Novel dendritic palladium nanostructure and its application in biosensing

A simple wet chemical route to the novel dendritic Pd nanostructure is reported. The nanostructure evolves from the initially generated spherical particles by the reaction of Pd(II) ions with hydrazine in the presence of polyglycol into urchinlike particles and then into the final dendrites. It is found that the polyglycol and hydrazine play the key roles on the formation of the novel structure. Only the urchinlike particles are obtained in the absence of polyglycol. The hydrazine acts as not only a reducing agent but also a matter to promote the dissolution of the initially generated Pd particles. A growth mechanism including the solid-liquid-solid (SLS) transformation and polyglycol-assisted oriented attachment process is proposed. This work reports the first example of the branched metallic Pd nanostructures, which might be of significance on the qualitative understanding of the morphology evolution of nanostructures and the achieving of desired nanostructures controllably. The electrocatalytic properties of the dendritic Pd nanostructure and its application for sensing H₂O₂ are also reported. The H ₂O₂ sensor based on a dendritic Pd-modified electrode has good stability and reproducibility. It has a wider linear range and a lower detection limit than those from spherical Pd particles.