{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T22:28:57Z","timestamp":1773700137856,"version":"3.50.1"},"reference-count":33,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2019,3,7]],"date-time":"2019-03-07T00:00:00Z","timestamp":1551916800000},"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>Tears are exceptionally rich sources of information on the health status of the eyes, as well as of whole body functionality, due to the presence of a large variety of salts and organic components whose concentration can be altered by pathologies, eye diseases and\/or inflammatory processes. Surface enhanced Raman spectroscopy (SERS) provides a unique method for analyzing low concentrations of organic fluids such as tears. In this work, a home-made colloid of gold nanoparticles has been used for preparing glass substrates able to efficiently induce an SERS effect in fluid samples excited by a He\u2013Ne laser ( \u03bb = 633 nm). The method has been preliminary tested on Rhodamine 6G aqueous solutions at different concentrations, proving the possibility to sense substance concentrations as low as few \u03bc M, i.e., of the order of the main tear organic components. A clear SERS response has been obtained for human tear samples, allowing an interesting insight into tear composition. In particular, aspartic acid and glutamic acid have been shown to be possible markers for two important human tear components, i.e., lactoferrin and lysozyme.<\/jats:p>","DOI":"10.3390\/s19051177","type":"journal-article","created":{"date-parts":[[2019,3,8]],"date-time":"2019-03-08T04:58:35Z","timestamp":1552021115000},"page":"1177","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["Characterization of Human Tear Fluid by Means of Surface-Enhanced Raman Spectroscopy"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6014-0588","authenticated-orcid":false,"given":"Carlo","family":"Camerlingo","sequence":"first","affiliation":[{"name":"Consiglio Nazionale delle Ricerche, SPIN-CNR, Via Campi Flegrei 34, 80078 Pozzuoli, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4791-6468","authenticated-orcid":false,"given":"Mikhail","family":"Lisitskiy","sequence":"additional","affiliation":[{"name":"Consiglio Nazionale delle Ricerche, SPIN-CNR, Via Campi Flegrei 34, 80078 Pozzuoli, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2743-5904","authenticated-orcid":false,"given":"Maria","family":"Lepore","sequence":"additional","affiliation":[{"name":"Dipartimento di Medicina Sperimentale, Universit\u00e0 della Campania \u201cL. Vanvitelli\u201d, 80138 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marianna","family":"Portaccio","sequence":"additional","affiliation":[{"name":"Dipartimento di Medicina Sperimentale, Universit\u00e0 della Campania \u201cL. Vanvitelli\u201d, 80138 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniela","family":"Montorio","sequence":"additional","affiliation":[{"name":"Dipt. di Neuroscienze e Scienze Riproduttive ed Odontostomatologiche, Universit\u00e1 di Napoli \u2019Federico II\u2019, 80121 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Salvatore Del","family":"Prete","sequence":"additional","affiliation":[{"name":"CISME\u2014Centro Interdipartimentale di Microscopia Elettronica, Universit\u00e1 di Napoli \u2019Federico II\u2019, 80100 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4253-1929","authenticated-orcid":false,"given":"Gilda","family":"Cennamo","sequence":"additional","affiliation":[{"name":"Dipt. di Sanit\u00e1 Pubblica, Universit\u00e1 di Napoli \u2019Federico II\u2019, 80131 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,3,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1186\/s13167-016-0065-3","article-title":"Tear fluid biomarkers in ocular and systemic disease: Potential use for predictive, preventive and personalised medicine","volume":"7","author":"Hagan","year":"2016","journal-title":"EPMA J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.baga.2015.05.001","article-title":"Biomarker sources for Parkinson\u2019s disease: Time to shed tears?","volume":"5","author":"Funke","year":"2015","journal-title":"Basal Ganglia"},{"key":"ref_3","first-page":"115001","article-title":"Monitoring early phases of orthodontic treatment by means of Raman spectroscopies","volume":"22","author":"Perillo","year":"2017","journal-title":"J. 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