Electrochemical preparation of copper-dendrimer nanocomposites:: picomolar detection of Cu2+ ions

The present work describes, for the first time, in situ electrochemical preparation of dendrimer-encapsulated Cu nanoparticles using a self-assembled monolayer of fourth-generation amine-terminated polyamidoamine (PAMAM) dendrimer as the template. Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) studies of the modified surface confirmed the presence of Cu nanoparticles entrapped in dendrimer film. Au electrode modified with a monolayer of the dendrimer enables preconcentration and subsequent voltammetric detection of Cu(2+) at picomolar concentrations. Further, Cu nanoparticles in the dendrimer monolayer could be electrochemically derivatised to Cu hexacyanoferrate, which exhibits specific crystal planes, unlike the random distribution of crystal planes in bulk-formed Cu hexacyanoferrate, which is another catalytically active material for sensor applications.