{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,11]],"date-time":"2025-11-11T13:22:19Z","timestamp":1762867339943,"version":"build-2065373602"},"reference-count":24,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2018,1,30]],"date-time":"2018-01-30T00:00:00Z","timestamp":1517270400000},"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>Ethanol concentration was quantified by the use of a compact surface plasmon resonance (SPR) system, which electrically detects hot electrons via a Schottky barrier. Although it is well known that SPR can be used as bio\/chemical sensors, implementation is not necessarily practical, due to the size and cost impediments associated with a system with variable wavelength or angle of incidence. However, scanning capability is not a prerequisite if the objective is to use SPR in a sensor. It is possible to build a small, inexpensive SPR sensor if the optics have no moving parts and a Schottky barrier is used for electrical current detection in place of a photodetector. This article reports on the design and performance of such a novel SPR sensor, and its application for quantifying ethanol concentration. As the concentration of ethanol is increased, the change in the angle dependence of the SPR current is observed. This change can be understood as a superposition of contributions of SPR coupled with the +3rd- and \u22123rd-order diffraction. Moreover, real-time monitoring of ethanol concentration was demonstrated using the proposed SPR system.<\/jats:p>","DOI":"10.3390\/s18020399","type":"journal-article","created":{"date-parts":[[2018,1,30]],"date-time":"2018-01-30T08:03:34Z","timestamp":1517299414000},"page":"399","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Compact Surface Plasmon Resonance System with Au\/Si Schottky Barrier"],"prefix":"10.3390","volume":"18","author":[{"given":"Takuya","family":"Tsukagoshi","sequence":"first","affiliation":[{"name":"Information and Robot Technology Research Initiative, The University of Tokyo, Tokyo 113-8656, Japan"}]},{"given":"Yuta","family":"Kuroda","sequence":"additional","affiliation":[{"name":"Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 113-8656, Japan"}]},{"given":"Kentaro","family":"Noda","sequence":"additional","affiliation":[{"name":"Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 113-8656, Japan"}]},{"given":"Nguyen","family":"Binh-Khiem","sequence":"additional","affiliation":[{"name":"Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 113-8656, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1433-9465","authenticated-orcid":false,"given":"Tetsuo","family":"Kan","sequence":"additional","affiliation":[{"name":"Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo 182-8585, Japan"}]},{"given":"Isao","family":"Shimoyama","sequence":"additional","affiliation":[{"name":"Information and Robot Technology Research Initiative, The University of Tokyo, Tokyo 113-8656, Japan"},{"name":"Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 113-8656, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2018,1,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"874","DOI":"10.1103\/PhysRev.106.874","article-title":"Plasma losses by fast electrons in thin films","volume":"106","author":"Ritchie","year":"1957","journal-title":"Phys. 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[Master\u2019s Thesis, Loyola University]."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/2\/399\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:53:04Z","timestamp":1760194384000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/2\/399"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,1,30]]},"references-count":24,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2018,2]]}},"alternative-id":["s18020399"],"URL":"https:\/\/doi.org\/10.3390\/s18020399","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2018,1,30]]}}}