{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T05:15:40Z","timestamp":1778130940472,"version":"3.51.4"},"reference-count":54,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2024,8,14]],"date-time":"2024-08-14T00:00:00Z","timestamp":1723593600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Industrial Collective Research (IGF)"},{"name":"RWTH Aachen University"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We present a sensor array of microscale organic electrochemical transistors (OECTs) using poly (3,4\u2212ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) as the channel material. The devices show high sensitivity and selectivity to detect dopamine (DA) with platinum (Pt) as a pseudo\u2212reference gate electrode. First, we describe the wafer\u2212scale fabrication process for manufacturing the PEDOT:PSS OECTs, and then we introduce a dilution method to adjust the thickness of the PEDOT:PSS film. Next, we investigate the effect of the film thickness on the sensitivity of DA detection. Reducing the film thickness enhances the sensitivity of DA detection within the concentration range of 1 \u03bcM to 100 \u03bcM. The OECTs show impressive sensitivitywith a limit of detection (LoD) as low as 1 nM and a high selectivity against uric acid (UA) and ascorbic acid (AA). Finally, we modify the surface of the Pt gate electrode with chitosan to improve the selectivity of OECTs at high concentrations of up to 100 \u00b5M to expand the detection range.<\/jats:p>","DOI":"10.3390\/s24165244","type":"journal-article","created":{"date-parts":[[2024,8,14]],"date-time":"2024-08-14T03:46:36Z","timestamp":1723607196000},"page":"5244","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Microscale Sensor Arrays for the Detection of Dopamine Using PEDOT:PSS Organic Electrochemical Transistors"],"prefix":"10.3390","volume":"24","author":[{"given":"Chunling","family":"Li","sequence":"first","affiliation":[{"name":"Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yingying","family":"He","sequence":"additional","affiliation":[{"name":"Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0405-2727","authenticated-orcid":false,"given":"Sven","family":"Ingebrandt","sequence":"additional","affiliation":[{"name":"Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6797-2443","authenticated-orcid":false,"given":"Xuan Thang","family":"Vu","sequence":"additional","affiliation":[{"name":"Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"20200102","DOI":"10.1002\/VIW.20200102","article-title":"Biosensors and sensors for dopamine detection","volume":"2","author":"Liu","year":"2020","journal-title":"View"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1007\/s11481-019-09851-4","article-title":"Where Is Dopamine and how do Immune Cells See it? Dopamine-Mediated Immune Cell Function in Health and Disease","volume":"15","author":"Matt","year":"2020","journal-title":"J. Neuroimmune Pharmacol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2025","DOI":"10.1021\/acssensors.8b00726","article-title":"Stress Biomarkers in Biological Fluids and Their Point-of-Use Detection","volume":"3","author":"Steckl","year":"2018","journal-title":"ACS Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"107392","DOI":"10.1016\/j.pharmthera.2019.07.003","article-title":"Dopamine outside the brain: The eye, cardiovascular system and endocrine pancreas","volume":"203","author":"Bucolo","year":"2019","journal-title":"Pharmacol. Ther."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1007\/s10571-018-0632-3","article-title":"Dopamine: Functions, Signaling, and Association with Neurological Diseases","volume":"39","author":"Klein","year":"2019","journal-title":"Cell. Mol. Neurobiol."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Kamal Eddin, F.B., and Wing Fen, Y. (2020). Recent Advances in Electrochemical and Optical Sensing of Dopamine. Sensors, 20.","DOI":"10.3390\/s20041039"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.jneumeth.2004.04.041","article-title":"High-sensitive liquid chromatographic method for determination of neuronal release of serotonin, noradrenaline and dopamine monitored by microdialysis in the rat prefrontal cortex","volume":"140","author":"Yoshitake","year":"2004","journal-title":"J. Neurosci. Methods"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"684","DOI":"10.1021\/ac971135z","article-title":"Capillary-electrophoresis-chips-with-integrated-electrochemical-detection","volume":"70","author":"Woolley","year":"1998","journal-title":"Anal. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.jneumeth.2004.03.021","article-title":"High-performance liquid chromatography\/tandem mass spectrometric assay for the simultaneous measurement of dopamine, norepinephrine, 5-hydroxytryptamine and cocaine in biological samples","volume":"138","author":"Hows","year":"2004","journal-title":"J. Neurosci. Methods"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1419","DOI":"10.1016\/j.saa.2008.04.014","article-title":"Raman, IR, UV-vis and EPR characterization of two copper dioxolene complexes derived from L-dopa and dopamine","volume":"71","author":"Barreto","year":"2008","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"899","DOI":"10.1016\/S0039-9140(02)00123-6","article-title":"Study on fluorescence property of dopamine and determination of dopamine by fluorimetry","volume":"57","author":"Wang","year":"2002","journal-title":"Talanta"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.trac.2015.09.006","article-title":"Chemically modified electrodes for electrochemical detection of dopamine in the presence of uric acid and ascorbic acid: A review","volume":"76","author":"Sajid","year":"2016","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Shin, J.W., Kim, K.J., Yoon, J., Jo, J., El-Said, W.A., and Choi, J.W. (2017). Silver Nanoparticle Modified Electrode Covered by Graphene Oxide for the Enhanced Electrochemical Detection of Dopamine. Sensors, 17.","DOI":"10.3390\/s17122771"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/j.snb.2012.07.052","article-title":"Graphene nano sheet-fabricated electrochemical sensor for the determination of dopamine in the presence of ascorbic acid using cetyltrimethylammonium bromide as the discriminating agent","volume":"173","author":"Liu","year":"2012","journal-title":"Sens. Actuators B Chem."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Si, B., and Song, E. (2018). Recent Advances in the Detection of Neurotransmitters. Chemosensors, 6.","DOI":"10.3390\/chemosensors6010001"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Kim, D.S., Kang, E.S., Baek, S., Choo, S.S., Chung, Y.H., Lee, D., Min, J., and Kim, T.H. (2018). Electrochemical detection of dopamine using periodic cylindrical gold nanoelectrode arrays. Sci. Rep., 8.","DOI":"10.1038\/s41598-018-32477-0"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Manbohi, A., and Ahmadi, S.H. (2019). Sensitive and selective detection of dopamine using electrochemical microfluidic paper-based analytical nanosensor. Sens. Bio-Sens. Res., 23.","DOI":"10.1016\/j.sbsr.2019.100270"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Lakard, S., Pavel, I.A., and Lakard, B. (2021). Electrochemical Biosensing of Dopamine Neurotransmitter: A Review. Biosensors, 11.","DOI":"10.3390\/bios11060179"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1902085","DOI":"10.1002\/adfm.201902085","article-title":"Tuning Channel Architecture of Interdigitated Organic Electrochemical Transistors for Recording the Action Potentials of Electrogenic Cells","volume":"29","author":"Liang","year":"2019","journal-title":"Adv. Funct. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e1400251","DOI":"10.1126\/sciadv.1400251","article-title":"High-performance transistors for bioelectronics through tuning of channel thickness","volume":"1","author":"Rivnay","year":"2015","journal-title":"Sci. Adv."},{"key":"ref_21","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. Mater."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Liao, J., Si, H., Zhang, X., and Lin, S. (2019). Functional Sensing Interfaces of PEDOT:PSS Organic Electrochemical Transistors for Chemical and Biological Sensors: A Mini Review. Sensors, 19.","DOI":"10.3390\/s19020218"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2133","DOI":"10.1038\/ncomms3133","article-title":"High transconductance organic electrochemical transistors","volume":"4","author":"Khodagholy","year":"2013","journal-title":"Nat. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2102039","DOI":"10.1002\/admi.202102039","article-title":"Organic Electrochemical Transistors: An Emerging Technology for Biosensing","volume":"9","author":"Marks","year":"2022","journal-title":"Adv. Mater. Interfaces"},{"key":"ref_25","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_26","doi-asserted-by":"crossref","unstructured":"Hempel, F., Law, J.K.Y., Nguyen, T.C., Lanche, R., Susloparova, A., Vu, X.T., and Ingebrandt, S. (2021). PEDOT:PSS Organic Electrochemical Transistors for Electrical Cell-substrate Impedance Sensing Down to Single Cells. Biosens. Bioelectron., 180.","DOI":"10.1016\/j.bios.2021.113101"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1002\/adma.201404378","article-title":"Flexible organic electrochemical transistors for highly selective enzyme biosensors and used for saliva testing","volume":"27","author":"Liao","year":"2015","journal-title":"Adv. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3874","DOI":"10.1002\/adma.201400263","article-title":"Electrocardiographic recording with conformable organic electrochemical transistor fabricated on resorbable bioscaffold","volume":"26","author":"Campana","year":"2014","journal-title":"Adv. Mater."},{"key":"ref_29","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_30","doi-asserted-by":"crossref","unstructured":"Tintelott, M., Kremers, T., Ingebrandt, S., Pachauri, V., and Vu, X.T. (2022). Realization of a PEDOT:PSS\/Graphene Oxide On-Chip Pseudo-Reference Electrode for Integrated ISFETs. Sensors, 22.","DOI":"10.3390\/s22082999"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1012","DOI":"10.1002\/adma.200902329","article-title":"Influence of device geometry on sensor characteristics of planar organic electrochemical transistors","volume":"22","author":"Cicoira","year":"2010","journal-title":"Adv. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3820","DOI":"10.1039\/c3tb20451k","article-title":"Highly selective and sensitive glucose sensors based on organic electrochemical transistors with graphene-modified gate electrodes","volume":"1","author":"Liao","year":"2013","journal-title":"J. Mater. Chem. B"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2707","DOI":"10.1021\/acs.jpclett.8b00912","article-title":"Toward Industrial-Scale Production of Perovskite Solar Cells: Screen Printing, Slot-Die Coating, and Emerging Techniques","volume":"9","author":"Rong","year":"2018","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"104282","DOI":"10.1016\/j.nanoen.2019.104282","article-title":"Sorting-free Utilization of Semiconducting Carbon Nanotubes for Large Thermoelectric Responses","volume":"67","author":"Hsu","year":"2020","journal-title":"Nano Energy"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2971","DOI":"10.1039\/C7TC00038C","article-title":"Inkjet printing wearable electronic devices","volume":"5","author":"Gao","year":"2017","journal-title":"J. Mater. Chem. C"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"5053","DOI":"10.1038\/s41467-019-13079-4","article-title":"All-printed large-scale integrated circuits based on organic electrochemical transistors","volume":"10","author":"Lassnig","year":"2019","journal-title":"Nat. Commun."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"14071","DOI":"10.1021\/acsami.6b02698","article-title":"Efficiency of the Switching Process in Organic Electrochemical Transistors","volume":"8","author":"Hutter","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2000523","DOI":"10.1002\/admt.202000523","article-title":"Recent Technological Advances in Fabrication and Application of Organic Electrochemical Transistors","volume":"5","author":"Chen","year":"2020","journal-title":"Adv. Mater. Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3538","DOI":"10.1002\/adfm.200601239","article-title":"Steady-State and Transient Behavior of Organic Electrochemical Transistors","volume":"17","author":"Bernards","year":"2007","journal-title":"Adv. Funct. Mater."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1016\/j.orgel.2018.09.010","article-title":"Device physics of organic electrochemical transistors","volume":"63","author":"Friedlein","year":"2018","journal-title":"Org. Electron."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Mantione, D., Del Agua, I., Sanchez-Sanchez, A., and Mecerreyes, D. (2017). Poly(3,4-ethylenedioxythiophene) (PEDOT) Derivatives: Innovative Conductive Polymers for Bioelectronics. Polymers, 9.","DOI":"10.3390\/polym9080354"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"457","DOI":"10.1016\/j.snb.2014.11.038","article-title":"Highly selective and sensitive glucose sensors based on organic electrochemical transistors using TiO2 nanotube arrays-based gate electrodes","volume":"208","author":"Liao","year":"2015","journal-title":"Sens. Actuators B Chem."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1007\/s00604-020-04352-1","article-title":"Needle-type organic electrochemical transistor for spatially resolved detection of dopamine","volume":"187","author":"Mariani","year":"2020","journal-title":"Microchim. Acta"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"4559","DOI":"10.1016\/j.bios.2011.05.025","article-title":"Highly sensitive dopamine biosensors based on organic electrochemical transistors","volume":"26","author":"Tang","year":"2011","journal-title":"Biosens. Bioelectron."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1039\/C3TB21079K","article-title":"Organic electrochemical transistors with graphene-modified gate electrodes for highly sensitive and selective dopamine sensors","volume":"2","author":"Liao","year":"2014","journal-title":"J. Mater. Chem. B"},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Gualandi, I., Tonelli, D., Mariani, F., Scavetta, E., Marzocchi, M., and Fraboni, B. (2016). Selective detection of dopamine with an all PEDOT:PSS Organic Electrochemical Transistor. Sci. Rep., 6.","DOI":"10.1038\/srep35419"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"127414","DOI":"10.1016\/j.snb.2019.127414","article-title":"Carbonized silk fabric-based flexible organic electrochemical transistors for highly sensitive and selective dopamine detection","volume":"304","author":"Ji","year":"2020","journal-title":"Sens. Actuators B Chem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"e50345","DOI":"10.7554\/eLife.50345","article-title":"Organic electrochemical transistor arrays for real-time mapping of evoked neurotransmitter release in vivo","volume":"9","author":"Xie","year":"2020","journal-title":"Elife"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Liang, Y., Guo, T., Zhou, L., Offenhausser, A., and Mayer, D. (2020). Label-Free Split Aptamer Sensor for Femtomolar Detection of Dopamine by Means of Flexible Organic Electrochemical Transistors. Materials, 13.","DOI":"10.3390\/ma13112577"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2337","DOI":"10.1021\/acsapm.1c01563","article-title":"Organic Electrochemical Transistor with Molecularly Imprinted Polymer-Modified Gate for the Real-Time Selective Detection of Dopamine","volume":"4","author":"Tang","year":"2022","journal-title":"Acs Appl. Polym. Mater."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"e202204134","DOI":"10.1002\/anie.202204134","article-title":"Fast-Scanning Potential-Gated Organic Electrochemical Transistors for Highly Sensitive Sensing of Dopamine in Living Rat Brain","volume":"61","author":"Li","year":"2022","journal-title":"Angew. Chem. Int. Ed. Engl."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1575","DOI":"10.1038\/ncomms2573","article-title":"In vivo recordings of brain activity using organic transistors","volume":"4","author":"Khodagholy","year":"2013","journal-title":"Nat. Commun."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"e2004790","DOI":"10.1002\/adma.202004790","article-title":"Microfabricated Ion-Selective Transistors with Fast and Super-Nernstian Response","volume":"32","author":"Han","year":"2020","journal-title":"Adv. Mater."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1002\/polb.22129","article-title":"Optimization of Organic Electrochemical Transistors for Sensor Applications","volume":"49","author":"Yaghmazadeh","year":"2010","journal-title":"J. Polym. Sci. Part B Polym. Phys."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/16\/5244\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:36:15Z","timestamp":1760110575000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/16\/5244"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,14]]},"references-count":54,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2024,8]]}},"alternative-id":["s24165244"],"URL":"https:\/\/doi.org\/10.3390\/s24165244","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,14]]}}}