{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T04:35:21Z","timestamp":1774326921080,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2019,11,4]],"date-time":"2019-11-04T00:00:00Z","timestamp":1572825600000},"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>Volatile organic compounds (VOCs) released by plants are closely associated with plant metabolism and can serve as biomarkers for disease diagnosis. Huanglongbing (HLB), also known as citrus greening or yellow shoot disease, is a lethal threat to the multi-billion-dollar citrus industry. Early detection of HLB is vital for removal of susceptible citrus trees and containment of the disease. Gas sensors are applied to monitor the air quality or toxic gases owing to their low-cost fabrication, smooth operation, and possible miniaturization. Here, we report on the development, characterization, and application of electrical biosensor arrays based on single-walled carbon nanotubes (SWNTs) decorated with single-stranded DNA (ssDNA) for the detection of four VOCs\u2014ethylhexanol, linalool, tetradecene, and phenylacetaldehyde\u2014that serve as secondary biomarkers for detection of infected citrus trees during the asymptomatic stage. SWNTs were noncovalently functionalized with ssDNA using \u03c0\u2013\u03c0 interaction between the nucleotide and sidewall of SWNTs. The resulting ssDNA-SWNT hybrid structure and device properties were investigated using Raman spectroscopy, ultraviolet (UV) spectroscopy, and electrical measurements. To monitor changes in the four VOCs, gas biosensor arrays consisting of bare SWNTs before and after being decorated with different ssDNA were employed to determine the different concentrations of the four VOCs. The data was processed using principal component analysis (PCA) and neural net fitting (NNF).<\/jats:p>","DOI":"10.3390\/s19214795","type":"journal-article","created":{"date-parts":[[2019,11,4]],"date-time":"2019-11-04T10:49:07Z","timestamp":1572864547000},"page":"4795","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["Gas Biosensor Arrays Based on Single-Stranded DNA-Functionalized Single-Walled Carbon Nanotubes for the Detection of Volatile Organic Compound Biomarkers Released by Huanglongbing Disease-Infected Citrus Trees"],"prefix":"10.3390","volume":"19","author":[{"given":"Hui","family":"Wang","sequence":"first","affiliation":[{"name":"Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education China Agri-Cultural University, Beijing 100083, China"},{"name":"Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture China Agri-Cultural University, Beijing 100083, China"},{"name":"Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA 92521, USA"},{"name":"Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pankaj","family":"Ramnani","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0198-0154","authenticated-orcid":false,"given":"Tung","family":"Pham","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claudia Chaves","family":"Villarreal","sequence":"additional","affiliation":[{"name":"Materials Science and Engineering Program, University of California-Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xuejun","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gang","family":"Liu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education China Agri-Cultural University, Beijing 100083, China"},{"name":"Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture China Agri-Cultural University, Beijing 100083, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2831-4154","authenticated-orcid":false,"given":"Ashok","family":"Mulchandani","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA 92521, USA"},{"name":"Materials Science and Engineering Program, University of California-Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1071\/AP03089","article-title":"Detection of Huanglongbing (citrus greening disease) in Timor-Leste (East Timor) and in Papua New Guinea","volume":"33","author":"Weinert","year":"2004","journal-title":"Australas. 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