{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,10]],"date-time":"2026-01-10T20:51:32Z","timestamp":1768078292201,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,2,7]],"date-time":"2022-02-07T00:00:00Z","timestamp":1644192000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004837","name":"Spanish Ministry of Science and Innovation","doi-asserted-by":"publisher","award":["RTI2018-095856-B-C22 (AEI\/FEDER)."],"award-info":[{"award-number":["RTI2018-095856-B-C22 (AEI\/FEDER)."]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this research, a compact electronic nose (e-nose) based on a shear horizontal surface acoustic wave (SH-SAW) sensor array is proposed for the NO2 detection, classification and discrimination among some of the most relevant surrounding toxic chemicals, such as carbon monoxide (CO), ammonia (NH3), benzene (C6H6) and acetone (C3H6O). Carbon-based nanostructured materials (CBNm), such as mesoporous carbon (MC), reduced graphene oxide (rGO), graphene oxide (GO) and polydopamine\/reduced graphene oxide (PDA\/rGO) are deposited as a sensitive layer with controlled spray and Langmuir\u2013Blodgett techniques. We show the potential of the mass loading and elastic effects of the CBNm to enhance the detection, the classification and the discrimination of NO2 among different gases by using Machine Learning (ML) techniques (e.g., PCA, LDA and KNN). The small dimensions and low cost make this analytical system a promising candidate for the on-site discrimination of sub-ppm NO2.<\/jats:p>","DOI":"10.3390\/s22031261","type":"journal-article","created":{"date-parts":[[2022,2,7]],"date-time":"2022-02-07T20:36:42Z","timestamp":1644266202000},"page":"1261","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Carbon SH-SAW-Based Electronic Nose to Discriminate and Classify Sub-ppm NO2"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6937-9838","authenticated-orcid":false,"given":"Carlos","family":"Cruz","sequence":"first","affiliation":[{"name":"Grupo de Tecnolog\u00eda de Sensores Avanzados (SENSAVAN), Instituto de Tecnolog\u00edas F\u00edsicas y de la Informaci\u00f3n (ITEFI), CSIC, 28006 Madrid, Spain"},{"name":"Department of Electronics, University of Alcala, 28871 Alcala de Henares, Madrid, Spain"}]},{"given":"Daniel","family":"Matatagui","sequence":"additional","affiliation":[{"name":"Grupo de Tecnolog\u00eda de Sensores Avanzados (SENSAVAN), Instituto de Tecnolog\u00edas F\u00edsicas y de la Informaci\u00f3n (ITEFI), CSIC, 28006 Madrid, Spain"},{"name":"Dpto. de Ingenier\u00eda Inform\u00e1tica, Escuela Polit\u00e9cnica Superior, Universidad Aut\u00f3noma de Madrid, 28049 Madrid, Spain"}]},{"given":"Cristina","family":"Ram\u00edrez","sequence":"additional","affiliation":[{"name":"Institute of Ceramics and Glass, ICV-CSIC, Kelsen 5, Cantoblanco, 28049 Madrid, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9153-7158","authenticated-orcid":false,"given":"Isidro","family":"Badillo-Ramirez","sequence":"additional","affiliation":[{"name":"Instituto de Ciencias Aplicadas y Tecnolog\u00eda, Universidad Nacional Aut\u00f3noma de M\u00e9xico, Circuito Exterior S\/N, Ciudad Universitaria, Ciudad de Mexico 04510, Mexico"},{"name":"Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN), Department of Health Technology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark"}]},{"given":"Emmanuel","family":"de la O-Cuevas","sequence":"additional","affiliation":[{"name":"Instituto de Ciencias Aplicadas y Tecnolog\u00eda, Universidad Nacional Aut\u00f3noma de M\u00e9xico, Circuito Exterior S\/N, Ciudad Universitaria, Ciudad de Mexico 04510, Mexico"},{"name":"Unidad Acad\u00e9mica de F\u00edsica, Universidad Aut\u00f3noma de Zacatecas, Zacatecas 98068, Mexico"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8024-2541","authenticated-orcid":false,"given":"Jos\u00e9 M.","family":"Saniger","sequence":"additional","affiliation":[{"name":"Instituto de Ciencias Aplicadas y Tecnolog\u00eda, Universidad Nacional Aut\u00f3noma de M\u00e9xico, Circuito Exterior S\/N, Ciudad Universitaria, Ciudad de Mexico 04510, Mexico"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2554-3119","authenticated-orcid":false,"given":"Mari Carmen","family":"Horrillo","sequence":"additional","affiliation":[{"name":"Grupo de Tecnolog\u00eda de Sensores Avanzados (SENSAVAN), Instituto de Tecnolog\u00edas F\u00edsicas y de la Informaci\u00f3n (ITEFI), CSIC, 28006 Madrid, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"111681","DOI":"10.1016\/j.jenvman.2020.111681","article-title":"A review of current air quality indexes and improvements under the multi-contaminant air pollution exposure","volume":"279","author":"Tan","year":"2021","journal-title":"J. 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