Combining PEDOT and PANI for Conductive Polymer Hybrid Materials with Enhanced Properties: From All-Plastic Electrodes to OECT Channels

Abstract

Conductive polymers (CPs) are key materials for the development of flexible, transparent, and metal-free electronic platforms. Among them, poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI) offer complementary properties in terms of conductivity, electroactivity, and chemical versatility. Here, we report a simple and versatile strategy to fabricate PEDOT–PANI hybrid materials by combining the chemical synthesis of PEDOT films on rigid and flexible substrates with the direct electrochemical polymerization of PANI by cyclic voltammetry, enabling precise control over material deposition. The resulting PEDOT–PANI composites were thoroughly characterized by Raman and UV–vis spectroscopy, electrochemical methods, and electrochemical quartz crystal microbalance (eQCM), confirming the successful integration of both polymers and revealing a synergistic combination of their properties. Compared to pristine PEDOT and PANI, the hybrid materials exhibit enhanced electroactivity, improved electrochemical stability in neutral media, and tunable pH-dependent behavior. The versatility of the PEDOT–PANI platforms was demonstrated through their implementation as metal-free all-plastic electrodes for bioelectrochemical sensing and as active channel materials in organic electrochemical transistors (OECTs). In both configurations, the presence of PANI introduces redox-active and functional groups that enhance pH sensitivity and enable enzyme electrostatic integration, while PEDOT ensures mechanical robustness and stable operation in aqueous environments. Overall, this work establishes a general and scalable methodology to engineer PEDOT–PANI hybrid materials with controllable properties on diverse substrates, opening opportunities for flexible electrochemical devices ranging from disposable biosensors to OECT-based bioelectronic platforms.