Browsing by Author "Ignat, Teodora"
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Item Nanostructured Au/Si substrate for organic molecule SERS detection(2009-09) Ignat, Teodora; Munoz, Roberto; Irina, Kleps; Obieta, Isabel; Mihaela, Miu; Simion, Monica; Iovu, Mircea; Tecnalia Research & InnovationNanoparticles of noble metals, such as gold and silver, exhibit unique and tunable optical properties on account of their surface plasmon resonance. In particular, gold nanoparticles on silicon substrates are attractive for future nanoscale sensors and optical devices due to their resistance to oxidation and due to their electrical and optical properties. In this study, we developed a nanostructured gold/macroporous silicon (Au/PS) substrate capped with 11-mercaptoundecanoic acid (11-MUA) with ultra-sensitive detection properties achieved in characterization, an approach based on surface-enhanced Raman scattering (SERS). Surface-enhanced Raman scattering allows us to detect substances at a low concentration level and to observe structural details of a thiol molecule bonded to small film thicknesses. Raman measurements were carried out at 514 nm and 785 nm. In order to emphasize the effect of the Si microstructuration on the efficiency of this new substrate (Au/PS) proposed for SERS experiments, the same molecule (11-MUA) was adsorbed on it as well as on gold/atomically flat silicon (Au/Si) and on commercial Klarite (Mesophotonics) substrates. Systematic studies realized by Raman spectroscopy, electron microscopy, and X-ray spectroscopy show the influence of silicon substrate texturing and metallic deposition conditions, including time and temperature on the optical phenomena.Item SERS-active substrate based on macroporous silicon(2009) Ignat, Teodora; Munoz, Roberto; Kleps, Irina; Miu, Mihaela; Obieta, Isabel; Simion, Monica; Tecnalia Research & InnovationNovel architectures with nanometric are very promising as build- ing blocks for future nanotechnological applications. Metallic substrates with ordered morphology have been shown to be very effective for surface-enhanced Raman scattering (SERS). The sensitivity of detection is increased by several orders of magnitude by using this technique. In this paper we investigate SERS on thermal evaporated gold layer / porous silicon substrate comparatively to a PVD-gold layer/flat silicon substrate.