Water-Based PEDOT:Nafion Dispersion for Organic Bioelectronics

• Published in: ACS applied materials & interfaces 2020-07, Vol.12 (26), p.29807-29817, Article acsami.0c06538
• Main Authors: Carli, Stefano, Di Lauro, Michele, Bianchi, Michele, Murgia, Mauro, De Salvo, Anna, Prato, Mirko, Fadiga, Luciano, Biscarini, Fabio
• Format: Article
• Language: English
• Subjects: Applications of Polymer, Composite, and Coating Materials
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.0c06538

The water dispersion of the conductive polymer poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonic acid) (PEDOT:PSS) is one of the most used material precursors in organic electronics also thanks to its industrial production. There is a growing interest for conductive polymers that could be alternative surrogates or replace PEDOT:PSS in some applications. A recent study by our group compared electrodeposited PEDOT:Nafion vs PEDOT:PSS in the use for neural recordings. Here, we introduce an easy and reproducible synthetic protocol to prepare a water dispersion of PEDOT:Nafion. The conductivity of the pristine material is on the order of 2 S cm–1 and was improved up to ≈6 S cm–1 upon treatment with ethylene glycol. Faster ion transfer was assessed by electrochemical impedance spectroscopy (EIS), and, interestingly, an improved adhesion was observed for coatings of the new PEDOT:Nafion dispersion on glass substrates, even without the addition of the silane cross-linker needed for PEDOT:PSS. As proof of concept, we demonstrate the use of this novel water dispersion of PEDOT:Nafion in three different organic electronic device architectures, namely, an organic electrochemical transistor (OECT), a memristor, and an artificial synapse.