We realize functional hybrid structures associating an inorganic material, silicon, with (bio)molecular species or an organometallic film. A multistep protocol is generally necessary : (1) organic grafting of a dense functionalized monolayer on oxide free silicon ; (2) covalent coupling of molecular entities by peptide bonding or "click chemistry". We often use well-defined H-terminated Si(111) surfaces to combine spectroscopic characterizations (FTIR, XPS) with scanning probe imaging (AFM/STM) for a quantitative determination of the surface composition. In some devices, a carbonated amorphous PECVD thin film is employed.
Current projects :
– Silicon biosensors for the monitoring of biomolecular interactions
We develop silicon biosensors based on the covalent anchoring of probes allowing for specific and selective recognition of targets. We used FTIR-ATR spectroscopy to quantify the composition of the molecular layers and to optimize the biomolecular interactions. We are currently working on the specific interactions between glycan probes and lectins targets [1] and DNA aptamers probes against the mycotoxin Ochratoxin A.
[1] “Quantitative assessment of the multivalent protein-carbohydrate interactions on silicon”, J. Yang, J.-N. Chazalviel, A. Siriwardena, R. Boukherroub, F. Ozanam, S. Szunerits, and A. C. Gouget-Laemmel, Analytical Chemistry, 86 (2014) 10340-10349.
– Photoswitching surfaces :
Photoswitchning surfaces are of interest in different fields. We investigate the photoswitching properties of organic photochromic compounds immobilized on silicon surfaces… Read more
– Conditioning and functionalization of silicon nitride
Silicon nitride thin-film is a common material in the microelectronic or glass industry thanks to its dielectric and mechanical properties. We investigate the surface chemistry of its oxyde free layer by tuning the silicon-nitrogen ratio and/or by H2 plasma treatment [1]. Various strategy of functionalization are envisaged.
[1] “Etching and Chemical Control of the Silicon Nitride Surface”, M. Brunet, D. Aureau, P. Chantraine, F. Guillemot, A. Etcheberry, A. C. Gouget-Laemmel and F. Ozanam, ACS Appl. Mater. Interfaces, 9 (2017), 3075-3084.
Recent works :
• Composition of organic monolayers by calibrated FTIR
• Alkyl monolayers hydrosilylation on H-Si(111) surfaces
• Covalent immobilization of molecular entities on functionalized silicon surfaces
• Acid / base titration acide in two dimensions
• Selective oxidation of alkyl monolayers in soft plasma
• Thermal desorption of organic monolayers grafted on silicon
• Electrochemical grafting on silicon