{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T05:22:18Z","timestamp":1767849738082,"version":"3.49.0"},"reference-count":43,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2018,10,19]],"date-time":"2018-10-19T00:00:00Z","timestamp":1539907200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61471324"],"award-info":[{"award-number":["61471324"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51425505"],"award-info":[{"award-number":["51425505"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51875534"],"award-info":[{"award-number":["51875534"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A carbon nanotube\/Fe3O4 thin film-based wireless passive gas sensor with better performance is proposed. The sensitive test mechanism of LC (Inductance and capacitance resonant) wireless sensors is analyzed and the reason for choosing Fe3O4 as a gas sensing material is explained. The design and fabrication process of the sensor and the testing method are introduced. Experimental results reveal that the proposed carbon nanotube (CNT)\/Fe3O4 based sensor performs well on sensing ammonia (NH3) at room temperature. The sensor exhibits not only an excellent response, good selectivity, and fast response and recovery times at room temperature, but is also characterized by good repeatability and low cost. The results for the wireless gas sensor\u2019s performance for different NH3 gas concentrations are presented. The developed device is promising for the establishment of wireless gas sensors in harsh environments.<\/jats:p>","DOI":"10.3390\/s18103542","type":"journal-article","created":{"date-parts":[[2018,10,19]],"date-time":"2018-10-19T10:08:02Z","timestamp":1539943682000},"page":"3542","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["A Room-Temperature CNT\/Fe3O4 Based Passive Wireless Gas Sensor"],"prefix":"10.3390","volume":"18","author":[{"given":"Tao","family":"Guo","sequence":"first","affiliation":[{"name":"Key Laboratory of Instrumentation Science &amp; Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tianhao","family":"Zhou","sequence":"additional","affiliation":[{"name":"Key Laboratory of Instrumentation Science &amp; Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China"},{"name":"Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7877-9278","authenticated-orcid":false,"given":"Qiulin","family":"Tan","sequence":"additional","affiliation":[{"name":"Key Laboratory of Instrumentation Science &amp; Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China"},{"name":"Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qianqian","family":"Guo","sequence":"additional","affiliation":[{"name":"Key Laboratory of Instrumentation Science &amp; Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China"},{"name":"Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fengxiang","family":"Lu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Instrumentation Science &amp; Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China"},{"name":"Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jijun","family":"Xiong","sequence":"additional","affiliation":[{"name":"Key Laboratory of Instrumentation Science &amp; Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China"},{"name":"Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,10,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"636","DOI":"10.1038\/ngeo325","article-title":"How a century of ammonia synthesis changed the world","volume":"1","author":"Erisman","year":"2008","journal-title":"Nat. Geosci."},{"key":"ref_2","unstructured":"Wolfe, D.W. (Natural History, 2001). Out of Thin Air\u2014Nitrogen Fixers, Natural History."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1016\/j.snb.2009.09.029","article-title":"Effects of O2 plasma treatment on NH3 sensing characteristics of multiwall carbon nanotube\/polyanilinecomposite films","volume":"143","author":"Yoo","year":"2009","journal-title":"Sens. Actuators B Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1007\/s00340-003-1266-8","article-title":"Ultra-sensitive ambient ammonia detection using CO2-laser-based photoacoustic spectroscopy","volume":"77","author":"Pushkarsky","year":"2003","journal-title":"Appl. Phys. B"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/j.jelechem.2007.05.016","article-title":"A Peculiar Cyclic Voltammetric Behavior of Polyaniline in Acetonitrile and Its Application in Ammonia Vapor Sensor","volume":"608","author":"Xu","year":"2007","journal-title":"J. Electroanal. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"91","DOI":"10.3390\/s20300091","article-title":"Room Temperature Ammonia and Humidity Sensing Using Highly Ordered Nanoporous Alumina Films","volume":"2","author":"Dickey","year":"2002","journal-title":"Sensors"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4728","DOI":"10.3390\/s90604728","article-title":"A Review of Wireless Sensor Technologies and Applications in Agriculture and Food Industry: State of the Art and Current Trends","volume":"9","author":"Luis","year":"2009","journal-title":"Sensors"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Mitchell, D., Kulkarni, A., Lostetter, A., Schupbach, M., Fraley, J., and Waits, R. (2009, January 8\u201312). Development and Testing of Harsh Environment, Wireless Sensor Systems for Industrial Gas Turbines. Proceedings of the ASME Turbo Expo 2009: Power for Land, Sea, and Air, Orlando, FL, USA.","DOI":"10.1115\/GT2009-60316"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Abu-Mahfouz, A.M., Isaac, S.J., Kruger, C.P., Aakvaag, N., and Fismen, B. (2014, January 6\u20139). Wireless gas sensing in South African underground platinum mines. Proceedings of the Wireless Communications and NETWORKING Conference, Istanbul, Turkey.","DOI":"10.1109\/WCNC.2014.6953135"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1016\/j.sna.2009.01.008","article-title":"A novel highly sensitive gas ionization sensor for ammonia detection","volume":"150","author":"Huang","year":"2009","journal-title":"Sens. Actuators A Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/S0925-4005(00)00685-7","article-title":"Conducting polyaniline composite: A reusable sensor material for aqueous ammonia","volume":"75","author":"Koul","year":"2001","journal-title":"Sens. Actuators B Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1016\/j.snb.2007.03.013","article-title":"Fabrication and gas sensitivity of polyaniline\u2013titanium dioxide nanocomposite thin film","volume":"125","author":"Tai","year":"2007","journal-title":"Sens. Actuators B Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1016\/j.snb.2013.01.014","article-title":"Enhanced sensitivity of ammonia sensor using graphene\/polyaniline nanocomposite","volume":"178","author":"Wu","year":"2013","journal-title":"Sens. Actuators B Chem."},{"key":"ref_14","unstructured":"Wathes, C.M., Demmers, T.G.M., and Xin, H. (2003, January 27\u201330). Ammonia Concentrations and Emissions in Livestock Production Facilities: Guidelines and Limits in the USA and UK. Proceedings of the 2003 ASAE Annual Meeting, Las Vegas, NV, USA."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1021\/nl034220x","article-title":"Carbon nanotube sensors forgas and organic vapor detection","volume":"3","author":"Li","year":"2003","journal-title":"Nano Lett."},{"key":"ref_16","first-page":"2587","article-title":"Selective detectionof acetone and hydrogen sulfide for the diagnosis of diabetes and halitosisusing SnO2nanofibers functionalized with reduced graphene oxide nanosheets","volume":"6","author":"Choi","year":"2014","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"37085","DOI":"10.1039\/C6RA02306A","article-title":"Fe3O4\/rGO nanocomposite: Synthesis and enhanced NOx gas-sensing properties at room temperature","volume":"6","author":"Yang","year":"2016","journal-title":"RSC Adv."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2824","DOI":"10.1039\/C2CS35335K","article-title":"ChemInform Abstract: Carbon Nanomaterials for Electronics, Optoelectronics, Photovoltaics, and Sensing","volume":"42","author":"Jariwala","year":"2013","journal-title":"Chem. Soc. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1652","DOI":"10.1021\/am200209e","article-title":"Instantaneous formation of metal and metal oxide nanoparticles on carbon nanotubes and graphene via solvent-free microwave heating","volume":"3","author":"Lin","year":"2011","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"622","DOI":"10.1126\/science.287.5453.622","article-title":"Nanotube molecular wires as chemical sensors","volume":"287","author":"Kong","year":"2000","journal-title":"Science"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1801","DOI":"10.1126\/science.287.5459.1801","article-title":"Extreme oxygen sensitivity of electronic properties of carbon nanotubes","volume":"287","author":"Collins","year":"2000","journal-title":"Science"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/S0009-2614(01)00111-7","article-title":"Gas adsorption in the inside and outside of single-walled carbon nanotubes","volume":"336","author":"Flujiwara","year":"2001","journal-title":"Chem. Phys. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1557\/PROC-593-173","article-title":"Effect of gas adsorption on the electrical properties of single-walled carbon nanotube mats","volume":"593","author":"Marliere","year":"2000","journal-title":"Proc. Mater. Res. Soc. Symp."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Sharma, D.K., Rajput, M., Akbar, S.A., and Kumar, A. (2015, January 17\u201320). Development of embedded system for carbon nano tube (CNT) based Ammonia (NH3) gas sensor. Proceedings of the IEEE India Conference, New Delhi, India.","DOI":"10.1109\/INDICON.2015.7443803"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Kumar, N., Sahatiya, P., and Dubey, P. (2014, January 8\u20139). Fabrication of CNT based Gas Sensor Using Interdigitated Gold Electrodes. Proceedings of the International Conference on Materials Processing and Characterisation, Hyderabad, India.","DOI":"10.1016\/j.mspro.2014.07.232"},{"key":"ref_26","unstructured":"Isa, S.S.M., Ramli, M.M., Jamlos, M.F., Hambali, N.A.M.A., Isa, M.M., Kasjoo, S.R., Ahmad, N., Nor, N.I.M., and Khalid, N. (2015, January 16\u201318). Multi-walled carbon nanotubes plastic NH3 gas sensor. Proceedings of the Asian Conference on Chemical Sensor, Penang, Malaysia."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1016\/j.proeng.2010.09.086","article-title":"Wireless interrogation techniques for sensors utilizing inductively coupled resonance circuits","volume":"5","author":"Salpavaara","year":"2010","journal-title":"Procedia Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1016\/j.conbuildmat.2011.06.029","article-title":"Application of a LTCC sensor for measuring moisture content of building materials","volume":"26","author":"Maksimovic","year":"2011","journal-title":"Constr. Build. Mater."},{"key":"ref_29","first-page":"109","article-title":"Readout methods for an inductively coupled resonance sensor used in pressure garment application","volume":"107","author":"Salpavaara","year":"2010","journal-title":"Sens. Actuators A Phys."},{"key":"ref_30","first-page":"777","article-title":"Equivalent Circuit Model and Parameter Extraction of Silicon-Based Planar Spiral Inductors","volume":"20","author":"Huang","year":"2005","journal-title":"Chin. J. Radio Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1016\/j.carbon.2013.12.044","article-title":"Gas sensing mechanism of carbon nanotubes: From single tubes to high-density networks","volume":"69","author":"Boyd","year":"2014","journal-title":"Carbon"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2582","DOI":"10.3390\/s120302582","article-title":"Integrating Metal-Oxide-Decorated CNT Networks with a CMOS Readout in a Gas Sensor","volume":"12","author":"Lee","year":"2012","journal-title":"Sensors"},{"key":"ref_33","unstructured":"Fonseca, M.A. (2007). Polymer\/Ceramic Wireless MEMS Pressure Sensors for Harsh Environments: High Temperature and Biomedical Applications, Georgia Institute of Technology."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"14386","DOI":"10.1039\/C8NR04524K","article-title":"Ambient N2 fixation to NH3 electrocatalyzed by a spinel Fe3O4 nanorod","volume":"10","author":"Liu","year":"2018","journal-title":"Nanoscale"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1109\/JSEN.2009.2035218","article-title":"The Effect on the Gas Selectivity of CNT-Based Gas Sensors by Binder in SWNT\/Silane Sol Solution","volume":"10","author":"Kim","year":"2009","journal-title":"IEEE Sens. J."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/j.matlet.2016.11.033","article-title":"Inkjet printing of polymer functionalized CNT gas sensor with enhanced sensing properties","volume":"189","author":"Alshammari","year":"2016","journal-title":"Mater. Lett."},{"key":"ref_37","unstructured":"Ke, S.C., and Shen, C.H. (2013, January 22\u201325). Fe3O4 magnetic enhanced CMOS MEMS compatible gas sensor. Proceedings of the IEEE International Conference of IEEE Region 10 (TENCON 2013), Xi\u2019an, China."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1016\/j.snb.2016.08.073","article-title":"A novel wireless gas sensor based on LTCC technology","volume":"239","author":"Ma","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"8206","DOI":"10.1007\/s10854-016-4825-6","article-title":"High performance sulfonic acid doped polyaniline\u2013polystyrene blend ammonia gas sensors","volume":"27","author":"Bhadra","year":"2016","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.snb.2013.12.062","article-title":"Reduced graphene oxide as an over-coating layer on silver nanostructures for detecting NH 3 gas at room temperature","volume":"194","author":"Tran","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"23107","DOI":"10.1021\/acsami.7b03702","article-title":"Single and Networked ZnO-CNT Hybrid Tetrapods for Selective Room-Temperature High-Performance Ammonia Sensors","volume":"9","author":"Postica","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_42","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_43","doi-asserted-by":"crossref","first-page":"43051","DOI":"10.1021\/acsami.7b13122","article-title":"Natural Carbonized Sugar as a Low-temperature Ammonia Sensor Material: Experimental, Theoretical and Computational Studies","volume":"9","author":"Ghule","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/10\/3542\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:26:46Z","timestamp":1760196406000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/10\/3542"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,10,19]]},"references-count":43,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2018,10]]}},"alternative-id":["s18103542"],"URL":"https:\/\/doi.org\/10.3390\/s18103542","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,10,19]]}}}