Combining PEDOT:PSS Polymer Coating with Metallic 3D Nanowires Electrodes to Achieve High Electrochemical Performances for Neuronal Interfacing Applications

Abstract

This study presents a novel approach to improve the performance of microelectrode arrays (MEAs) used for electrophysiological studies of neuronal networks. The integration of 3D nanowires (NWs) with MEAs increases the surface‐to‐volume ratio, which enables subcellular interactions and high‐resolution neuronal signal recording. However, these devices suffer from high initial interface impedance and limited charge transfer capacity due to their small effective area. To overcome these limitations, the integration of conductive polymer coatings, poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) is investigated as a mean of improving the charge transfer capacity and biocompatibility of MEAs. The study combines platinum silicide‐based metallic 3D nanowires electrodes with electrodeposited PEDOT:PSS coatings to deposit ultra‐thin (<50 nm) layers of conductive polymer onto metallic electrodes with very high selectivity. The polymer‐coated electrodes were fully characterized electrochemically and morphologically to establish a direct relationship between synthesis conditions, morphology, and conductive features. Results show that PEDOT‐coated electrodes exhibit thickness‐dependent improved stimulation and recording performances, offering new perspectives for neuronal interfacing with optimal cell engulfment to enable the study of neuronal activity with acute spatial and signal resolution at the sub‐cellular level.

Soft Bioelectronics Using Nanomaterials and Nanostructures for Neuroengineering

“…40 Moreover, conductive polymers, such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PE-DOT:PSS), can be selectively deposited onto nanoneedle electrodes (Figure 3b, v) to lower the contact impedance owing to their high ionic/electrical charge-transfer capabilities. 62 In the application of optically responsive and transparent nanomaterials, Au NP-decorated TiO 2 nanowire arrays (Figure 3c, i), which convert light into electrical signals through their photovoltaic effect, can be used as retinal implants to restore visual responses in blind mice by replacing damaged photoreceptor cells with nanowires. 41 In another example, transparent electrodes can be fabricated using mesh-type networks of Ag− Au core−shell nanowires 63 (Figure 3c, ii) or ultrathin graphene interconnects 43,44 (Figure 3c, iii, iv).…”

“…(v) Nanoneedle electrodes coated with PEDOT:PSS. Reproduced from ref (). Copyright 2023 John Wiley and Sons.…”

“…Additionally, graphene-based deep-brain stimulation electrodes (Figure b, iv) have been fabricated for neural recording and stimulation, effectively preventing the MRI artifacts that are typically induced by metal electrodes . Moreover, conductive polymers, such as poly­(3,4-ethylenedioxythiophene)-poly­(styrenesulfonate) (PEDOT:PSS), can be selectively deposited onto nanoneedle electrodes (Figure b, v) to lower the contact impedance owing to their high ionic/electrical charge-transfer capabilities …”

A comprehensive review on the biomedical frontiers of nanowire applications

“… Surface functionalization can enhance nanowire performance, but it may also unintentionally alter desirable features like electrical conductivity, optical characteristics, or mechanical strength. [ 214 , 215 ]. Utilizing various materials, such as conductive polymers and nanowires, can result in synergistic effects and enhanced features.…”

Enhanced Electrostatic Safety and Thermal Compatibility of Special Powders Based on Surface Modification

“…Moreover, conductive polymers, especially for polyaniline (PANI), can also be used as an efficient conductive additive due to its outstanding π-electrons delocalization process and significant electrostatic transport characteristics [ 16 , 17 ]. For this purpose, Lee et al fabricated carbon nanotube (CNT)/PANI composites by optimizing the PANI content with a simple solution process, which could precisely control the electrical conductivity of the CNT structure [ 18 ].…”