{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T22:01:38Z","timestamp":1791842498796,"version":"4.3.4"},"reference-count":35,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,1,6]],"date-time":"2020-01-06T00:00:00Z","timestamp":1578268800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"undefined  &lt;span style=&quot;color:gray;font-size:10px;&quot;&gt;undefined&lt;\/span&gt;","award":["HI18C1039"],"award-info":[{"award-number":["HI18C1039"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Salivary pepsin is a promising marker for the non-invasive diagnosis of laryngopharyngeal reflux (LPR). For reliable results regarding pepsin in saliva, it is critical to standardize the collection, storage, and pre-processing methods. In this study, we optimized the saliva collection protocols, including storage conditions, i.e., solution, temperature, and time, and the pre-processing filter for pepsin. Moreover, we prepared a simple immunochromatographic strip for the rapid detection of pepsin and evaluated its sensing performance. As a result, we selected a polypropylene (PP) filter as the pre-processing filter for salivary pepsin in low resource settings, such as those where point of care testing (POCT) is conducted. This filter showed a similar efficiency to the centrifuge (standard method). Finally, we detected the pepsin using gold nanoparticles conjugated with monoclonal pepsin antibody. Under optimized conditions, the lower limit of detection for pepsin test strips was determined as 0.01 \u03bcg\/mL. Furthermore, we successfully detected the salivary pepsin in real saliva samples of LPR patients, which were pre-processed by the PP filter. Therefore, we expect that our saliva collection protocol and pepsin immunochromatographic strip can be utilized as useful tools for a non-invasive diagnosis\/screening of LPR in POCT.<\/jats:p>","DOI":"10.3390\/s20010325","type":"journal-article","created":{"date-parts":[[2020,1,6]],"date-time":"2020-01-06T10:34:46Z","timestamp":1578306886000},"page":"325","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Optimization of Saliva Collection and Immunochromatographic Detection of Salivary Pepsin for Point-of-Care Testing of Laryngopharyngeal Reflux"],"prefix":"10.3390","volume":"20","author":[{"given":"Young Ju","family":"Lee","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, College of Medicine, Kyung Hee University, Seoul 02447, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiyoon","family":"Kwon","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Natural Science, Kwangwoon University, Seoul 01897, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sanggyeong","family":"Shin","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Natural Science, Kwangwoon University, Seoul 01897, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4081-5207","authenticated-orcid":false,"given":"Young-Gyu","family":"Eun","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology\u2013Head and Neck Surgery, Kyung Hee University Medical Center, Seoul 02447, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jae Ho","family":"Shin","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Natural Science, Kwangwoon University, Seoul 01897, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gi-Ja","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, College of Medicine, Kyung Hee University, Seoul 02447, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1067\/mhn.2002.125760","article-title":"Laryngopharyngeal reflux: Position statement of the committee on speech, voice, and swallowing disorders of the american academy of otolaryngology-head and neck surgery","volume":"127","author":"Koufman","year":"2002","journal-title":"Otolaryngol. 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