{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,18]],"date-time":"2026-01-18T12:16:30Z","timestamp":1768738590283,"version":"3.49.0"},"reference-count":37,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2019,12,13]],"date-time":"2019-12-13T00:00:00Z","timestamp":1576195200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/EEA\/50014\/2019"],"award-info":[{"award-number":["UID\/EEA\/50014\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["FCT COFASP\/0005\/2015"],"award-info":[{"award-number":["FCT COFASP\/0005\/2015"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A sensing configuration for the real-time monitoring, detection, and quantification of dissolved carbon dioxide (dCO2) was developed for aquaculture and other applications in freshwater and saline water. A chemical sensing membrane, based on a colorimetric indicator, is combined with multimode optical fiber and a dual wavelength light-emitting diode (LED) to measure the dCO2-induced absorbance changes in a self-referenced ratiometric scheme. The detection and processing were achieved with an embeded solution having a mini spectrometer and microcontroller. For optrode calibration, chemical standard solutions using sodium carbonate in acid media were used. Preliminary results in a laboratory environment showed sensitivity for small added amounts of CO2 (0.25 mg\u00b7L\u22121). Accuracy and response time were not affected by the type of solution, while precision was affected by salinity. Calibration in freshwater showed a limit of detection (LOD) and a limit of quantification (LOQ) of 1.23 and 1.87 mg\u00b7L\u22121, respectively. Results in saline water (2.5%) showed a LOD and LOQ of 1.05 and 1.16 mg\u00b7L\u22121, respectively. Generally, performance was improved when moving from fresh to saline water. Studies on the dynamics of dissolved CO2 in a recirculating shallow raceway system (SRS+RAS) prototype showed higher precision than the tested commercial sensor. The new sensor is a compact and robust device, and unlike other sensors used in aquaculture, stirring is not required for correct and fast detection. Tests performed showed that this new sensor has a fast accurate detection as well as a strong potential for assessing dCO2 dynamics in aquaculture applications.<\/jats:p>","DOI":"10.3390\/s19245513","type":"journal-article","created":{"date-parts":[[2019,12,13]],"date-time":"2019-12-13T11:27:22Z","timestamp":1576236442000},"page":"5513","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Dissolved Carbon Dioxide Sensing Platform for Freshwater and Saline Water Applications: Characterization and Validation in Aquaculture Environments"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1031-9261","authenticated-orcid":false,"given":"J.P.","family":"Mendes","sequence":"first","affiliation":[{"name":"CIQUP-Chemistry Research Unit, University of Porto, 4169-007 Porto, Portugal"},{"name":"Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal"},{"name":"INESCTEC-Institute for Systems and Computer Engineering, Technology and Science, 4200-465 Porto, Portugal"},{"name":"CIIMAR\u2014Interdisciplinary Centre of Marine and Environmental Research, 4450-208 Matosinhos, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6205-9479","authenticated-orcid":false,"given":"L.","family":"Coelho","sequence":"additional","affiliation":[{"name":"INESCTEC-Institute for Systems and Computer Engineering, Technology and Science, 4200-465 Porto, Portugal"}]},{"given":"B.","family":"Kovacs","sequence":"additional","affiliation":[{"name":"Department of General and Physical Chemistry, Faculty of Natural Sciences, University of P\u00e9cs, H-7624 P\u00e9cs, Hungary"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3810-5943","authenticated-orcid":false,"given":"J.M.M.M. de","family":"Almeida","sequence":"additional","affiliation":[{"name":"INESCTEC-Institute for Systems and Computer Engineering, Technology and Science, 4200-465 Porto, Portugal"},{"name":"Department of Physics, School of Sciences and Technology, University of Tr\u00e1s-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8392-9581","authenticated-orcid":false,"given":"C.M.","family":"Pereira","sequence":"additional","affiliation":[{"name":"CIQUP-Chemistry Research Unit, University of Porto, 4169-007 Porto, Portugal"},{"name":"Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1484-2068","authenticated-orcid":false,"given":"P.A.S.","family":"Jorge","sequence":"additional","affiliation":[{"name":"INESCTEC-Institute for Systems and Computer Engineering, Technology and Science, 4200-465 Porto, Portugal"},{"name":"Department of Physics and Astronomy, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal"}]},{"given":"M.T.","family":"Borges","sequence":"additional","affiliation":[{"name":"CIIMAR\u2014Interdisciplinary Centre of Marine and Environmental Research, 4450-208 Matosinhos, Portugal"},{"name":"Department of Biology, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1076","DOI":"10.1016\/j.snb.2016.07.141","article-title":"Extruded colour-based plastic film for the measurement of dissolved CO2","volume":"237","author":"Mills","year":"2016","journal-title":"Sens. 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