SERS on mesostructured thin films with silver nanoparticles
نویسندگان
چکیده
Mesostructured 2d-hexagonal sol-gel films were prepared by dip-coating method. Their structures were detected by X-ray diffraction. Silver nanoparticles reduced from Ag ion (silver nitrate) to Ag were deposited into the channels of the structure produced by the neutral surfactant Brij58. Surface enhanced raman spectroscopy technique was used to characterize the films. Spectra of films without metallic particles were compared to those with silver nanoparticles; the earliest exhibit an increased intensity on the 885, 955, 1061, 1129, 1230,1429, 1521, and 1796 cm bands. This enhancement due to SERS is the result of the surface plasmon excitation inside the silver particles causing a reactivation of the Raman scattering from the molecules on the surface colloids. Photoconductivity studies were performed on mesostructured films with silver colloids. φl0 and φμτ parameters are bigger than those from photorefractive crystals KnbO3:Fe . The photovoltaic effect increases with AgNO3 concentration. Mesostructured film without silver colloids shows a small photovoltaic parameter.
منابع مشابه
In situ fabricated polymer-silver nanocomposite thin film as an inexpensive and efficient substrate for surface-enhanced Raman scattering.
The utility of polymer-metal nanocomposite thin films with in situ generated silver nanoparticles as substrates for surface-enhanced Raman scattering (SERS) is demonstrated. Thin films of poly(vinyl alcohol) and poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) containing Ag nanoparticles generated in situ through thermal annealing and photoirradiation, respectively (Ag-PVA and Ag-PVVV), ar...
متن کاملLoading of exponentially grown LBL films with silver nanoparticles and their application to generalized SERS detection.
Feature film: Thin films made by exponential layer-by-layer growth display high diffusivity and can be readily infiltrated with inorganic nanoparticles. They can sequestrate molecular systems from solution as a function of the composition of their layers, while providing intense surface-enhanced Raman scattering (SERS) signals (see picture).
متن کاملSurface-enhanced Raman scattering: a powerful tool for chemical identification.
The nature of "hot spots" in surface-enhanced Raman scattering (SERS) and the novel fabrication of Ag thin films for efficient SERS measurements are the main focus of this review. By using 4-aminobenzenthiol or 1,4-phenylenediisocyanide molecules we can characterize the nanogap formed by a metal nanoparticle and a flat metal substrate, or the gap between two spherical metal nanoparticles. These...
متن کاملDIFFERENT APPROACHES FOR SURFACE MODIFICATIONS: FORMATION OF INHIBITIVE FILM ON COPPER SURFACES AND SURFACES FUNCTIONALISED WITH Ag NANOPARTICLES
OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNLOGY P.O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Kirsi Yliniemi Name of the dissertation Different Approaches for Surface Modifications: Formation of Inhibitive Film on Copper Surfaces and Surfaces Functionalised with Ag Nanoparticles Manuscript submitted 28 November 2007 Manuscript revised N/A Date of the defence 28 March 2008 Monog...
متن کاملA SERS and electrical sensor from gas-phase generated Ag nanoparticles self-assembled on planar substrates.
Optical excitation of coupled plasmonic nanoparticles supports intense localized electromagnetic "hot-spots" which enable a variety of surface enhanced spectroscopies with the best known example being surface enhanced Raman scattering (SERS), currently of great interest for sensing applications. In this study, we present a novel SERS and electrical dual transduction chemical sensor based on gas...
متن کامل