Biomolecule-friendly conducting PEDOT interface for long-term bioelectronic devices
Qichao Pan, Qing Wu, Qingsong Sun, Xingyin Zhou, Cheng Lei, Shouyan Zhang, Yupeng Yuan, Zuwei Zhang, Jinyi Ma, Yaopeng Zhang, Bo Zhu
Abstract
One of the main challenges in biosensing devices is the development of a biocompatible and stable long-term biosensing interface to efficiently convert biological information into detectable electrical signals. Herein, we propose a facile and universal strategy to fabricate protein-encapsulated poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) materials for signal transduction using the biopolymer chitosan as both the crosslinker of PEDOT:PSS and the bioprotectant of proteins. The solid electrostatic interaction between chitosan and PSS was verified using Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), which makes PEDOT:PSS curable at room temperature, with good film formability and excellent aqueous stability. Electrochemical measurements revealed a low impedance for electron communication of the PEDOT:PSS/chitosan electrode through the solid-liquid interface. Notably, the bioactivity test using glucose oxidase (GOx) as a model protein encapsulated in PEDOT:PSS/chitosan demonstrated its exceptionally high bioactivity retention (94 % of their original catalytic activity), leading to a biosensor with high sensitivity and stability. Consequently, the developed glucose biosensor demonstrated a broad response range from 0.05 to 36.53 mM and a low limit of detection of 0.02 mM, with favorable long-term stability. To confirm its versatility, the proposed PEDOT:PSS/chitosan platform was successfully employed to detect lactate and epinephrine, which are the main components of biofluids. This work provides a straightforward and effective method for the fabrication of bio-device interfaces, demonstrating significant potential for applications in biosensors, biofuel cells, and other biosensing devices.