Imaging

@article{marega_two-dimensional_2010,

title = {Two-dimensional diffusion-ordered NMR spectroscopy as a tool for monitoring functionalized carbon nanotube purification and composition},

author = {Riccardo Marega and Vincent Aroulmoji and Massimo Bergamin and Luigi Feruglio and Francesca Dinon and Alberto Bianco and Erminio Murano and Maurizio Prato},

doi = {10.1021/nn100257h},

issn = {1936-086X},

year  = {2010},

date = {2010-04-01},

journal = {ACS nano},

volume = {4},

number = {4},

pages = {2051--2058},

abstract = {Functionalized carbon nanotube (CNT) derivatives are currently under thorough investigation in different biomedical investigations. In this field of research, the composition of sample either in terms of covalently attached or physisorbed moieties can greatly affect the observed results and hamper the comparison between different studies. Therefore, the availability of a fast and reliable analytical technique to assess both the type of interaction (covalent vs noncovalent) and the composition of CNT conjugates is of great importance. Here we describe that the two-dimensional diffusion-ordered (DOSY) NMR spectroscopy is extremely useful to discriminate between conjugated and unconjugated polyethylene glycol groups in samples obtained by condensation with oxidized single-walled carbon nanotubes (SWNTs). This fast and nondestructive technique allows us to follow the removal of unconjugated polyethylene glycol chains during the purification. In particular, DOSY analysis reveal that about 1/3 (wt %) of the polyethylene glycol used for the condensation remained physisorbed to functionalized SWNTs after dialysis. Complete elimination of physisorbed polyethylene glycol was achieved using diafiltration.},

keywords = {carbon, Diffusion, I2CT, Magnetic Resonance Spectroscopy, Nanotubes, Polyethylene Glycols, Solubility, Team-Bianco, Temperature, water},

pubstate = {published},

tppubtype = {article}

}

@article{marega_diffusion-ordered_2009,

title = {Diffusion-ordered NMR spectroscopy in the structural characterization of functionalized carbon nanotubes},

author = {Riccardo Marega and Vincent Aroulmoji and Francesca Dinon and Lisa Vaccari and Silvia Giordani and Alberto Bianco and Erminio Murano and Maurizio Prato},

doi = {10.1021/ja902728w},

issn = {1520-5126},

year  = {2009},

date = {2009-07-01},

journal = {Journal of the American Chemical Society},

volume = {131},

number = {25},

pages = {9086--9093},

abstract = {The emerging applications of functionalized carbon nanotubes (CNTs) in various research domains necessitate the use of many different analytical techniques to confirm their structural modifications in a fast and reliable manner. Thus far, NMR spectroscopy has not been among the main tools for characterization of organically modified carbon nanostructures. (1)H analysis is limited because the signals in these derivatives are typically weak and broad, resulting in uncertainties of a few parts per million, and because of the strong interference of residual solvent signals. To overcome these limitations, we investigated the applicability of proton NMR spectroscopy based on gradient-edited diffusion pulse sequences (1D diffusion-ordered spectroscopy, DOSY) in the characterization of CNT derivatives. In general, diffusion NMR experiments allow the separation of NMR signals of different species present in a mixture, according to their own diffusion coefficients, merging spectroscopy information with size analysis. In the present study, a selected set of CNT derivatives was synthesized and analyzed using 1D DOSY experiments by applying strong magnetic field gradients (up to 42.6 G cm(-1)). Colorimetric tests (i.e., Kaiser test) and TGA analysis support the NMR findings, which are related to isolated and/or bundled short SWNTs, on the basis of TEM and AFM characterization. The overall results show that the diffusion-based NMR spectroscopy is a fast and promising approach for the characterization of covalently modified CNT derivatives.},

keywords = {carbon, Diffusion, I2CT, Magnetic Resonance Spectroscopy, Nanotubes, Oxidation-Reduction, Surface Properties, Team-Bianco},

pubstate = {published},

tppubtype = {article}

}

@article{kostarelos_cellular_2007,

title = {Cellular uptake of functionalized carbon nanotubes is independent of functional group and cell type},

author = {Kostas Kostarelos and Lara Lacerda and Giorgia Pastorin and Wei Wu and Sébastien Wieckowski and Jacqueline Luangsivilay and Sylvie Godefroy and Davide Pantarotto and Jean-Paul Briand and Sylviane Muller and Maurizio Prato and Alberto Bianco},

doi = {10.1038/nnano.2006.209},

issn = {1748-3395},

year  = {2007},

date = {2007-02-01},

journal = {Nature Nanotechnology},

volume = {2},

number = {2},

pages = {108--113},

keywords = {Animals, carbon, Cell Membrane, Cells, Cultured, Diffusion, Humans, I2CT, Nanotubes, Team-Bianco},

pubstate = {published},

tppubtype = {article}

}