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Boukherroub R.,Institute Of Recherche Interdisciplinaire Iri Usr 3078
Tetrahedron Letters | Year: 2012

A new approach utilizing graphite oxide as an oxidizing agent is applied for the oxidative aromatization of 1,4-dihydropyridines. Graphite oxide efficiently aromatized Hantzsch 1,4-dihydropyridines into their corresponding pyridine derivatives in excellent yields. The reaction was carried out in toluene at 100 °C. © 2012 Elsevier Ltd. All rights reserved.

Qu X.,Pukyong National University | Qu X.,Changchun Normal University | Pan G.,Institute Of Recherche Interdisciplinaire Iri Usr 3078 | Yang H.K.,Pukyong National University | And 5 more authors.
Optical Materials | Year: 2012

NaYF 4 and NaYF 4 (Eu 3+, Tb 3+, Yb 3+/Er 3+) nano- and microstructures were successfully synthesized through a facile and effective polyol-mediated route with ethylene glycol (EG) as solvent. The factors including the molar ratio of F -/Y 3+, reaction temperature and reaction time were well studied in the influences on size, morphology and phase transition of samples. The experimental results indicate that the F -/Y 3+ ratio and reaction temperature play key roles in crystal phase and morphology of the product. Higher molar ratio of F -/Y 3+ and higher temperature as well as longer reaction time facilitate α cubic structure-to-β hexagonal structure phase transition, which behaves as a dissolution-recrystallization transformation process. Photoluminescence measurements demonstrated that the as-prepared β-NaYF 4 is one good up- and down-conversion luminescent host material. © 2012 Elsevier B.V. All rights reserved.

Bitziou E.,University of Warwick | Rudd N.C.,University of Warwick | Szunerits S.,Institute Of Recherche Interdisciplinaire Iri Usr 3078 | Szunerits S.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Unwin P.R.,University of Warwick
Journal of Electroanalytical Chemistry | Year: 2010

Three systems for photoelectrochemical measurements on the microscale have been implemented and compared: (i) an arrangement in which a fibre illuminates a disc-shaped ultramicroelectrode (UME) face-on; (ii) face-on illumination of a ring UME; and (iii) illumination through a fibre-coupled ring UME assembly. These set-ups have been used to study the classic system in which photoexcited tris(2,2′-bipyridine) ruthenium (II), Ru(bpy)32+, reduces methyl viologen dication, MV2+, to the radical cation, MV+. Detection of MV+ at the UME allows the kinetics to be determined and mass-transport at the various configurations to be assessed. It is shown that face-on illumination of either disc or ring-shaped UMEs can be treated in a straight forward way with simplifications such as a uniform light intensity distribution. On the other hand, while the fibre-coupled ring arrangement is potentially easier and simpler to deploy, it does not appear as amenable to such straightforward treatments. Deviations between experiment and theory in the latter case are attributed to complications such as natural convection and non-uniform light distribution, to which this format appears to be more sensitive. © 2010 Elsevier B.V. All rights reserved.

Nhung N.P.,Institut Universitaire de France | Coffinier Y.,Institute Of Recherche Interdisciplinaire Iri Usr 3078 | Boukherroub R.,Institute Of Recherche Interdisciplinaire Iri Usr 3078
Journal of Nanoscience and Nanotechnology | Year: 2016

Nanostructured silicon was formed by an electroless etching method using a mixture of NaBF4 and AgNO3 . The fabricated nanostructured silicon was used as a support of new surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The results showed that the fabricated silicon surface was able to analyze a peptide mixture (composed of Des-arg1-Bradykinin, Angiotensin I, Glu1-Fibrinopeptide I, and Neurotensin) with high sensitivity. Furthermore, the influence of chemical function terminated surface (such as: -CH3 , -CH3 degradation, -CF3 , -COOH, -C6 F5 ) on the efficiency of SALDI analysis was also studied. We pointed out that the chemical modification of the silicon surface improved the efficient performance of SALDI-MS surface and the performance of SALDI-MS substrate, depending dramatically on chemical function termination. © 2016 American Scientific Publishers All rights reserved.

Touahir L.,Ecole Polytechnique - Palaiseau | Niedziolka-Jonsson J.,Institute Of Recherche Interdisciplinaire Iri Usr 3078 | Niedziolka-Jonsson J.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Galopin E.,Institute Of Recherche Interdisciplinaire Iri Usr 3078 | And 10 more authors.
Langmuir | Year: 2010

The paper reports on a novel surface plasmon resonance (SPR) substrate architecture based on the coating of a gold (Au) or silver (Ag) substrate with 5 nm thin amorphous silicon?carbon alloy films. Ag/a-Si1?xC x:H and Au/a-Si1?xCx:H multilayers are found to provide a significant advantage in terms of sensitivity over both Ag and Au for SPR refractive index sensing. The possibility for the subsequent linking of stable organic monolayers through Si?C bonds is demonstrated. In a proof-of-principle experiment that this structure can be used for real-time biosensing experiments, amine terminated biotin was covalently linked to the acid-terminated SPR surface and the specific streptavidin?biotin interaction recorded. © 2010 American Chemical Society.

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