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Abstract: Thin nanostructured chalcogenide films were grown using the oblique angle deposition (OAD) technique and subsequently polymerized with thin poly(amino-p-xylylene) (PPX) films. Our objective was twofold, i.e., to use deposited polymeric thin films to allow the attachment of biomolecules to chalcogenide glass thin films, and at the same time, to increase surface area by OAD to enhance surface functionality. The effectiveness of this approach was evaluated by Fourier transform infrared spectroscopy (FTIR), together with a combination of fluorescent protein immobilization and confocal microscopy characterization. It is shown that the presence of amine groups on the surface of the polymer coated chalcogenide thin films yield a notable increment of surface coverage with proteins at large evaporation oblique angles which is expected to enhance detection performance of the film in biosensor applications. [Copyright &y& Elsevier]

Abstract: The surface of nanostructured silicon (porous silicon) was biofunctionalized by the deposition of 3-aminopropyltriethoxysilane from solution, leading to high density of amine groups covering the surface which would promote the further immobilization of biomolecules. In addition, porous silicon Bragg reflectors were developed for their use in the visible range. The optical behavior of these structures was previously designed by the use of a computational program, from which the optical constants and thickness of the individual porous silicon layers were determined. The possibility of using these structures as biosensors has been explored, based on the significant changes in the reflectance spectra before and after exposing the porous silicon optical structures to biomolecules. In particular, it is shown that there is a notable shift of the reflectance maximum associated to the Bragg reflector after immobilization of polyclonal mouse antibodies. Thus, the experimental results open the possibility of developing biosensors based on the variation of the position of the optical spectrum of porous silicon based devices. [Copyright &y& Elsevier]

Porous silicon (PS) multilayer stacks were developed for their use as interference filters in the visible range. The optical behavior of these structures was previously simulated by the use of a computational program, from which the optical constants and thickness of the individual PS layers were determined. The possibility of using these structures as biosensors has been explored, based on the significant changes in the reflectance spectra before and after exposing the PS multilayer to proteins (antibodies). In particular, it is shown that there is a notably reduction of reflectance from PS structures when this material is exposed to polyclonal mouse antibodies. Thus, the experimental results open the possibility of developing biosensors based on the variation of the shape and/or position of the optical or photoluminescent spectrum from PS. [Copyright &y& Elsevier]