Title of article :
Raman spectroscopy of organic dyes adsorbed on pulsed laser deposited silver thin films
Author/Authors :
E. Fazio، نويسنده , , F. Neri، نويسنده , , A. Valenti، نويسنده , , P.M. Ossi، نويسنده , , S. Trusso، نويسنده , , R.C. Ponterio، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2013
Pages :
6
From page :
259
To page :
264
Abstract :
The results of a surface-enhanced Raman scattering (SERS) study performed on representative organic and inorganic dyes adsorbed on silver nanostructured thin films are presented and discussed. Silver thin films were deposited on glass slides by focusing the beam from a KrF excimer laser (wavelength 248 nm, pulse duration 25 ns) on a silver target and performing the deposition in a controlled Ar atmosphere. Clear Raman spectra were acquired for dyes such as carmine lake, garanza lake and brazilwood overcoming their fluorescence and weak Raman scattering drawbacks. UV–visible absorption spectroscopy measurements were not able to discriminate among the different chromophores usually referred as carmine lake (carminic, kermesic and laccaic acid), as brazilwood (brazilin and brazilein) and as garanza lake (alizarin and purpurin). SERS measurements showed that the analyzed samples are composed of a mixture of different chromophores: brazilin and brazilein in brazilwood, kermesic and carminic acid in carmine lake, alizarin and purpurin in garanza lake. Detection at concentration level as low as 10−7 M in aqueous solutions was achieved. Higher Raman intensities were observed using the excitation line of 632.8 nm wavelength with respect to the 785 nm, probably due to a pre-resonant effect with the molecular electronic transitions of the dyes.
Keywords :
Laser ablation , Cultural heritage , Nanoparticles , Surface-enhanced Raman spectroscopy , Pigments
Journal title :
Applied Surface Science
Serial Year :
2013
Journal title :
Applied Surface Science
Record number :
1007379
Link To Document :
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