{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T07:21:22Z","timestamp":1778570482839,"version":"3.51.4"},"reference-count":39,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T00:00:00Z","timestamp":1769644800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001665","name":"Agence Nationale de la Recherche","doi-asserted-by":"crossref","award":["ANR-15-CE19-0006"],"award-info":[{"award-number":["ANR-15-CE19-0006"]}],"id":[{"id":"10.13039\/501100001665","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001665","name":"Agence Nationale de la Recherche","doi-asserted-by":"crossref","award":["ANR-19-CE19-0002-01"],"award-info":[{"award-number":["ANR-19-CE19-0002-01"]}],"id":[{"id":"10.13039\/501100001665","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Poly(3,4-ethylenedioxythiophene)\u2013polystyrene sulfonate (PEDOT:PSS) is widely used to fabricate conductive organic coatings for electrodes in electrophysiology. As these devices move toward clinical translation, establishing sterilization methods that preserve their functional properties is essential. Ethylene oxide (EtO) is routinely used for sterilizing heat- and moisture-sensitive medical devices due to its high penetration efficiency and low thermal load. However, the absence of systematic studies evaluating its impact on PEDOT:PSS raises concerns about the compatibility of EtO sterilization with organic electrophysiology interfaces. Here, we report the first comprehensive evaluation of EtO sterilization on PEDOT:PSS electrodes electrochemically deposited onto cortical interfaces designed for intraoperative monitoring and stimulation. EtO exposure induced only minimal changes in surface topography, with no detectable alteration of the electrical or electrochemical performance of the electrodes. Impedance spectroscopy, cyclic voltammetry, and charge-injection capacity measurements all revealed that EtO-treated electrodes retained properties comparable to untreated controls. Moreover, EtO-sterilized PEDOT:PSS coatings demonstrated robust long-term stability under accelerated lifetime testing, exhibiting negligible degradation over extended operation. These findings demonstrate that EtO sterilization is fully compatible with PEDOT:PSS-based bioelectronic interfaces and constitutes a viable pathway toward their safe and effective integration into clinical electrophysiology. This work represents an important step toward translating organic conducting polymer technologies into real-world biomedical applications.<\/jats:p>","DOI":"10.3390\/s26030877","type":"journal-article","created":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T09:12:01Z","timestamp":1769677921000},"page":"877","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Impact of Ethylene Oxide Sterilization on PEDOT:PSS Electrophysiology Electrodes"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2564-1109","authenticated-orcid":false,"given":"Ali","family":"Maziz","sequence":"first","affiliation":[{"name":"Laboratoire d\u2019Analyse et d\u2019Architecture des Systemes-Centre National de la Recherche Scientifique (LAAS-CNRS), 7 Avenue du Colonel Roche, 31400 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Clement","family":"Cointe","sequence":"additional","affiliation":[{"name":"Laboratoire d\u2019Analyse et d\u2019Architecture des Systemes-Centre National de la Recherche Scientifique (LAAS-CNRS), 7 Avenue du Colonel Roche, 31400 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Benjamin","family":"Reig","sequence":"additional","affiliation":[{"name":"Laboratoire d\u2019Analyse et d\u2019Architecture des Systemes-Centre National de la Recherche Scientifique (LAAS-CNRS), 7 Avenue du Colonel Roche, 31400 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian","family":"Bergaud","sequence":"additional","affiliation":[{"name":"Laboratoire d\u2019Analyse et d\u2019Architecture des Systemes-Centre National de la Recherche Scientifique (LAAS-CNRS), 7 Avenue du Colonel Roche, 31400 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1146\/annurev.bioeng.10.061807.160518","article-title":"Neural stimulation and recording electrodes","volume":"10","author":"Cogan","year":"2008","journal-title":"Annu. Rev. Biomed. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"664","DOI":"10.1038\/10223","article-title":"Real-time control of a robot arm using simultaneously recorded neurons in the motor cortex","volume":"2","author":"Chapin","year":"1999","journal-title":"Nat. Neurosci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1038\/35042582","article-title":"Real-time prediction of hand trajectory by ensembles of cortical neurons in primates","volume":"408","author":"Wessberg","year":"2000","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1146\/annurev.neuro.051508.135241","article-title":"The science of neural interface systems","volume":"32","author":"Hatsopoulos","year":"2009","journal-title":"Annu. Rev. Neurosci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/S1474-4422(08)70291-6","article-title":"Deep brain stimulation of the subthalamic nucleus for the treatment of Parkinson\u2019s disease","volume":"8","author":"Benabid","year":"2009","journal-title":"Lancet Neurol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"109388","DOI":"10.1016\/j.jneumeth.2021.109388","article-title":"Neural tissue-microelectrode interaction: Brain micromotion, electrical impedance, and flexible microelectrode insertion","volume":"365","author":"Sharafkhani","year":"2022","journal-title":"J. Neurosci. Methods"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jneumeth.2005.08.015","article-title":"Response of brain tissue to chronically implanted neural electrodes","volume":"148","author":"Polikov","year":"2005","journal-title":"J. Neurosci. Methods"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"862","DOI":"10.1038\/s41551-017-0154-1","article-title":"Glial responses to implanted electrodes in the brain","volume":"1","author":"Salatino","year":"2017","journal-title":"Nat. Biomed. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3393","DOI":"10.1016\/j.biomaterials.2008.04.047","article-title":"Conducting polymers for neural interfaces: Challenges in developing an effective long-term implant","volume":"29","author":"Green","year":"2008","journal-title":"Biomaterials"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1374","DOI":"10.1039\/c0py00077a","article-title":"Electroactive polymers for neural interfaces","volume":"1","author":"Asplund","year":"2010","journal-title":"Polym. Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1038\/nnano.2008.174","article-title":"Carbon nanotube coating improves neuronal recordings","volume":"3","author":"Keefer","year":"2008","journal-title":"Nat. Nanotechnol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1107","DOI":"10.1021\/nl050637m","article-title":"Carbon nanotube substrates boost neuronal electrical signaling","volume":"5","author":"Lovat","year":"2005","journal-title":"Nano Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1016\/j.cobme.2018.06.001","article-title":"Graphene-based neurotechnologies for advanced neural interfaces","volume":"6","author":"Lu","year":"2018","journal-title":"Curr. Opin. Biomed. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3970","DOI":"10.1002\/adma.200801984","article-title":"Nanomaterials for neural interfaces","volume":"21","author":"Kotov","year":"2009","journal-title":"Adv. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/S0925-4005(02)00448-3","article-title":"Electrochemical deposition and characterization of poly (3, 4-ethylenedioxythiophene) on neural microelectrode arrays","volume":"89","author":"Cui","year":"2003","journal-title":"Sens. Actuators B Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1016\/j.actbio.2004.09.006","article-title":"Ordered surfactant-templated poly (3, 4-ethylenedioxythiophene)(PEDOT) conducting polymer on microfabricated neural probes","volume":"1","author":"Yang","year":"2005","journal-title":"Acta Biomater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1088\/1741-2560\/3\/1\/007","article-title":"Chronic neural recordings using silicon microelectrode arrays electrochemically deposited with a poly (3, 4-ethylenedioxythiophene)(PEDOT) film","volume":"3","author":"Ludwig","year":"2006","journal-title":"J. Neural Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"014001","DOI":"10.1088\/1741-2560\/8\/1\/014001","article-title":"Poly (3, 4-ethylenedioxythiophene)(PEDOT) polymer coatings facilitate smaller neural recording electrodes","volume":"8","author":"Ludwig","year":"2011","journal-title":"J. Neural Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1002\/adfm.200801473","article-title":"Multifunctional nanobiomaterials for neural interfaces","volume":"19","author":"Abidian","year":"2009","journal-title":"Adv. Funct. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1586\/erd.09.58","article-title":"Development of bioactive conducting polymers for neural interfaces","volume":"7","author":"Lovell","year":"2010","journal-title":"Expert Rev. Med. Devices"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1567","DOI":"10.1002\/adfm.200801141","article-title":"Conducting-polymer nanomaterials for high-performance sensor applications: Issues and challenges","volume":"19","author":"Yoon","year":"2009","journal-title":"Adv. Funct. Mater."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1645","DOI":"10.1002\/adfm.200600669","article-title":"Micropatterned polypyrrole: A combination of electrical and topographical characteristics for the stimulation of cells","volume":"17","author":"Gomez","year":"2007","journal-title":"Adv. Funct. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"14978","DOI":"10.1021\/acsami.8b01059","article-title":"Patterning highly conducting conjugated polymer electrodes for soft and flexible microelectrochemical devices","volume":"10","author":"Khaldi","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"115182","DOI":"10.1016\/j.bios.2023.115182","article-title":"Hollow ring-like flexible electrode architecture enabling subcellular multi-directional neural interfacing","volume":"227","author":"Vajrala","year":"2023","journal-title":"Biosens. Bioelectron."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3637","DOI":"10.1016\/j.biomaterials.2009.03.043","article-title":"Cell attachment functionality of bioactive conducting polymers for neural interfaces","volume":"30","author":"Green","year":"2009","journal-title":"Biomaterials"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"5875","DOI":"10.1016\/j.biomaterials.2012.05.017","article-title":"Substrate dependent stability of conducting polymer coatings on medical electrodes","volume":"33","author":"Green","year":"2012","journal-title":"Biomaterials"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1302","DOI":"10.1016\/j.polymer.2011.01.042","article-title":"Structural, chemical and electrochemical characterization of poly (3, 4-Ethylenedioxythiophene)(PEDOT) prepared with various counter-ions and heat treatments","volume":"52","author":"King","year":"2011","journal-title":"Polymer"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"762","DOI":"10.1002\/adhm.201200182","article-title":"Hybrid conducting polymer\u2013hydrogel conduits for axonal growth and neural tissue engineering","volume":"1","author":"Abidian","year":"2012","journal-title":"Adv. Healthc. Mater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"11287","DOI":"10.1038\/ncomms11287","article-title":"Structural control of mixed ionic and electronic transport in conducting polymers","volume":"7","author":"Rivnay","year":"2016","journal-title":"Nat. Commun."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"100035","DOI":"10.1016\/j.snr.2021.100035","article-title":"Progress in conducting polymers for biointerfacing and biorecognition applications","volume":"3","author":"Maziz","year":"2021","journal-title":"Sens. Actuators Rep."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"H268","DOI":"10.1002\/adma.201102378","article-title":"Highly conformable conducting polymer electrodes for in vivo recordings","volume":"23","author":"Khodagholy","year":"2011","journal-title":"Adv. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1700232","DOI":"10.1002\/adfm.201700232","article-title":"Development and translation of PEDOT: PSS microelectrodes for intraoperative monitoring","volume":"28","author":"Ganji","year":"2018","journal-title":"Adv. Funct. Mater."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1016\/j.snb.2018.08.007","article-title":"PEDOT: PSS coating on gold microelectrodes with excellent stability and high charge injection capacity for chronic neural interfaces","volume":"275","author":"Pranti","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1109\/TNSRE.2011.2109399","article-title":"In vitro and in vivo evaluation of PEDOT microelectrodes for neural stimulation and recording","volume":"19","author":"Venkatraman","year":"2011","journal-title":"IEEE Trans. Neural Syst. Rehabil. Eng."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1109\/TBME.2015.2445713","article-title":"Chronic in vivo evaluation of PEDOT\/CNT for stable neural recordings","volume":"63","author":"Kozai","year":"2015","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1038\/nn.3905","article-title":"NeuroGrid: Recording action potentials from the surface of the brain","volume":"18","author":"Khodagholy","year":"2015","journal-title":"Nat. Neurosci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3557","DOI":"10.1038\/s41596-020-0389-2","article-title":"Tutorial: Guidelines for standardized performance tests for electrodes intended for neural interfaces and bioelectronics","volume":"15","author":"Boehler","year":"2020","journal-title":"Nat. Protoc."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Vajrala, V.S., Saunier, V., Nowak, L.G., Flahaut, E., Bergaud, C., and Maziz, A. (2021). Nanofibrous PEDOT-Carbon Composite on Flexible Probes for Soft Neural Interfacing. Front. Bioeng. Biotechnol., 9.","DOI":"10.3389\/fbioe.2021.780197"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.synthmet.2013.12.013","article-title":"Morphology and conductivity of PEDOT layers produced by different electrochemical routes","volume":"189","author":"Castagnola","year":"2014","journal-title":"Synth. Met."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/3\/877\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T05:15:01Z","timestamp":1769836501000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/3\/877"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,29]]},"references-count":39,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["s26030877"],"URL":"https:\/\/doi.org\/10.3390\/s26030877","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,29]]}}}