Surface-Enhanced Raman Scattering on Ordered Metal Nanodot Array Obtained Using Anodic Porous Alumina

The fabrication of an ordered array of Au nanodots using anodic porous alumina as an evaporation mask, and its application to a substrate for the measurement of surface-enhanced Raman scattering (SERS) were studied. One of the advantageous points of using anodic porous alumina as a template to fabricate nanostructures is that the size, shape and arrangement of the obtained nanostructures can be controlled by changing the geometrical structures of the porous alumina. Au nanodot arrays were obtained by thermal evaporation method. The SERS signals of pyridine molecules adsorbed on the nanodots were detected. The intensity of the SERS signals was strongly dependent on the arrangement of the nanodots. The enhancement factor of the intensity of the incident light on Au nanodots was analyzed by numerical calculations based on finite-difference time-domain (FDTD) method. The obtained SERS substrates are expected to be used for Raman spectra measurement with high sensitivity.