{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,6]],"date-time":"2026-11-06T00:34:00Z","timestamp":1793925240785,"version":"4.8.0"},"reference-count":32,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2024,8,22]],"date-time":"2024-08-22T00:00:00Z","timestamp":1724284800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Japan Society for the Promotion of Science","award":["21H01957"],"award-info":[{"award-number":["21H01957"]}]},{"name":"Japan Society for the Promotion of Science","award":["22H02102"],"award-info":[{"award-number":["22H02102"]}]},{"name":"Japan Society for the Promotion of Science","award":["23K17926"],"award-info":[{"award-number":["23K17926"]}]},{"name":"Japan Society for the Promotion of Science","award":["24H00070"],"award-info":[{"award-number":["24H00070"]}]},{"name":"Japan Society for the Promotion of Science","award":["JP22be1004205"],"award-info":[{"award-number":["JP22be1004205"]}]},{"DOI":"10.13039\/100009619","name":"AMED","doi-asserted-by":"publisher","award":["21H01957"],"award-info":[{"award-number":["21H01957"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"AMED","doi-asserted-by":"publisher","award":["22H02102"],"award-info":[{"award-number":["22H02102"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"AMED","doi-asserted-by":"publisher","award":["23K17926"],"award-info":[{"award-number":["23K17926"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"AMED","doi-asserted-by":"publisher","award":["24H00070"],"award-info":[{"award-number":["24H00070"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"AMED","doi-asserted-by":"publisher","award":["JP22be1004205"],"award-info":[{"award-number":["JP22be1004205"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>Two-layer microfluidic devices with porous membranes have been widely used in bioapplications such as microphysiological systems (MPS). Porous electrodes, instead of membranes, have recently been incorporated into devices for electrochemical cell analysis. Generally, microfluidic channels are prepared using soft lithography and assembled into two-layer microfluidic devices. In addition to soft lithography, three-dimensional (3D) printing has been widely used for the direct fabrication of microfluidic devices because of its high flexibility. However, this technique has not yet been applied to the fabrication of two-layer microfluidic devices with porous electrodes. This paper proposes a novel fabrication process for this type of device. In brief, Pluronic F-127 ink was three-dimensionally printed in the form of sacrificial layers. A porous Au electrode, fabricated by sputtering Au on track-etched polyethylene terephthalate membranes, was placed between the top and bottom sacrificial layers. After covering with polydimethylsiloxane, the sacrificial layers were removed by flushing with a cold solution. To the best of our knowledge, this is the first report on the sacrificial approach-based fabrication of two-layer microfluidic devices with a porous electrode. Furthermore, the device was used for electrochemical assays of serotonin and could successfully measure concentrations up to 5 \u00b5M. In the future, this device can be used for MPS applications.<\/jats:p>","DOI":"10.3390\/mi15081054","type":"journal-article","created":{"date-parts":[[2024,8,22]],"date-time":"2024-08-22T04:26:57Z","timestamp":1724300817000},"page":"1054","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Fabrication of Two-Layer Microfluidic Devices with Porous Electrodes Using Printed Sacrificial Layers"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4750-4025","authenticated-orcid":false,"given":"Kosuke","family":"Ino","sequence":"first","affiliation":[{"name":"Graduate School of Engineering, Tohoku University, 6-6-11-604 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"An","family":"Konno","sequence":"additional","affiliation":[{"name":"Graduate School of Environmental Studies, Tohoku University, 6-6-11-604 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoshinobu","family":"Utagawa","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, Tohoku University, 6-6-11-604 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taiyo","family":"Kanno","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, Tohoku University, 6-6-11-604 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuyuki","family":"Iwase","sequence":"additional","affiliation":[{"name":"Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8847-1581","authenticated-orcid":false,"given":"Hiroya","family":"Abe","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, Tohoku University, 6-6-11-604 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan"},{"name":"Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki-aza Aoba 6-3, Aoba-ku, Sendai 980-8578, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hitoshi","family":"Shiku","sequence":"additional","affiliation":[{"name":"Graduate School of Engineering, Tohoku University, 6-6-11-604 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan"},{"name":"Graduate School of Environmental Studies, Tohoku University, 6-6-11-604 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1038\/s41576-022-00466-9","article-title":"Human organs-on-chips for disease modelling, drug development and personalized medicine","volume":"23","author":"Ingber","year":"2022","journal-title":"Nat. Rev. Genet."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"18158","DOI":"10.1021\/acs.analchem.3c03684","article-title":"Vasculature-on-a-chip with a porous membrane electrode for in situ electrochemical detection of nitric oxide released from endothelial cells","volume":"95","author":"Utagawa","year":"2023","journal-title":"Anal. Chem."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1038\/s41378-020-00184-4","article-title":"Electrochemical measurement of serotonin by Au-CNT electrodes fabricated on microporous cell culture membranes","volume":"6","author":"Chapin","year":"2020","journal-title":"Microsyst. Nanoeng."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1038\/s41378-020-00208-z","article-title":"3D-Printed electrochemical sensor-integrated transwell systems","volume":"6","author":"Chapin","year":"2020","journal-title":"Microsyst. Nanoeng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1002\/(SICI)1522-2683(20000101)21:1<27::AID-ELPS27>3.0.CO;2-C","article-title":"Fabrication of microfluidic systems in poly(dimethylsiloxane)","volume":"21","author":"McDonald","year":"2000","journal-title":"Electrophoresis"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"745","DOI":"10.1016\/j.tcb.2011.09.005","article-title":"From 3D cell culture to organs-on-chips","volume":"21","author":"Huh","year":"2011","journal-title":"Trends Cell Biol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1230","DOI":"10.1039\/C4LC01246A","article-title":"Microfluidic cell sorting: A review of the advances in the separation of cells from debulking to rare cell isolation","volume":"15","author":"Reyes","year":"2015","journal-title":"Lab Chip"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1038\/s43586-021-00073-8","article-title":"3D extrusion bioprinting","volume":"1","author":"Zhang","year":"2021","journal-title":"Nat. Rev. Method. Prim."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1016\/j.jbiosc.2020.06.014","article-title":"Fabrication of three-dimensional calcium alginate hydrogels using sacrificial templates of sugar","volume":"130","author":"Ino","year":"2020","journal-title":"J. Biosci. Bioeng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"869","DOI":"10.1089\/3dp.2021.0147","article-title":"Improving the 3D printability of sugar glass to engineer sacrificial vascular templates","volume":"10","author":"Moeun","year":"2022","journal-title":"3D Print. Addit. Manuf."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Homan, K.A., Kolesky, D.B., Skylar-Scott, M.A., Herrmann, J., Obuobi, H., Moisan, A., and Lewis, J.A. (2016). Bioprinting of 3D convoluted renal proximal tubules on perfusable chips. Sci. Rep., 6.","DOI":"10.1038\/srep34845"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Utagawa, Y., Ino, K., Hiramoto, K., and Shiku, H. (2023). Simple, rapid, and large-scale fabrication of multi-branched hydrogels based on viscous fingering for cell culture applications. Macromol. Biosci., 23.","DOI":"10.1002\/mabi.202300069"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"6201","DOI":"10.1021\/acs.langmuir.1c00364","article-title":"Bio-inspired incrustation interfacial polymerization of dopamine and cross-linking with gelatin toward robust, biodegradable three-dimensional hydrogels","volume":"37","author":"Abe","year":"2021","journal-title":"Langmuir"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"111012","DOI":"10.1016\/j.matdes.2022.111012","article-title":"3D printing sacrificial templates for manufacturing hydrogel constructs with channel networks","volume":"222","author":"Pan","year":"2022","journal-title":"Mater. Des."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Brossard, R., Brouchet, T., and Malloggi, F. (2019). Replication of a printed volatile mold: A novel microfabrication method for advanced microfluidic systems. Sci. Rep., 9.","DOI":"10.1038\/s41598-019-53729-7"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Li, S., Li, H., Shang, X., He, J., and Hu, Y. (2023). Recent advances in 3D printing sacrificial templates for fabricating engineered vasculature. MedComm: Biomater. Appl., 2.","DOI":"10.1002\/mba2.46"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1007\/s10856-015-5493-4","article-title":"Pluronic F-127 hydrogel as a promising scaffold for encapsulation of dental-derived mesenchymal stem cells","volume":"26","author":"Diniz","year":"2015","journal-title":"J. Mater. Sci. Mater. Med."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Zhou, K., Dey, M., Ayan, B., Zhang, Z., Ozbolat, V., Kim, M.H., Khristov, V., and Ozbolat, I.T. (2021). Fabrication of PDMS microfluidic devices using nanoclay-reinforced Pluronic F-127 as a sacrificial ink. Biomed. Mater., 16.","DOI":"10.1088\/1748-605X\/abe55e"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"269","DOI":"10.2174\/1570159X19666210921100542","article-title":"Gut serotonin as a general membrane permeability regulator","volume":"20","year":"2022","journal-title":"Curr. Neuropharmacol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"12330","DOI":"10.1021\/acs.analchem.0c02016","article-title":"Enterochromaffin cell-enriched monolayer platform for assaying serotonin release from human primary intestinal cells","volume":"92","author":"Wang","year":"2020","journal-title":"Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1096","DOI":"10.1039\/D2AY01627C","article-title":"A portable electrochemical sensing platform for serotonin detection based on surface-modified carbon fiber microelectrodes","volume":"15","author":"Han","year":"2023","journal-title":"Anal. Methods"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3722","DOI":"10.1021\/ac800143t","article-title":"Electrophoretic cell manipulation and electrochemical gene-function analysis based on a yeast two-hybrid system in a microfluidic device","volume":"80","author":"Yasukawa","year":"2008","journal-title":"Anal. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"229","DOI":"10.2116\/analsci.20C017","article-title":"Electrorotation rates of K562 cells accompanied by erythroid differentiation induced by sodium butyrate","volume":"37","author":"Takeuchi","year":"2021","journal-title":"Anal. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1007\/s44211-022-00072-z","article-title":"Electrofusion of cells with different diameters by generating asymmetrical electric field in the microwell array","volume":"38","author":"Onohara","year":"2022","journal-title":"Anal. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1021\/acs.langmuir.2c02235","article-title":"Controlled transport of individual microparticles using dielectrophoresis","volume":"39","author":"Zaman","year":"2023","journal-title":"Langmuir"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2959","DOI":"10.1039\/c2lc40213k","article-title":"Gelatin methacrylate as a promising hydrogel for 3D microscale organization and proliferation of dielectrophoretically patterned cells","volume":"12","author":"Ahadian","year":"2012","journal-title":"Lab Chip"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"7976","DOI":"10.1021\/ac0513616","article-title":"A scalable addressable positive-dielectrophoretic cell-sorting array","volume":"77","author":"Taff","year":"2005","journal-title":"Anal. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Yasukawa, T., Yamada, J., Shiku, H., Matsue, T., and Suzuki, M. (2020). Microfluidic separation of blood cells based on the negative dielectrophoresis operated by three dimensional microband electrodes. Micromachines, 11.","DOI":"10.3390\/mi11090833"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"803","DOI":"10.2116\/analsci.21C002","article-title":"Selective trapping and retrieval of single cells using microwell array devices combined with dielectrophoresis","volume":"37","author":"Hata","year":"2021","journal-title":"Anal. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Suzuki, M., Minakuchi, Y., Mizutani, F., and Yasukawa, T. (2021). Discrimination of cell-differentiation using a cell-binding assay based on the conversion of cell-patterns with dielectrophoresis. Biosens. Bioelectron., 175.","DOI":"10.1016\/j.bios.2020.112892"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Hata, M., Suzuki, M., and Yasukawa, T. (2022). Selective retrieval of antibody-secreting hybridomas in cell arrays based on the dielectrophoresis. Biosens. Bioelectron., 209.","DOI":"10.1016\/j.bios.2022.114250"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"6648","DOI":"10.1002\/anie.201201602","article-title":"Local redox-cycling-based electrochemical chip device with deep microwells for evaluation of embryoid bodies","volume":"51","author":"Ino","year":"2012","journal-title":"Angew. Chem. Int. Ed."}],"container-title":["Micromachines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-666X\/15\/8\/1054\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:40:58Z","timestamp":1760110858000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-666X\/15\/8\/1054"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,22]]},"references-count":32,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2024,8]]}},"alternative-id":["mi15081054"],"URL":"https:\/\/doi.org\/10.3390\/mi15081054","relation":{},"ISSN":["2072-666X"],"issn-type":[{"value":"2072-666X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,22]]}}}