%0 Journal Article
%A Sensi, Matteo
%A Berto, Marcello
%A Candini, Andrea
%A Liscio, Andrea
%A Cossarizza, Andrea
%A Beni, Valerio
%A Biscarini, Fabio
%A Bortolotti, Carlo Augusto
%D 2019
%T Modulating the Faradic Operation of All-Printed Organic
Electrochemical Transistors by Facile in Situ Modification of the
Gate Electrode
%U https://acs.figshare.com/articles/journal_contribution/Modulating_the_Faradic_Operation_of_All-Printed_Organic_Electrochemical_Transistors_by_Facile_in_Situ_Modification_of_the_Gate_Electrode/7851044
%R 10.1021/acsomega.8b03319.s001
%2 https://acs.figshare.com/ndownloader/files/14617253
%K faradic operation regime
%K faradic response
%K All-Printed Organic Electrochemical Transistors
%K gate voltage values
%K Gate Electrode Organic electrochemical transistors
%K faradic regime
%K gate electrode material
%K additive manufacturing techniques
%K OECT
%K redox processes
%K carbon gate
%X Organic electrochemical
transistors (OECTs) operated in the faradic
regime were shown as outperforming transducers of bioelectric signals in vitro and in vivo. Fabrication by additive
manufacturing techniques fosters OECTs as ideal candidates for point-of-care
applications, as well as imposes limitations on the choice of materials
and their processing conditions. Here, we address the question of
how the response of fully printed OECTs depends on gate electrode
material. Toward this end, we investigate the redox processes underlying
the operation of OECTs under faradic regime, to show OECTs with carbon
gate (C-gate) that exhibit no current modulation gate voltages <1.2
V. This is a hallmark that no interference with the faradic operation
of the device enabled by redox processes occurs when operating C-gate
OECTs in the low-voltage range as label-free biosensors for the detection
of electroactive (bio)molecules. To tune the faradic response of the
device, we electrodeposited Au on the carbon gate (Au–C-gate),
obtaining a device that operates at lower gate voltage values than
C-gate OECT. The presence of gold on the gate allowed further modification
of the electrical performances by functionalization of the Au–C-gate
with different self-assembled monolayers by fast potential-pulse-assisted
method. Moreover, we show that the presence in the electrolyte solution
of an external redox probe can be used to drive the faradic response
of both C- and Au–C-gate OECTs, impacting on the gate potential
window that yields effective drain current modulation. The results
presented here suggest possible new strategies for controlling the
faradic operation regime of OECTs sensors by chemical modification
of the gate surface.
%I ACS Publications