High Surface-Enhanced Raman Scattering (SERS) sensitivity of R6G by fabrication of silver nanoparticles over GaN nanowires

A composite structure made of Ag nanoparticles adsorbed on GaN nanowires were used as a Surface-Enhanced Raman Scattering (SERS) substrate. With Rhodamine 6G used as a SERS probe, high enhancement factor of 9*10¹¹ was derived. Detection limit as low as 10^-12M was observed. Intensity of the SERS was correlated to the adsorbing pattern of the Ag nanoparticles. Low Ag coverage corresponded to isolated spherical Ag nanoparticles, which intensify the SERS. High Ag coverage, however, corresponded to larger particles and island growth, which causes low SERS magnification.