Nos tutelles



Accueil > Groupes scientifiques > Electrochimie et Couches Minces > Organisation et Interactions Moléculaires sur les Surfaces

Covalent grafting of molecular probes on functionalized silicon surfaces

par Rosso Michel - publié le , mis à jour le

Participants : P. Allongue, J.-N. Chazalviel, A.C. Gouget-Laemmel, C. Henry de Villeneuve, A. Moraillon, F. Ozanam
PhD students and post-docs : T. Aschl, J. Yang (2014), E. Perez (2011), L. Touahir, S. Sam, J. Andresa

The grafting of organic molecules on surfaces is a crucial step for many applications. We developed a method for covalently attaching in mild conditions biomolecules, photochromic or ligand probes on a carboxylic acid-terminated monolayer grafted on silicon surface (see page).
We use a two-step amidation process consisting of the activation of the acid functions with a peptide coupling reagent EDC in the presence of NHS followed by the aminolysis with organic molecules probes modified by an amino linker (H2N-R) (Fig.1a). Each step is carefully analyzed by AFM imaging and quantitative IR-ATR spectroscopy (see page) to control the chemical composition of the layer and to optimize the reaction yield (Fig.1b). We also investigated the kinetics of the activation and aminolysis reaction by in-situ IR-ATR spectroscopy. For these measurements, the silicon prism is directly put into contact with a solution containing the reagents and the evolution of the reaction is followed in real-time (Fig. 1c,d).
All the protocols developed on crystalline silicon surface have been transferred onto thin films of amorphous silicon or on porous silicon for the development of biosensors (see page).

Figure 1 : (a) Multi-step functionalization of molecular probes modified by an amino linker on a carboxy-terminated monolayer ; (b) IR-ATR spectra corresponding to the carboxy-terminated surface (black), after activation in EDC/NHS (red) and aminolysis with an amino-methylpyridine (blue) ; (c-d) An in-situ real-time IR-ATR spectroscopy study of the kinetics of the activation reaction of the carboxyl-terminated surface (1st step Fig. 1a) : (c) IR spectra in the carbonyl region corresponding to the ester-NHS vibrations and (d) variation of the activation yield as a function of time.

Publications :

[1] A. Moraillon A. C. Gouget-Laemmel, F. Ozanam, and J.-N. Chazalviel, Amidation of monolayers on silicon in physiological buffers : a quantitative IR study, J. Phys. Chem. C 112 (2008) 7158-7167.

[2] S. Sam, L. Touahir, J. Salvador Andresa, P. Allongue, J.- N. Chazalviel, A. C. Gouget-Laemmel, C. Henry de Villeneuve, A. Moraillon, F. Ozanam, N. Gabouze, and S. Djebbar, Semiquantitative Study of the EDC/NHS Activation of Acid Terminal Groups at Modified Porous Silicon Surfaces, Langmuir 26 (2), 809-814 (2009).

[3] L. Touahir, J.-N. Chazalviel, S. Sam, A. Moraillon, C. Henry de Villeneuve, P. Allongue, F. Ozanam, A. C. Gouget-Laemmel, Kinetics of activation of carboxyls to succinimidyl ester groups in monolayers grafted on silicon : An in-situ real-time IR study, J. Phys. Chem. C, 115 (2011) 6782-6787

[4] A.C. Gouget-Laemmel, J. Yang, M. A. Lodhi, A. Siriwardena, D. Aureau, R. Boukherroub, J.-N. Chazalviel, F. Ozanam, S. Szunerits, Functionalization of azide-terminated silicon surfaces with glycans using “click” chemistry : XPS and FTIR study, J. Phys. Chem. C 117 (2013) 368-375.