{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T09:21:01Z","timestamp":1763457661268,"version":"build-2065373602"},"reference-count":15,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2017,12,1]],"date-time":"2017-12-01T00:00:00Z","timestamp":1512086400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61575181"],"award-info":[{"award-number":["61575181"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"publisher","award":["201562008"],"award-info":[{"award-number":["201562008"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2016YFC0302101"],"award-info":[{"award-number":["2016YFC0302101"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Strategic Priority Research Program CAS","award":["XDA11040301"],"award-info":[{"award-number":["XDA11040301"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Raman spectroscopy has great potential as a tool in a variety of hydrothermal science applications. However, its low sensitivity has limited its use in common sea areas. In this paper, we develop a near-concentric cavity-enhanced Raman spectroscopy system to directly detect bicarbonate in seawater for the first time. With the aid of this near-concentric cavity-enhanced Raman spectroscopy system, a significant enhancement in HCO3\u2212 detection has been achieved. The obtained limit of detection (LOD) is determined to be 0.37 mmol\/L\u2014much lower than the typical concentration of HCO3\u2212 in seawater. By introducing a specially developed data processing scheme, the weak HCO3\u2212 signal is extracted from the strong sulfate signal background, hence a quantitative analysis with R2 of 0.951 is made possible. Based on the spectra taken from deep sea seawater sampling, the concentration of HCO3\u2212 has been determined to be 1.91 mmol\/L, with a relative error of 2.1% from the reported value (1.95 mmol\/L) of seawater in the ocean. It is expected that the near-concentric cavity-enhanced Raman spectroscopy system could be developed and used for in-situ ocean observation in the near future.<\/jats:p>","DOI":"10.3390\/s17122784","type":"journal-article","created":{"date-parts":[[2017,12,1]],"date-time":"2017-12-01T12:30:16Z","timestamp":1512131416000},"page":"2784","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["A Direct Bicarbonate Detection Method Based on a Near-Concentric Cavity-Enhanced Raman Spectroscopy System"],"prefix":"10.3390","volume":"17","author":[{"given":"Dewang","family":"Yang","sequence":"first","affiliation":[{"name":"College of Information Science & Engineering, Ocean University of China, Qingdao 266000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jinjia","family":"Guo","sequence":"additional","affiliation":[{"name":"College of Information Science & Engineering, Ocean University of China, Qingdao 266000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chunhao","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Information Science & Engineering, Ocean University of China, Qingdao 266000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qingsheng","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Information Science & Engineering, Ocean University of China, Qingdao 266000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ronger","family":"Zheng","sequence":"additional","affiliation":[{"name":"College of Information Science & Engineering, Ocean University of China, Qingdao 266000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,12,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1038\/nature12857","article-title":"The changing carbon cycle of the coastal ocean","volume":"504","author":"Bauer","year":"2013","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Pilson, M.E. (2012). An Introduction to the Chemistry of the Sea, Cambridge University Press.","DOI":"10.1017\/CBO9781139047203"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1146\/annurev.marine.010908.163834","article-title":"Ocean acidification: The other CO2 problem","volume":"1","author":"Doney","year":"2009","journal-title":"Annu. Rev. Mar. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"9630","DOI":"10.1021\/es0511725","article-title":"Seeing a deep ocean CO2 enrichment experiment in a new light: Laser Raman detection of dissolved CO2 in seawater","volume":"39","author":"Dunk","year":"2005","journal-title":"Environ. Sci. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2509","DOI":"10.5194\/bg-9-2509-2012","article-title":"Detecting anthropogenic carbon dioxide uptake and ocean acidification in the North Atlantic Ocean","volume":"9","author":"Bates","year":"2012","journal-title":"Biogeosci. Discuss."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"308","DOI":"10.1021\/cr0503557","article-title":"The Marine Inorganic Carbon Cycle","volume":"107","author":"Millero","year":"2007","journal-title":"Chem. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"195A","DOI":"10.1366\/0003702041389319","article-title":"Raman spectroscopy in the deep ocean: Successes and challenges","volume":"58","author":"Pasteris","year":"2004","journal-title":"Appl. Spectrosc."},{"key":"ref_8","unstructured":"Brewer, P.G., Dunk, R.M., White, S.N., Peltzer, E.T., Bowie, B., and Walz, P.M. (2004). First Attempts at Direct Raman Detection of the Oceanic Carbonate System, American Geophysical Union."},{"key":"ref_9","unstructured":"Scholl, J., Brewer, P., Peltzer, E., and Walz, P. (2017, December 01). Liquid-Core Waveguide for Enhanced Laser Raman Spectroscopy in Oceanic Applications. Available online: http:\/\/citeseerx.ist.psu.edu\/viewdoc\/download?doi=10.1.1.598.451&rep=rep1&type=pdf."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"739","DOI":"10.1016\/j.dsr.2003.11.005","article-title":"Development of a laser Raman spectrometer for deep-ocean science","volume":"51","author":"Brewer","year":"2004","journal-title":"Deep-Sea Res. Part I"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"7803","DOI":"10.1021\/acs.analchem.5b01462","article-title":"Cavity-enhanced Raman spectroscopy of natural gas with optical feedback cw-diode lasers","volume":"87","author":"Hippler","year":"2015","journal-title":"Anal. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2143","DOI":"10.1364\/OL.33.002143","article-title":"Near-confocal cavity-enhanced Raman spectroscopy for multitrace-gas detection","volume":"33","author":"Li","year":"2008","journal-title":"Opt. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1970","DOI":"10.1063\/1.1353190","article-title":"Enhanced Raman sensitivity using an actively stabilized external resonator","volume":"72","author":"Taylor","year":"2001","journal-title":"Rev. Sci. Instrum."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"7744","DOI":"10.1364\/AO.55.007744","article-title":"Highly sensitive Raman system for dissolved gas analysis in water","volume":"55","author":"Yang","year":"2016","journal-title":"Appl. Opt."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"12377","DOI":"10.3390\/s150612377","article-title":"Investigation of two novel approaches for detection of sulfate ion and methane dissolved in sediment pore water using Raman spectroscopy","volume":"15","author":"Du","year":"2015","journal-title":"Sensors"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/12\/2784\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:52:07Z","timestamp":1760208727000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/12\/2784"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,12,1]]},"references-count":15,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2017,12]]}},"alternative-id":["s17122784"],"URL":"https:\/\/doi.org\/10.3390\/s17122784","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2017,12,1]]}}}