Aligned silver nanorod arrays for surface-enhanced Raman spectroscopy

A convenient nanotechnique is used to place analyte molecules between closely spaced silver nanorods for investigating surface-enhanced Raman scattering (SERS). The route involves letting absorption of saturated AgNO3 solution in the pores of the porous anodic alumina templates, followed by drying and decomposition of the salt at high temperatures. The silver nanorod arrays boast a high SERS enhancement and large dynamic range. The interrod-coupling-induced enhancement was attributed to the broadening of the plasmon resonance peak because the probability of the resonance covering both the excitation wavelength and the Raman peak increases with its width. The method will be useful in the development of plasmon-based analytical devices, specifically SERS-based biosensors.