Glancing angle deposition of silver nanostructures for use in surface enhanced Raman scattering

Raman spectroscopy is an important technique that has evolved into many advanced methods, used in a wide range of fields, ranging from artwork analysis to security. In this study, we have found through template-assisted glancing angle deposition, highly ordered silver nanostructures could be fabricated across a nano-imprinted polymer to produce surface enhanced Raman scattering substrates. Various nominal film thicknesses at 85° incident angle and then deposition angles were used to fabricate the substrates, which were then characterised by scanning electron microscopy and their Raman performance was assessed using trans-1, 2-bis (4-pyridyl) ethylene as the Raman probe. Observations show that the best thickness for glancing angle deposition at 85° to be 400 nm (relative to the quartz crystal microbalance) produced the best Raman signal enhancement. The nanostructures consisted of nanorods with 851 – 1360 nm average length. Scanning electron microscopy images reveal samples had good uniformity and consistency in all films grown by this method, as the surface features provide regularly spaced nucleation sties. These findings lead show that highly sensitive surface enhanced Raman scattering substrates can be reproduced consistently cheaply.