dias and António M. Peres

Chemosensors 2018, 6(3), 28; https://doi.org/10.3390/chemosensors6030028 - 19 Jul 2018

Cited by 21 | Viewed by 5295

Abstract

Honey-rich composition in biologically active compounds makes honey a food products highly appreciated due to the nutritional and healthy properties. Food-manufacturing is very prone to different types of adulterations and fraudulent labelling making it urgent to establish accurate, fast and cost-effective analytical techniques [...] Read more.

Honey-rich composition in biologically active compounds makes honey a food products highly appreciated due to the nutritional and healthy properties. Food-manufacturing is very prone to different types of adulterations and fraudulent labelling making it urgent to establish accurate, fast and cost-effective analytical techniques for honey assessment. In addition to the classical techniques (e.g., physicochemical analysis, microscopy, chromatography, immunoassay, DNA metabarcoding, spectroscopy), electrochemical based-sensor devices have arisen as reliable and green techniques for food analysis including honey evaluation, allowing in-situ and on-line assessment, being a user-friendly procedure not requiring high technical expertise. In this work, the use of electronic tongues, also known as taste sensor devices, for honey authenticity and assessment is reviewed. Also, the versatility of electronic tongues to qualitative (e.g., botanical and/or geographical origin assessment as well as detection of adulteration) and quantitative (e.g., assessment of adulterants levels, determination of flavonoids levels or antibiotics and insecticides residues, flavonoids) honey analysis is shown. The review is mainly focused on the research outputs reported during the last decade aiming to demonstrate the potentialities of potentiometric and voltammetric multi-sensor devices, pointing out their main advantages and present and future challenges for becoming a practical quality analytical tool at industrial and commercial levels. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

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12 pages, 1447 KiB

Open AccessReview

Exploring the Emotion of Disgust: Differences in Smelling and Feeling

by Lorenzo D. Stafford, Diana S. Fleischman, Nicholas Le Her and Thomas Hummel

Chemosensors 2018, 6(1), 9; https://doi.org/10.3390/chemosensors6010009 - 16 Feb 2018

Cited by 3 | Viewed by 5858

Abstract

Disgust evolved to motivate humans away from disease cues and may heighten discernment of these cues. Disease cues are often best perceived through our sense of smell, however very few studies have examined how eliciting disgust influences smell intensity or valence. In two [...] Read more.

Disgust evolved to motivate humans away from disease cues and may heighten discernment of these cues. Disease cues are often best perceived through our sense of smell, however very few studies have examined how eliciting disgust influences smell intensity or valence. In two novel experiments we investigated how domains of disgust induction influence odor perception. In experiment 1 participants (n = 90) were randomly allocated to one of two kinds of Disgust Induction (DI): Pathogen (DI-P), Moral (DI-M) or a Control (DI-C), followed by an evaluation of three affectively distinct odors (disgust-related, neutral, liked). Using a modified procedure in experiment 2, participants (n = 70) were again randomly assigned to one of the three disgust induction conditions, but here they evaluated one (disgust-related) odor during disgust induction. In experiment 2 we also measured feelings of disgust and anger. In experiment 1, surprisingly, we found overall ratings of odor disgust were lower in the DI-P compared to other groups, whereas in experiment 2, odor disgust was higher in the DI-P versus the DI-M/DI-C conditions, which also differed from each other. We also found that whereas feelings of disgust were higher in DI-P, in contrast, anger was higher for those individuals in the DI-M condition. These findings suggest that compared to a Control condition, inducing state Pathogen and Moral disgust lead to higher perceived odor disgust, whereas feelings of disgust/anger yield divergent effects. The work here also demonstrates that methodologies utilizing odor perception (disgust) can be a useful addition to measuring changes in state disgust. Full article

(This article belongs to the Special Issue Electronic nose’s, Machine Olfaction and Electronic Tongue’s)

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