Tissue-like electrophysiological electrode interface construction by multiple crosslinked polysaccharide-based hydrogel

A reliable electrophysiological electrode interface (EEI) between bioelectronic devices and biological tissues is indispensable to achieve the high fidelity recording of bioelectricity. However, there is an inherent tradeoff among EEI's electrochemical characteristics, mechanical properties and biocompatibility when considering the desired nanostructure and optimum composition. Here, we proposed a mechanically matched, highly conductive and biocompatible EEI, a tissue-like metal-doped hydrogel which could enable excellent electro-biosensing, by bringing disulfide modified silver nanowires into difunctional hyaluronan/carboxymethyl chitosan composite. The intensity of cortical signals at specific frequency domain recorded by the hydrogel-based EEI is doubled, which is significant for the diagnosis of epilepsy. Furthermore, the natural gel matrix could lead to seamless bio-integration between EEI and the tissue site of interest, minimizing signal dissipation without causing obvious inflammatory response. Overall, the EEI we designed contributes to improving tissue-device integration as well as bioelectronic device's performance and further leads to more effective human-computer interfaces.