{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T16:14:27Z","timestamp":1775837667700,"version":"3.50.1"},"reference-count":17,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2018,2,1]],"date-time":"2018-02-01T00:00:00Z","timestamp":1517443200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The KIST Institutional Program","award":["2E26840"],"award-info":[{"award-number":["2E26840"]}]},{"DOI":"10.13039\/501100003710","name":"Korea Health Industry Development Institute","doi-asserted-by":"publisher","award":["HI14C3319"],"award-info":[{"award-number":["HI14C3319"]}],"id":[{"id":"10.13039\/501100003710","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Faradaic electrochemical impedance spectroscopy (f-EIS) in the presence of redox reagent, e.g., [Fe(CN)6]3\u2212\/4\u2212, is widely used in biosensors owing to its high sensitivity. However, in sensors detecting amyloid beta (A\u03b2), the redox reagent can cause the aggregation of A\u03b2, which is a disturbance factor in accurate detection. Here, we propose an interdigitated microelectrode (IME) based f-EIS technique that can alleviate the aggregation of A\u03b2 and achieve high sensitivity by buffer control. The proposed method was verified by analyzing three different EIS-based sensors: non-faradaic EIS (nf-EIS), f-EIS, and the proposed f-EIS with buffer control. We analyzed the equivalent circuits of nf-EIS and f-EIS sensors. The dominant factors of sensitivity were analyzed, and the impedance change rates via A\u03b2 reaction was compared. We measured the sensitivity of the IME sensors based on nf-EIS, f-EIS, and the proposed f-EIS. The results demonstrate that the proposed EIS-based IME sensor can detect A\u03b2 with a sensitivity of 7.40-fold and 10.93-fold higher than the nf-EIS and the f-EIS sensors, respectively.<\/jats:p>","DOI":"10.3390\/s18020426","type":"journal-article","created":{"date-parts":[[2018,2,2]],"date-time":"2018-02-02T04:20:50Z","timestamp":1517545250000},"page":"426","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":34,"title":["Amyloid Beta Detection by Faradaic Electrochemical Impedance Spectroscopy Using Interdigitated Microelectrodes"],"prefix":"10.3390","volume":"18","author":[{"given":"Jin","family":"Park","sequence":"first","affiliation":[{"name":"Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea"},{"name":"Department of Electrical Engineering, Korea University, Seoul 02841, Korea"}]},{"given":"Hye","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, Seoul 02447, Korea"},{"name":"Department of Electrical Engineering, Korea University, Seoul 02841, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3542-3885","authenticated-orcid":false,"given":"Ji-Hoon","family":"Lee","sequence":"additional","affiliation":[{"name":"Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea"}]},{"given":"Jung","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Korea University, Seoul 02841, Korea"}]},{"given":"Jinsik","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Medical Biotechnology, College of Life Science and Biotechnology, Dongguk University, Seoul 10326, Korea"}]},{"given":"Kyo","family":"Hwang","sequence":"additional","affiliation":[{"name":"Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, Seoul 02447, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7702-716X","authenticated-orcid":false,"given":"Byung","family":"Lee","sequence":"additional","affiliation":[{"name":"Center for BioMicrosystems, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2018,2,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1016\/j.jobcr.2015.12.002","article-title":"Biosensors and their applications\u2014A review","volume":"6","author":"Mehrotra","year":"2016","journal-title":"J. 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