Platinum thin films are deposited on anodic aluminium oxide (AAO) templates by atomic layer deposition
(ALD). The highly ordered island-like platinum nanostructures formed on the AAO template
produce a high Raman scattering signal because of the periodical hexagonal arrangement. As an illustration,
dramatic enhancement is achieved using Rhodamine 6G (R6G) as a molecular probe.Fieldemission
scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) show that the
gap between the island-like structures is below 10 nm. Owing to activation by the incident laser beam,
the localized electromagnetic field on the platinum island surface can be dramatically enhanced by the
sub-10 nm regime subsequently amplifying the Raman signal. Finite-difference time-domain (FDTD)
calculation matches the experimental phenomena suggesting that the excellent surface-enhanced
Raman scattering (SERS) characteristics of the platinum structure arise from the high density and
abundance of hot spots. Because the platinum film is inert in air, the SERS enhancing substrate can be
used reliably in many trace chemical and biological detection applications.