Copolymerized Dopamine Enables the Enhancement of Anti-Oxidation, Conductivity and Adhesion of the Platinum-Coated Silver Nanowires/Polyacrylamide Hydrogel Electrode

Stretchable electrode materials are promising in the development of implantable bioelectronics because they can permit the seamless integration with the soft, curvilinear surfaces of tissues or organs to maintain the device function. For the design of implantable bioelectrodes, stable signal transduction remains challenging, which relies on the sustained adhesion, chemical inertness, and structure integrity of the device-tissue interfaces in moisture. Herein, a organic-inorganic soft electrode composed of Platinum-coated silver nanowires crosslinked chemically with polydopamine-polyacrylamide (Ag@Pt NW-PDAPAM) was developed with robust conductivity, anti-oxidation ability and self-healing capacity. The in-situ polymerization of dopamine for the synthesis of Ag@Pt NW based on Galvanic reaction resulted in the formation of inorganic/organic core-shell nanowire electrode with robust conductivity, antioxidation ability and cytocompatibility. Moreover, the exposure of catechol moiety of nanowires contributed to strong hydrogen bonding and π-π aromatic interactions with the as synthesized PDAPAM hydrogel, leading to the formation of a organic-inorganic hybrid electrode with strechability, adhesion, and reversible self-repair capacity. Integrating Ag@Pt/PDAPAM on the thin film PDMS substrate, a resultant soft device show adhesion and stable electricical conductivity, which provides the potential application of long-term monitor of physiological signals after implatation.