Seed-mediated growth of uniform gold nanoparticle arrays

We demonstrated through electron microscopic characterizations that the semi-hexagonal Au nanoparticle arrays supported on solid surfaces prepared by a polymer template approach could be enlarged uniformly by using a solution-based seed-mediated growth. The semi-hexagonal particle arrangement is largely retained after the growth as evident by the similar Fourier transform patterns obtained before and after the growth, indicating that the growth occurs over the seed particles on the surface. The shape and size of the augmented particles can be tuned by varying the growth conditions. The particle density can be conveniently varied by using polymer templates with different chain lengths. The growth mechanism is briefly discussed. Strong surface -enhanced Raman signals of molecules adsorbed on the 40-60 nm grown particles are observed.