{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,15]],"date-time":"2026-03-15T03:30:22Z","timestamp":1773545422912,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2015,3,17]],"date-time":"2015-03-17T00:00:00Z","timestamp":1426550400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this study, we describe a novel solid-state thin-film Ag\/AgCl reference electrode (SSRE) that was coated with a protective layer of graphene oxide (GO). This layer was prepared by drop casting a solution of GO on the Ag\/AgCl thin film. The potential differences exhibited by the SSRE were less than 2 mV for 26 days. The cyclic voltammograms of the SSRE were almost similar to those of a commercial reference electrode, while the diffusion coefficient of Fe(CN)63\u2212 as calculated from the cathodic  peaks of the SSRE was 6.48 \u00d7 10\u22126 cm2\/s. The SSRE was used in conjunction with a laboratory-made working electrode to determine its suitability for practical use. The average pH sensitivity of this combined sensor was 58.5 mV\/pH in the acid-to-base direction; the correlation coefficient was greater than 0.99. In addition, an integrated pH sensor that included the SSRE was packaged in a secure digital (SD) card and tested. The average sensitivity of the chip was 56.8 mV\/pH, with the correlation coefficient being greater than 0.99. In addition, a pH sensing test was also performed by using a laboratory-made potentiometer, which showed a sensitivity of 55.4 mV\/pH, with the correlation coefficient being greater than 0.99.<\/jats:p>","DOI":"10.3390\/s150306469","type":"journal-article","created":{"date-parts":[[2015,3,17]],"date-time":"2015-03-17T11:04:24Z","timestamp":1426590264000},"page":"6469-6482","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":68,"title":["A Solid-State Thin-Film Ag\/AgCl Reference Electrode Coated with Graphene Oxide and Its Use in a pH Sensor"],"prefix":"10.3390","volume":"15","author":[{"given":"Tae","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Medical System Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sung","family":"Hong","sequence":"additional","affiliation":[{"name":"Department of Medical System Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sung","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Medical System Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Korea"},{"name":"School of Mechatronics, Gwangju Institute of Science and Technology (GIST),  Gwangju 500-712, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,3,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2043","DOI":"10.3390\/s8042043","article-title":"Electrochemical sensors for clinic analysis","volume":"8","author":"Wang","year":"2008","journal-title":"Sensors"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4955","DOI":"10.3390\/s90604955","article-title":"Metal Oxides and Ion-Exchanging Surfaces as pH Sensors in Liquids: State-of-the-Art and Outlook","volume":"6","author":"Kurzweil","year":"2009","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"664","DOI":"10.1039\/C0LC00293C","article-title":"Nanoporous platinum solid-state reference electrode with layer-by-layer polyelectrolyte junction for pH sensing chip","volume":"11","author":"Noh","year":"2011","journal-title":"Lab Chip"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/S0925-4005(98)00043-4","article-title":"Problems associated with the thin-film Ag\/AgCl reference electrode and a novel structure with improved durability","volume":"46","author":"Suzuki","year":"1998","journal-title":"Sens. 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