Showing papers by "Cinzia Casiraghi published in 2010"
TL;DR: Graphene oxide exfoliated sheets were used as two dimensional platforms to covalently tether on their surface thousands of optically active quaterthiophene molecules (T4), using an innovative microwave-assisted silanization reaction as mentioned in this paper.
Abstract: Graphene oxide (GO) exfoliated sheets were used as two dimensional platforms to covalently tether on their surface thousands of optically active quaterthiophene molecules (T4), using an innovative microwave-assisted silanization reaction. This method allowed to perform GO functionalization in one-step, under mild conditions in a few tens of minutes rather than days. The hybrid GOT4 could be processed in either H2O or apolar organic solvents and deposited as single sheets, microplatelets or macroscopic membranes. Absorption/emission spectroscopy reveals that GOT4 combines limited T4-T4 interactions with strong T4-GO ones. These findings, combined with the ‘user-friendly’ engineering approach presented here, pave the way towards the bottom-up fabrication of new GO-based tailored materials for electronics, sensors and biological applications.
82 citations
TL;DR: In this article, a set of metallic nanodisks placed one above another was used to achieve a cascaded enhancement of the Raman signal at optical frequencies, and the optical properties of reproducible arrays of these structures were studied using scanning confocal Raman spectroscopy.
Abstract: We present composite plasmonic nanostructures designed to achieve cascaded enhancement of electromagnetic fields at optical frequencies. Our structures were made with the help of electron-beam lithography and comprise a set of metallic nanodisks placed one above another. The optical properties of reproducible arrays of these structures were studied by using scanning confocal Raman spectroscopy. We show that our composite nanostructures robustly demonstrate dramatic enhancement of the Raman signals when compared to those measured from constituent elements.
45 citations
TL;DR: In this article, the effect of different dielectric environments on the properties of graphene by Raman spectroscopy was studied, and it was shown that water immersion reduces the effects of charged impurities.
Abstract: We have studied the effect of different dielectric environments on the properties of graphene by Raman spectroscopy. Graphene was produced by micromechanical exfoliation of graphite and deposited on a silicon substrate covered with 300 nm of silicon oxide (Si/SiO2). Graphene was immersed in water, ethanol and chloroform, which have a dielectric constant of 80, 30 and 4.8, at room temperature, respectively. We show that water immersion reduces the effect of charged impurities. Ethanol produces strong changes in the Raman spectrum. Graphene rolls and wrinkles once immersed in ethanol, as observed by optical microscope. Finally, chloroform produces a strong p-doping as observed by the up-shift of the G and 2D peaks. This shows that Raman spectroscopy is able to characterize the electrostatic environment of graphene (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
8 citations
Journal Article•
TL;DR: In this article, a production error on page 4 was reported, where the eighth line in the third paragraph should read as "intensities (10 W, spot size 500 nm)...
Abstract: This Letter was published online on 9 December 2010 with a production error on page 4. On page 4, left-hand column, the eighth line in the third paragraph should read as ‘‘intensities (10 W, spot size 500 nm). . .’’. The Letter has been corrected as of 14 December 2010. The text is correct in the printed version of the journal. PRL 105, 269906 (2010) P HY S I CA L R EV I EW LE T T E R S week ending 31 DECEMBER 2010
3 citations
1 citations