{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T04:42:19Z","timestamp":1782794539261,"version":"3.54.5"},"reference-count":16,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2016,12,13]],"date-time":"2016-12-13T00:00:00Z","timestamp":1481587200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"FCT\/MEC through national funds and when applicable co-funded by FEDER \u2013 PT2020 partnership agreement","award":["UID\/EEA\/50008\/2013"],"award-info":[{"award-number":["UID\/EEA\/50008\/2013"]}]},{"name":"FCT\/MEC through national funds and when applicable co-funded by FEDER \u2013 PT2020 partnership agreement","award":["SFRH\/BD\/88899\/2012"],"award-info":[{"award-number":["SFRH\/BD\/88899\/2012"]}]},{"name":"FCT\/MEC through national funds and when applicable co-funded by FEDER \u2013 PT2020 partnership agreement","award":["IF\/01664\/2014"],"award-info":[{"award-number":["IF\/01664\/2014"]}]},{"DOI":"10.13039\/100013239","name":"CESAM","doi-asserted-by":"publisher","award":["UID\/AMB\/50017"],"award-info":[{"award-number":["UID\/AMB\/50017"]}],"id":[{"id":"10.13039\/100013239","id-type":"DOI","asserted-by":"publisher"}]},{"name":"FCT\/MEC through national funds and the co-funding by the FEDER","award":["SFRH\/BPD\/104265\/2014"],"award-info":[{"award-number":["SFRH\/BPD\/104265\/2014"]}]},{"name":"Italian Ministry of University and Research","award":["PON 03PE_00155_1 OPTOFER"],"award-info":[{"award-number":["PON 03PE_00155_1 OPTOFER"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We report the optimization of the length of a D-shaped plastic optical fiber (POF) sensor for refractive index (RI) sensing from a numerical and experimental point of view. The sensing principle is based on total internal reflection (TIR). POFs with 1 mm in diameter were embedded in grooves, realized in planar supports with different lengths, and polished to remove the cladding and part of the core. All D-shaped POF sensors were tested using aqueous medium with different refractive indices (from 1.332 to 1.471) through intensity-based configuration. Results showed two different responses. Considering the refractive index (RI) range (1.33\u20131.39), the sensitivity and the resolution of the sensor were strongly dependent on the sensing region length. The highest sensitivity (resolution of 6.48 \u00d7 10\u22123 refractive index units, RIU) was obtained with 6 cm sensing length. In the RI range (1.41\u20131.47), the length of the sensing region was not a critical aspect to obtain the best resolution. These results enable the application of this optical platform for chemical and biochemical evanescent field sensing. The sensor production procedure is very simple, fast, and low-cost.<\/jats:p>","DOI":"10.3390\/s16122119","type":"journal-article","created":{"date-parts":[[2016,12,13]],"date-time":"2016-12-13T10:15:52Z","timestamp":1481624152000},"page":"2119","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":70,"title":["Refractive Index Sensing with D-Shaped Plastic Optical Fibers for Chemical and Biochemical Applications"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6681-1282","authenticated-orcid":false,"given":"Filipa","family":"Sequeira","sequence":"first","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, 3810-193 Aveiro, Portugal"},{"name":"CESAM, University of Aveiro, 3810-193 Aveiro, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5845-9354","authenticated-orcid":false,"given":"Daniel","family":"Duarte","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, 3810-193 Aveiro, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8804-593X","authenticated-orcid":false,"given":"L\u00facia","family":"Bilro","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, 3810-193 Aveiro, Portugal"},{"name":"I3N\/FSCOSD, Department of Physics, University of Aveiro, 3810-193 Aveiro, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7963-3892","authenticated-orcid":false,"given":"Alisa","family":"Rudnitskaya","sequence":"additional","affiliation":[{"name":"CESAM, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria","family":"Pesavento","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Pavia, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luigi","family":"Zeni","sequence":"additional","affiliation":[{"name":"Department of Industrial and Information Engineering, Second University of Naples, 81031 Aversa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7769-0984","authenticated-orcid":false,"given":"Nunzio","family":"Cennamo","sequence":"additional","affiliation":[{"name":"Department of Industrial and Information Engineering, Second University of Naples, 81031 Aversa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,12,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"536","DOI":"10.1016\/j.snb.2016.02.074","article-title":"Development of LSPR based U-Bent Plastic Optical Fiber Sensors","volume":"230","author":"Gowri","year":"2016","journal-title":"Sens. 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