PEDOT:PSS Organic Electrochemical Transistors for Cell Sensing Applications

Abstract

Event Abstract Back to Event PEDOT:PSS Organic Electrochemical Transistors for Cell Sensing Applications Felix Hempel1*, Jessica Law2, Anna Susloparova3, Vivek Pachauri4 and Sven Ingebrandt3 1 University of Applied Sciences Kaiserslautern, Department of Informatics and Microsystem Technology, Germany 2 RAM Group DE GmbH, Germany 3 University of Applied Sciences Kaiserslautern, Department of Informatics and Microsystem Technology, Germany 4 University of Applied Sciences Kaiserslautern, Department of Informatics and Microsystem Technology, Germany Motivation Polymer-based biosensors gained a lot of attention over recent years. Their versatility in combination with easy fabrication methods and their high biocompatibility made those devices a new and exciting alternative for cell sensing applications. Especially poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) is a promising material for such organic electrochemical transistor (OECT) devices. PEDOT:PSS has shown its capability for several different purposes such as glucose sensing (Zhu et al., 2004), gas sensing (Lin, Chen, Hu, Tunney, & Ho, 2009), action potential measurements (Ludwig, Uram, Yang, Martin, & Kipke, 2006), and for in vivo applications (Khodagholy et al., 2011). We demonstrate a wafer-scale fabrication approach for the realization of OECT biosensors on conventional substrates such as silicon and glass as well as on flexible, polymeric substrates. Devices fabricated in such a process were characterized using state-of-the-art surface characterization and electronic measurement tools and exhibit excellent sensor characteristics with transconductance values exceeding conventional silicon-based platforms. Different strategies for surface modification of the OECTs were employed in order to realize different biosensor applications. In the first example we demonstrate the use of our OECTs for Electical Cell-substrate Impedance Sensing (ECIS) with a focus on interfacing single cells (e.g. HEK 293, Fig. 1). We intend to use our OECT platform for cell sensing in high throughput drug-screening. Devices could be produced such cheap that disposable sensors like with standard plastic cell culture dishes would be possible. Material and Methods Interdigitated electrodes made of gold on glass or silicon substrates were the base for the OECTs. The fabricated devices were encapsulated for cell assays in the same way as described in earlier publications. Different cells were cultured right on the surface of the OECT devices while the medium was replaced every second day. For cell impedance measurements the chips were measured latest one day after the cells were plated on the device surface. The electronic readout was performed with our transistor transfer function (TTF) box (Ingebrandt, Yeung, Krause, & Offenhäusser, 2005) as well as with a commercial available parameter analyser (4200-SCS, Keithley Instruments Inc., USA). Results and Discussion OECTs with different gate designs and different thickness of PEDOT:PSS layers were fabricated and characterized. By increasing the gate area, higher transconductance values were achieved, which made those chips more suitable for impedimetric measurements. The transconductance values ranged from 0.2 mS to 10 mS depending on the layer thickness and gate area of the IDE chips (Fig. 2). Measured impedance spectra showed significant differences between cell free transistor gates and gates with adherent cells, comparable to the data achieved with silicon based field-effect transistors. The fabricated OECTs showed significantly improved transconductance values compared to silicon FETs of similar dimensions. In the next experiments the devices need to be compared in terms of signal-to-noise ratio for cell sensing applications. Conclusion We demonstrated PEDOT:PSS OECTs, which offer promising properties for their usage as cell based biosensors. The performance of the devices can keep up with other well established sensors that have been used in this field for years. Although these devices show clear advantages for biosensing applications their disadvantages in terms of long-term stability in cell culture conditions have to be resolved. References Ingebrandt, S., Yeung, C.-K., Krause, M., & Offenhäusser, A. (2005). Neuron–transistor coupling: interpretation of individual extracellular recorded signals. European Biophysics Journal, 34(2), 144-154. Khodagholy, D., Doublet, T., Gurfinkel, M., Quilichini, P., Ismailova, E., Leleux, P., Malliaras, G. G. (2011). Highly conformable conducting polymer electrodes for in vivo recordings. Advanced Materials, 23(36), H268-H272. Lin, C.-Y., Chen, J.-G., Hu, C.-W., Tunney, J. J., & Ho, K.-C. (2009). Using a PEDOT: PSS modified electrode for detecting nitric oxide gas. Sensors and Actuators B: Chemical, 140(2), 402-406. Ludwig, K. A., Uram, J. D., Yang, J., Martin, D. C., & Kipke, D. R. (2006). Chronic neural recordings using silicon microelectrode arrays electrochemically deposited with a poly (3, 4-ethylenedioxythiophene)(PEDOT) film. Journal of Neural Engineering, 3(1), 59. Zhu, Z.-T., Mabeck, J. T., Zhu, C., Cady, N. C., Batt, C. A., & Malliaras, G. G. (2004). A simple poly (3, 4-ethylene dioxythiophene)/poly (styrene sulfonic acid) transistor for glucose sensing at neutral pH. Chemical Communications (13), 1556-1557. Figure Legend Figure 1: Colored SEM image of an adherent HEK 293 cell on an OECT gate, Figure 2: Transfer characteristic of an OECT with a gate area of 40 µm × 40µm (a); Transfer-function measurement of the same chip (b) Figure 1 Acknowledgements We thank the Stiftung Rheinland Pfalz für Innovation Nr.: 1083 („Biosensor Nanoelektroden aus Graphen oder reduziertem Graphen-Oxid“) Keywords: PEDOT:PSS, ECIS, Organic electrochemical transistor, OECT Conference: MEA Meeting 2016 | 10th International Meeting on Substrate-Integrated Electrode Arrays, Reutlingen, Germany, 28 Jun - 1 Jul, 2016. Presentation Type: Poster Presentation Topic: MEA Meeting 2016 Citation: Hempel F, Law J, Susloparova A, Pachauri V and Ingebrandt S (2016). PEDOT:PSS Organic Electrochemical Transistors for Cell Sensing Applications. Front. Neurosci. Conference Abstract: MEA Meeting 2016 | 10th International Meeting on Substrate-Integrated Electrode Arrays. doi: 10.3389/conf.fnins.2016.93.00108 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 22 Jun 2016; Published Online: 24 Jun 2016. * Correspondence: Dr. Felix Hempel, University of Applied Sciences Kaiserslautern, Department of Informatics and Microsystem Technology, Zweibrücken, Germany, felix.hempel@hs-kl.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Felix Hempel Jessica Law Anna Susloparova Vivek Pachauri Sven Ingebrandt Google Felix Hempel Jessica Law Anna Susloparova Vivek Pachauri Sven Ingebrandt Google Scholar Felix Hempel Jessica Law Anna Susloparova Vivek Pachauri Sven Ingebrandt PubMed Felix Hempel Jessica Law Anna Susloparova Vivek Pachauri Sven Ingebrandt Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.