Bio-compatible PEDOT-MOF/(PHE)2 enhanced micro-ECoG electrode for multi-mode neural recording and regulation

A PEDOT-MOF/polypeptide modified multi-modal micro-ECoG electrode is proposed. • PEDOT-MOF achieves dual functions of ROS sensing and efficient scavenging. • Polypeptide/DEX enhances electrode biocompatibility and reduces inflammation. • In vivo validation of multi-modal ECoG/ROS recording and immunomodulation The limited biocompatibility of conventional flexible electrode materials often triggers host immune responses, manifesting as glial encapsulation and the overproduction of reactive oxygen species (ROS). Meanwhile, ROS accumulation further exacerbates local inflammation and induces irreversible cellular damage. Therefore, constructing a highly biocompatible electrode-tissue interface and developing multi-modal microelectrodes capable of recording and regulating in-vivo ROS concentrations are critical for alleviating immune responses and clarifying the underlying mechanisms of electrode failure. In this work, we proposed a novel modification strategy for micro-electrocorticography (micro-ECoG) electrodes to enable multi-modal neural recordings (ECoG and ROS) and regulations (drug deliver and ROS catalyze). For this purpose, the electrode surface is modified with Cu-metal-organic framework (Cu-MOF)-doped poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS), denoted as PEDOT-MOF. Additionally, a highly biocompatible polypeptide coating loaded with anti-inflammatory drugs is introduced to further suppress immune reactions. In vitro experiments reveal that PEDOT-MOF exhibits excellent electrochemical performance and detection sensitivity to H₂O₂, indicating its multifunctionality to catalyze the ROS for mitigating oxidative stress and monitor dynamic changes in ROS concentration in real time. In vivo implantation studies confirm that microelectrodes modified with the drug-loaded polypeptide coating exhibit lower interface impedance and higher SNR. Collectively, these results highlight the significant application potential of PEDOT-MOF-modified micro-ECoG electrodes combined with a drug-loaded polypeptide coating, which may address key challenges in current implantable neural electrode technology. It should be noted that, due to partial channel attenuation over chronic implantation and spatial diffusion effects of dexamethasone, this platform is more suited for monitoring relative ROS dynamic trends. Future optimizations will further advance the capability toward accurate in-vivo ROS absolute quantification.