{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T19:47:13Z","timestamp":1774381633323,"version":"3.50.1"},"reference-count":40,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2021,10,25]],"date-time":"2021-10-25T00:00:00Z","timestamp":1635120000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Homocysteine (Hcy) is a non-protein, sulfur-containing amino acid, which is recognized as a possible risk factor for coronary artery and other pathologies when its levels in the blood exceed the normal range of between 5 and 12 \u03bcmol\/L (hyperhomocysteinemia). At present, standard procedures in laboratory medicine, such as high-performance liquid chromatography (HPLC), are commonly employed for the quantitation of total Hcy (tHcy), i.e., the sum of the protein-bound (oxidized) and free (homocystine plus reduced Hcy) forms, in biological fluids (particularly, serum or plasma). Here, the response of Aerosol Jet-printed organic electrochemical transistors (OECTs), in the presence of either reduced (free) and oxidized Hcy-based solutions, was analyzed. Two different experimental protocols were followed to this end: the former consisting of gold (Au) electrodes\u2019 biothiol-induced thiolation, while the latter simply used bare platinum (Pt) electrodes. Electrochemical impedance spectroscopy (EIS) analysis was performed both to validate the gold thiolation protocol and to gain insights into the reduced Hcy sensing mechanism by the Au-gated OECTs, which provided a final limit of detection (LoD) of 80 nM. For the OECT response based on Platinum gate electrodes, on the other hand, a LoD of 180 nM was found in the presence of albumin-bound Hcy, with this being the most abundant oxidized Hcy-form (i.e., the protein-bound form) in physiological fluids. Despite the lack of any biochemical functionalization supporting the response selectivity, the findings discussed in this work highlight the potential role of OECT in the development of low-cost point-of-care (POC) electronic platforms that are suitable for the evaluation, in humans, of Hcy levels within the physiological range and in cases of hyperhomocysteinemia.<\/jats:p>","DOI":"10.3390\/ijms222111507","type":"journal-article","created":{"date-parts":[[2021,10,25]],"date-time":"2021-10-25T21:40:21Z","timestamp":1635198021000},"page":"11507","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Homocysteine Solution-Induced Response in Aerosol Jet Printed OECTs by Means of Gold and Platinum Gate Electrodes"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4500-4457","authenticated-orcid":false,"given":"Pasquale","family":"D\u2019Angelo","sequence":"first","affiliation":[{"name":"IMEM-CNR, Parco Area delle Scienze 37\/A, I 43124 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1990-0119","authenticated-orcid":false,"given":"Mario","family":"Barra","sequence":"additional","affiliation":[{"name":"CNR-SPIN, c\/o Dipartimento di Fisica \u201cEttore Pancini\u201d, P.le Tecchio 80, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Patrizia","family":"Lombari","sequence":"additional","affiliation":[{"name":"Department of Precision Medicine, University of Campania \u201cLuigi Vanvitelli\u201d, via L. De Crecchio 7, 80138 Naples, Italy"},{"name":"Department of Translational Medical Science, University of Campania \u201cLuigi Vanvitelli\u201d, via Via Pansini, Bldg., 80131 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Annapaola","family":"Coppola","sequence":"additional","affiliation":[{"name":"Department of Precision Medicine, University of Campania \u201cLuigi Vanvitelli\u201d, via L. De Crecchio 7, 80138 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Davide","family":"Vurro","sequence":"additional","affiliation":[{"name":"IMEM-CNR, Parco Area delle Scienze 37\/A, I 43124 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giuseppe","family":"Tarabella","sequence":"additional","affiliation":[{"name":"Camlin Italy Srl, Via Budellungo 2, 43124 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Simone Luigi","family":"Marasso","sequence":"additional","affiliation":[{"name":"IMEM-CNR, Parco Area delle Scienze 37\/A, I 43124 Parma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Margherita","family":"Borriello","sequence":"additional","affiliation":[{"name":"Department of Precision Medicine, University of Campania \u201cLuigi Vanvitelli\u201d, via L. De Crecchio 7, 80138 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Federico","family":"Chianese","sequence":"additional","affiliation":[{"name":"Physics Department, University of Naples \u201cFederico II\u201d, P.le Tecchio, 80, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4048-9392","authenticated-orcid":false,"given":"Alessandra F.","family":"Perna","sequence":"additional","affiliation":[{"name":"Department of Translational Medical Science, University of Campania \u201cLuigi Vanvitelli\u201d, via Via Pansini, Bldg., 80131 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antonio","family":"Cassinese","sequence":"additional","affiliation":[{"name":"CNR-SPIN, c\/o Dipartimento di Fisica \u201cEttore Pancini\u201d, P.le Tecchio 80, 80125 Naples, Italy"},{"name":"Physics Department, University of Naples \u201cFederico II\u201d, P.le Tecchio, 80, 80125 Naples, Italy"},{"name":"Istututo Nazionale di Fisica Nucleare, Sezione di Napoli, P.le Tecchio, 80, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Diego","family":"Ingrosso","sequence":"additional","affiliation":[{"name":"Department of Precision Medicine, University of Campania \u201cLuigi Vanvitelli\u201d, via L. De Crecchio 7, 80138 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1825","DOI":"10.1016\/j.bios.2010.09.046","article-title":"Conductive polymer-based sensors for biomedical applications","volume":"26","author":"Nambiar","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_2","first-page":"8-1","article-title":"Electrolyte-gated organic FET (EGOFET) and organic electrochemical FET (OECFET)","volume":"Volume 2","author":"Khanna","year":"2019","journal-title":"Flexible Electronics"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"17086","DOI":"10.1038\/natrevmats.2017.86","article-title":"Organic electrochemical transistors","volume":"3","author":"Rivnay","year":"2018","journal-title":"Nat. Rev. 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