{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T13:42:29Z","timestamp":1772804549748,"version":"3.50.1"},"reference-count":46,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2020,10,9]],"date-time":"2020-10-09T00:00:00Z","timestamp":1602201600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100014188","name":"Ministry of Science and ICT, South Korea","doi-asserted-by":"publisher","award":["NRF-2018R1A4A1025623"],"award-info":[{"award-number":["NRF-2018R1A4A1025623"]}],"id":[{"id":"10.13039\/501100014188","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ministry of Education, South Korea","award":["2020R1I1A3069757"],"award-info":[{"award-number":["2020R1I1A3069757"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Patch-type hydrogel electrodes have received increasing attention in biomedical applications due to their high biocompatibility and conformal adherence. However, their poor mechanical properties and non-uniform electrical performance in a large area of the hydrogel electrode should be improved for use in wearable devices for biosignal monitoring. Here, we developed self-adherent, biocompatible hydrogel electrodes composed of biodegradable gelatin and conductive polymers for electrocardiography (ECG) measurement. After incorporating conductive poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) into gelatin hydrogels crosslinked by natural crosslinkers (genipin), the mechanical properties and electrical conductivity of the hydrogel electrodes were improved and additionally optimized by adjusting the amounts of crosslinker and PEDOT:PSS, respectively. Furthermore, the effect of dimethyl sulfoxide, as a dopant, on the conductivity of hydrogels was investigated. The gelatin-based, conductive hydrogel patch displayed self-adherence to human skin with an adhesive strength of 0.85 N and achieved conformal contact with less skin irritation compared to conventional electrodes with a chemical adhesive layer. Eyelet-type hydrogel electrodes, which were compatible with conventional ECG measurement instruments, exhibited a comparable performance in 12-lead human ECG measurement with commercial ECG clinical electrodes (3M Red Dot). These self-adherent, biocompatible, gelatin-based hydrogel electrodes could be used for monitoring various biosignals, such as in electromyography and electroencephalography.<\/jats:p>","DOI":"10.3390\/s20205737","type":"journal-article","created":{"date-parts":[[2020,10,9]],"date-time":"2020-10-09T10:19:23Z","timestamp":1602238763000},"page":"5737","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":46,"title":["Self-Adherent Biodegradable Gelatin-Based Hydrogel Electrodes for Electrocardiography Monitoring"],"prefix":"10.3390","volume":"20","author":[{"given":"Yechan","family":"Lee","sequence":"first","affiliation":[]},{"given":"Sang-Gu","family":"Yim","sequence":"additional","affiliation":[]},{"given":"Gyeong Won","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]},{"given":"Sodam","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]},{"given":"Hong Sung","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]},{"given":"Dae Youn","family":"Hwang","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]},{"given":"Beum-Soo","family":"An","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]},{"given":"Jae Ho","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]},{"given":"Sungbaek","family":"Seo","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]},{"given":"Seung Yun","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Biomaterials Science (BK21 Four Program), College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1161\/01.RES.0000163635.62927.34","article-title":"Adipose tissue, inflammation, and cardiovascular disease","volume":"96","author":"Berg","year":"2015","journal-title":"Circ. Res."},{"key":"ref_2","first-page":"72","article-title":"ECG beat classification method for ECG printout with principle components analysis and support vector machines","volume":"1","author":"Thanapatay","year":"2010","journal-title":"ICEIE"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"844","DOI":"10.5805\/SFTI.2015.17.5.844","article-title":"A study of sensing locations for ECG monitoring clothing based on the skin change rate","volume":"17","author":"Cho","year":"2015","journal-title":"Fash. Text. Res. J."},{"key":"ref_4","first-page":"162","article-title":"Thin film electrodes as elements of telemedicine systems","volume":"91","author":"Korzeniewska","year":"2015","journal-title":"Prz. Elektrotech."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Hoffmann, K.P., and Ruff, R. (2007). Flexible dry surface-electrodes for ECG long-term monitoring. IEEE EMBS, 5739\u20135742.","DOI":"10.1109\/IEMBS.2007.4353650"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/j.jelectrocard.2010.12.004","article-title":"A comparison of conductive textile-based and silver\/silver chloride gel electrodes in exercise electrocardiogram recordings","volume":"44","author":"Marozas","year":"2011","journal-title":"J. Electrocardiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/S0924-4247(01)00766-X","article-title":"Design and fabrication of a high-density metal microelectrode array for neural recording","volume":"96","author":"Xu","year":"2002","journal-title":"Sens. Actuator A Phys."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"8721","DOI":"10.1021\/jp911256h","article-title":"Nanoporous Pt microelectrode for neural stimulation and recording: In vitro characterization","volume":"114","author":"Park","year":"2010","journal-title":"J. Phys. Chem. C"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1109\/TBME.1977.326117","article-title":"Minimizing electrode motion artifact by skin abrasion","volume":"24","author":"Tam","year":"1977","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1325","DOI":"10.1021\/acsmacrolett.7b00829","article-title":"Flexible and shape-reconfigurable hydrogel interlocking adhesives for high adhesion in wet environments based on anisotropic swelling of hydrogel microstructures","volume":"6","author":"Park","year":"2017","journal-title":"ACS Macro Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"014107","DOI":"10.1088\/1468-6996\/11\/1\/014107","article-title":"Conducting polymer-hydrogels for medical electrode applications","volume":"11","author":"Green","year":"2010","journal-title":"Sci. Technol. Adv. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1124","DOI":"10.1557\/jmr.2006.0145","article-title":"Impedance spectroscopy and nanoindentation of conducting poly (3, 4-ethylenedioxythiophene) coatings on microfabricated neural prosthetic devices","volume":"21","author":"Yang","year":"2006","journal-title":"J. Mater. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/S0956-5663(03)00220-3","article-title":"Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode","volume":"19","year":"2003","journal-title":"Biosens. Bioelectron."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"6086","DOI":"10.1039\/C4TA00484A","article-title":"Nanostructured conductive polypyrrole hydrogels as high-performance, flexible supercapacitor electrodes","volume":"2","author":"Shi","year":"2014","journal-title":"J. Mater. Chem. A"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1800275","DOI":"10.1002\/adhm.201800275","article-title":"Multifunctional smart skin adhesive patches for advanced health care","volume":"7","author":"Hwang","year":"2018","journal-title":"Adv. Healthc. Mater."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Tavakoli, J., and Tang, Y. (2017). Hydrogel based sensors for biomedical applications: An updated review. Polymers, 9.","DOI":"10.3390\/polym9080364"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3442","DOI":"10.1021\/acsnano.9b09533","article-title":"Winding-locked carbon nanotubes\/polymer nanofibers helical yarn for ultrastretchable conductor and strain sensor","volume":"14","author":"Gao","year":"2020","journal-title":"ACS Nano"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"27099","DOI":"10.1039\/C9TA11084D","article-title":"A stretchable, conformable, and biocompatible graphene strain sensor based on a structured hydrogel for clinical application","volume":"7","author":"Cai","year":"2019","journal-title":"J. Mater. Chem. A"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Lou, C., Li, R., Li, Z., Liang, T., Wei, Z., Run, M., Yan, X., and Liu, X. (2016). Flexible graphene electrodes for prolonged dynamic ECG monitoring. Sensors, 16.","DOI":"10.3390\/s16111833"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1642","DOI":"10.1039\/C8CS00595H","article-title":"Hydrogel bioelectronics","volume":"48","author":"Yuk","year":"2019","journal-title":"Chem. Soc. Rev."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.synthmet.2015.03.010","article-title":"Conducting poly (3, 4-ethylenedioxythiophene): Poly (styrene-sulfonate) film electrode with superior long-term electrode stability in water and synergistically enhanced electrocatalytic ability for application in electrochemical sensors","volume":"204","author":"Zhang","year":"2015","journal-title":"Synth. Met."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1002\/(SICI)1521-4095(200004)12:7<481::AID-ADMA481>3.0.CO;2-C","article-title":"Poly (3, 4-ethylenedioxythiophene) and its derivatives: Past, present, and future","volume":"12","author":"Groenendaal","year":"2000","journal-title":"Adv. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1121","DOI":"10.1002\/pola.28482","article-title":"Scientific importance of water-processable PEDOT-PSS and preparation, challenge and new application in sensors of its film electrode: A review","volume":"55","author":"Wen","year":"2017","journal-title":"J. Polym. Sci. A Polym. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1039\/b919944f","article-title":"Thermo-sensitive, injectable, and tissue adhesive sol-gel transition hyaluronic acid\/pluronic composite hydrogels prepared from bio-inspired catechol-thiol reaction","volume":"6","author":"Lee","year":"2010","journal-title":"Soft Matter"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1038\/nbt.2958","article-title":"3D bioprinting of tissues and organs","volume":"32","author":"Murphy","year":"2014","journal-title":"Nat. Biotechnol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3814","DOI":"10.1002\/adfm.201500006","article-title":"Tissue adhesive catechol-modified hyaluronic acid hydrogel for effective, minimally invasive cell therapy","volume":"25","author":"Shin","year":"2015","journal-title":"Adv. Funct. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1558","DOI":"10.1021\/acsami.9b18646","article-title":"Self-healing and highly stretchable gelatin hydrogel for self-powered strain sensor","volume":"12","author":"Wang","year":"2020","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.foodhyd.2011.04.016","article-title":"Ultrasonic study of the gelation of gelatin: Phase diagram, hysteresis and kinetics","volume":"26","author":"Parker","year":"2012","journal-title":"Food Hydrocoll."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"4827","DOI":"10.1016\/S0142-9612(02)00235-1","article-title":"Stabilization of gelatin films by crosslinking with genipin","volume":"23","author":"Bigi","year":"2002","journal-title":"Biomaterials"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1002\/term.267","article-title":"Gelatin microspheres crosslinked with genipin for local delivery of growth factors","volume":"4","author":"Solorio","year":"2010","journal-title":"J. Tissue Eng. Regen. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4017","DOI":"10.1002\/app.13563","article-title":"Crosslinking structures of gelatin hydrogels crosslinked with genipin or a water-soluble carbodiimide","volume":"91","author":"Liang","year":"2004","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_32","unstructured":"Yang, T. (2012). Mechanical and Swelling Properties of Hydrogels. [Ph.D. Thesis, KTH Royal Institute of Technology]."},{"key":"ref_33","first-page":"1558","article-title":"Electroconductive gelatin methacryloyl-PEDOT:PSS composite hydrogels: Design, synthesis, and properties","volume":"4","author":"Spencer","year":"2018","journal-title":"ACS Biomater. Sci. Eng."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2740","DOI":"10.1038\/s41467-018-05222-4","article-title":"Mechanically tunable conductive interpenetrating network hydrogels that mimic the elastic moduli of biological tissue","volume":"9","author":"Feig","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1625","DOI":"10.1039\/C8TB02763C","article-title":"Considerations for hydrogel applications to neural bioelectronics","volume":"7","author":"Goding","year":"2019","journal-title":"J. Mater. Chem. B"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"4236","DOI":"10.1039\/C6NR08375G","article-title":"Perovskite solar cells with a DMSO-treated PEDOT:PSS hole transport layer exhibit higher photovoltaic performance and enhanced durability","volume":"9","author":"Huang","year":"2017","journal-title":"Nanoscale"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1021\/acsami.5b08753","article-title":"Simultaneously enhancing the cohesion and electrical conductivity of PEDOT:PSS conductive polymer films using DMSO Additives","volume":"8","author":"Lee","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"100194","DOI":"10.1016\/j.wndm.2020.100194","article-title":"Gross and histopathological effects of dimethyl sulfoxide on wound healing in rats","volume":"30","author":"Kant","year":"2020","journal-title":"Wound Med."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1002\/adfm.201101775","article-title":"Highly conductive and transparent PEDOT:PSS films with a fluorosurfactant for stretchable and flexible transparent electrodes","volume":"22","author":"Vosgueritchian","year":"2012","journal-title":"Adv. Funct. Mater."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2578","DOI":"10.1007\/s12221-015-5616-z","article-title":"The effects of DMSO on structure and properties of PVA\/PEDOT:PSS blended fiber","volume":"16","author":"Wang","year":"2015","journal-title":"Fibers Polym."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1850043","DOI":"10.1142\/S1793604718500431","article-title":"Study on the effect of DMSO on the changes in the conductivity of PEDOT:PSS","volume":"11","author":"Hwang","year":"2018","journal-title":"Funct. Mater. Lett."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2721","DOI":"10.1161\/01.CIR.0000145144.56673.59","article-title":"Practice standards for electrocardiographic monitoring in hospital settings","volume":"110","author":"Drew","year":"2004","journal-title":"Circulation"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1016\/S1350-4533(97)00013-1","article-title":"Nonlinear high pass filter for R-wave detection in ECG signal","volume":"19","author":"Keselbrener","year":"1997","journal-title":"Med. Eng. Phys."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Guo, D.G., Tay, F.E., Yu, L.M., Xu, L., Nyan, M.N., Chong, F.W., Yap, K.L., and Xu, B. (2008, January 1\u20133). A wearable BSN-based ECG-recording system using micromachined electrode for continuous arrhythmia monitoring. Proceedings of the 5th International Summer School and Symposium on Medical Devices and Biosensors, Hong Kong, China.","DOI":"10.1109\/ISSMDBS.2008.4575011"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1803309","DOI":"10.1002\/adma.201803309","article-title":"Bioinspired adhesive architectures: From skin patch to integrated bioelectronics","volume":"31","author":"Baik","year":"2019","journal-title":"Adv. Mater."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1902720","DOI":"10.1002\/adfm.201902720","article-title":"Ultra-adaptable and wearable photonic skin based on a shape-memory, responsive cellulose derivative","volume":"29","author":"Yi","year":"2019","journal-title":"Adv. Funct. Mater."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/20\/5737\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:17:53Z","timestamp":1760177873000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/20\/5737"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,10,9]]},"references-count":46,"journal-issue":{"issue":"20","published-online":{"date-parts":[[2020,10]]}},"alternative-id":["s20205737"],"URL":"https:\/\/doi.org\/10.3390\/s20205737","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,10,9]]}}}