▎ 摘　　要

A graphene oxide based nanostructure has been fabricated from covalently grafted palladium nanoparticles (PdNPs) with the assistance of sulfur atom (denoted as Pd-S-GO). This nanostructure displays an excellent selective electrocatalytic performance towards ethanol oxidation reaction (EOR) after electrochemical reduction (denoted as Pd-S-ERGO) while ethanol has been used as fuel for direct ethanol fuel cells (DEFCs). The SEM image shows that the PdNPs were uniformly attached onto the surface of graphene with the assistance of sulfur atom. The electrochemical properties of the anode catalyst have been evaluated using cyclic voltammetry (CV) and chronoamperometry (CA) in 0.5 M NaOH electrolyte. The Pd-S-ERGO anode catalyst shows a comparable onset potential (-0.6 V) on CV and long-term stability on amperometric measurements with higher and stable i(f)/i(b) ratio, 6.4. Very importantly, the better selective electrocatalytic performance has been found towards EOR over many of oxidizable small organic molecules with better stability and reproducibility. The experimental results indicated that the biosensor has excellent electrocatalytic activity to ethanol such as, better concentration range (1 to 50 mM) and detection limit (0.12 mM). Such a design of Pd-S-ERGO film to modify electrode holds a great promise as a new biocompatible platform for the development of enzyme free biosensors.