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Novel glycidyl-terminated organosilicon coupling agents possessing a trialkoxysilyl head group and a very long hydrocarbon chain (C22) were synthesized. Their ability to afford densely packed self-assembled monolayers (SAMs) grafted on silica-based surfaces was investigated. Transmission FT-IR spectra showed that the most regular films were obtained by using trichloracetic acid as the catalyst (10 M%). Atomic force microscopy (AFM) and optical ellipsometry were consistent with well ordered monolayers exhibiting a marked decrease of the surface roughness. Epifluorescence microscopy revealed that these SAMs possessed a better surface reactivity than monolayers obtained with the commercially available (3-glycidoxypropyl) trimethoxysilane (GPTS) upon grafting of a fluorescent probe (dansylcadaverin). Moreover, direct attachment of fluorescent antibodies (RAG-TRITC) through covalent binding led to higher mean fluorescence intensities, showing that these new SAMs possess high potential for the immobilization of biological molecules.

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The synthesis and characterisation of the cyclobutyl complex Tp(Me2)NbCl(c-C4H7)(MeC[triple bond]CMe) completes the family of cycloalkyl complexes Tp(Me2)NbCl(c-C(n)H(2n-1)), n = 3-6. The properties of the cyclobutyl complex are qualitatively similar to those of its cyclopentyl and cyclohexyl analogues, and dramatically different from those of the cyclopropyl derivative. Most conspicuously, the cyclobutyl system has an alpha-C-H agostic interaction in the dominant isomer, with no evidence for the alpha-C-C agostic character found for the smaller ring. C-C agostic character therefore seems to be unique to the cyclopropyl complex, where the acute C-C-C angles destabilise the C-C bonding orbitals.

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An acoustic Love wave immunosensor dedicated to detect biological species such as bacteria, viruses or toxins is described in this paper. We present and analyze results of antibody grafting on the Love wave device using GPTS as coupling agent between SiO 2 sensor surface and the sensitive biomembrane layer composed of antibodies. Goat anti-mouse (GAM) antibodies at concentrations from 2µg/ml to 50 µg/ml were introduced on the sensor brass cell. The saturation of the sensor surface by antibodies appears at a concentration of 20 µg/ml. The detection threshold of this primary antibody is around 2 µg/ml, and the lowest concentration allowing antigen detection is around 5 µg/ml. Mater. Res. Soc. Symp. Proc. Vol. 915