23 research outputs found
Peptide immobilisation on porous silicon surface for metal ions detection
In this work, a Glycyl-Histidyl-Glycyl-Histidine (GlyHisGlyHis) peptide is covalently anchored to the porous silicon PSi surface using a multi-step reaction scheme compatible with the mild conditions required for preserving the probe activity. In a first step, alkene precursors are grafted onto the hydrogenated PSi surface using the hydrosilylation route, allowing for the formation of a carboxyl-terminated monolayer which is activated by reaction with N-hydroxysuccinimide in the presence of a peptide-coupling carbodiimide N-ethyl-N'-(3-dimethylaminopropyl)-carbodiimide and subsequently reacted with the amino linker of the peptide to form a covalent amide bond. Infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy are used to investigate the different steps of functionalization
Coulomb screening by mobile charges: applications to materials science, chemistry, and biology
Etats électroniques localisés dans a-Sil-xCx:H massif et poreux (Spectroscopie IR et photoluminescence)
PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF
Interface silicium/couche organique (Maîtrise des propriétés et fonctionnalisation)
PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF
Electrochemically Formed Porous Silica
Controlled electrochemical formation of porous silica can be realized in dilute aqueous, neutral-pH, fluoride medium. Formation of a porous film is initiated by sweeping the potential applied to silicon to values higher than 20 V. Film formation, reaching a steady state, may be pursued in a wide range of potentials, including lower potentials. The origin of a threshold potential for porous film initiation has been explained quantitatively. All of the films appear mesoporous. Films grown at high potentials exhibit a variety of macrostructures superimposed on the mesoporosity. These macrostructures result from selective dissolution of silica induced by local pH lowering due to oxygen evolution. Films grown at potentials lower than 15 V appear uniform on the micrometer scale. However, all of the films also exhibit a stratified structure on the scale of a few tens of nanometres. This periodic structure can be traced back to the oscillatory behavior observed during the electrochemical dissolution of silicon in fluoride medium. It suggests that periodic breaking of the growing film may be responsible for this morphology
Greffages d'espèces organiques à la surface du silicium
PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF
Couches organiques ultra minces greffées sur SI (111) pour la microélectronique
PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF