Composition-selective fabrication of ordered intermetallic Au–Cu nanowires and their application to nano-size electrochemical glucose detection

Bimetallic nanostructures can provide distinct and improved physicochemical properties by the coupling effect of the two metal components, making them promising materials for a variety of applications. Herein, we report composition-selective fabrication of ordered intermetallic Au–Cu nanowires (NWs) by two-step chemical vapor transport method and their application to nano-electrocatalytic glucose detection. Ordered intermetallic Au₃Cu and AuCu₃ NWs are topotaxially fabricated by supplying Cu-containing chemicals to pre-synthesized single-crystalline Au NW arrays. The composition of fabricated Au–Cu NWs can be selected by changing the concentration of Cu-containing species. Interestingly, Au₃Cu NW electrodes show unique electrocatalytic activity for glucose oxidation, allowing us to detect glucose without interference from ascorbic acid. Such interference-free detection of glucose is attributed to the synergistic effect, induced by incorporation of Cu in Au. We anticipate that Au₃Cu NWs could show possibility as efficient nano-size electrochemical glucose sensors and the present fabrication method can be employed to fabricate valuable ordered intermetallic nanostructures. (paper)