초록 |
Surface plasmons have attracted great attentions as surface-enhanced Raman scattering (SERS) chemical sensors since the large field enhancements can provide reproducible hot spots. Here we investigate the particle-film plasmon couplings of high-density gold nanostar (GNS) arrays assembled on various substrates (Ag, Au, Si, glass). In particular, we show how the GNS surface densities affect the E-field enhancements from the particle-film plasmon couplings by analyzing the finite-difference time-domain (FDTD) calculation of E-fields and the experimental SERS intensities. Finally, we verify optimally designed SERS substrates based on GNSs on metal films which can detect attomole level of target molecules. In addition, we present flexible SERS-active substrate based on GNS embedded elastomeric films. This work provides a new platform for the development of ultra-sensitive and flexible SERS devices for identification of explosive materials and biomolecules attached on arbitrary surfaces. |