{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T12:24:31Z","timestamp":1772713471116,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2022,8,20]],"date-time":"2022-08-20T00:00:00Z","timestamp":1660953600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Second Century Fund (C2F), Chulalongkorn University"},{"name":"Rachadapisek Sompote Fund for Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This work demonstrated a ZnO-coated optical fiber sensor for the detection of a volatile organic compound (VOC) biomarker for diabetes for detecting isopropanol (IPA) markers. A coreless silica fiber (CSF) was connected to a single-mode fiber (SMF) at both ends to achieve a SMF\u2013CSF\u2013SMF structure. CSF is the sensing region where multimode interference (MMI) generates higher light interaction at the interface between the fiber and sensing medium, leading to enhanced sensitivity. Optimization of the CSF length was conducted numerically to attain the highest possible coupling efficiency at the output. Surface functionalization was achieved via hydrothermal growth of ZnO nanorods directly onto the CSF at low temperatures. The optical fiber-based sensor was successfully fabricated and tested with 20%, 40%, 60%, 80%, and 100% of IPA. The sensor response was recorded using an optical spectrometer and analyzed for sensor sensitivity. The fabricated sensor shows the potential to detect isopropanol with the sensitivity of 0.053 nm\/%IPA vapor. Further improvement of the sensor sensitivity and selectivity is also proposed for future work.<\/jats:p>","DOI":"10.3390\/s22166273","type":"journal-article","created":{"date-parts":[[2022,8,22]],"date-time":"2022-08-22T01:56:40Z","timestamp":1661133400000},"page":"6273","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["ZnO Nanorods Coated Single-Mode\u2013Multimode\u2013Single-Mode Optical Fiber Sensor for VOC Biomarker Detection"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4322-1420","authenticated-orcid":false,"given":"Kankan","family":"Swargiary","sequence":"first","affiliation":[{"name":"International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7351-5716","authenticated-orcid":false,"given":"Prattakorn","family":"Metem","sequence":"additional","affiliation":[{"name":"International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand"},{"name":"Functional NanoMaterials Group, Department of Applied Physics, KTH Royal Institute of Technology, Hannes Alfv\u00e9ns v\u00e4g 12, 11419 Stockholm, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chayapol","family":"Kulatumyotin","sequence":"additional","affiliation":[{"name":"International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Suphavit","family":"Thaneerat","sequence":"additional","affiliation":[{"name":"International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Noppasin","family":"Ajchareeyasoontorn","sequence":"additional","affiliation":[{"name":"International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pannathorn","family":"Jitpratak","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Program, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tanujjal","family":"Bora","sequence":"additional","affiliation":[{"name":"Center of Excellence in Nanotechnology, Asian Institute of Technology, Pathumthani 12120, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3324-0986","authenticated-orcid":false,"given":"Waleed S.","family":"Mohammed","sequence":"additional","affiliation":[{"name":"Center of Research in Optoelectronics, Communication and Control Systems (BU-CROCCS), School of Engineering, Bangkok University, Pathumthani 12120, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0074-3504","authenticated-orcid":false,"given":"Joydeep","family":"Dutta","sequence":"additional","affiliation":[{"name":"Functional NanoMaterials Group, Department of Applied Physics, KTH Royal Institute of Technology, Hannes Alfv\u00e9ns v\u00e4g 12, 11419 Stockholm, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4176-3341","authenticated-orcid":false,"given":"Charusluk","family":"Viphavakit","sequence":"additional","affiliation":[{"name":"International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"15119","DOI":"10.1016\/j.ceramint.2016.06.145","article-title":"Detection of hazardous volatile organic compounds (VOCs) by metal oxide nanostructures-based gas sensors: A review","volume":"42","author":"Mirzaei","year":"2016","journal-title":"Ceram. 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