{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T11:14:10Z","timestamp":1789902850751,"version":"4.0.1"},"reference-count":78,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2016,10,29]],"date-time":"2016-10-29T00:00:00Z","timestamp":1477699200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Tungsten trioxide is the second most commonly used semiconducting metal oxide in gas sensors. Semiconducting metal oxide (SMOX)-based sensors are small, robust, inexpensive and sensitive, making them highly attractive for handheld portable medical diagnostic detectors. WO3 is reported to show high sensor responses to several biomarkers found in breath, e.g., acetone, ammonia, carbon monoxide, hydrogen sulfide, toluene, and nitric oxide. Modern material science allows WO3 samples to be tailored to address certain sensing needs. Utilizing recent advances in breath sampling it will be possible in the future to test WO3-based sensors in application conditions and to compare the sensing results to those obtained using more expensive analytical methods.<\/jats:p>","DOI":"10.3390\/s16111815","type":"journal-article","created":{"date-parts":[[2016,10,31]],"date-time":"2016-10-31T11:09:46Z","timestamp":1477912186000},"page":"1815","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":109,"title":["Understanding the Potential of WO3 Based Sensors for Breath Analysis"],"prefix":"10.3390","volume":"16","author":[{"given":"Anna","family":"Staerz","sequence":"first","affiliation":[{"name":"Institute of Physical and Theoretical Chemistry (IPTC), University of Tuebingen, Auf der Morgenstelle 15, D-72076 Tuebingen, Germany"},{"name":"Center for Light-Matter Interaction, Sensors &amp; Analytics (LISA+), University of Tuebingen, Auf der Morgenstelle 15, D-72076 Tuebingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Udo","family":"Weimar","sequence":"additional","affiliation":[{"name":"Institute of Physical and Theoretical Chemistry (IPTC), University of Tuebingen, Auf der Morgenstelle 15, D-72076 Tuebingen, Germany"},{"name":"Center for Light-Matter Interaction, Sensors &amp; Analytics (LISA+), University of Tuebingen, Auf der Morgenstelle 15, D-72076 Tuebingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicolae","family":"Barsan","sequence":"additional","affiliation":[{"name":"Institute of Physical and Theoretical Chemistry (IPTC), University of Tuebingen, Auf der Morgenstelle 15, D-72076 Tuebingen, Germany"},{"name":"Center for Light-Matter Interaction, Sensors &amp; Analytics (LISA+), University of Tuebingen, Auf der Morgenstelle 15, D-72076 Tuebingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,10,29]]},"reference":[{"key":"ref_1","first-page":"1","article-title":"NIH Public Access","volume":"2","author":"Dweik","year":"2008","journal-title":"J Breath Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2374","DOI":"10.1073\/pnas.68.10.2374","article-title":"Quantitative analysis of urine vapor and breath by gas-liquid partition chromatography","volume":"68","author":"Pauling","year":"1971","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"10201","DOI":"10.1088\/1752-7155\/7\/1\/010201","article-title":"Breath analysis-past, present and future: A special issue in honour of Michael Phillips\u2019 70th birthday","volume":"7","author":"Risby","year":"2013","journal-title":"J. Breath Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"333","DOI":"10.3109\/10715769409145633","article-title":"Alveolar gradient of pentane in normal human breath","volume":"20","author":"Phillips","year":"1994","journal-title":"Free Radic. Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"8323","DOI":"10.1021\/acsami.5b12062","article-title":"MOF-Based Membrane Encapsulated ZnO Nanowires for Enhanced Gas Sensor Selectivity","volume":"8","author":"Drobek","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"52252","DOI":"10.1039\/C5RA07213A","article-title":"Highly sensitive and humidity-independent ethanol sensors based on In2O3 flower\/SnO2 nanoparticle composites","volume":"5","author":"Liu","year":"2015","journal-title":"RSC Adv."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.mattod.2014.08.017","article-title":"Breath analysis by nanostructured metal oxides as chemo-resistive gas sensors","volume":"18","author":"Righettoni","year":"2015","journal-title":"Mater. Today"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.aca.2012.06.002","article-title":"Breath acetone monitoring by portable Si:WO3 gas sensors","volume":"738","author":"Righettoni","year":"2012","journal-title":"Anal. Chim. Acta"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1016\/j.snb.2006.02.015","article-title":"Ethanol and ozone sensing characteristics of WO3 based sensors activated by Au and Pd","volume":"120","author":"Labidi","year":"2006","journal-title":"Sens. Actuators B Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1016\/j.proeng.2012.09.157","article-title":"Synthesis of WO3 nanorod based thin films for ethanol and H2 Sensing","volume":"47","author":"Ahmad","year":"2012","journal-title":"Procedia Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"12460","DOI":"10.1039\/C5NR02571K","article-title":"Hierarchical Nanostructured WO3-SnO2 for Selective Sensing of Volatile Organic Compounds","volume":"7","author":"Nayak","year":"2015","journal-title":"Nanoscale"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3297","DOI":"10.1021\/ac00092a004","article-title":"Gas-Phase Biosensor for Ethanol","volume":"66","author":"Mitsubayashi","year":"1994","journal-title":"Anal. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"47101","DOI":"10.1088\/1752-7155\/9\/4\/047101","article-title":"Monitoring breath markers under controlled conditions","volume":"9","author":"Righettoni","year":"2015","journal-title":"J. Breath Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"5442","DOI":"10.1021\/ic049522w","article-title":"Highly Sensitive WO3 Hollow-Sphere Gas Sensors","volume":"43","author":"Li","year":"2004","journal-title":"Inorg. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"53130","DOI":"10.1039\/C4RA06654E","article-title":"Rh-catalyzed WO3 with anomalous humidity dependence of gas sensing characteristics","volume":"4","author":"Choi","year":"2014","journal-title":"RSC Adv."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3581","DOI":"10.1021\/ac902695n","article-title":"Si:WO3 Sensors for Highly Selective Detection of Acetone for Easy Diagnosis of Diabetes by Breath Analysis","volume":"82","author":"Righettoni","year":"2010","journal-title":"Anal. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4794","DOI":"10.1021\/cm800761e","article-title":"Ferroelectric WO3 Nanoparticles for Acetone Selective Detection","volume":"20","author":"Wang","year":"2008","journal-title":"Chem. Mater."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5891","DOI":"10.1021\/acsnano.6b01196","article-title":"Mesoporous WO3 Nanofibers with Protein Templated Nanoscale Catalysts for Detection of Trace Biomarkers in Exhaled Breath","volume":"10","author":"Kim","year":"2016","journal-title":"ACS Nano"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1016\/S1570-0232(04)00657-9","article-title":"Determination of acetone in human breath by gas chromatography-mass spectrometry and solid-phase microextraction with on-fiber derivatization","volume":"810","author":"Deng","year":"2004","journal-title":"J. Chromatogr. B Anal. Technol. Biomed. Life Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1246\/cl.1992.639","article-title":"Gold-Loaded Tungsten Oxide Sensor for Detection of Ammonia in Air","volume":"4","author":"Maekawa","year":"1992","journal-title":"Chem. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1149\/1.1393270","article-title":"Fabrication of Highly Selective Tungsten Oxide Ammonia Sensors","volume":"147","author":"Llobet","year":"2000","journal-title":"J. Electrochem. Soc."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1011","DOI":"10.1016\/j.proeng.2014.11.331","article-title":"Effect of hexagonal WO3 morphology on NH3 sensing","volume":"87","author":"Pap","year":"2014","journal-title":"Proc. Eng."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1080\/10426910701385440","article-title":"Synthesis and Sensing Properties to NH3 of Hexagonal WO3 Metastable Nanopowders","volume":"22","author":"Wang","year":"2007","journal-title":"Mater. Manuf. Process."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1149\/1.1556055","article-title":"NH3 Interaction with Catalytically Modified Nano-WO3 Powders for Gas Sensing Applications","volume":"150","author":"Centeno","year":"2003","journal-title":"J. Electrochem. Soc."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1038\/ki.1997.324","article-title":"Quantitative analysis of ammonia on the breath of patients in end-stage renal failure","volume":"52","author":"Davies","year":"1997","journal-title":"Kidney Int."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1016\/j.apsusc.2015.04.226","article-title":"Controlled synthesis of monodisperse WO3\u00b7H2O square nanoplates and their gas sensing properties","volume":"349","author":"Miao","year":"2015","journal-title":"Appl. Surf. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"18638","DOI":"10.1021\/acsami.5b05081","article-title":"Nanoscale Heterostructures Based on Fe2O3@WO3\u2212x Nanoneedles and Their Direct Integration into Flexible Transducing Platforms for Toluene Sensing","volume":"7","author":"Vallejos","year":"2015","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1016\/j.snb.2013.12.011","article-title":"Highly sensitive and selective hydrogen sulfide and toluene sensors using Pd functionalized WO3 nanofibers for potential diagnosis of halitosis and lung cancer","volume":"193","author":"Kim","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2609","DOI":"10.1039\/C4CC09725D","article-title":"Catalyst-loaded porous WO3 nanofibers using catalyst-decorated polystyrene colloid templates for detection of biomarker molecules","volume":"51","author":"Choi","year":"2015","journal-title":"Chem. Commun. (Camb.)"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1063\/1.3050524","article-title":"A selective nanosensing probe for nitric oxide","volume":"93","author":"Gouma","year":"2008","journal-title":"Appl. Phys. Lett."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"10591","DOI":"10.1021\/am402456s","article-title":"Extremely sensitive and selective NO probe based on villi-like WO3 nanostructures for application to exhaled breath analyzers","volume":"5","author":"Moon","year":"2013","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1016\/S0925-4005(01)00572-X","article-title":"Detection and quantification of nitric oxide in human breath using a semiconducting oxide based chemiresistive microsensor","volume":"76","author":"Fruhberger","year":"2001","journal-title":"Sens. Actuators B Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3634","DOI":"10.1116\/1.576517","article-title":"Electrical properties of tungsten trioxide films","volume":"8","author":"Xu","year":"1990","journal-title":"J. Vac. Sci. Technol. A Vac. Surf."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"488","DOI":"10.1016\/j.snb.2007.07.013","article-title":"H2S sensors based on tungsten oxide nanostructures","volume":"128","author":"Rout","year":"2008","journal-title":"Sens. Actuators B Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"9061","DOI":"10.1021\/am501394r","article-title":"Fast responding exhaled-breath sensors using WO3 hemitubes functionalized by graphene-based electronic sensitizers for diagnosis of diseases","volume":"6","author":"Choi","year":"2014","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"748","DOI":"10.1111\/j.1600-051X.2007.01116.x","article-title":"Intra- and extra-oral halitosis: Finding of a new form of extra-oral blood-borne halitosis caused by dimethyl sulphide","volume":"34","author":"Tangerman","year":"2007","journal-title":"J. Clin. Periodontol."},{"key":"ref_37","unstructured":"Christian, J., Gaur, R.P.S., Wolfe, T., and Trasorras, J.R.L. (2011). Tungsten Chemicals and Their Applications, International Tungsten Industry Association."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2175","DOI":"10.1002\/adfm.201002477","article-title":"Nanostructured tungsten oxide-properties, synthesis, and applications","volume":"21","author":"Zheng","year":"2011","journal-title":"Adv. Funct. Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"4698","DOI":"10.1007\/s10854-015-2896-4","article-title":"Synthesis of WO3 and its gas sensing: A review","volume":"26","author":"Long","year":"2015","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.snb.2010.09.040","article-title":"CO sensing mechanism with WO3 based gas sensors","volume":"151","author":"Simion","year":"2010","journal-title":"Sens. Actuators B Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"12467","DOI":"10.3390\/s130912467","article-title":"NO and NO2 sensing properties of WO3 and Co3O4 based gas sensors","volume":"13","author":"Akamatsu","year":"2013","journal-title":"Sensors"},{"key":"ref_42","unstructured":"Baumann, S.L. (2003). Detektions-Mechanismen Auf WO3 Bei Einsatz in Verbrennungsabgasen, Dissertation Jutus Liebig Universit\u00e4t Gie\u00dfen. (In German)."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1415","DOI":"10.1016\/S0955-2219(03)00417-5","article-title":"Structure engineering of WO3 nanoparticles for porous film applications by advanced reactive gas deposition","volume":"24","author":"Reyes","year":"2004","journal-title":"J. Eur. Ceram. Soc."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1023\/A:1014405811371","article-title":"Conduction model of metal oxide gas sensors","volume":"7","author":"Barsan","year":"2001","journal-title":"J. Electroceramics"},{"key":"ref_45","unstructured":"Weil, M., and Schubert, W. (2013). The Beautiful Colours of Tungsten Oxides, International Tungsten Industry Association."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"6985","DOI":"10.1039\/C5CE00526D","article-title":"In situ high temperature X-ray diffraction, transmission electron microscopy and theoretical modeling for the formation of WO3 crystallites","volume":"17","author":"Pokhrel","year":"2015","journal-title":"CrystEngComm"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.apsusc.2009.07.102","article-title":"Effect of annealing temperature on the photocatalytic activity of WO3 for O2 evolution","volume":"256","author":"Xin","year":"2009","journal-title":"Appl. Surf. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1016\/0022-4596(79)90199-3","article-title":"Structural study of a new hexagonal form of tungsten trioxide","volume":"29","author":"Gerand","year":"1979","journal-title":"J. Solid State Chem."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Faller, A., and Michael, S. (2016). Der K\u00f6rper des Menschen: Einf\u00fchrung in Bau und Funktion, Georg Thiem Verlag. [17th ed.]. (In German).","DOI":"10.1055\/b-004-129994"},{"key":"ref_50","unstructured":"Available online: http:\/\/www.draeger.com\/sites\/assets\/PublishingImages\/Products\/cdi_alcotest_9510\/TR\/measuring_alcohol_in_the_body_br_9044525_en.pdf."},{"key":"ref_51","unstructured":"Lemaire, N. (2005). Technical Evaluation: ACS and Dr\u00e4ger Breath Alcohol Ignition Interlock Devices (BAIIDs), European Conference of Transport Research Institutes."},{"key":"ref_52","unstructured":"Rosenberg, E. (2015). A Study of the Accuracy and Precision of Selected Breath Alcohol Measurement Devices (\u2018Breathalyzers\u2019), Vienna University of Technology. TUW CTA 2015\/27EN."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"125502","DOI":"10.1088\/0957-4484\/27\/12\/125502","article-title":"Mask-less deposition of Au\u2013SnO2 nanocomposites on CMOS MEMS platform for ethanol detection","volume":"27","author":"Santra","year":"2016","journal-title":"Nanotechnology"},{"key":"ref_54","first-page":"427","article-title":"Performance analysis of zinc oxide based alcohol sensors","volume":"4","author":"Kumar","year":"2015","journal-title":"J. Appl. Sci. Eng. Res."},{"key":"ref_55","doi-asserted-by":"crossref","unstructured":"Comini, E. (2016). Metal oxide nanowire chemical sensors: Innovation and quality of life. Mater. Today, in press.","DOI":"10.1016\/j.mattod.2016.05.016"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1016\/j.snb.2016.05.032","article-title":"Fluctuation enhanced gas sensing with WO3-based nanoparticle gas sensors modulated by UV light at selected wavelengths","volume":"234","author":"Trawka","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3390\/chemosensors3010001","article-title":"First Fifty Years of Chemoresistive Gas Sensors","volume":"3","author":"Neri","year":"2015","journal-title":"Chemosensors"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1102","DOI":"10.1016\/S0140-6736(66)92194-5","article-title":"Acetone in alveolar air, and the control of diabetes","volume":"2","author":"Rooth","year":"1966","journal-title":"Lancet"},{"key":"ref_59","first-page":"859","article-title":"Diagnosis of kidney failure by analysis of the concentration of ammonia in exhaled human breath","volume":"4","author":"Essiet","year":"2013","journal-title":"J. Emerg. Trends Eng. Appl. Sci."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1016\/j.snb.2010.05.050","article-title":"From doping to phase transformation: Ammonia sensing performances of chloroalkoxide-derived WO3 powders modified with chromium","volume":"148","author":"Epifani","year":"2010","journal-title":"Sens. Actuators B Chem."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/S0167-2991(08)61666-3","article-title":"Selective oxidation of ammonia to nitrogen over silica supported molybdena catalysts. A structure-selectivity relationship","volume":"72","author":"Koningsberger","year":"1992","journal-title":"Stud. Surface Sci. Catal."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"37101","DOI":"10.1088\/1752-7155\/7\/3\/037101","article-title":"Factors influencing breath ammonia determination","volume":"7","author":"Solga","year":"2013","journal-title":"J. Breath Res."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1016\/j.snb.2015.10.005","article-title":"Enhanced toluene sensing performance of gold-functionalized WO3\u00b7H2O nanosheets","volume":"223","author":"Li","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"43","DOI":"10.5271\/sjweh.2497","article-title":"Exposure to toluene. Uptake, distribution and elimination in man","volume":"8","author":"Carlsson","year":"1982","journal-title":"Scand. J. Work. Environ. Heal."},{"key":"ref_65","first-page":"13","article-title":"Effect of High-Humidity Aging on Performance of Tungsten Oxide-Type Aromatic Compound Sensors","volume":"24","author":"Itoh","year":"2012","journal-title":"Sens. Mater."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1136\/thx.51.3.233","article-title":"Exhaled nitric oxide: A new lung function test","volume":"51","author":"Barnes","year":"1996","journal-title":"Thorax"},{"key":"ref_67","first-page":"E829","article-title":"New insights into the regulation of inducible nitric oxide synthesis","volume":"266","author":"Morris","year":"1994","journal-title":"Am. J. Physiol."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.proeng.2014.11.254","article-title":"Selective chemosensing and diagnostic breathanalyzer","volume":"87","author":"Gouma","year":"2014","journal-title":"Procedia Eng."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1164\/rccm.9120-11ST","article-title":"An Official ATS Clinical Practice Guideline: Interpretation of Exhaled Nitric Oxide Levels (FENO) for Clinical Applications","volume":"184","author":"Dweik","year":"2011","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1183\/09031936.05.00015205","article-title":"Nasal NO: Normal values in children age 6 through to 17 years","volume":"26","author":"Struben","year":"2005","journal-title":"Eur. Respir. J."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"2104","DOI":"10.1164\/ajrccm.160.6.ats8-99","article-title":"Recommendations for Standardized Procedures for the Online and Offline Measurement of Exhaled Lower Respiratory Nitric Oxide and Nasal Nitric Oxide in Adults and Children\u20141999","volume":"160","author":"Offline","year":"1999","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_72","first-page":"56","article-title":"Clinical applications of breath testing","volume":"2","author":"Paschke","year":"2010","journal-title":"Med. Rep."},{"key":"ref_73","unstructured":"Aerocrine (2007). Mastering the Measurement of Feno Nitric Oxide Monitoring System NIOX\u00ae Flex\u2014Nitric Oxide Monitoring System, Aerocrine."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"889","DOI":"10.1099\/jmm.0.46118-0","article-title":"Hydrogen sulfide-producing bacteria in tongue biofilm and their relationship with oral malodour","volume":"54","author":"Washio","year":"2005","journal-title":"J. Med. Microbiol."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"17106","DOI":"10.1088\/1752-7155\/4\/1\/017106","article-title":"Comparison of breath and in-mouth collection for the measurement of oral malodorous compounds by gas chromatography using sulfur chemiluminescence detection","volume":"4","author":"Paetznick","year":"2010","journal-title":"J. Breath Res."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"1504","DOI":"10.1111\/j.1151-2916.2001.tb00868.x","article-title":"Gas-Sensing Properties of Nanocrystalline WO3 Films Made by Advanced Reactive Gas Deposition","volume":"84","author":"Solis","year":"2001","journal-title":"J. Am. Ceram. Soc."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1111\/prd.12111","article-title":"Periodontal diseases as a source of halitosis: A review of the evidence and treatment approaches for dentists and dental hygienists","volume":"71","author":"Laleman","year":"2016","journal-title":"Periodontol. 2000"},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"1124","DOI":"10.1021\/acssensors.6b00422","article-title":"Novel templating route using Pt infiltrated block copolymer micro-particles for catalytic Pt functionalized macroporous WO3 nanofibers and its application in breath pattern recognition","volume":"1","author":"Choi","year":"2016","journal-title":"ACS Sens."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/11\/1815\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:34:20Z","timestamp":1760211260000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/11\/1815"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,10,29]]},"references-count":78,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2016,11]]}},"alternative-id":["s16111815"],"URL":"https:\/\/doi.org\/10.3390\/s16111815","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,10,29]]}}}