Polyaminoacid-induced growth of metal nanoparticles on layer-by-layer templates

We report on preparation of redox-active nanoscale layer-by-layer (LbL) films with polyaminoacid-decorated surfaces that serve for both nucleation and growth of uniformly distributed gold nanoparticles at ambient conditions. We found that a poly-L-tyrosine (pTyr), a synthetic polyaminoacid, was able to direct nanoparticle formation to solid, flexible, and patterned surfaces preventing particle agglomeration. The gold particles were 8 +/- 2 nm in diameter, surrounded by 3-6 nm polyaminoacid shell, and confined to the topmost polyaminoacid layer. The reported results on bioinspired gold formation can be readily expanded to any inorganic-selective surface and provide a simple, robust, and nontoxic method to obtain nonaggregated inorganic nanoparticles at ambient conditions.