Vertical silver nanorod growth as a surface-enhanced Raman scattering

Abstract

We report an optimization of the fabrication method on arrays of vertically grown nanometer scaled silver rod using nanosphere (polystyrene) lift-off on SiO 2 wafer as a surface-enhance Raman scattering substrate by thermal evaporation technology as well as real-time vapor phase detection of CHCl 3 by the radiation of fiber optic coupled 785 nm diode laser. Raman peak at 668.2 cm -1 for CHCl 3 (C-H stretching band) was compared to the peak at 1088.4 cm -1 of 1-propanethiol (CH 3 rock band) and the detection limit of CHCl 3 vapor phase contamination level was estimated as a function of the peak intensity ratio of 668.2 vs. 1088.4. The detectable range using Ag nanorod wells on SiO 2 substrate was 20-800 ppm. We were able to make significant steps toward developing cost effective nano-pattern as a Raman sensor.