Pd@Au Core-Shell Octahedral, truncated Octahedral, and cubic nanocrystals as nonenzymatic glucose sensors for drinks

Abstract

Core-shell PdAu octahedrons (Oct), PdAu truncated octahedrons (t-Oct), and PdAu nanocubes (NC) were successfully synthesised, and their specific activities, in terms of electrochemical surface area (ECSA), in the glucose oxidation reaction (GOR) and glucose sensors were systematically studied. Kinetic studies using electrochemical quartz crystal microbalance show that the specific activities (SA1) of the nanocrystals were in the order of t-Oct > Oct > NC, in which the number of moles of glucose per ECSA for PdAu t-Oct was 2.56 × 10-8 mol·cm−2, indicating that glucose was easily bonded to t-Oct with the (2 1 1) facet. By contrast, the results of specific activity (SA2), estimated by the moles of electrons over ECSA, showed the order of Oct > t-Oct > NC. The SA2 of PdAu Oct was 6.25 × 10-7 mol·cm−2. The facile electron transfer of GORs occurred via PdAu Oct with an electron-rich Au shell. Additionally, PdAu Oct demonstrated high recoveries when used as a glucose sensor for energy drinks.