{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,18]],"date-time":"2026-10-18T01:43:37Z","timestamp":1792287817879,"version":"4.4.0"},"reference-count":43,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2019,12,18]],"date-time":"2019-12-18T00:00:00Z","timestamp":1576627200000},"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>The aim of this work is to investigate the gas sensing performance of single wall carbon nanotubes (SWCNTs)-based conductive sensors operating at low\u2013medium temperatures (&lt;250 \u00b0C). The investigated sensing films consists of an SWCNT network obtained by drop-casting a SWCNT suspension. Starting from this base preparation, different sensing devices were obtained by decorating the SWCNT network with materials suitable for enhancing the sensitivity toward the target gas. In particular, in this paper, nano-particles of gold and of TiO2 were used. In the paper, the performance of the different sensing devices, in terms of response time, sensitivity toward NO2 and cross-sensitivity to O2, CO and water vapor, were assessed and discussed. Sensors based on decorated SWCNT films showed high performance; in particular, the decoration with Au nano-particles allows for a large enhancement of sensitivity (reaching 10%\/1 ppm at 240 \u00b0C) and a large reduction of response time. On the other hand, the addition of TiO2 nanoparticles leads to a satisfactory improvement of the sensitivity as well as a significant reduction of the response time at moderate temperatures (down to 200 \u00b0C). Finally, the suitability of using Au decorated SWCNTs-based sensors for room temperature sensing is demonstrated.<\/jats:p>","DOI":"10.3390\/s20010012","type":"journal-article","created":{"date-parts":[[2019,12,23]],"date-time":"2019-12-23T03:15:01Z","timestamp":1577070901000},"page":"12","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Highly Sensitive Detection of NO2 by Au and TiO2 Nanoparticles Decorated SWCNTs Sensors"],"prefix":"10.3390","volume":"20","author":[{"given":"Ada","family":"Fort","sequence":"first","affiliation":[{"name":"Department of Information Engineering and Mathematical Sciences, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2779-4878","authenticated-orcid":false,"given":"Enza","family":"Panzardi","sequence":"additional","affiliation":[{"name":"Department of Information Engineering and Mathematical Sciences, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0952-3134","authenticated-orcid":false,"given":"Ammar","family":"Al-Hamry","sequence":"additional","affiliation":[{"name":"Chair Measurement and Sensor Technology, Department of electrical Engineering and Information Technology, Chemnitz University of Technology, 09107 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2509-6566","authenticated-orcid":false,"given":"Valerio","family":"Vignoli","sequence":"additional","affiliation":[{"name":"Department of Information Engineering and Mathematical Sciences, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Mugnaini","sequence":"additional","affiliation":[{"name":"Department of Information Engineering and Mathematical Sciences, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tommaso","family":"Addabbo","sequence":"additional","affiliation":[{"name":"Department of Information Engineering and Mathematical Sciences, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7166-1266","authenticated-orcid":false,"given":"Olfa","family":"Kanoun","sequence":"additional","affiliation":[{"name":"Chair Measurement and Sensor Technology, Department of electrical Engineering and Information Technology, Chemnitz University of Technology, 09107 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1038\/354056a0","article-title":"Helical microtubules of graphitic carbon","volume":"354","author":"Iijima","year":"1991","journal-title":"Nature"},{"key":"ref_2","first-page":"220","article-title":"Carbon Nanotube Assembly and Integration for Applications Nanoscale","volume":"14","author":"Venkataraman","year":"2019","journal-title":"Res. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1016\/j.snb.2009.04.012","article-title":"Novel capacitive sensor: Fabrication from carbon nanotube arrays and sensing property characterization","volume":"140","author":"Chen","year":"2009","journal-title":"Sens. Actuators B Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1016\/j.diamond.2019.01.020","article-title":"An optimized resistive CNT-based gas sensor with a novel configuration by top electrical contact","volume":"93","author":"Zandi","year":"2019","journal-title":"Diam. Relat. Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2280","DOI":"10.1063\/1.1610251","article-title":"Selective gas detection using a carbon nanotube sensor","volume":"83","author":"Chopra","year":"2003","journal-title":"Appl. Phys. Lett."},{"key":"ref_6","unstructured":"Kroto, H.W., and Fischer, D.C.J.E. (2003). The Fullerenes: New Horizons for the Chemistry, Physics and Astrophysics of Carbon, Cambridge University Press."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2204","DOI":"10.1063\/1.107080","article-title":"Electronic structure of chiral graphene tubules","volume":"60","author":"Saito","year":"1992","journal-title":"Appl. Phys. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"493904","DOI":"10.1155\/2009\/493904","article-title":"A Review of Carbon Nanotubes-Based Gas Sensors","volume":"2009","author":"Wang","year":"2009","journal-title":"J. Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1108\/SR-10-2016-0230","article-title":"A review on recent advances of CNTs as gas sensors","volume":"37","author":"Rana","year":"2017","journal-title":"Sens. Rev."},{"key":"ref_10","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_11","doi-asserted-by":"crossref","first-page":"333","DOI":"10.3103\/S1068337215040064","article-title":"Gas sensors based on functionalized carbon nanotubes","volume":"50","author":"Aroutiounian","year":"2015","journal-title":"J. Contemp. Phys."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ziegler, D., Bekyarova, E., Marchisio, A., Tulliani, J., and Naishadham, K. (2018, January 28\u201331). Highly Selective Ozone Sensors Based on Functionalized Carbon Nanotubes. Proceedings of the 2018 IEEE SENSORS, New Delhi, India.","DOI":"10.1109\/ICSENS.2018.8589868"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1186\/s11671-017-1945-8","article-title":"Mechanism and Application of Carbon Nanotube Sensors in SF6 Decomposed Production Detection: A Review","volume":"12","author":"Zhang","year":"2017","journal-title":"Nanoscale Res. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1088\/0957-4484\/13\/2\/312","article-title":"Gas molecule adsorption in carbon nanotubes and nanotube bundles","volume":"13","author":"Zhao","year":"2002","journal-title":"Nanotechnology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/j.snb.2013.12.050","article-title":"MWCNT-conducting polymer composite based ammonia gas sensors: A new approach for complete recovery process","volume":"194","author":"Sharma","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"George, J., Abdelghani, A., Bahoumina, P., Tantot, O., Baillargeat, D., Frigui, K., Bila, S., Hallil, H., and Dejous, C. (2019). CNT-Based Inkjet-Printed RF Gas Sensor: Modification of Substrate Properties during the Fabrication Process. Sensors, 19.","DOI":"10.3390\/s19081768"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"035001","DOI":"10.1088\/2058-8585\/aacc8f","article-title":"Flexible NO2 gas sensor based on single-walled carbon nanotubes on polytetrafluoroethylene substrates","volume":"3","author":"Agarwal","year":"2018","journal-title":"Flex. Print. Electron."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.snb.2014.12.086","article-title":"Highly sensitive and selective flexible H2S gas sensors based on Cu nanoparticle decorated SWCNTs","volume":"210","author":"Asad","year":"2015","journal-title":"Sens. Actuators B Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"877","DOI":"10.1021\/nl034061h","article-title":"Alcohol Vapor Sensors Based on Single-Walled Carbon Nanotube Field Effect Transistors","volume":"3","author":"Someya","year":"2003","journal-title":"Nano Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"123112","DOI":"10.1063\/1.2187510","article-title":"Mechanism of NO2 detection in carbon nanotube field effect transistor chemical sensors","volume":"88","author":"Zhang","year":"2006","journal-title":"Appl. Phys. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5133","DOI":"10.3390\/s100505133","article-title":"Carbon Nanostructure-Based Field-Effect Transistors for Label-Free Chemical\/Biological Sensors","volume":"10","author":"Hu","year":"2010","journal-title":"Sensors"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.moem.2017.02.002","article-title":"Carbon nanotubes: Sensor properties. A review","volume":"2","author":"Zaporotskova","year":"2016","journal-title":"Mod. Electron. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"349","DOI":"10.5194\/jsss-3-349-2014","article-title":"Room temperature carbon nanotube based sensor for carbon monoxide detection","volume":"3","author":"Hannon","year":"2014","journal-title":"J. Sens. Sens. Syst."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2576","DOI":"10.1007\/s11431-013-5337-8","article-title":"A carbon monoxide sensor based on single-walled carbon nanotubes doped with copper chloride","volume":"56","author":"Zhang","year":"2013","journal-title":"Sci. China Technol. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.snb.2007.07.108","article-title":"Hybrid metal oxide and multiwall carbon nanotube films for low temperature gas sensing","volume":"127","author":"Espinosa","year":"2007","journal-title":"Sens. Actuators B Chem."},{"key":"ref_26","unstructured":"Jaaniso, R., and Tan, O.K. (2013). Carbon nanotube and metal oxide hybrid materials for gas sensing. Woodhead Publishing Series in Electronic and Optical Materials. Semiconductor Gas Sensors, Woodhead Publishing."},{"key":"ref_27","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 Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.snb.2005.07.067","article-title":"WO3 films modified with functionalized multi-wall carbon nanotubes: Morphological, compositional and gas response studies","volume":"115","author":"Bittencourt","year":"2006","journal-title":"Sens. Actuators B Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"105501","DOI":"10.1088\/0957-4484\/21\/10\/105501","article-title":"Metal-modified and vertically aligned carbon nanotube sensors array for landfill gas monitoring applications","volume":"21","author":"Penza","year":"2010","journal-title":"Nanotechnology"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3477","DOI":"10.1016\/j.carbon.2010.05.045","article-title":"Room-temperature, selective detection of benzene at trace levels using plasma-treated metal-decorated multiwalled carbon nanotubes","volume":"48","author":"Leghrib","year":"2010","journal-title":"Carbon"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"260382","DOI":"10.1155\/2015\/260382","article-title":"Gas sensors based on locally heated multiwall carbon nanotubes decorated with metal nanoparticles","volume":"2015","author":"Savu","year":"2015","journal-title":"J. Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4597","DOI":"10.1016\/j.proci.2018.07.083","article-title":"Towards the development of an efficient low-NOx ammonia combustor for a micro gas turbine","volume":"37","author":"Okafor","year":"2019","journal-title":"Proc. Combust. Inst."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1007\/978-3-030-04324-7_1","article-title":"Low temperature NO2 sensor based on YCoO3 and TiO2 nanoparticle composites","volume":"539","author":"Addabbo","year":"2019","journal-title":"Lect. Notes Electr. Eng."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Kumar, S., Pavelyev, V., Mishra, P., and Tripathi, N. (2017, January 25\u201327). Sensitive detection of nitrogen dioxide using gold nanoparticles decorated single walled carbon nanotubes. Proceedings of the International Conference ITNT 2017- \u201cInformation Technology and Nanotechnology 2017\u201d, Samara, Russia.","DOI":"10.18287\/1613-0073-2017-1900-74-77"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Addabbo, T., Bertocci, F., Fort, A., Mugnaini, M., Vignoli, V., and Shahin, L. (2013, January 6\u20139). Versatile measurement system for characterization of gas sensing materials. Proceedings of the 2013 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), Minneapolis, MN, USA.","DOI":"10.1109\/I2MTC.2013.6555561"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1686","DOI":"10.1016\/j.carbon.2009.02.021","article-title":"Advanced carbon nanotube\/polymer composite infrared sensors","volume":"47","author":"Pradhan","year":"2009","journal-title":"Carbon"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Sharma, R., Al-Hamry, A., Vijayragavan, S., Benchirouf, A., Sanli, A., M\u00fcller, C., and Kanoun, O. (2014, January 11\u201314). Single-wall carbon nanotubes based near-infrared sensors on flexible substrate. Proceedings of the 2014 IEEE 11th International Multi-Conference on Systems, Signals & Devices (SSD14), Barcelona, Spain.","DOI":"10.1109\/SSD.2014.6808867"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1134","DOI":"10.1016\/j.snb.2016.09.095","article-title":"Effect of single wall carbon nanotube networks on gas sensor response and detection limit","volume":"240","author":"Kumar","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"M\u00fcller, C., Al-Hamry, A., Kanoun, O., Rahaman, M., Zahn, D., Matsubara, E., and Rosolen, J. (2019). Humidity Sensing Behavior of Endohedral Li-Doped and Undoped SWCNT\/SDBS Composite Films. Sensors, 19.","DOI":"10.3390\/s19010171"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1007\/s40820-014-0023-3","article-title":"Zinc oxide nanostructures for NO2 gas\u2013sensor applications: A review","volume":"7","author":"Kumar","year":"2015","journal-title":"Nano-Micro Lett."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1080\/10739149.2017.1340896","article-title":"Nanomaterial-based gas sensors: A review","volume":"46","author":"Xu","year":"2018","journal-title":"Instrum. Sci. Technol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1088\/0957-4484\/11\/2\/303","article-title":"Chemical control of nanotube electronics","volume":"11","author":"Peng","year":"2000","journal-title":"Nanotechnology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1109\/TIM.2017.2785118","article-title":"Quartz-Crystal Microbalance Gas Sensors Based on TiO2 Nanoparticles","volume":"67","author":"Addabbo","year":"2018","journal-title":"IEEE Trans. Instrum. Meas."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/1\/12\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:43:27Z","timestamp":1760190207000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/1\/12"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,12,18]]},"references-count":43,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2020,1]]}},"alternative-id":["s20010012"],"URL":"https:\/\/doi.org\/10.3390\/s20010012","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,12,18]]}}}