Nanostructured thin films as surface-enhanced Raman scattering substrates

Nanoporous thin films with silver nanoparticles were synthesized with a bottom–up approach, and its potential as effective surface-enhanced Raman scattering (SERS) substrates was demonstrated. The use of mesoporous titania films as substrates allowed to control the growth of nanoparticles on the film surface. Atomic force microscopy measurements, Ultraviolet-visible and X-ray diffraction analysis confirmed the photoreduction of Ag+ to Ag0 with the formation of nanoparticles with crystallite dimensions of 32 to 36 nm. The new substrates allowed the detection of two analytes (rhodamine B isothiocyanate and cytochrome c), present in solutions at very low concentrations, highlighting their potential in SERS sensing. Reproducibility, homogeneity, enhancement factor of the substrate, consistency of results and detection limits were also assessed. Copyright © 2012 John Wiley & Sons, Ltd.