Cu2O nanowires with exposed {111} facet for nonenzymatic detection of glucose in complex biological fluids

Accurate glucose sensing in complex biological fluids could enable diagnostics for home healthcare. However, glucose oxidase (GO(x)) has been suffered from poor reproducibility and chemical instability due to intrinsic nature of enzymes. Here, we report a free-standing and robust reduced graphene oxide wrapped Cu foam (rGO/CuF)-supported Cu2O nanowires (Cu2O NWs) with exposed {111} facet via facile electrodeposition route. When being used as an electrode for nonenzymic glucose detection, Cu2O NWs@rGO/CuF exhibited the distinguished performances with powerful reliability for analyzing human plasma and even whole blood samples. These unprecedented performances could be ascribed to nanoscale hydrophilic structure of Cu2O NWs, which could control the fouling level especially for protein. Moreover, taking into account the Cu2O NWs with exposed {111} facet, Cu2O NWs {111} could reduce ion diffusion distance and couple with improved electronic conductivity, thus leading to high glucose sensitivity. Through the theoretical calculations, a reliable interpretation of the catalytic mechanism with Cu2O NWs {111} has been provided. This study deepens the understanding of hydrophilic nanostructure and facet-dependent activity of Cu2O NWs and points out a strategy to improve their sensitivity and stability.