{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T04:29:49Z","timestamp":1772252989266,"version":"3.50.1"},"reference-count":21,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2019,6,17]],"date-time":"2019-06-17T00:00:00Z","timestamp":1560729600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency","doi-asserted-by":"publisher","award":["none"],"award-info":[{"award-number":["none"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We have investigated human-stress monitoring by making use of salivary nitrate, which can be a candidate for stress markers, with ion-selective field-effect transistors (ISFETs). ISFETs are suitable for on-site single-drop analysis of salivary nitrate within 10 s. However, when ISFETs are used for salivary nitrate, ISFETs have a problem that is called the initial drift. The initial drift makes accurate nitrate monitoring difficult. Thus, the purpose of this study is to prevent the initial drift and to search for a new, simple polymer to possess a better performance of sensor responses than conventional matrix membranes, such as PVC. In this research, we investigated ISFETs using specific matrix membranes, for example KP-13, Pellethane\u00ae\u00ad\u00ad, and P7281-PU. The initial drift was evaluated from the fluctuations of the response values generated by the ISFETs when immersed in saliva or aqueous solution. As a result, P7281-PU showed a prevention effect on the initial drift, both in the whole saliva and in various solutions. Furthermore, the cause of drift may be H+ diffusion, and the drift prevention effect of P7281-PU may be affected by urethane bond capturing H+ in the ion-selective membrane. This result suggests that a continuous nitrate monitoring is feasible and may be applied to wearable sensors.<\/jats:p>","DOI":"10.3390\/s19122713","type":"journal-article","created":{"date-parts":[[2019,6,17]],"date-time":"2019-06-17T03:24:41Z","timestamp":1560741881000},"page":"2713","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Investigation of Polyurethane Matrix Membranes for Salivary Nitrate ISFETs to Prevent the Drift"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0136-2284","authenticated-orcid":false,"given":"Shuto","family":"Osaki","sequence":"first","affiliation":[{"name":"Aist-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, AIST, Suita 565-0043, Japan"},{"name":"Department of Applied Physics, Graduate School of Engineering, Osaka University, Suita 565-0043, Japan"}]},{"given":"Takuya","family":"Kintoki","sequence":"additional","affiliation":[{"name":"Aist-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, AIST, Suita 565-0043, Japan"},{"name":"Department of Applied Chemistry, Graduate School of Engineering, Osaka Institute of Technology, Osaka 535-8585, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7503-9098","authenticated-orcid":false,"given":"Takayo","family":"Moriuchi-Kawakami","sequence":"additional","affiliation":[{"name":"Department of Applied Chemistry, Graduate School of Engineering, Osaka Institute of Technology, Osaka 535-8585, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1098-8289","authenticated-orcid":false,"given":"Kenichi","family":"Kitamura","sequence":"additional","affiliation":[{"name":"National Institute of Technology, Toba College, Toba 517-8501, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0593-3371","authenticated-orcid":false,"given":"Shin-ichi","family":"Wakida","sequence":"additional","affiliation":[{"name":"Aist-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, AIST, Suita 565-0043, Japan"},{"name":"Department of Applied Physics, Graduate School of Engineering, Osaka University, Suita 565-0043, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2019,6,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1146\/annurev.clinpsy.1.102803.143938","article-title":"Stress and depression","volume":"Volume 1","author":"Hammen","year":"2005","journal-title":"Annual Review of Clinical Psychology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1865","DOI":"10.1017\/S0033291716000349","article-title":"Depressive vulnerability, stressful life events and episode onset of major depression: A longitudinal model","volume":"46","author":"Kendler","year":"2016","journal-title":"Psychol. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1146\/annurev.psych.48.1.191","article-title":"The effects of stressful life events on depression","volume":"48","author":"Kessler","year":"1997","journal-title":"Annu. Rev. Psychol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1146\/annurev.physiol.67.040403.120816","article-title":"Endocrinology of the stress response","volume":"Volume 67","author":"Charmandari","year":"2005","journal-title":"Annual Review of Physiology"},{"key":"ref_5","first-page":"541","article-title":"Free epinephrine, norepinephrine and dopamine in saliva and plasma of healthy-adults","volume":"30","author":"Schwab","year":"1992","journal-title":"Eur. J. Clin. Chem. Clin. Biochem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1034\/j.1399-3003.1999.13b18.x","article-title":"Salivary Contribution to Exhaled Nitric Oxide","volume":"13","author":"Zetterquist","year":"1999","journal-title":"Eur. Respir. J."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"8","DOI":"10.3164\/jcbn.2008002","article-title":"Dynamic aspect of reactive oxygen and nitric oxide in oral cavity","volume":"42","author":"Sato","year":"2008","journal-title":"J. Clin. Biochem. Nutr."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1006\/jmcc.1998.0839","article-title":"NO: The primary EDRF","volume":"31","author":"Fleming","year":"1999","journal-title":"J. Mol. Cell. Cardiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.ctim.2012.11.004","article-title":"Effects of woodland walking on salivary stress markers cortisol and chromogranin A","volume":"21","author":"Toda","year":"2013","journal-title":"Complement. Ther. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"728","DOI":"10.37358\/RC.18.3.6186","article-title":"Salivary alpha-amylase activity\u2014A novel non-invasive biomarker in clinical pathology","volume":"69","author":"Cozma","year":"2018","journal-title":"Revista De Chimie"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1995","DOI":"10.1021\/ac00286a048","article-title":"Response of ion-selective field effect transistors to carbon-dioxide and organic-acids","volume":"57","author":"Fogt","year":"1985","journal-title":"Anal. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2275","DOI":"10.1039\/an9941902275","article-title":"20 Years of ion-selective field-effect transistors","volume":"119","author":"Janata","year":"1994","journal-title":"Analyst"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1021\/ac00156a025","article-title":"Elimination of neutral species interference at the ion-sensitive membrane semiconductor-device interface","volume":"60","author":"Li","year":"1988","journal-title":"Anal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/S0003-2670(02)00475-0","article-title":"Reducing the interference from CO2 or organic acids in ion-selective polymer membrane sensors having a field-effect transistor as internal reference element","volume":"464","author":"Reichmuth","year":"2002","journal-title":"Anal. Chim. Acta"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1016\/S0039-9140(00)00408-2","article-title":"Application of an ion-selective field effect transistor with a photocured polymer membrane in nephrology for determination of potassium ions in dialysis solutions and in blood plasma","volume":"52","author":"Abramova","year":"2000","journal-title":"Talanta"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3108","DOI":"10.1021\/ac00114a003","article-title":"Thrombogenic Properties of untreated and poly(ethylene oxide)-modified polymeric matrices useful for preparing intraarterial ion-selective electrodes","volume":"67","author":"Espadastorre","year":"1995","journal-title":"Anal. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1021\/bk-1992-0487.ch019","article-title":"Polymeric matrix membrane field-effect transistors\u2014Sodium-ion sensors for medical applications","volume":"Volume 487","author":"Wakida","year":"1992","journal-title":"ACS Symposium Series"},{"key":"ref_18","unstructured":"Moriuchi, T. (2018, January 15\u201319). Development of stable ISFETs for salivary nitrate to acute stress monitoring. Proceedings of the 17th International Meeting on Chemical Sensors, Vienna, Austria."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Wakida, S. (2019, January 14\u201319). Stable ISFET sensors for stress monitoring. Proceedings of the Advanced Environmental, Chemical, and Biological Sensing Technologies XV, Baltimore, MD, USA.","DOI":"10.1117\/12.2518851"},{"key":"ref_20","first-page":"235","article-title":"Highly sensitive nitrate-sensing materials for ion-selective field-effect transistors for single-drop rain analysis","volume":"19","author":"Wakida","year":"2007","journal-title":"Sens. Mater."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/S0021-9673(04)00979-3","article-title":"Simultaneous determination of nitrite, nitrate, thiocyanate and uric acid in human saliva by capillary zone electrophoresis and its application to the study of daily variations","volume":"1051","author":"Tanaka","year":"2004","journal-title":"J. Chromatogr. 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