Vertical Gold Nanowires Stretchable Electrochemical\nElectrodes

Abstract

Conventional\nelectrodes produced from gold or glassy carbon are\noutstanding electrochemical platforms for biosensing applications\ndue to their chemical inertness and wide electrochemical window, but\nare intrinsically rigid and planar in nature. Hence, it is challenging\nto seamlessly integrate them with soft and curvilinear biological\ntissues for real-time wearable or implantable electronics. In this\nwork, we demonstrate that vertically gold nanowires (v-AuNWs) possess\nan enokitake-like structure, with the nanoparticle (head) on one side\nand nanowires (tail) on the opposite side of the structure, and can\nserve as intrinsically stretchable, electrochemical electrodes due\nto the stronger nanowire-elastomer bonding forces preventing from\ninterfacial delamination under strains. The exposed head side of the\nelectrode comprising v-AuNWs can achieve a detection limit for H₂O₂ of 80 μM, with a linear range of 0.2–10.4\nmM at 20% strain, with a reasonably high sensitivity using chronoamperometry.\nThis excellent electrochemical performance in the elongated state,\nin conjunction with low-cost wet-chemistry fabrication, demonstrates\nthat v-AuNWs electrodes may become a next-generation sensing platform\nfor conformally integrated, in vivo biodiagnostics.