Surface-enhanced Raman scattering of SnO2bulk material and colloidal solutions

Abstract

Surface enhanced Raman scattering (SERS) effects on tin dioxide in the form of bulk material, nanostructured thin films and colloidal solutions were investigated. Raman spectra are characterized by the three Raman scattering peaks at 478, 633, and 776 cm −1 , assigned to the Eg, A1g and B2g modes, typical of rutile SnO2. In presence of the silver nanoparticles, in addition to the enhancement intensity of some of the fundamental tin dioxide rutile Raman features, the appearance of a new Raman scattering peak at about 600 cm −1 is observed. This spectral features is observed, in presence of silver nanoparticles, also in other SnO2 based system such as pulsed laser deposited thin films, with different stoichiometry, and in water colloidal solutions. The observed SERS effects are explained in terms of electric-field gradient mechanism that are generated near a metal surface. In particular, the appearance of a peak near 600 cm −1 is attributed to the Raman activation of the infrared Eu transverse optical (TO) mode.

Synthesis and properties of (Fe, Al) co-doped SnO2 nanoparticles

“…Rutile SnO 2 with six atom unit cell gives 18 possible vibrations. In fact, AlCl 3 , Fe (NO 3 ) 2 have a vibration mode at 633cm -1 [20]. While E u has two acoustic, one Optic mode.…”

Simultaneous electrochemical determination of epinephrine and uric acid in the presence of ascorbic acid using SnO2/graphene nanocomposite modified glassy carbon electrode

“…1B. The SnO 2 sample is characterized by a broad and structure-less band in the 450-650 cm -1 range, attributed to the presence of the amorphous SnO 2 phase [29] Moreover, a peak is barely visible at 633 cm −1 , corresponding to A 1g mode in good agreement with those observed in a single-crystal SnO 2 or poly-microcrystalline films [30]. The little shifting of D band was correlated with the structural changes, determined by the chemical bond interaction between GO and SnO 2 .…”

Phage–AgNPs complex as SERS probe for U937 cell identification

“…The selection rule for this process differed markedly from the usual Raman selection rules. The SERS-induced occurrence of new Raman peaks was attributed to the lowering of the symmetry of the investigated molecules or to the presence of a steep field close to the nanoparticles metal surface (Fazio et al, 2012).…”

“…Surface Enhanced Raman Spectroscopy (SERS) is a very sensitive analytic tool, suitable even for single molecule detection. In SERS, metal nanoparticles, such as silver or gold nanoparticles, can particularly enhance the Raman spectra of the molecules through amplifying the local electromagnetic field incident on a sample adsorbed on a metal surface (Aroca et al, 2005;Ko et al, 2008;Agarwal et al, 2011;Fazio et al, 2013). The sensitivity of SERS has been shown to be as high as 10 14 -10 15 (Nie and Emory, 1997;Kneipp et al, 1997).…”