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The microfluidic chip platform was developed for this purpose through 3D printing. The Fabry\u2013Perot cavity was incorporated in the microfluidic chip perpendicularly to the sample flow, which was of approximately 3.7 \u00b5L\/s. The optofluidic fiber sensor platform coupled with a low-cost optical power meter detector was characterized using different concentrations of glucose solutions. In the linear regression analysis, the optical power shift was correlated with the refractive index and a sensitivity of \u221286.6 dB\/RIU (r2 = 0.996) was obtained. Good results were obtained in terms of stability with a maximum standard deviation of 0.03 dB and a sensor resolution of 5.2 \u00d7 10\u22124 RIU. The feasibility of the optofluidic fiber sensor for dynamic analyses of refractive index with low sample usage was confirmed through real-time measurements.<\/jats:p>","DOI":"10.3390\/s22239377","type":"journal-article","created":{"date-parts":[[2022,12,2]],"date-time":"2022-12-02T03:28:04Z","timestamp":1669951684000},"page":"9377","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Real-Time Measurement of Refractive Index Using 3D-Printed Optofluidic Fiber Sensor"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1704-6745","authenticated-orcid":false,"given":"Jo\u00e3o M.","family":"Le\u00e7a","sequence":"first","affiliation":[{"name":"i3N & Physics Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Yannis","family":"Magalh\u00e3es","sequence":"additional","affiliation":[{"name":"i3N & Physics Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9129-3539","authenticated-orcid":false,"given":"Paulo","family":"Antunes","sequence":"additional","affiliation":[{"name":"i3N & Physics Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0772-8953","authenticated-orcid":false,"given":"Vanda","family":"Pereira","sequence":"additional","affiliation":[{"name":"i3N & Physics Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal"},{"name":"ISOPlexis\u2014Sustainable Agriculture and Food Technology Center, University of Madeira, Campus da Penteada, 9020-105 Funchal, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1170-7530","authenticated-orcid":false,"given":"Marta S.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"i3N & Physics Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1109\/JSTQE.2015.2466071","article-title":"A review of single-mode fiber optofluidics","volume":"22","author":"Blue","year":"2016","journal-title":"IEEE J. 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