TY - JOUR
T1 - Electrosynthesis of Biocompatible Free-Standing PEDOT Thin Films at a Polarized Liquid|Liquid Interface
AU - Lehane, Rob A.
AU - Gamero-Quijano, Alonso
AU - Malijauskaite, Sigita
AU - Holzinger, Angelika
AU - Conroy, Michele
AU - Laffir, Fathima
AU - Kumar, Amit
AU - Bangert, Ursel
AU - McGourty, Kieran
AU - Scanlon, Micheál D.
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/3/23
Y1 - 2022/3/23
N2 - Conducting polymers (CPs) find applications in energy conversion and storage, sensors, and biomedical technologies once processed into thin films. Hydrophobic CPs, like poly(3,4-ethylenedioxythiophene) (PEDOT), typically require surfactant additives, such as poly(styrenesulfonate) (PSS), to aid their aqueous processability as thin films. However, excess PSS diminishes CP electrochemical performance, biocompatibility, and device stability. Here, we report the electrosynthesis of PEDOT thin films at a polarized liquid|liquid interface, a method nonreliant on conductive solid substrates that produces free-standing, additive-free, biocompatible, easily transferrable, and scalable 2D PEDOT thin films of any shape or size in a single step at ambient conditions. Electrochemical control of thin film nucleation and growth at the polarized liquid|liquid interface allows control over the morphology, transitioning from 2D (flat on both sides with a thickness of <50 nm) to "Janus" 3D (with flat and rough sides, each showing distinct physical properties, and a thickness of >850 nm) films. The PEDOT thin films were p-doped (approaching the theoretical limit), showed high π-πconjugation, were processed directly as thin films without insulating PSS and were thus highly conductive without post-processing. This work demonstrates that interfacial electrosynthesis directly produces PEDOT thin films with distinctive molecular architectures inaccessible in bulk solution or at solid electrode-electrolyte interfaces and emergent properties that facilitate technological advances. In this regard, we demonstrate the PEDOT thin film's superior biocompatibility as scaffolds for cellular growth, opening immediate applications in organic electrochemical transistor (OECT) devices for monitoring cell behavior over extended time periods, bioscaffolds, and medical devices, without needing physiologically unstable and poorly biocompatible PSS.
AB - Conducting polymers (CPs) find applications in energy conversion and storage, sensors, and biomedical technologies once processed into thin films. Hydrophobic CPs, like poly(3,4-ethylenedioxythiophene) (PEDOT), typically require surfactant additives, such as poly(styrenesulfonate) (PSS), to aid their aqueous processability as thin films. However, excess PSS diminishes CP electrochemical performance, biocompatibility, and device stability. Here, we report the electrosynthesis of PEDOT thin films at a polarized liquid|liquid interface, a method nonreliant on conductive solid substrates that produces free-standing, additive-free, biocompatible, easily transferrable, and scalable 2D PEDOT thin films of any shape or size in a single step at ambient conditions. Electrochemical control of thin film nucleation and growth at the polarized liquid|liquid interface allows control over the morphology, transitioning from 2D (flat on both sides with a thickness of <50 nm) to "Janus" 3D (with flat and rough sides, each showing distinct physical properties, and a thickness of >850 nm) films. The PEDOT thin films were p-doped (approaching the theoretical limit), showed high π-πconjugation, were processed directly as thin films without insulating PSS and were thus highly conductive without post-processing. This work demonstrates that interfacial electrosynthesis directly produces PEDOT thin films with distinctive molecular architectures inaccessible in bulk solution or at solid electrode-electrolyte interfaces and emergent properties that facilitate technological advances. In this regard, we demonstrate the PEDOT thin film's superior biocompatibility as scaffolds for cellular growth, opening immediate applications in organic electrochemical transistor (OECT) devices for monitoring cell behavior over extended time periods, bioscaffolds, and medical devices, without needing physiologically unstable and poorly biocompatible PSS.
UR - http://www.scopus.com/inward/record.url?scp=85126624501&partnerID=8YFLogxK
U2 - 10.1021/jacs.1c12373
DO - 10.1021/jacs.1c12373
M3 - Article
C2 - 35262332
AN - SCOPUS:85126624501
SN - 0002-7863
VL - 144
SP - 4853
EP - 4862
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 11
ER -