{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,8]],"date-time":"2026-06-08T12:31:10Z","timestamp":1780921870264,"version":"3.54.1"},"reference-count":33,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2022,11,30]],"date-time":"2022-11-30T00:00:00Z","timestamp":1669766400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Austrian Federal Ministry for Science and Research in the frame of the ASEA UNINE"},{"name":"National Research Council of Thailand (NRCT)"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A highly sensitive and selective formaldehyde sensor was successfully fabricated using hybrid materials of nitrogen-doped double-walled carbon nanotubes (N-DWCNTs) and polyvinylpyrrolidone (PVP). Double-walled carbon nanotubes (DWCNTs) and N-DWCNTs were produced by high-vacuum chemical vapor deposition using ethanol and benzylamine, respectively. Purified DWCNTs and N-DWCNTs were dropped separately onto the sensing substrate. PVP was then dropped onto pre-dropped DWCNT and N-DWCNTs (hereafter referred to as PVP\/DWCNTs and PVP\/N-DWCNTs, respectively). As-fabricated sensors were used to find 1,2-dichloroethane, dichloromethane, formaldehyde and toluene vapors in parts per million (ppm) at room temperature for detection measurement. The sensor response of N-DWCNTs, PVP\/DWCNTs and PVP\/N-DWCNTs sensors show a high response to formaldehyde but a low response to 1,2-dichloroethane, dichloromethane and toluene. Remarkably, PVP\/N-DWCNTs sensors respond sensitively and selectively towards formaldehyde vapor, which is 15 times higher than when using DWCNTs sensors. This improvement could be attributed to the synergistic effect of the polymer swelling and nitrogen-sites in the N-DWCNTs. The limit of detection (LOD) of PVP\/N-DWCNTs was 15 ppm, which is 34-fold higher than when using DWCNTs with a LOD of 506 ppm. This study demonstrated the high sensitivity and selectivity for formaldehyde-sensing applications of high-performance PVP\/N-DWCNTs hybrid materials.<\/jats:p>","DOI":"10.3390\/s22239329","type":"journal-article","created":{"date-parts":[[2022,11,30]],"date-time":"2022-11-30T08:46:41Z","timestamp":1669798001000},"page":"9329","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Highly Sensitive and Selective Formaldehyde Gas Sensors Based on Polyvinylpyrrolidone\/Nitrogen-Doped Double-Walled Carbon Nanotubes"],"prefix":"10.3390","volume":"22","author":[{"given":"Thanattha","family":"Chobsilp","sequence":"first","affiliation":[{"name":"Department of Materials and Production Technology Engineering, Faculty of Engineering, King Mongkut\u2019s University of Technology North Bangkok, Bangkok 10800, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thotsaphon","family":"Threrujirapapong","sequence":"additional","affiliation":[{"name":"Department of Materials and Production Technology Engineering, Faculty of Engineering, King Mongkut\u2019s University of Technology North Bangkok, Bangkok 10800, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Visittapong","family":"Yordsri","sequence":"additional","affiliation":[{"name":"National Metal and Materials Technology Center, Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alongkot","family":"Treetong","sequence":"additional","affiliation":[{"name":"National Nanotechnology Center, Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saowaluk","family":"Inpaeng","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Faculty of Science, Burapha University, Chonburi 20131, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karaked","family":"Tedsree","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Faculty of Science, Burapha University, Chonburi 20131, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paola","family":"Ayala","sequence":"additional","affiliation":[{"name":"Electronic Properties of Materials, Faculty of Physics, University of Vienna, 1090 Vienna, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Pichler","sequence":"additional","affiliation":[{"name":"Electronic Properties of Materials, Faculty of Physics, University of Vienna, 1090 Vienna, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4175-7803","authenticated-orcid":false,"given":"Lei","family":"Shi","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6928-3809","authenticated-orcid":false,"given":"Worawut","family":"Muangrat","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Faculty of Engineering, Burapha University, Chonburi 20131, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.1002\/1097-0142(19810301)47:5+<1055::AID-CNCR2820471302>3.0.CO;2-3","article-title":"Mechanisms of chemical carcinogenesis","volume":"47","author":"Miller","year":"1981","journal-title":"Cancer"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1093\/toxsci\/kfq365","article-title":"Chemical carcinogenesis","volume":"120","author":"Cohen","year":"2011","journal-title":"Toxicol. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1186\/s41021-021-00183-5","article-title":"Formaldehyde exposure and leukemia risk: A comprehensive review and network-based toxicogenomic approach","volume":"43","author":"Kang","year":"2021","journal-title":"Genes Environ."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1110","DOI":"10.1021\/ac50057a026","article-title":"Sampling of formaldehyde in air with coated solid sorbent and determination by high performance liquid chromatography","volume":"52","author":"Beasley","year":"1980","journal-title":"Anal. Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"738","DOI":"10.1016\/j.jpba.2005.12.033","article-title":"Simultaneous determination of formic acid and formaldehyde in pharmaceutical excipients using headspace GC\/MS","volume":"41","author":"Hu","year":"2006","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"182","DOI":"10.1016\/j.snb.2018.11.156","article-title":"Rapid and sensitive detection of formaldehyde using portable 2-dimensional gas chromatography equipped with photoionization detectors","volume":"283","author":"Zhu","year":"2019","journal-title":"Sens. Actuators B"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Tang, R., Shi, Y., Hou, Z., and Wei, L. (2017). Carbon nanotube-based chemiresistive sensors. Sensors, 17.","DOI":"10.3390\/s17040882"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Camilli, L., and Passacantando, M. (2018). Advances on Sensors Based on Carbon Nanotubes. Chemosensors, 6.","DOI":"10.20944\/preprints201811.0262.v1"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.sna.2019.03.053","article-title":"Carbon nanotubes and its gas-sensing applications: A review","volume":"291","author":"Han","year":"2019","journal-title":"Sens. Actuators A"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"599","DOI":"10.1021\/acs.chemrev.8b00340","article-title":"Carbon Nanotube Chemical Sensors","volume":"119","author":"Schroeder","year":"2019","journal-title":"Chem. Rev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"115095","DOI":"10.1016\/j.mseb.2021.115095","article-title":"A review on carbon nanotube: An overview of synthesis, properties, functionalization, characterization, and the application","volume":"268","author":"Rathinavel","year":"2021","journal-title":"Mater. Sci. Eng. B"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"042803","DOI":"10.1116\/6.0000992","article-title":"Selective volatile organic compound gas sensor based on carbon nanotubes functionalized with ZnO nanoparticles","volume":"39","author":"Xiang","year":"2021","journal-title":"J. Vac. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1010","DOI":"10.1016\/j.snb.2008.07.010","article-title":"An enrichment method to detect low concentration formaldehyde","volume":"134","author":"Wang","year":"2008","journal-title":"Sens. Actuators B"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.snb.2011.12.112","article-title":"Multi-wall carbon nanotube gas sensors modified with amino-group to detect low concentration of formaldehyde","volume":"168","author":"Xie","year":"2012","journal-title":"Sens. Actuators B"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"100005","DOI":"10.1016\/j.greeac.2022.100005","article-title":"Carbon-metal oxide nanocomposites for selective detection of toxic and hazardous volatile organic compounds (VOC)\u2014A review","volume":"1","author":"Gakhar","year":"2022","journal-title":"Green Anal. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"923","DOI":"10.1080\/03602559.2014.979506","article-title":"A versatile polymer for biomedical and beyond medical applications","volume":"54","author":"Teodorescu","year":"2015","journal-title":"Polym. Plast. Technol. Eng."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"5095","DOI":"10.1007\/s10854-014-2277-4","article-title":"Gas sensors based on MWCNTs-PVP composite films for 1,2-dichloroethane vapor detection","volume":"25","author":"Xie","year":"2014","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2462","DOI":"10.1002\/pssb.201100067","article-title":"Selective differential ammonia gas sensor based on N-doped SWCNT films","volume":"248","author":"Battie","year":"2011","journal-title":"Phys. Status Solidi B"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1016\/j.carbon.2013.09.064","article-title":"Boron- and nitrogen-doped multi-wall carbon nanotubes for gas detection","volume":"66","author":"Adjizian","year":"2014","journal-title":"Carbon"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1800004","DOI":"10.1002\/pssa.201800004","article-title":"Unravel the active site in nitrogen-doped double-walled carbon nanotubes for nitrogen dioxide gas sensor","volume":"215","author":"Muangrat","year":"2018","journal-title":"Phys. Status Solidi A"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"125404","DOI":"10.1103\/PhysRevB.71.125404","article-title":"Pressure screening in the interior of primary shells in double-wall carbon nanotubes","volume":"71","author":"Arvanitidis","year":"2005","journal-title":"Phys. Rev. B"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"193411","DOI":"10.1103\/PhysRevB.72.193411","article-title":"Double-wall carbon nanotubes under pressure: Probing the response of individuals tubes and their intratube correlation","volume":"72","author":"Arvanitidis","year":"2005","journal-title":"Phys. Rev. B"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"883","DOI":"10.1016\/0008-6223(95)00017-8","article-title":"Physics of carbon nanotubes","volume":"33","author":"Dresselhaus","year":"1995","journal-title":"Carbon"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/S0009-2614(02)00686-3","article-title":"Morphology, diameter distribution and Raman scattering measurements of double-walled carbon nanotubes synthesized by catalytic decomposition of methane","volume":"359","author":"Ren","year":"2002","journal-title":"Chem. Phys. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1016\/j.carbon.2013.10.002","article-title":"Microwave plasma-assisted regeneration of carbon nanosheets with bi- and trilayer of graphene and their application to photovoltaic cells","volume":"67","author":"Wang","year":"2014","journal-title":"Carbon"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"177","DOI":"10.3762\/bjnano.6.17","article-title":"X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms","volume":"6","author":"Susi","year":"2015","journal-title":"Beilstein J. Nanotechnol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1007\/s12221-012-0471-7","article-title":"Flexible VOC sensors using conductive polymers and porous membranes for application to textiles","volume":"13","author":"Kim","year":"2012","journal-title":"Fibers Polym."},{"key":"ref_28","first-page":"20","article-title":"Quantum resistive vapour sensors made of polymer coated carbon nanotubes random networks for biomarkers detection","volume":"3","author":"Kumar","year":"2013","journal-title":"Chem. Sens."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.talanta.2014.02.005","article-title":"Conducting polymer coated single-walled carbon nanotube gas sensors for the detection of volatile organic compounds","volume":"123","author":"Badhulika","year":"2014","journal-title":"Talanta"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Liu, Z., Yang, T., Dong, Y., and Wang, Z. (2018). A room temperature VOCs gas sensor based on a layer by layer multi-walled carbon nanotubes\/poly-ethylene glycol composite. Sensors, 18.","DOI":"10.3390\/s18093113"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"131606","DOI":"10.1016\/j.snb.2022.131606","article-title":"Tailoring surface properties with O\/N doping in CNT aerogel film to obtain sensitive and selective sensor for volatile organic compounds detection","volume":"359","author":"Prakash","year":"2022","journal-title":"Sens. Actuators B"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1007\/s42452-020-2055-2","article-title":"Theoretical study of pure\/doped (nitrogen and boron) carbon nanotubes for chemical sensing of formaldehyde","volume":"2","author":"Dwivedi","year":"2020","journal-title":"SN Appl. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1021\/nl034220x","article-title":"Carbon nanotube sensors for gas and organic vapor detection","volume":"3","author":"Li","year":"2003","journal-title":"Nano Lett."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/23\/9329\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:30:20Z","timestamp":1760146220000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/23\/9329"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,30]]},"references-count":33,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["s22239329"],"URL":"https:\/\/doi.org\/10.3390\/s22239329","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11,30]]}}}