Guided-mode-resonance-coupled plasmonic-active SiO(2) nanotubes for surface enhanced Raman spectroscopy

We demonstrate a surface enhanced Raman scattering (SERS) substrate by integrating plasmonic-active SiO(2) nanotubes into Si(3)N(4) gratings. First, the dielectric grating that is working under guided mode resonance (GMR) provides enhanced electric field for localized surface plasmon polaritons on the surface of metallic nanoparticles. Second, we use SiO(2) nanotubes with densely assembled silver nanoparticles to provide a large amount of "hot spots" without significantly damping the GMR mode of the grating. Experimental measurement on Rhodamine-6G shows a constant enhancement factor of 8 ∼ 10 in addition to the existing SERS effect across the entire surface of the SiO(2) nanotubes.