References of "Humbert, Christophe"
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See detailAdsorption properties of decyl thiocyanate and decanethiol on platinum substrates studied by sum-frequency generation spectroscopy
Sartenaer, Yannick; Dreesen, Laurent ULg; Humbert, Christophe et al

in Surface Science (2007), 601

Recently, thiocyanate groups were successfully used as precursors for thiolate assemblies. Indeed, they provide a useful alternative to thiol groups for self-assembly on metallic substrates. In order to ... [more ▼]

Recently, thiocyanate groups were successfully used as precursors for thiolate assemblies. Indeed, they provide a useful alternative to thiol groups for self-assembly on metallic substrates. In order to check the adsorption properties and the quality of the thiocyanate-based self-assembled monolayers (SAMs), we use sum-frequency generation spectroscopy (SFG) and apply it to characterize the ad-layers of two similar molecules: decanethiol (DT) and decyl thiocyanate (DTCN) adsorbed on platinum surfaces. By comparing the SFG signals of the methyl and methylene vibration modes, we show that DTCN SAMs are less ordered than DT ones. These effects are related to the SAMs quality which depends on the molecular packing as highlighted by scanning tunnelling microscopy and X-ray photoelectron spectroscopy. [less ▲]

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See detailOn the Protoporphyrin Monolayers Conformation
Humbert, Christophe; Dreesen, Laurent ULg; Sartenaer, Yannick et al

in Chemphyschem : A European Journal of Chemical Physics and Physical Chemistry (2006), 7

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See detailThiocyanate and thiol self-assembling process on platinum investigated by means of sum-frequency generation
Sartenaer, Yannick; Tourillon, Gérard; Louette, Pierre et al

Poster (2005, September)

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See detailMolecular conformation and electronic properties of protoporphyrin-IX self-assembled monolayers adsorbed on Pt(111) surface
Humbert, Christophe; Volcke, Cédric; Sartenaer, Yannick et al

Poster (2005, September)

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See detailSum-frequency generation from surface species in porous silicon
Mattei, Giorgio; Valentini, Veronica; Yakovlev, Vladimir et al

in Phys. Stat. Sol. (a) (2005), 202(8), 1487-1491

For the first time, the sum-frequency generation (SFG) spectra of surface species have been measured in porous silicon (PS) layers. The range of the vibrations 2000–2300 cm–1 for the native species Si–Hx ... [more ▼]

For the first time, the sum-frequency generation (SFG) spectra of surface species have been measured in porous silicon (PS) layers. The range of the vibrations 2000–2300 cm–1 for the native species Si–Hx has been explored. Furthermore for the studied mesoporous materials, it has been found that, as opposed to the infrared absorption, the SFG signal increases with porosity. Finally, the angular dependence and the enhancement of the SFG signal were measured in a one-dimensional PS photonic crystal structure with a defect producing an energy level in the photonic band gap. [less ▲]

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See detailSum-frequency generation spectrocopy applied to model biosensors systems
Dreesen, Laurent ULg; Sartenaer, Yannick; Humbert, Christophe et al

Conference (2004, November)

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See detailTwo-color-sum-frequency generation characterization of a protein monolayer adsorbed on a metallic substrate
Dreesen, Laurent ULg; Sartenaer, Yannick; Humbert, Christophe et al

Poster (2004, June)

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See detailTwo-color-sum-frequency generation characterization of a protein monolayer adsorbed on a metallic substrate
Dreesen, Laurent ULg; Sartenaer, Yannick; Humbert, Christophe et al

Poster (2004, May 25)

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See detailPicosecond laser for performance of efficient nonlinear spectroscopy from 10 to 21 mm
Mani, A. A.; Schultz, Z. D.; Gewirth, A. A. et al

in Optics Letters (2004), 29(3), 274-276

Laser tunability from 10 to 21 mm is obtained by use of an optical parametric oscillator based on a KTP crystal followed by a difference-frequency stage with a CdSe crystal. An all-solid-state picosecond ... [more ▼]

Laser tunability from 10 to 21 mm is obtained by use of an optical parametric oscillator based on a KTP crystal followed by a difference-frequency stage with a CdSe crystal. An all-solid-state picosecond Nd:YAG oscillator mode locked by a frequency-doubling nonlinear mirror is used for synchronous pumping. [less ▲]

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See detailMethanol dissociative adsorption on Pt(1 0 0) as studied by nonlinear vibrational spectroscopy
Vidal, Franck; Busson, B.; Six, C. et al

in Journal of Electroanalytical Chemistry (2004), 563

The methanol dissociative adsorption on Pt(1 0 0) at low potentials in the hydrogen region is studied using nonlinear vibrational sum-frequency generation (SFG) spectroscopy. It is shown that adsorbed ... [more ▼]

The methanol dissociative adsorption on Pt(1 0 0) at low potentials in the hydrogen region is studied using nonlinear vibrational sum-frequency generation (SFG) spectroscopy. It is shown that adsorbed hydrogen atoms effectively block atop sites at the surface. In the hydrogen potential region, CO produced by the methanol dissociation adsorbs at step-edges and in bridge sites on terraces as shown by the characteristic stretching frequencies observed for adsorbed CO. [less ▲]

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See detailPotential-dependent structure of the interfacial water on the gold electrode
Nihonyanagi, Satoshi; Ye, Shen; Uosaki, Kohei et al

in Surface Science (2004), 573

Doubly tunable sum frequency generation (SFG) spectra demonstrate that the water molecules at gold/electrolyte interface change their orientation with applied potential. At negative potentials, water ... [more ▼]

Doubly tunable sum frequency generation (SFG) spectra demonstrate that the water molecules at gold/electrolyte interface change their orientation with applied potential. At negative potentials, water molecules in the double layer align with their oxygen atom pointing to the solution. As potential became positive to be close to the potential of zero charge (PZC), the SFG signal decreased, suggesting the OH groups of the water molecule are either in random orientation or parallel to the electrode. As potential became more positive than the PZC, the SFG signal increased again with the oxygen-up orientation as same as in the negative potential region, indicating that water molecules interact with the adsorbed sulfate anions. The peak position of the SFG spectra indicates a relatively disordered state of water molecules at the gold electrode surface, in contrast to the previously observed ice-like structure of water at electrolyte/oxide interfaces. [less ▲]

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See detailProbing Ligand–Protein Recognition with Sum-Frequency Generation Spectroscopy: The Avidin–Biocytin Case
Dreesen, Laurent ULg; Sartenaer, Yannick; Humbert, Christophe et al

in Chemphyschem : A European Journal of Chemical Physics and Physical Chemistry (2004), 5

Infrared/visible sum-frequency generation (SFG) spectroscopy is used to study the recognition of a protein (avidin) by a derived vitamin (biocytin) adsorbed on a calcium fluoride substrate. The ... [more ▼]

Infrared/visible sum-frequency generation (SFG) spectroscopy is used to study the recognition of a protein (avidin) by a derived vitamin (biocytin) adsorbed on a calcium fluoride substrate. The specificity of the process is tested by replacing avidin with bovine serum albumin or presaturated avidin. The SFG spectroscopy shows drastic modifications in the CH and NH spectral ranges only upon exposure of the biocytin film to avidin. The comparison of the SFG data with Fourier transform infrared reflection absorption spectra (FT-IRRAS) in the same spectral ranges illustrates the advantages of nonlinear spectroscopy for studying and detecting recognition between biomolecules. [less ▲]

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See detailMolecule orientation in self-assembled monolayers determined by infrared-visible sum-frequency generation spectroscopy
Mani, A. A.; Schultz, Z. D.; Champagne, B. et al

in Applied Surface Science (2004), 237

The molecular orientation in self-assembled monolayers of thiophenol (TP) on Ag(1 1 1) and of para-nitroanilinododecane-thiol (NAT) on Au was investigated by infrared-visible sum-frequency generation ... [more ▼]

The molecular orientation in self-assembled monolayers of thiophenol (TP) on Ag(1 1 1) and of para-nitroanilinododecane-thiol (NAT) on Au was investigated by infrared-visible sum-frequency generation between 500 and 1500 cm-1. Ab initio calculations were performed to determine the interface nonlinear response. The combined experimental and theoretical results reveal that the S–C bond of TP is tilted 37° from the Ag(1 1 1) surface normal, with the aromatic ring plane perpendicular to the surface. On Au, the tilt angle of the NAT molecule stabilizes below 60° at the end of film growth. [less ▲]

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See detailSum-frequency generation characterization of the molecular recognition of avidin by biocytin films adsorbed on metallic substrates
Dreesen, Laurent ULg; Humbert, Christophe; Sartenaer, Yannick et al

Poster (2003, June)

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See detailStudy by sum-frequency generation spectroscopy of a model biosensor : the biocytin-avidin complex
Sartenaer, Yannick; Dreesen, Laurent ULg; Mani, Alaa Adin et al

Poster (2003, May)

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See detailE lectron–phonon couplings at C60 interfaces: a case study by two- color, infrared–visible sum–frequency generation spectroscopy
Caudano, Yves; Silien, C.; Humbert, Christophe et al

in Journal of Electron Spectroscopy & Related Phenomena (2003), 129

We demonstrate the ability of doubly resonant sum–frequency generation (DR-SFG) to investigate electron–phonon couplings at C60 –metal interfaces. Due to its coupling to electronic transitions, the ... [more ▼]

We demonstrate the ability of doubly resonant sum–frequency generation (DR-SFG) to investigate electron–phonon couplings at C60 –metal interfaces. Due to its coupling to electronic transitions, the totally symmetric Ag(2) vibration of C60 exhibits a huge enhancement of its nonlinear response for sum–frequency energies above the molecular electronic gap. We attribute this resonance to the coupling of the pentagonal pinch mode with the tiu lowest unoccupied molecular orbital (LUMO) of C60. [less ▲]

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See detailStudy by the sum-frequency generation spectroscopy of a model biosensor : The biocytin-avidin complex*
Sartenaer, Y.; Dreesen, Laurent ULg; Humbert, Christophe et al

in Physicalia Magazine (2003), 25(3), 221-229

Infrared-visible sum-frequency generation (SFG) spectroscopy is used to study the recognition of a protein (avidin) by a derivated vitamin (biocytin). No interaction is observed when the measurements are ... [more ▼]

Infrared-visible sum-frequency generation (SFG) spectroscopy is used to study the recognition of a protein (avidin) by a derivated vitamin (biocytin). No interaction is observed when the measurements are performed on metallic substrates in the normal co-propagative configuration. When the biocytin layer is deposited on a CaF2 substrate and the SFG measurements are performed in the total internal reflection configuration, drastic modifications in the C-H and N-H spectral ranges attest the molecular recognition of avidin by biocytin. The specificity of the recognition process is confirmed by replacing avidin by other proteins. [less ▲]

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See detailProbing a molecular electronic transition by two-colour sum-frequency generation spectroscopy
Humbert, Christophe; Dreesen, Laurent ULg; Nihonyanagi, S. et al

in Applied Surface Science (2003), 212–213

We demonstrate that a new emerging technique, two-colour sum-frequency generation (SFG) spectroscopy, can be used to probe the molecular electronic properties of self-assembled monolayers (SAMs). In the ... [more ▼]

We demonstrate that a new emerging technique, two-colour sum-frequency generation (SFG) spectroscopy, can be used to probe the molecular electronic properties of self-assembled monolayers (SAMs). In the CH spectral range (2800–3200 cm-1), we show that the sum-frequency generation signal of a porphyrin alkanethiol derivative adsorbed on Pt(1 1 1) reaches a maximum intensity at ~435 nm SFG wavelength. This wavelength corresponds to the porphyrin moiety specific p–p*$ molecular electronic transition which is called the Soret or B band. This resonant behaviour is not observed for 1-dodecanethiol SAMs, which are devoid of molecular electronic transition in the investigated visible spectral range. [less ▲]

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See detailTwo-color sum-frequency generation spectroscopy: a powerful tool for the study of self-assembled monolayers
Dreesen, Laurent ULg; Humbert, Christophe; Thiry, Paul et al

Poster (2002, July)

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See detailTwo-color sum-frequency generation spectroscopy: a powerful tool for the study of self-assembled monolayers
Dreesen, Laurent ULg; Humbert, Christophe; Celebi, Michael et al

Poster (2002, June)

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