Employing materials assembly to elucidate surface interactions of amino acids with Au nanoparticles

Biomolecule-directed growth and assembly of nanomaterials utilizes highly specific interactions to provide the exciting prospect of producing a new generation of precisely arranged, stimuli responsive, and reconfigurable nanoarrayed structures for a wide range of applications from catalysis to energy storage. With an objective to create a much needed fundamental understanding of the complex biotic/abiotic interfacial interactions, this paper presents a systematic study of surface interactions of a series of amino acids with Au nanoparticles. We have employed a self-assembly based method that monitors changes in the optical properties and aggregate size of Au nanoparticles in response to their binding with selected amino acid residues. The observations were used to derive information on the binding strength and ligand surface arrangement. Our experimental results follow previously derived computational trends in the surface affinities of the residues, thus suggesting that our approach may be used to assess the binding abilities and interligand interactions of biomacromolecules on nanomaterial surfaces.