Paschalis Gkoupidenis1,Katharina Lieberth1,Daria Harig1,Paul Blom1,Fabrizio Torricelli2
Max Planck Institute for Polymer Research1,University of Brescia2
Paschalis Gkoupidenis1,Katharina Lieberth1,Daria Harig1,Paul Blom1,Fabrizio Torricelli2
Max Planck Institute for Polymer Research1,University of Brescia2
Due to their ability to convert ions-to-electrons organic electrochemical transistor (OECT) are an attractive alternative for biosensing.<sup>[1,2] </sup>A major advantage is that due to a volumetric capacitance they combine high amplification with operation at low voltages in aqueous environment.<sup>[3]</sup> We recently have shown that by using the OECT as an inverter in a current driven mode, where a constant current is applied over the channel by an external power supply, its sensitivity can be further enhanced.<sup>[4] </sup>This mode of operation has been used to monitor reversible opening and closing of tight junctions in the epithelial colon carcinoma (Caco-2) cell line.<sup>[5,6]</sup> These experiments were carried out using slow voltage scan rates to avoid hysteresis in the OECT characteristics. In this study we demonstrate that the dynamics of the OECT can be used to further enhance it sensitivity. The quantitative agreement between experiment and modelling of the transient OECT characteristics in current driven mode allows us to use the hysteresis at fast scan rates as a new figure of merit. Next to the enhanced sensitivity other advantages of this dynamic mode of operation are the reduced electrical stress and the ability to in-situ measure temporal barrier modulation effects.<br/><br/>[1] N. Y. Shim, D. A. Bernards, D. J. Macaya, J. A. DeFranco, M. Nikolou, R. M. Owens, G. G. Malliaras, <i>Sensors</i> <b>2009</b>, 9896.<br/>[2] L. H. Jimison, S. A. Tria, D. Khodagholy, Gurfinkel M., E. Lanzarini, A. Hama, G. G. Malliaras, R. M. Owens, <i>Adv. Mater.</i> <b>2012</b>, 5919.<br/>[3] J. Rivnay, P. Leleux, M. Sessolo, D. Khodagholy, T. Hervé, M. Fiocchi, G. G. Malliaras, <i>Adv. Mater. </i><b>2013</b>, <i>25</i>, 7010.<br/>[4] M. Ghittorelli, L. Lingstedt, P. Romele, N. I. Craciun, Z.M. Kovács-Vajna, P.W.M. Blom, F. Torricelli, <i>Nat. Commun.</i> <b>2018</b>, 1441;<br/>[5] L. V. Lingstedt, M. Ghittorelli, M. Brückner, J. Reinholz, N. I. Crăciun, F. Torricelli, V. Mailänder, P. Gkoupidenis, P. W. M. Blom, <i>Adv. Healthcare Mater.</i> <b>2019</b>, <i>8</i>, e1900128.<br/>[6] K. Lieberth, M. Brückner, F. Torricelli, V. Mailänder, P. Gkoupidenis, P.W.M. Blom, <i>Adv. </i><i>Mater. Tech.</i> <b>2021 </b><i>6</i>, 2000940)