Facile one-pot preparation of Pd-Au/PEDOT/graphene nanocomposites and their high electrochemical sensing performance for caffeic acid detection

In this study, bimetallic Pd-Au/PEDOT/graphene (Pd-Au/PEDOT/rGO) nanocomposites were facilely prepared in an aqueous medium by a one-pot method. In addition to the Pd-Au/PEDOT nanoparticles, dendritic bimetallic Pd-Au nanoclusters were also obtained in the composites, which were verified by transmission electron microscopy and element analysis mapping characterization. The morphology of the nanocomposites was greatly influenced by the molar ratio of the added metal salt precursors. X-ray photoelectron spectroscopy and X-ray diffraction analyses indicated the presence of synergism and electron exchange between the Pd-Au bimetallic nanostructures, which play an important role in the enhancement of the electrocatalytic activity of the composite toward the oxidation of caffeic acid (CA). Under optimized conditions, the Pd-Au/PEDOT/rGO modified glassy carbon electrode showed a wide linear range of 0.001-55 mu M and a low detection limit of 0.37 nM (S/N = 3) for CA detection. These results provide valuable insight on the development of novel modified electrodes based on bimetallic graphene nanocomposites for high performance electrochemical sensors.