Preparation of Resilient Organic Electrochemical Transistors Based on Blend Films with Flexible Crosslinkers

Organic electrochemical transistors (OECTs) exhibit high biocompatibility and are expected to be applied in biological sensors. This study focused on crosslinking agents in blend films of a mixed conducting polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), and a thermoresponsive polymer, poly(N-isopropylacrylamide) (PNIPAM), as channel layers to realize reversible temperature response. In addition to the conventional (3-glycidyloxypropyl) trimethoxysilane (GOPS) crosslinker, a poly(ethylene glycol) diglycidyl ether (PEGDE) flexible crosslinker was used to overcome the volume expansion caused by the temperature change. Structural analysis revealed that PNIPAM was segregated on the surface and that the PEGDE crosslinker increased the crystallinity of PEDOT. Blend films with binary crosslinkers (PEGDE and GOPS) exhibited reversible response to temperature cycling. Therefore, the use of a flexible crosslinker in functional blend films can facilitate the fabrication of biosensing OECT devices with higher resilience to the fluctuation of surrounding conditions.