Villeneuve-la-Rivière, France
Villeneuve-la-Rivière, France

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Szunerits S.,Interdisciplinary Research Institute IRI | Szunerits S.,Lille University of Science and Technology | Ghodbane S.,BeSt coating GmbH | Niedziolka-Jonsson J.,Interdisciplinary Research Institute IRI | And 10 more authors.
Journal of Physical Chemistry C | Year: 2010

The paper reports on the fabrication of a localized surface plasmon resonance (LSPR) interface with nanocrystalline diamond (NCD) as overcoating. The LSPR interface is formed through thermal evaporation of a 4 nm gold film onto quartz substrates and postannealed at 800 °C. The resulting gold nanostructures (Au NSs) are further coated with nanocrystalline diamond (NCD) films produced by hot filament-assisted chemical vapor deposition (HFCVD) at 800 °C. The influence of the NCD film thickness on the wavelength at maximum absorption (λmax) was investigated by recording UV-vis transmission spectra in air. The experimentally obtained data were compared to the theoretically calculated one. The possibility to introduce chemical functions on the quartz/Au NSs/NCD interfaces was demonstrated by (i) photochemical oxidation of the NCD overcoating and subsequent reaction of the oxidized surface with perfluorodecyltrichlorosilane or (ii) chemical linking of the 4-nitrobenzene diazonium salt directly onto as-grown hydrogen-terminated NCD films. © 2010 American Chemical Society.

Ayat M.,University of Science and Technology Houari Boumediene | Boarino L.,INRIM - Istituto Nazionale di Ricerca Metrologica | Boukherroub R.,Interdisciplinary Research Institute IRI | Kechouane M.,University of Science and Technology Houari Boumediene
Nanoscale Research Letters | Year: 2014

In this work, we report the fabrication of ordered silicon structures by chemical etching of silicon in vanadium oxide (V2O5)/hydrofluoric acid (HF) solution. The effects of the different etching parameters including the solution concentration, temperature, and the presence of metal catalyst film deposition (Pd) on the morphologies and reflective properties of the etched Si surfaces were studied. Scanning electron microscopy (SEM) was carried out to explore the morphologies of the etched surfaces with and without the presence of catalyst. In this case, the attack on the surfaces with a palladium deposit begins by creating uniform circular pores on silicon in which we distinguish the formation of pyramidal structures of silicon. Fourier transform infrared spectroscopy (FTIR) demonstrates that the surfaces are H-terminated. A UV-Vis-NIR spectrophotometer was used to study the reflectance of the structures obtained. A reflectance of 2.21% from the etched Si surfaces in the wavelength range of 400 to 1,000 nm was obtained after 120 min of etching while it is of 4.33% from the Pd/Si surfaces etched for 15 min. © 2014, Ayat et al.; licensee Springer.

Ayat M.,University of Science and Technology Houari Boumediene | Boarino L.,INRIM - Istituto Nazionale di Ricerca Metrologica | Boukherroub R.,Interdisciplinary Research Institute IRI
ECS Transactions | Year: 2015

In this work we report the fabrication of ordered macroporous silicion structures by chemical etching of silicon in vanadium oxide (V2O5) and hydrofluoric acid (HF) solution. The effects of the different etching parameters, including the etching time and the presence of metal catalyst film deposition (Pd, Ag), on the morphologies and the optical properties of the etched Si surfaces were studied. It has been found that the morphology depends on the etching time and on the presence and the type of the catalyst. The results show that the attack of the silicon surface coated with Palladium or Silver deposit begins by creating circular pores. In addition, long etching time leads to the formation of porous pyramidal structures inside the macropores. A reflectance around 1,64% and a contact angle of 148° for the Ag/Si structures were observed. © The Electrochemical Society.

Corbel C.,French National Center for Scientific Research | Corbel C.,University of Southern Brittany | Corbel C.,University of California at Santa Barbara | Zhang B.,North China Electrical Power University | And 9 more authors.
Chemistry and Biology | Year: 2015

Cyclin-dependent kinase 5 (CDK5) is a multifunctional enzyme that plays numerous roles, notably in brain development. CDK5 is activated through its association with the activators, p35 and p39, rather than by cyclins. Proteolytic procession of the N-terminal part of its activators has been linked to Alzheimer's disease and various other neuropathies. The interaction with the proteolytic product p25 prolongs CDK5 activation and modifies the substrate specificity. In order to discover small-molecule inhibitors of the interaction between CDK5 and p25, we have used a bioluminescence resonance energy transfer (BRET)-based screening assay. Among the 1,760 compounds screened, the generic drug tamoxifen has been identified. The inhibition of the CDK5 activity by tamoxifen was notably validated by monitoring the phosphorylation state of tau protein. The study of the molecular mechanism of inhibition indicates that tamoxifen interacts with p25 to block the CDK5/p25 interaction and pave the way for new treatments of tauopathies. © 2015 Elsevier Ltd. All rights reserved.

Saad N.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Saad N.,Lebanese University | Dufour R.,University of Lille Nord de France | Dufour R.,Interdisciplinary Research Institute IRI | And 11 more authors.
Journal of Applied Physics | Year: 2012

In this work, we propose acoustic characterization as a new method to probe wetting states on a superhydrophobic surface. The analysis of the multiple reflections of a longitudinal acoustic wave from solid-liquid and solid-vapor interfaces enables to distinguish between the two well known Cassie-Baxter and Wenzel wetting configurations. The phenomenon is investigated experimentally on silicon micro-pillars superhydrophobic surfaces and numerically using a finite difference time domain method. Numerical calculations of reflection coefficients show a good agreement with experimental measurements, and the method appears as a promising alternative to optical measurement methods. © 2012 American Institute of Physics.

Madani A.,Ferhat Abbas University Setif | Nessark B.,Ferhat Abbas University Setif | Boukherroub R.,Interdisciplinary Research Institute IRI | Chehimi M.M.,University Paris Diderot
Journal of Electroanalytical Chemistry | Year: 2011

PPy/CdS composite films made from polypyrrole (PPy) with embedded semiconductor (CdS) quantum dots were obtained by electropolymerization of pyrrole in the presence the CdS nanoparticles dispersed in the electrolytic aqueous solution. For the characterization of the modified surface electrode by PPy-CdS, the scan electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV-visible were used. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) have been used to investigate the electrochemical behaviour of the resulting materials. The illumination effects are also observed in the reduced form of the polymer. This study showed that the presence of CdS nanoparticles in the polypyrrole film improves the optical properties of PPy via a simple preparation method and show that these films have potential in the photoelectrochemical applications such as photovoltaic cells. © 2010 Elsevier B.V. All rights reserved.

Qi H.,Lille University of Science and Technology | Qi H.,Interdisciplinary Research Institute IRI | Cantrelle F.-X.,Lille University of Science and Technology | Benhelli-Mokrani H.,University of Paris Descartes | And 7 more authors.
Biochemistry | Year: 2015

The capacity of endogenous Tau to bind DNA has been recently identified in neurons under physiological or oxidative stress conditions. Characterization of the protein domains involved in Tau-DNA complex formation is an essential first step in clarifying the contribution of Tau-DNA interactions to neurological biological processes. To identify the amino acid residues involved in the interaction of Tau with oligonucleotides, we have characterized a Tau-DNA complex using nuclear magnetic resonance spectroscopy. Interaction of an AT-rich or GC-rich 22 bp oligonucleotide with Tau showed multiple points of anchoring along the intrinsically disordered Tau protein. The main sites of contact characterized here correspond to the second half of the proline-rich domain (PRD) of Tau and the R2 repeat in the microtubule binding domain. This latter interaction site includes the PHF6∗ sequence known to govern Tau aggregation. The characterization was pursued by studying the binding of phosphorylated forms of Tau, displaying multiple phosphorylation sites mainly in the PRD, to the same oligonucleotide. No interaction of phospho-Tau with the oligonucleotide was detected, suggesting that pathological Tau phosphorylation could affect the physiological function of Tau mediated by DNA binding. © 2015 American Chemical Society.

Dufour R.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Dufour R.,Interdisciplinary Research Institute IRI | Harnois M.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Coffinier Y.,Interdisciplinary Research Institute IRI | And 3 more authors.
Langmuir | Year: 2010

Following the achievement of superhydrophobicity which prevents water adhesion on a surface, superomniphobicity extends this high repellency property to a wide range of liquids, including oils, solvents, and other low surface energy liquids. Recent theoretical approaches have yield to specific microstructures design criterion to achieve such surfaces, leading to superomniphobic structured silicon substrate. To transfer this technology on a flexible substrate, we use a polydimethylsiloxane (PDMS) molding process followed by surface chemical modification. It results in so-called sticky superomniphobic surfaces, exhibiting large apparent contact angles (>150°) along with large contact angle hysteresis (>10°). We then focus on the modified Cassie equation, considering the 1D aspect of wetting, to explain the behavior of droplets on these surfaces and compare experimental data to previous works to confirm the validity of this model. © 2010 American Chemical Society.

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