Engineering › Biomedical Engineering

Advanced Chemical Sensor Technologies

Works Count: 123114

Wikipedia

Description

This cluster of papers focuses on the advances in breath analysis technology, particularly the use of electronic nose and sensor arrays to detect volatile organic compounds in exhaled breath for disease diagnosis, with a specific emphasis on lung cancer. The research covers various aspects such as diagnostic potential, colorimetric sensor arrays, and machine olfaction.

Keywords

Breath Analysis; Electronic Nose; Volatile Organic Compounds; Disease Diagnosis; Sensor Array; Exhaled Breath; Lung Cancer; Diagnostic Potential; Colorimetric Sensor; Machine Olfaction

ANALYZER FOR ACCURATE ESTIMATION OF RESPIRATORY GASES IN ONE-HALF CUBIC CENTIMETER SAMPLES

1947-01-01

P. F. Scholander

A colorimetric sensor array for odour visualization

2000-08-17

Neal A. Rakow , Kenneth S. Suslick

[43] Malondialdehyde determination as index of lipid Peroxidation

1990-01-01

H. H. Draper , M. Hadley

A MICROCOLORIMETRIC METHOD FOR THE DETERMINATION OF INORGANIC PHOSPHORUS

1953-06-01

Hertha H. Taussky , Ephraim Shorr , Gloria Kurzmann

Sensory Evaluation Techniques

2006-12-13

Morten Meilgaard , B. Thomas Carr , B. Thomas Carr

From listing the steps involved in a sensory evaluation project to presenting advanced statistical methods, Sensory Evaluation Techniques, Fourth Edition covers all phases of sensory evaluation. Like its bestselling predecessors, … From listing the steps involved in a sensory evaluation project to presenting advanced statistical methods, Sensory Evaluation Techniques, Fourth Edition covers all phases of sensory evaluation. Like its bestselling predecessors, this edition continues to detail all sensory tests currently in use, to promote the effective employment of these tests,

INFRARED SPECTRA OF INORGANIC COMPOUNDS

1971-01-01

Richard A. Nyquist , R. O. Kagel

Microdetermination of Long-chain Fatty Acids in Plasma and Tissues

1960-09-01

Vincent P. Dole , Hans Meinertz

Exhaled breath condensate: methodological recommendations and unresolved questions

2005-08-31

Ildikó Horváth , J.F. Hunt , Peter J. Barnes

Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen … Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. Concentrations of these mediators are influenced by lung diseases and modulated by therapeutic interventions. Similarly EBC pH also changes in respiratory diseases. The aim of the American Thoracic Society/European Respiratory Society Task Force on EBC was to identify the important methodological issues surrounding EBC collection and assay, to provide recommendations for the measurements and to highlight areas where further research is required. Based on the currently available evidence and the consensus of the expert panel for EBC collection, the following general recommendations were put together for oral sample collection: collect during tidal breathing using a noseclip and a saliva trap; define cooling temperature and collection time (10 min is generally sufficient to obtain 1-2 mL of sample and well tolerated by patients); use inert material for condenser; do not use resistor and do not use filter between the subject and the condenser. These are only general recommendations and certain circumstances may dictate variation from them. Important areas for future research involve: ascertaining mechanisms and site of exhaled breath condensate particle formation; determination of dilution markers; improving reproducibility; employment of EBC in longitudinal studies; and determining the utility of exhaled breath condensate measures for the management of individual patients. These studies are required before recommending this technique for use in clinical practice.

View PDF Chat

Analysis of discrimination mechanisms in the mammalian olfactory system using a model nose

1982-09-01

Krishna Persaud , George H. Dodd

The use of conductivity measurements in organic solvents for the characterisation of coordination compounds

1971-10-01

W. J. Geary

Measurement of Low Energy Beta-Emitters in Aqueous Solution by Liquid Scintillation Counting of Emulsions.

1965-06-01

Michael S. Patterson , Ronald C. Greene

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMeasurement of Low Energy Beta-Emitters in Aqueous Solution by Liquid Scintillation Counting of Emulsions.M. S. Patterson and R. C. GreeneCite this: Anal. Chem. 1965, 37, 7, 854–857Publication … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMeasurement of Low Energy Beta-Emitters in Aqueous Solution by Liquid Scintillation Counting of Emulsions.M. S. Patterson and R. C. GreeneCite this: Anal. Chem. 1965, 37, 7, 854–857Publication Date (Print):June 1, 1965Publication History Published online1 May 2002Published inissue 1 June 1965https://pubs.acs.org/doi/10.1021/ac60226a017https://doi.org/10.1021/ac60226a017research-articleACS PublicationsRequest reuse permissionsArticle Views815Altmetric-Citations1127LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

‘Pheromones’: a New Term for a Class of Biologically Active Substances

1959-01-01

П. Карлсон , Martin Lüscher

On-line monitoring of volatile organic compounds at pptv levels by means of proton-transfer-reaction mass spectrometry (PTR-MS) medical applications, food control and environmental research

1998-02-01

W. Lindinger , Armin Hansel , Alfons Jordan

Estimation of product of lipid peroxidation (malonyl dialdehyde) in biochemical systems

1966-08-01

Z Placer , Linda L. Cushman , B. Connor Johnson

Multisensor data fusion: A review of the state-of-the-art

2011-08-28

Bahador Khaleghi , Alaa Khamis , Fakhreddine Karray +1 more

A brief history of electronic noses

1994-03-01

Julian W. Gardner , Philip N. Bartlett

A distillation method for the quantitative determination of malonaldehyde in rancid foods

1960-01-01

Basil G. Tarladgis , Betty M. Watts , MARGARET T. YOUNATHAN +1 more

Summary An improved distillation method is described for the quantitative determination of malonaldehyde in foods containing oxidized fats. The procedure is compared with other methods in current use for the … Summary An improved distillation method is described for the quantitative determination of malonaldehyde in foods containing oxidized fats. The procedure is compared with other methods in current use for the determination of malonaldehyde. A high correlation of TBA numbers with rancid odor in cooked meats was established.

Sterols as ecological indicators

1979-05-01

Wen-Yen Huang , W. G. Meinschein

Diagnostic potential of breath analysis—focus on volatile organic compounds

2004-07-30

Wolfram Miekisch , Jochen K. Schubert , Gabriele Noeldge‐Schomburg

Determination of malonaldehyde precursor in tissues by thiobarbituric acid test

1978-05-01

Mitsuru Uchiyama , Midori Mihara

Applications and Advances in Electronic-Nose Technologies

2009-06-29

A. D. Wilson , Manuela Baietto

Electronic-nose devices have received considerable attention in the field of sensor technology during the past twenty years, largely due to the discovery of numerous applications derived from research in diverse … Electronic-nose devices have received considerable attention in the field of sensor technology during the past twenty years, largely due to the discovery of numerous applications derived from research in diverse fields of applied sciences. Recent applications of electronic nose technologies have come through advances in sensor design, material improvements, software innovations and progress in microcircuitry design and systems integration. The invention of many new e-nose sensor types and arrays, based on different detection principles and mechanisms, is closely correlated with the expansion of new applications. Electronic noses have provided a plethora of benefits to a variety of commercial industries, including the agricultural, biomedical, cosmetics, environmental, food, manufacturing, military, pharmaceutical, regulatory, and various scientific research fields. Advances have improved product attributes, uniformity, and consistency as a result of increases in quality control capabilities afforded by electronic-nose monitoring of all phases of industrial manufacturing processes. This paper is a review of the major electronic-nose technologies, developed since this specialized field was born and became prominent in the mid 1980s, and a summarization of some of the more important and useful applications that have been of greatest benefit to man.

View PDF Chat

786. Studies in adsorption. Part XI. A system of classification of solution adsorption isotherms, and its use in diagnosis of adsorption mechanisms and in measurement of specific surface areas of solids

1960-01-01

C. H. Giles , T. H. MacEwan , S. N. Nakhwa +1 more

C. H. Giles, T. H. MacEwan, S. N. Nakhwa and D. Smith, J. Chem. Soc., 1960, 3973 DOI: 10.1039/JR9600003973 C. H. Giles, T. H. MacEwan, S. N. Nakhwa and D. Smith, J. Chem. Soc., 1960, 3973 DOI: 10.1039/JR9600003973

Electronic Nose: Current Status and Future Trends

2008-01-19

Frank Örner -Rock , Nicolae Bârsan , Udo Weimar

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic Nose: Current Status and Future TrendsFrank Röck, Nicolae Barsan, and Udo WeimarView Author Information Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic Nose: Current Status and Future TrendsFrank Röck, Nicolae Barsan, and Udo WeimarView Author Information Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany Cite this: Chem. Rev. 2008, 108, 2, 705–725Publication Date (Web):January 19, 2008Publication History Received23 August 2007Published online19 January 2008Published inissue 1 February 2008https://pubs.acs.org/doi/10.1021/cr068121qhttps://doi.org/10.1021/cr068121qresearch-articleACS PublicationsCopyright © 2008 American Chemical SocietyRequest reuse permissionsArticle Views27646Altmetric-Citations1134LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Atmospheric chemistry,Chromatography,Gases,Ions,Sensors Get e-Alerts

The colorimetric micro-determination of non-esterified fatty acids in plasma

1964-02-01

W. G. Duncombe

Formulae for Determination of Chlorophyllous Pigments Extracted with <i>N,N</i>-Dimethylformamide

1982-06-01

Rami Moran

The extraction of chlorophylls in higher plant tissue using N,N-dimethylformamide expedites the process and enables the determination of small samples with low pigment level.Absorption spectra of Chl a, Chl b, … The extraction of chlorophylls in higher plant tissue using N,N-dimethylformamide expedites the process and enables the determination of small samples with low pigment level.Absorption spectra of Chl a, Chl b, and Pchl and of their acidified derivatives, the phaeophytins, were recorded. Conversion of Chl b to its corresponding acidified product occurs much more slowly than that of Chl a and Pchl. When acidified, Pchl differs from Chl a and Chl b by the disappearance of the red band in the absorption spectrum. Specific extinction coefficients were determined and formulae for quantitative determination of pigments concentrations were developed. When concentrations of pigments are low, as in etiolated plant material, the absorption spectra of the chlorophylls can be distorted due to the presence of other substances simultaneously extracted; formulae for pigment determination under such circumstances were also derived.

View PDF Chat

Solvent assisted flavour evaporation - a new and versatile technique for the careful and direct isolation of aroma compounds from complex food matrices

1999-08-03

Wolfgang Engel , Wolfgang Bahr , Peter Schieberle

A modified ninhydrin colorimetric analysis for amino acids

1957-03-01

Hyman Rosen

Cross-Reactive Chemical Sensor Arrays

2000-06-24

Keith J. Albert , Nathan S. Lewis , Caroline L. Schauer +4 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCross-Reactive Chemical Sensor ArraysKeith J. Albert, Nathan S. Lewis, Caroline L. Schauer, Gregory A. Sotzing, Shannon E. Stitzel, Thomas P. Vaid, and David R. WaltView Author Information … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCross-Reactive Chemical Sensor ArraysKeith J. Albert, Nathan S. Lewis, Caroline L. Schauer, Gregory A. Sotzing, Shannon E. Stitzel, Thomas P. Vaid, and David R. WaltView Author Information The Max Tishler Laboratory for Organic Chemistry, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 Cite this: Chem. Rev. 2000, 100, 7, 2595–2626Publication Date (Web):June 24, 2000Publication History Received17 August 1999Published online24 June 2000Published inissue 1 July 2000https://doi.org/10.1021/cr980102wCopyright © 2000 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views8788Altmetric-Citations1031LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (729 KB) Get e-AlertsSUBJECTS:Electrodes,Elements,Mixtures,Polymers,Sensors Get e-Alerts

Colorimetric Determination of Hydrogen Peroxide

1943-05-18

George M. Eisenberg

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTColorimetric Determination of Hydrogen PeroxideGeorge EisenbergCite this: Ind. Eng. Chem. Anal. Ed. 1943, 15, 5, 327–328Publication Date (Print):May 18, 1943Publication History Published online1 May 2002Published inissue 18 … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTColorimetric Determination of Hydrogen PeroxideGeorge EisenbergCite this: Ind. Eng. Chem. Anal. Ed. 1943, 15, 5, 327–328Publication Date (Print):May 18, 1943Publication History Published online1 May 2002Published inissue 18 May 1943https://doi.org/10.1021/i560117a011RIGHTS & PERMISSIONSArticle Views8733Altmetric-Citations821LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (228 KB) Get e-Alerts

A review of the volatiles from the healthy human body

2014-01-13

Ben de Lacy Costello , A Amann , Huda Al-Kateb +5 more

A compendium of all the volatile organic compounds (VOCs) emanating from the human body (the volatolome) is for the first time reported. 1840 VOCs have been assigned from breath (872), … A compendium of all the volatile organic compounds (VOCs) emanating from the human body (the volatolome) is for the first time reported. 1840 VOCs have been assigned from breath (872), saliva (359), blood (154), milk (256), skin secretions (532) urine (279), and faeces (381) in apparently healthy individuals. Compounds were assigned CAS registry numbers and named according to a common convention where possible. The compounds have been grouped into tables according to their chemical class or functionality to permit easy comparison. Some clear differences are observed, for instance, a lack of esters in urine with a high number in faeces. Careful use of the database is needed. The numbers may not be a true reflection of the actual VOCs present from each bodily excretion. The lack of a compound could be due to the techniques used or reflect the intensity of effort e.g. there are few publications on VOCs from blood compared to a large number on VOCs in breath. The large number of volatiles reported from skin is partly due to the methodologies used, e.g. collecting excretions on glass beads and then heating to desorb VOCs. All compounds have been included as reported (unless there was a clear discrepancy between name and chemical structure), but there may be some mistaken assignations arising from the original publications, particularly for isomers. It is the authors' intention that this database will not only be a useful database of VOCs listed in the literature, but will stimulate further study of VOCs from healthy individuals. Establishing a list of volatiles emanating from healthy individuals and increased understanding of VOC metabolic pathways is an important step for differentiating between diseases using VOCs.

Diagnosing lung cancer in exhaled breath using gold nanoparticles

2009-08-30

Gang Peng , Ulrike Tisch , Orna Adams +7 more

Junctional intercellular communication: the cell-to-cell membrane channel.

1981-10-01

W. R. Loewenstein

INDOCYANINE GREEN: OBSERVATIONS ON ITS PHYSICAL PROPERTIES, PLASMA DECAY, AND HEPATIC EXTRACTION*

1960-04-01

Gilbert R. Cherrick , Samuel W. Stein , Carroll M. Leevy +1 more

Indocyanine green 1 (ICG) is a tricarbocyanine dye (Figure 1) which has been used in the indi- cator dilution technique for measuring cardiac output (1, 2).Animal studies (3) and prelimi- … Indocyanine green 1 (ICG) is a tricarbocyanine dye (Figure 1) which has been used in the indi- cator dilution technique for measuring cardiac output (1, 2).Animal studies (3) and prelimi- nary observations of human subjects (4, 5) have suggested that this dye may have characteristics that could make its uptake, storage, and excretion by the liver helpful indices of hepatic function.The present investigations were carried out to determine whether indocyanine green has proper- ties that may render it suitable for assessing liver function and hepatic blood flow in man.METHODS AND PROCEDURES Physical properties.Indocyanine green was prepared for intravenous administration by dissolving the dye in distilled water to a concentration of 5 mg per ml.Read- ings of dye concentration were made in a Beckman DU spectrophotometer at 815 m/1.Volume of distribution of radioiodinated human serum albumin 2 was compared with the initial volume of dis- tribution of ICG in 4 normal subjects.Each subject was given approximately 20 /Ac of the I3"-labeled albumin and 50 mg of ICG in a rapid intravenous injection.Ve- nous

View PDF Chat

Volatile organic compounds in breath as markers of lung cancer: a cross-sectional study

1999-06-01

Michael Phillips , Kevin Gleeson , J. M. B. Hughes +4 more

Ammonia sensors and their applications—a review

2005-03-17

B. Timmer , Wouter Olthuis , Albert van den Berg

View PDF Chat

Complex Ions. I. The Identification of Complex Ions in Solution by Spectrophotometric Measurements

1941-02-01

W. C. Vosburgh , Gerald R. Cooper

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComplex Ions. I. The Identification of Complex Ions in Solution by Spectrophotometric MeasurementsWarren C. Vosburgh and Gerald R. CooperCite this: J. Am. Chem. Soc. 1941, 63, 2, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComplex Ions. I. The Identification of Complex Ions in Solution by Spectrophotometric MeasurementsWarren C. Vosburgh and Gerald R. CooperCite this: J. Am. Chem. Soc. 1941, 63, 2, 437–442Publication Date (Print):February 1, 1941Publication History Published online1 May 2002Published inissue 1 February 1941https://pubs.acs.org/doi/10.1021/ja01847a025https://doi.org/10.1021/ja01847a025research-articleACS PublicationsRequest reuse permissionsArticle Views3651Altmetric-Citations755LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Standard Methods for the Examination of Water and Wastewater

1982-01-01

S.H. Jenkins

Humus Chemistry—Genesis, Composition, Reactions

1983-02-01

J. W. Parsons

A new tool for the evaluation of the analytical procedure: Green Analytical Procedure Index

2018-01-06

Justyna Płotka‐Wasylka

The Optoelectronic Nose: Colorimetric and Fluorometric Sensor Arrays

2018-09-12

Zheng Li , Jon R. Askim , Kenneth S. Suslick

A comprehensive review on the development and state of the art of colorimetric and fluorometric sensor arrays is presented. Chemical sensing aims to detect subtle changes in the chemical environment … A comprehensive review on the development and state of the art of colorimetric and fluorometric sensor arrays is presented. Chemical sensing aims to detect subtle changes in the chemical environment by transforming relevant chemical or physical properties of molecular or ionic species (i.e., analytes) into an analytically useful output. Optical arrays based on chemoresponsive colorants (dyes and nanoporous pigments) probe the chemical reactivity of analytes, rather than their physical properties (e.g., mass). The chemical specificity of the olfactory system does not come from specific receptors for specific analytes (e.g., the traditional lock-and-key model of substrate-enzyme interactions), but rather olfaction makes use of pattern recognition of the combined response of several hundred olfactory receptors. In a similar fashion, arrays of chemoresponsive colorants provide high-dimensional data from the color or fluorescence changes of the dyes in these arrays as they are exposed to analytes. This provides chemical sensing with high sensitivity (often down to parts per billion levels), impressive discrimination among very similar analytes, and exquisite fingerprinting of extremely similar mixtures over a wide range of analyte types, in both the gas and liquid phases. Design of both sensor arrays and instrumentation for their analysis are discussed. In addition, the various chemometric and statistical analyses of high-dimensional data (including hierarchical cluster analysis (HCA), principal component analysis (PCA), linear discriminant analysis (LDA), support vector machines (SVMs), and artificial neural networks (ANNs)) are presented and critiqued in reference to their use in chemical sensing. A variety of applications are also discussed, including personal dosimetry of toxic industrial chemical, detection of explosives or accelerants, quality control of foods and beverages, biosensing intracellularly, identification of bacteria and fungi, and detection of cancer and disease biomarkers.

Carbon Nanotube Chemical Sensors

2018-09-18

Vera Schroeder , Suchol Savagatrup , Maggie He +2 more

Carbon nanotubes (CNTs) promise to advance a number of real-world technologies. Of these applications, they are particularly attractive for uses in chemical sensors for environmental and health monitoring. However, chemical … Carbon nanotubes (CNTs) promise to advance a number of real-world technologies. Of these applications, they are particularly attractive for uses in chemical sensors for environmental and health monitoring. However, chemical sensors based on CNTs are often lacking in selectivity, and the elucidation of their sensing mechanisms remains challenging. This review is a comprehensive description of the parameters that give rise to the sensing capabilities of CNT-based sensors and the application of CNT-based devices in chemical sensing. This review begins with the discussion of the sensing mechanisms in CNT-based devices, the chemical methods of CNT functionalization, architectures of sensors, performance parameters, and theoretical models used to describe CNT sensors. It then discusses the expansive applications of CNT-based sensors to multiple areas including environmental monitoring, food and agriculture applications, biological sensors, and national security. The discussion of each analyte focuses on the strategies used to impart selectivity and the molecular interactions between the selector and the analyte. Finally, the review concludes with a brief outlook over future developments in the field of chemical sensors and their prospects for commercialization.

View PDF Chat

Fenaroli's Handbook of Flavor Ingredients

2004-12-03

George A. Burdock

Updated to reflect the latest data, Fenaroli's Handbook of Flavor Ingredients, Fifth Edition is the newest edition of an industry standard. It features more than 100 newly designated GRAS substances, … Updated to reflect the latest data, Fenaroli's Handbook of Flavor Ingredients, Fifth Edition is the newest edition of an industry standard. It features more than 100 newly designated GRAS substances, expanded information on aroma and taste thresholds, and the most current regulatory information. It includes synonyms, international codes, sen

Object oriented design with applications

1992-09-01

D. C. Ince

ATS/ERS Recommendations for Standardized Procedures for the Online and Offline Measurement of Exhaled Lower Respiratory Nitric Oxide and Nasal Nitric Oxide, 2005

2005-04-07

Sensory Evaluation Techniques

2020-04-15

Morten Meilgaard , Gail Vance Civille , B. Thomas Gillies

Sensory Evaluation Techniques

1999-06-24

Morten Meilgaard , B. Thomas Carr , Gail Vance Civille

Qualitative Analysis of Flavor and Fragrance Volatiles by Glass Capillary Gas Chromatography

1980-01-01

WALTER JENNINGS , Takayuki Shibamoto

Volatile Compounds in Foods and Beverages

2017-11-22

Henk Maarse

Collects the information available in the literature on volatile compounds in foods and beverages. This information is given in 17 chapters, each dealing with a specific product or product group. … Collects the information available in the literature on volatile compounds in foods and beverages. This information is given in 17 chapters, each dealing with a specific product or product group. Only compounds that are major constituents and/or contribute significantly to the flavor of the relevant

[42] Determination of aldehydic lipid peroxidation products: Malonaldehyde and 4-hydroxynonenal

1990-01-01

Hermann Esterbauer , Kevin H. Cheeseman

3,4-Diaminobenzophenone as an Effective Reactive MALDI Matrix for Simple and Sensitive Detection of α-Ketoacid Compounds

2025-06-25

Mengzhen Wang , Ling Ling , Jie Wen +2 more | Analytical Chemistry

Determination of α-ketoacids is very important for disease diagnosis as well as for quality control of food and pharmaceuticals. In order to determine α-ketoacids by a simple, rapid, and simultaneous … Determination of α-ketoacids is very important for disease diagnosis as well as for quality control of food and pharmaceuticals. In order to determine α-ketoacids by a simple, rapid, and simultaneous method in complex samples, a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method has been reported herein through the development of an efficient reactive matrix. In this method, a MALDI matrix, 3,4-diaminobenzophenone (DABP), is first used to generate imidazole derivatives through its rapid reaction with α-ketoacids, which enables simple, rapid, sensitive, and selective detection of α-ketoacids by MALDI-TOF MS. The ionization efficiency of α-ketoacids is significantly improved by the use of DABP as the reactive matrix, as compared with the common alkaline matrices, such as 1,5-diaminonaphthalene and 9-aminoacridine. After optimization, the proposed method shows a lower limit of detection (0.8 μM for α-ketoglutaric acid; 0.45 μM for pyruvic acid), good linearity (R2 > 0.999), high accuracy (95.1-102.9%), and acceptable reproducibility (RSD: 0.8-4.9%). Owing to the above advantages, this method can be successfully used for the determination of α-ketoacids in real samples, including α-KG-supplemented capsules, onions, and beer, thereby demonstrating its potential for routine determination of α-ketoacids in complex samples.

Hyperspectral Imaging Technology Empowering Dynamic Monitoring of VOCs: A Breakthrough High-Spatial-Temporal Resolution Detection Method

2025-06-25

Yikai Li , Chengzhi Xing , Jian Chen +4 more | Analytical Chemistry

Volatile organic compounds (VOCs) and their secondary pollutants pose significant risks to both the environment and human health. In response to air pollution control policies, the emissions of conventional pollutants, … Volatile organic compounds (VOCs) and their secondary pollutants pose significant risks to both the environment and human health. In response to air pollution control policies, the emissions of conventional pollutants, such as NO2 and SO2, have been preliminarily controlled. As a result, the reduction of VOC emissions has become a key measure for further improving air quality. Industrial activities are the primary anthropogenic source of VOCs, highlighting the urgent need for effective methods to detect VOC plume concentrations and monitor their dispersion and transport. This study proposes a hyperspectral rapid imaging system (HRIS), which achieves innovative advancements in noise removal, signal enhancement, and chromatic aberration correction. These breakthroughs enable, for the first time, high spatiotemporal resolution and synchronous observation of multiple VOC components, with final imaging results available within minutes. In two experimental setups, the system successfully measured the concentrations and emission fluxes of formaldehyde (HCHO), nitrobenzene (C6H5NO2), benzoic acid (CH3C6H3O2), nitrogen dioxide (NO2), and sulfur dioxide (SO2), with the highest emission flux recorded at 0.45 ± 0.13 kg/h. The application of HRIS facilitates the development of dynamic VOC emission inventories, providing critical data to support the design of future emission reduction strategies.

Soft sensor modeling method for Pichia pastoris fermentation process based on domain adaptation ensemble LSTM

2025-06-25

Bo Wang , Jun Wei , Yongxian Song +1 more | Alexandria Engineering Journal

Engineering Advancements in Taste Detection

2025-06-24

Rifna Elenjikkal Jerome | CRC Press eBooks

Advantages and Disadvantages of Conventional and Objective-Based Sensory Techniques

2025-06-24

Sahar Akhavan‐Mahdavi , Hadiseh Bagheri | CRC Press eBooks

Burned Area Detection in the Eastern Canadian Boreal Forest Using a Multi-Layer Perceptron and MODIS-Derived Features

2025-06-24

Hadi Mahmoudi Meimand , Jiaxin Chen , Daniel Kneeshaw +2 more | Remote Sensing

Wildfires play a critical role in boreal forest ecosystems, yet their increasing frequency poses significant challenges for carbon emissions, ecosystem stability, and fire management. Accurate burned area detection is essential … Wildfires play a critical role in boreal forest ecosystems, yet their increasing frequency poses significant challenges for carbon emissions, ecosystem stability, and fire management. Accurate burned area detection is essential for assessing post-fire landscape recovery and fire-induced carbon fluxes. This study develops, compares, and optimizes machine learning (ML)-based models for burned area classification in the eastern Canadian boreal forest from 2000 to 2023 using MODIS-derived features extracted from Google Earth Engine (GEE), and the feature extraction includes maximum, minimum, mean, and median values per feature to enhance spectral representation and reduce noise. The dataset was randomly split into training (70%), validation (15%), and testing (15%) sets for model development and assessment. Combined labels were used due to class imbalance, and the model performance was assessed using kappa and the F1-score. Among the ML techniques tested, deep learning (DL) with a Multi-Layer Perceptron (MLP) outperformed Support Vector Machines (SVMs) and Random Forest (RF) by demonstrating superior classification accuracy in detecting burned area. It achieved an F1-score of 0.89 for burned pixels, confirming its potential for improving the long-term wildfire monitoring and management in boreal forests. Despite the computational demands of processing large-scale remote sensing data at 250 m resolution, the MLP modeling approach that we used provides an efficient, effective, and scalable solution for long-term burned area detection. These findings underscore the importance of tuning both network architecture and regularization parameters to improve the classification of burned pixels, enhancing the model robustness and generalizability.

Adaptive Machine Learning for Electronic Nose‐Based Forensic VOC Classification

2025-06-24

Ivan Shtepliuk , Kerstin Montelius , Jens Eriksson +1 more | Advanced Science

Odor detection as forensic evidence is an emerging and transformative approach for identifying individuals in cases where conventional techniques- such as DNA profiling, fingerprints, or gas chromatography-mass spectroscopy- are insufficient. … Odor detection as forensic evidence is an emerging and transformative approach for identifying individuals in cases where conventional techniques- such as DNA profiling, fingerprints, or gas chromatography-mass spectroscopy- are insufficient. Key challenges include distinguishing between living and deceased individuals, differentiating human from animal remains, and estimating postmortem intervals. While specially trained dogs remain the gold standard in some contexts, there is growing demand for faster, scalable, and cost-effective alternatives. Here, a bio-inspired electronic nose comprising 32 metal-oxide sensors, integrated with machine learning, is presented as a non-invasive, real-time, and reliable tool for volatile organic compound profiling. The system accurately classifies postmortem versus antemortem human biosamples (98.1%), discriminates human from animal tissue (97.2%), and estimates postmortem intervals with high temporal resolution. This study introduces a robust AI-driven olfactory platform for forensic scent detection, highlighting its potential to complement or replace traditional methods. By coupling volatilome analysis with sensor miniaturization and algorithmic refinement, this approach lays the groundwork for next-generation forensic diagnostics and odor-based biomarker discovery.

A chemiresistive MEMS acetone gas sensor based on p-Rh<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si39.svg" display="inline" id="d1e672"><mml:msub><mml:mrow/><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math>O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si40.svg" display="inline" id="d1e680"><mml:msub><mml:mrow/><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:math>-n-WO<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="…

2025-06-24

Yucai Zhang , Peisi Yin , Fei Song +7 more | Sensors and Actuators B Chemical

Science of Objective-Based Sensory Techniques and Their Adaptation in the Food Industry

2025-06-24

V. Chandrasekar , Eyarkai Nambi Vijayaram , Jaganmohan Rengarajan | CRC Press eBooks

Engineering Advancements in Aroma Detection

2025-06-24

Nirmal Thirunavookarasu | CRC Press eBooks

A Hydrophobic Ratiometric Fluorescent Indicator Film Using Electrospinning for Visual Monitoring of Meat Freshness

2025-06-23

Xiaodong Zhai , Xingdan Ma , Yue Sun +7 more | Foods

A ratiometric fluorescent film with high gas sensitivity and stability was developed using electrospinning technology for monitoring food spoilage. 5(6)-Carboxyfluorescein (5(6)-FAM) was used as the indicator, combined with the internal … A ratiometric fluorescent film with high gas sensitivity and stability was developed using electrospinning technology for monitoring food spoilage. 5(6)-Carboxyfluorescein (5(6)-FAM) was used as the indicator, combined with the internal reference Rhodamine B (RHB), to establish a composite ratiometric fluorescent probe (FAM@RHB). The hydrophobic fluorescent films were fabricated by incorporating FAM@RHB probes into polyvinylidene fluoride (PVDF) at varying molar ratios through electrospinning. The FR-2 film with a 2:8 ratio of 5(6)-FAM to RHB exhibited the best performance, demonstrating excellent hydrophobicity with a water contact angle (WCA) of 113.45° and good color stability, with a ΔE value of 2.05 after 14 days of storage at 4 °C. Gas sensitivity tests indicated that FR-2 exhibited a limit of detection (LOD) of 0.54 μM for trimethylamine (TMA). In the application of monitoring the freshness of pork and beef at 4 °C, the fluorescence color of the FR-2 film significantly changed from orange–yellow to green, enabling the visual monitoring of meat freshness. Hence, this study provides a new approach for intelligent food packaging.

What Are Our Food/Water Isotherms Really Telling Us? A New Way to Look at Old Data

2025-06-23

Steven Abbott , Kaja Harton , Nobuyuki Matubayasi +1 more | Royal Society of Chemistry eBooks

It is standard practice in the food industry to measure moisture isotherm data to both predict empirical values via fitting functions and use the fitting parameters to extract molecular insight … It is standard practice in the food industry to measure moisture isotherm data to both predict empirical values via fitting functions and use the fitting parameters to extract molecular insight into sorption mechanisms. This task is complicated by the existence of competing models that are based on different assumptions. But it is worse than that; the most common models, GAB and BET, are based on overly simplistic assumptions that are paradoxical when applied to food. Here we show that the ABC isotherm, founded on the statistical thermodynamic fluctuation theory, allows us to understand molecular interactions that underlie sorption in foods from isotherm data. Because we can convert GAB and BET parameters directly into ABC (other popular schemas require a bit more effort), it is possible to re-analyse the historical data. Using analyses that are both visual (curves representing underlying interactions) and numerical (universal ABC parameters), we can compare and contrast interactions at the molecular level. The method is easy to implement standalone, or via a free, web-based app.

Water Hardness from Photos of Dried Drop Stains: Reporter Salts Enable Low-Concentration Detection

2025-06-23

S Amrutha , Bruno C. Batista , Beni B. Dangi +1 more | Environmental Science & Technology

Water hardness is critical in domestic and industrial systems, typically measured by titration, atomic absorption spectroscopy, or inductively coupled plasma mass spectrometry. Here, we present a novel, photo-based method for … Water hardness is critical in domestic and industrial systems, typically measured by titration, atomic absorption spectroscopy, or inductively coupled plasma mass spectrometry. Here, we present a novel, photo-based method for quantifying water hardness using deposit patterns formed during the evaporation of hard water mixed with highly concentrated solutions of the reporter salts NaHCO3 and NaCl. This indirect approach enables the detection of hardness levels as low as 25 ppm, an improvement by a factor of 1,400 over earlier stain-based studies. Our method leverages high-resolution imaging, automated sample preparation, and advanced image analysis, including machine learning, to detect subtle morphological changes in the deposit patterns. A robotic drop imager (RODI) generated over 16,000 images, from which 47 geometric and textural metrics were extracted to train high-dimensional linear regression models and multilayer perceptron (MLP) networks. Using synthetic water samples with hardness levels of up to 250 ppm, we achieved prediction accuracies exceeding 91% for sodium bicarbonate-based patterns. Extending this methodology, we validated the methodology on real-world tap water, demonstrating its potential as a cost-effective alternative to traditional techniques and a versatile tool for water quality monitoring.

Optical fiber-tip sensor for detection of carvone and limonene ratio in liquid binary mixture

2025-06-23

Ivan Martinček , Daniel Káčik | Sensors and Actuators A Physical

Detection of Exhaled Volatile Organic Compounds as Noninvasive Biomarkers for Pancreatic Adenocarcinoma

2025-06-23

Kyle R Stephens , Walter R F Donica , Prejesh Philips +7 more | Annals of Surgical Oncology

Self‐Powered Multi‐Functional Sensor System Based on Pomegranate‐Inspired Composites for Advanced Cardiovascular Disease Prediction and Diagnosis Within an Integrated Traditional Chinese and Western Medicine Framework

2025-06-23

Youwei Zhao , Qingzheng Jia , Yuxuan Zhang +4 more | Advanced Functional Materials

Abstract Wearable medical devices are gaining significant attention for their potential in intelligent health monitoring, particularly in response to the needs of an aging global population. However, conventional systems often … Abstract Wearable medical devices are gaining significant attention for their potential in intelligent health monitoring, particularly in response to the needs of an aging global population. However, conventional systems often suffer from limitations in power supply, mechanical adaptability, and real‐time diagnostic capabilities. In this work, a flexible, self‐powered intelligent sensing system is reported, based on a carbon cloth substrate modified with a pomegranate‐inspired Polyaniline‐Prussian blue (CC@PANI‐PB) composite. This multifunctional composite simultaneously serves as a high‐performance cathode material for lithium‐oxygen (Li‐O₂) batteries and as an active sensing layer for pressure and ECG signal acquisition. The unique microstructured morphology and optimized interfacial interactions enable both high energy output and ultrasensitive tactile sensing. The resulting sensor exhibits a wide detection range (30–100 000 Pa), exceptional mechanical durability (over 9000 cycles), and ultrahigh sensitivity (S max = 4.16 × 10⁷ kPa⁻¹). Integrated with a Li‐O₂ energy unit and signal processing module, the system enables continuous pulse signal acquisition and ECG classification, achieving a disease prediction accuracy of 95.90% and ECG classification accuracy of 93.75%. This integrated platform demonstrates strong potential for next‐generation wearable healthcare systems, combining real‐time sensing, energy autonomy, and intelligent diagnosis within a unified framework.

Correction to “A Comprehensive Review of VOCs as a Key Indicator in Food Authentication”

2025-06-23

| eFood

YOLOv8m for Automated Pepper Variety Identification: Improving Accuracy with Data Augmentation

2025-06-22

M. Barbosa , Fernanda Aguiar , Suely dos Santos Sousa +3 more | Applied Sciences

This research addresses the critical need for an efficient and precise identification of Capsicum spp. fruit varieties within the post-harvest contexts to enhance quality control and ensure consumer satisfaction. Employing … This research addresses the critical need for an efficient and precise identification of Capsicum spp. fruit varieties within the post-harvest contexts to enhance quality control and ensure consumer satisfaction. Employing the YOLOv8m convolutional neural network, the study identified eight distinct pepper varieties: Pimento, Bode, Cambuci, Chilli, Fidalga, Habanero, Jalapeno, and Scotch Bonnet. A dataset comprising 1476 annotated images was utilized and significantly expanded through data augmentation techniques, including rotation, flipping, and contrast adjustments. Comparative analysis reveals that training with the augmented dataset yielded significant improvements across key performance indicators, particularly in box precision, recall, and mean average precision (mAP50 and mAP95), underscoring the effectiveness of data augmentation. These findings underscore the considerable potential of CNNs to advance the AgriFood sector through increased automation and efficiency. While acknowledging the constraints of a controlled image dataset, subsequent research should prioritize expanding the dataset and conducting real-world testing to confirm the model’s robustness across various environmental factors. This study contributes to the field by illustrating the application of deep learning methodologies to enhance agricultural productivity and inform decision-making.

IR-Bot: an autonomous robotic system for real-time chemical mixture analysis via infrared spectroscopy and machine learning

2025-06-22

Xiaoyu Yue , Tao Song , Jiaqi Cao +5 more | CCS Chemistry

Application of the Spectroelectrochemistry of the Resazurin/Resorufin System to the Determination of Milk Quality

2025-06-22

Achim Habekost | World journal of chemical education

Influence of Cooking Methods on Flavor Parameters and Sensory Quality of Tibetan Sheep Meat Examined Using an Electronic Nose, an Electronic Tongue, GC–IMS, and GC–MS

2025-06-22

Shengfang Ge , Lijuan Han , Shengzhen Hou +6 more | Foods

To explore the influence of cooking methods on the flavor parameters of Tibetan sheep, various techniques such as atmospheric-pressure (AP), high-pressure (HP), atmospheric-pressure high-pressure (APHP), and high-pressure atmospheric-pressure (HPAP) cooking … To explore the influence of cooking methods on the flavor parameters of Tibetan sheep, various techniques such as atmospheric-pressure (AP), high-pressure (HP), atmospheric-pressure high-pressure (APHP), and high-pressure atmospheric-pressure (HPAP) cooking were tested. The results indicated that APHP and HP cooking yielded the best sensory qualities, accounting for 26.15% and 25.51%, respectively. The HP group had the highest amino acid content at 34%, enhancing the meat’s sweet taste due to alanine, glycine, arginine, and methionine. Among 40 detected fatty acids, the order of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), and n-6/n-3 content was AP > APHP > HPAP > HP (p < 0.05). An electronic tongue and nose identified aroma components across the four cooking methods. Similarities in aroma were observed among the samples after cooking, while significant differences were found in the aroma components between the AP group and the other three cooking methods (p < 0.05). The gas chromatography–ion mobility spectrometry (GC–IMS) and gas chromatography–mass spectrometry (GC–MS) analyses of the meat in the four groups indicated that there were significant differences in volatile compounds among meat cooked with different methods (p < 0.05), with 56 and 365 flavor compounds detected by the two analytical techniques, respectively. Moreover, the GC–MS results indicated that the flavor substance content in the HP group accounted for 30.80% among these four sample groups. This comprehensive analysis showed that high-pressure steaming could significantly improve the flavor quality of Tibetan sheep, providing a theoretical basis and empirical reference for the optimization of pre-treatment conditions and the processing of Tibetan sheep.

Proposed SmartBarrel System for Monitoring and Assessment of Wine Fermentation Processes Using IoT Nose and Tongue Devices

2025-06-21

Sotirios Kontogiannis , M. Tsoumani , George Kokkonis +2 more | Sensors

This paper introduces SmartBarrel, an innovative IoT-based sensory system that monitors and forecasts wine fermentation processes. At the core of SmartBarrel are two compact, attachable devices—the probing nose (E-nose) and … This paper introduces SmartBarrel, an innovative IoT-based sensory system that monitors and forecasts wine fermentation processes. At the core of SmartBarrel are two compact, attachable devices—the probing nose (E-nose) and the probing tongue (E-tongue), which mount directly onto stainless steel wine tanks. These devices periodically measure key fermentation parameters: the nose monitors gas emissions, while the tongue captures acidity, residual sugar, and color changes. Both utilize low-cost, low-power sensors validated through small-scale fermentation experiments. Beyond the sensory hardware, SmartBarrel includes a robust cloud infrastructure built on open-source Industry 4.0 tools. The system leverages the ThingsBoard platform, supported by a NoSQL Cassandra database, to provide real-time data storage, visualization, and mobile application access. The system also supports adaptive breakpoint alerts and real-time adjustment to the nonlinear dynamics of wine fermentation. The authors developed a novel deep learning model called V-LSTM (Variable-length Long Short-Term Memory) to introduce intelligence to enable predictive analytics. This auto-calibrating architecture supports variable layer depths and cell configurations, enabling accurate forecasting of fermentation metrics. Moreover, the system includes two fuzzy logic modules: a device-level fuzzy controller to estimate alcohol content based on sensor data and a fuzzy encoder that synthetically generates fermentation profiles using a limited set of experimental curves. SmartBarrel experimental results validate the SmartBarrel’s ability to monitor fermentation parameters. Additionally, the implemented models show that the V-LSTM model outperforms existing neural network classifiers and regression models, reducing RMSE loss by at least 45%. Furthermore, the fuzzy alcohol predictor achieved a coefficient of determination (R2) of 0.87, enabling reliable alcohol content estimation without direct alcohol sensing.

Actuator-Driven, Purge-Free Formaldehyde Gas Sensor Based on Single-Walled Carbon Nanotubes

2025-06-21

Shinsuke Ishihara , Mandeep K. Chahal , Jan Labuta +4 more | Nanomaterials

Formaldehyde vapor (HCHO) is a harmful chemical substance and a potential air contaminant, with a permissible level in indoor spaces below 0.08 ppm (80 ppb). Thus, highly sensitive gas sensors … Formaldehyde vapor (HCHO) is a harmful chemical substance and a potential air contaminant, with a permissible level in indoor spaces below 0.08 ppm (80 ppb). Thus, highly sensitive gas sensors for the continuous monitoring of HCHO are in demand. The electrical conductivity of semiconducting nanomaterials (e.g., single-walled carbon nanotubes (SWCNTs)) makes them sensitive to chemical substances adsorbed on their surfaces, and a variety of portable and highly sensitive chemiresistive gas sensors, including those capable of detecting HCHO, have been developed. However, when monitoring low levels of vapors (<1 ppm) found in ambient air, most chemiresistive sensors face practical issues, including false responses to interfering effects (e.g., fluctuations in room temperature and humidity), baseline drift, and the need to apply a purge gas. Here, we report an actuator-driven, purge-free chemiresistive gas sensor that is capable of reliably detecting 0.05 ppm of HCHO in the air. This sensor is composed of an HCHO→HCl converter (powdery hydroxylamine salt, HA), an HCl detector (a SWCNT-based chemiresistor), and an HCl blocker (a thin plastic plate). Upon exposure to HCHO, the HA emits HCl vapor, which diffuses onto the adjacent SWCNTs, increasing their electrical conductivity through p-doping. Meanwhile, inserting a plastic plate between HA and SWCNTs makes the conductivity of SWCNTs insensitive to HCHO. Thus, via periodic actuation (insertion and removal) of the plastic plate, HCHO can be detected reliably over a wide concentration range (0.05–15 ppm) with excellent selectivity over other volatile organic compounds. This actuator-driven system is beneficial because it does not require a purge gas for sensor recovery or baseline correction. Moreover, since the response to HCHO is synchronized with the actuation timing of the plate, even small (~0.8%) responses to 0.05 ppm of HCHO can be clearly separated from larger noise responses (>1%) caused by interfering effects and baseline drift. We believe that this work provides substantial insights into the practical implementation of nanomaterial-based chemiresistive gas sensors.

Identification of Polymeric Nanoparticles Using Strategic Peptide Sensor Configurations and Machine Learning

2025-06-21

Shion Hasegawa , Toshiki Sawada , Yuzo Kitazawa +3 more | ACS Sensors

Environmental pollution by miniaturized plastics such as micro- and nanoplastics continues to escalate, posing serious risks to ecosystems and human health. Therefore, there is an urgent need to detect or … Environmental pollution by miniaturized plastics such as micro- and nanoplastics continues to escalate, posing serious risks to ecosystems and human health. Therefore, there is an urgent need to detect or identify the plastics. Although the techniques for microplastics have been advanced, those for nanoplastics remain challenging owing to the difficulty of sample collection and sensing reliability. In this study, the identification of polymeric nanoparticles dispersed in water was demonstrated using peptide sensors with a microenvironment-sensitive fluorophore. The fluorescence spectra obtained from peptide sensors were different depending on the polymer species of polymeric nanoparticles. Supervised and unsupervised machine learning on the signal patterns of fluorescence intensities obtained from the spectra successfully identified polymeric nanoparticles with slightly different chemical structures. Systematic evaluation revealed the critical role of both the number and combination of peptide sensors in achieving the precise identification of polymeric nanoparticles. Our approach offers new and foundational insights into the forthcoming identification of nanoplastics dispersed in water.

Introduction

2025-06-20

| Royal Society of Chemistry eBooks

This chapter introduces selected ion flow tube mass spectrometry (SIFT-MS) and describes how it complements established chromatographic techniques for volatile organic compound (VOC) analysis. It outlines the scope of application … This chapter introduces selected ion flow tube mass spectrometry (SIFT-MS) and describes how it complements established chromatographic techniques for volatile organic compound (VOC) analysis. It outlines the scope of application of the technique in terms of matrices, analytes, and sample formats, before summarising the contents of the rest of the book – both in terms of principles and procedures.

Method Development – Phase I (Procedure 3)

2025-06-20

| Royal Society of Chemistry eBooks

The first part of this book introduced the SIFT-MS technique and highlighted the different analytical approach compared with the conventional GC and LC techniques. Following the in-principle assessment of method … The first part of this book introduced the SIFT-MS technique and highlighted the different analytical approach compared with the conventional GC and LC techniques. Following the in-principle assessment of method suitability for SIFT-MS in Procedure 1 (Chapter 6), this chapter presents a generic procedure for the first phase of headspace-SIFT-MS method development. This phase covers exploratory full-scan analysis of the matrix, development and initial testing of the targeted method, data acquisition, data evaluation, and decision-making on the suitability of results (i.e., are they fit for purpose?). Many concepts are relevant more broadly than routine analysis.

Method Development – Phase II (Procedure 4)

2025-06-20

| Royal Society of Chemistry eBooks

Following on from a successful first phase of method development (Procedure 3, Chapter 8), in which specificity and sensitivity were the focus, this chapter provides guidance for decision making in … Following on from a successful first phase of method development (Procedure 3, Chapter 8), in which specificity and sensitivity were the focus, this chapter provides guidance for decision making in quantitation, robustness testing, and development of a method-specific system suitability test. Quantitation is discussed in three parts – defining the requirements, calibration, and use of calculations (e.g., to overcome interference). Although routine headspace analysis is the primary application to which the chapter is addressed, the principles have broad utility in SIFT-MS method development.

Method Validation and Documentation (Procedure 5)

2025-06-20

| Royal Society of Chemistry eBooks

As a chromatography-free analytical technique, selected ion flow tube mass spectrometry (SIFT-MS) speciates and quantifies volatile compounds in the gas phase using a very different approach to traditional laboratory techniques. … As a chromatography-free analytical technique, selected ion flow tube mass spectrometry (SIFT-MS) speciates and quantifies volatile compounds in the gas phase using a very different approach to traditional laboratory techniques. Nevertheless, as described in this chapter, guidelines for analytical method validation, such as ICH Q2(R1), are readily adapted to both automated headspace-SIFT-MS analysis and less conventional SIFT-MS approaches. Additionally, recommendations are made for documentation of SIFT-MS methods for quality systems and routine use.

Sample Preparation and Delivery

2025-06-20

| Royal Society of Chemistry eBooks

As a direct-analysis technique, SIFT-MS has differing sample preparation and sample delivery requirements to GC, the most widely used technique for analysing volatile compounds. This chapter summarises the general principles … As a direct-analysis technique, SIFT-MS has differing sample preparation and sample delivery requirements to GC, the most widely used technique for analysing volatile compounds. This chapter summarises the general principles of effective sample delivery to SIFT-MS instruments, with reference to the GC methods. Then it describes all common sample introduction approaches utilised with SIFT-MS. Since sampling approaches generally parallel those used with the established chromatographic techniques, the focus is on sample preparation and sample delivery.

The facile discriminative detection of four synthetic antioxidants in edible oil by a multi-signal sensor array based on the Bop-Cu nanozyme combining machine learning

2025-06-20

Xinyue Zhang , Linxue Zhen , Zhichun Bi +4 more | Food Research International

First measurements of the methane concentration and its carbon stable isotope composition in the breath of Costa Ricans

2025-06-20

Germain Esquivel‐Hernández , Mario Villalobos‐Forbes , Andrés Abarca-Herrera +2 more | Pure and Applied Chemistry

Abstract Breath research has demonstrated that mammals, including humans, produce methane (CH 4 ) due to microbial activity in the gastrointestinal tract under anoxic conditions. Overall, humans are classified as … Abstract Breath research has demonstrated that mammals, including humans, produce methane (CH 4 ) due to microbial activity in the gastrointestinal tract under anoxic conditions. Overall, humans are classified as methane producers if they exhale methane concentrations at least 1 ppmv higher than the environmental level. Here, we present the first measurements of CH 4 concentration and its carbon stable isotope composition (δ 13 C-CH 4 ) in the breath of Costa Rican individuals. Samples were collected from a total of 51 volunteers aged between 5 and 72 years, using Tedlar bags, and analyzed using laser spectroscopy. We found that 56 % and 62 % of female (N = 14) and male (N = 16) individuals, respectively, can be considered as methane producers and emitted CH 4 concentrations up to 37.9 ppmv with δ 13 C-CH 4 values up to −75.0 ‰. The δ 13 C-CH 4 values also confirmed that the exhaled methane was produced by all the individuals evaluated. Despite our data being preliminary, our work can be useful for future breath studies in Latin American populations that incorporate isotopic techniques (e.g., laser spectroscopy and isotope ratio mass spectrometry) and consider how dietary factors or intestinal microbiota may influence levels of methane emission among different age groups .

Research on Malodor Component Identification Based on Sensor Array

2025-06-20

Jiaxing Xie , Wei Chen , Shiyun Chen +7 more | Sensors

With the rising demand for improved living standards and environmental protection, malodor pollution has emerged as a critical concern for both the public and regulatory authorities. Accurate prediction of malodor … With the rising demand for improved living standards and environmental protection, malodor pollution has emerged as a critical concern for both the public and regulatory authorities. Accurate prediction of malodor gas composition is essential for effective environmental monitoring and safety management. However, existing online malodor detection systems often suffer from short-term sensor drift, compromising their accuracy and long-term stability. To address these challenges, this study proposes an advanced electronic nose (e-nose) detection framework based on a time series data analysis. This study presents a novel approach utilizing a multi-channel sensor array for gas sampling, which establishes a robust mapping relationship between sensor response patterns and gas concentration distributions. To address the challenges of sensor drift and enhance system stability, we propose an innovative Encoder-Decoder architecture IED-CNN-LSTM incorporating external compensation mechanisms. Experimental results demonstrate that the proposed IED-CNN-LSTM model outperforms conventional methods significantly in both prediction accuracy and long-term stability. The framework achieves enhanced feature extraction from sensor time series data, enabling more precise and reliable detection of malodorous compounds. This research contributes an effective solution for real-time environmental monitoring applications while offering substantial improvements in both performance metrics and practical implementation for industrial and regulatory scenarios.

Traceability of wolfberry origin: A lightweight step-by-step fusion network combining an electronic nose and a hyperspectral system

2025-06-20

Siyuan Wang , Qinghua Li , Xingyu Wen +4 more | Sensors and Actuators A Physical

TinyML-Based Real-Time Drift Compensation for Gas Sensors Using Spectral–Temporal Neural Networks

2025-06-20

Adir Krayden , M. Avraham , Halim Ashkar +3 more | Chemosensors

The implementation of low-cost sensitive and selective gas sensors for monitoring fruit ripening and quality strongly depends on their long-term stability. Gas sensor drift undermines the long-term reliability of low-cost … The implementation of low-cost sensitive and selective gas sensors for monitoring fruit ripening and quality strongly depends on their long-term stability. Gas sensor drift undermines the long-term reliability of low-cost sensing platforms, particularly in precision agriculture. We present a real-time drift compensation framework based on a lightweight Temporal Convolutional Neural Network (TCNN) combined with a Hadamard spectral transform. The model operates causally on incoming sensor data, achieving a mean absolute error below 1 mV on long-term recordings (equivalent to <1 particle per million (ppm) gas concentration). Through quantization, we compress the model by over 70%, without sacrificing accuracy. Demonstrated on a combustion-type gas sensor system (dubbed GMOS) for ethylene monitoring, our approach enables continuous, drift-corrected operation without the need for recalibration or dependence on cloud-based services, offering a generalizable solution for embedded environmental sensing—in food transportation containers, cold storage facilities, de-greening rooms and directly in the field.

Research on Volatile Allergenic Substances in Chinese Lacquer: An Integrated Analysis of Their Composition, Detection, Mechanisms, and Prevention

2025-06-20

Yao Wang , Jiancheng Hou , T. Wang +2 more | Polymers

As a natural polymerized material, Chinese lacquer has numerous applications, although its processing is associated with volatile organic compounds (VOCs), which will cause a health risk. This paper was mainly … As a natural polymerized material, Chinese lacquer has numerous applications, although its processing is associated with volatile organic compounds (VOCs), which will cause a health risk. This paper was mainly focused on the detection of volatiles in the Chinese lacquer and its possible allergy mechanisms based on the properties of the lacquer, such as the main components, chemical properties, and allergy mechanisms of the unit phenols, aldehydes, and ketones and terpenes in the volatiles. Based on the detection technology (such as GC/MS) and allergy mechanism, a variety of prevention and control strategies are proposed, including the use of cyclodextrin–chitosan embedding technology to reduce the antigenicity of lacquer phenols and the directional modification of the active site of laccase to inhibit the generation of quinone toxicity products, as well as the research and development of antioxidant protective equipment for different volatiles, the installation of ventilation and purification devices, and the addition of antioxidants. They are all aimed at providing scientific evidence and practical guidance for the safe use of lacquer, the health protection of the practitioners, and the sustainable development of the related industries.

A Stretchable Self-Healing Temperature Sensor Based On Pu-Ta@Mxene Fiber For Body Surface Temperature Monitoring

2025-06-20

Z.W. Wang | Theoretical and Natural Science

Sensitivity, repeatability, and mechanical properties have been the focus of research on flexible temperature sensors. However, existing temperature sensors suffer from low sensitivity and untimely array sensing. In this paper, … Sensitivity, repeatability, and mechanical properties have been the focus of research on flexible temperature sensors. However, existing temperature sensors suffer from low sensitivity and untimely array sensing. In this paper, a core-sheath structured fiber based on modified tannic acid (meta), carbon nanotubes (CNT), Mene, and polyurethane (PU) is investigated, which is made of a sheath consisting of a layer of PU wrapped around a core consisting of TA, CNT, and Mene, and exhibits excellent mechanical properties and self-healing ability. Through experimental testing, the tensile strength of the fiber reaches 6.35 MPa and the elongation at break is 66.43%, showing good elasticity and flexibility. Utilizing the characteristics of the core-sheath structure, the fibers were able to achieve self-healing at 80C when cut by the knife. The sensitivity of the fibers to temperature changes was different in different temperature zones. In the low temperature range (-5C to 20C), the TCR was high at 5.58 %C-1, while in the higher temperature range (20C to 60C), the TCR was 2.08 %C-1. The TCR of the fibers was also higher in the low temperature range (-5C to 20C). In addition, human breath cycle tests were conducted and showed excellent reliability. In addition, an array sensor circuit was developed and designed to accurately measure the spatial temperature distribution, thereby increasing the sensor's usefulness in a variety of applications.

Preparing the Automated SIFT-MS Instrument for Analysis (Procedure 2)

2025-06-20

| Royal Society of Chemistry eBooks

Selected ion flow tube mass spectrometry (SIFT-MS) instruments have different operational procedures compared to conventional chromatographic instruments, since they are based on different principles. This chapter describes, in a general … Selected ion flow tube mass spectrometry (SIFT-MS) instruments have different operational procedures compared to conventional chromatographic instruments, since they are based on different principles. This chapter describes, in a general manner, how to prepare a SIFT-MS instrument for analysis, together with a coupled robotic autosampler. Additionally, in support of good analytical practice, the automated SIFT-MS performance tune and manual performance checks are summarised.

The Principles of the SIFT-MS Technique

2025-06-20

| Royal Society of Chemistry eBooks

The selected ion flow tube mass spectrometry (SIFT-MS) technique operates on very different principles to the more established chromatographic methods. This chapter provides a comprehensive introduction to how SIFT-MS instruments … The selected ion flow tube mass spectrometry (SIFT-MS) technique operates on very different principles to the more established chromatographic methods. This chapter provides a comprehensive introduction to how SIFT-MS instruments work, the ion–molecule reaction (IMR) chemistry that provides both comprehensive and specific analysis, and the utilisation of these reactions for high-sensitivity, quantitative analysis. It also describes how the IMR data are stored in the SIFT-MS library. The library supports streamlined SIFT-MS method development, as described in the final major section. At the conclusion of this chapter, the reader has sufficient understanding to generate quality data when the principles are applied in the context of later procedures.

Other Selected Applications

2025-06-20

| Royal Society of Chemistry eBooks

SIFT-MS has diverse applications in real-time volatile organic compound (VOC) monitoring, in addition to routine headspace analysis. This chapter summarises selected case studies that illustrate this breadth of application, including … SIFT-MS has diverse applications in real-time volatile organic compound (VOC) monitoring, in addition to routine headspace analysis. This chapter summarises selected case studies that illustrate this breadth of application, including analysis of human breath – its first application, protection of workers from very toxic VOCs, environmental air analysis, and industrial process monitoring. These applications illustrate the diversity of analytes and sample introduction approaches that can be accommodated by SIFT-MS instruments.

SIFT-MS Data Analysis

2025-06-20

| Royal Society of Chemistry eBooks

SIFT-MS utilises direct, soft chemical ionisation coupled with mass spectrometric detection, rather than chromatographic separation, to analyse samples with high specificity. This means that SIFT-MS data differ significantly from GC … SIFT-MS utilises direct, soft chemical ionisation coupled with mass spectrometric detection, rather than chromatographic separation, to analyse samples with high specificity. This means that SIFT-MS data differ significantly from GC and LC data in that they are a superposition of mass spectra of the different reactive compounds (analytes and matrix). Building on the principles of SIFT-MS, this chapter provides a comprehensive overview of both the quality assurance of SIFT-MS data and the interpretation and processing of the data. It covers compound identification and various other data-handling approaches for full scan mode data. Processing of selected ion monitoring (SIM) mode data across a variety of applications is described, together with more general principles for method development, routine headspace analysis, and research. Both acquisition modes are illustrated using data from numerous real-world applications.

Routine Headspace Applications

2025-06-20

| Royal Society of Chemistry eBooks

Automated headspace-SIFT-MS analysis – by means of static headspace analysis (SHA), multiple headspace extraction (MHE), and the method of standard additions (MoSA) – can be utilised in diverse applications for … Automated headspace-SIFT-MS analysis – by means of static headspace analysis (SHA), multiple headspace extraction (MHE), and the method of standard additions (MoSA) – can be utilised in diverse applications for routine analysis of volatile compounds. In this chapter, selected case studies are used to illustrate the practical implementation of the principles and procedures described in the earlier parts of the book, while sampling the routine headspace analysis applications of SIFT-MS.

Quality Assurance

2025-06-20

| Royal Society of Chemistry eBooks

Assuring the quality of analytical data is of extreme importance in routine analysis. This chapter describes how three critical components of quality data are assured for SIFT-MS through analytical instrument … Assuring the quality of analytical data is of extreme importance in routine analysis. This chapter describes how three critical components of quality data are assured for SIFT-MS through analytical instrument qualification, system suitability, and utilisation of analytical controls such as calibration and quality control check standards. It also includes guidance for transferring a validated test method to another SIFT-MS instrument.