The fabrication and electrical characterization of protein fibril-templated one-dimensional palladium nanostructures

Biological systems such as DNA and viruses have been frequently used as templates for the synthesis of functional nanomaterials. Here, we employed protein fibrils to direct the fabrication of one dimensional palladium nanostructures by incubating aged solution of sodium tetrachloropalladate(II) with pre-formed insulin fibrils for half an hour, followed by the hydrogen reduction at 600 °C. The size of the palladium nanoparticles was well controlled simply by varying the aging temperature of the sodium tetrachloropalladate(II) solution. The chemical identity of the formed palladium nanostructures along the fibrils was evaluated by X-ray photoelectron spectroscopy. The electrical properties of palladium nanoparticle were further examined by scanning conductance microscopy, which indicated that the metallic palladium nanostructures exhibited higher electrical resistance than expected, probably due to the palladium oxide within the palladium nanoparticle and the gaps between metallic palladium and palladium oxide.