Attachment of an aromatic dendritic macromolecule to gold surfaces

Surface immobilization of dendrons and dendrimers presents an exciting opportunity for creating a wide variety of functionalized polymeric architectures suitable for the immobilization of biomolecules. Dendritic molecules contain multifunctional groups that can be efficiently modified to control the properties of the resulting polymers. We are developing strategies to generate a highly functionalized surface using multifunctional and rigid dendrons immobilized onto different substrates. In this paper, electrochemical methods and scanning probe microscopy were used to explore the immobilization of a dendritic macromolecule (3,5-bis(3,5-dinitrobenzoylamino)benzoic acid) or (D-NO₂) onto gold electrodes. D-NO₂ adsorbs spontaneously by dipping the metal surface in dendron solution and also via grafting of cystamine covalent attached to gold electrode. Reduction of this layer generates the hydroxylamine product. The resulting redox-active layer exhibits a well-behaved redox response for the adsorbed nitroso/hydroxylamine couple.