title: Protein conformational changes revealed by optical spectroscopic reflectometry in porous silicon multilayers.
abstract: The protein-ligand molecular interactions imply strong geometrical and structural rearrangements of the biological complex which are normally detected by high sensitivity optical techniques such as time-resolved fluorescence microscopy. In this work, we have measured, by optical spectroscopic reflectometry in the visible-near-infrared region, the interaction between a sugar binding protein (SBP), covalently bound on the surface of a porous silicon (PSi) microcavity, and glucose, at different concentrations and temperatures. Variable-angle spectroscopic ellipsometric (VASE) characterization of protein-functionalized PSi layers confirms that the protein-ligand system has an overall volume smaller than the SBP alone.
authors.affiliation: National Council of Research, Institute for Microelectronic and Microsystems, Department of Naples, Via P Castellino 111, I-80131 Naples, Italy.
authors.forename: Edoardo De
authors.initials: ED
authors.lastname: Tommasi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Rea
authors.forename: Ivo
authors.initials: I
authors.lastname: Rendina
authors.forename: Lucia
authors.initials: L
authors.lastname: Rotiroti
authors.forename: Luca De
authors.initials: LD
authors.lastname: Stefano