Atomic layer deposition on three dimensional silicon substrates for optical biosensors applications
Substrat silice 3D pour des applications biocapteur optique
Résumé
This thesis manuscript presents the investigations and potential applications as a (bio)sensor platform of the conform thin layers of ZnO and/or Al2O3/ZnO nanolaminates, deposited by atomic layer deposition (ALD) on the various substrates. First, a study of the optical properties of ZnO thin films (20 and 50 nm) deposited by ALD technique on the large areas of ordered silicon nanowires (SiNWs), produced by combining nanosphere lithography and metal-assisted chemical etching, was performed. These methods allowed the morphology and the organization control of SiNWs on a large area. The detailed study of structural and optical properties of core-shell SiNWs/ZnO heterostructure was done by utilizing XRD, SEM, reflectance and photoluminescence spectroscopy, respectively. Integration of SiNWs arrays as core and ZnO as shell can have a strong impact on the development of sensing elements with improved properties. In the further investigations, ZnO films formed by ALD as an optical biosensor platform for the detection of Grapevine virus A-type proteins (GVA-antigens) were represented. The GVA-antigen detection was performed using the changes in the GVA related PL band behavior. The biosensor selectivity has been proved. The possibility to detect GVA-antigens without additional labels has been demonstrated. Thus, label free and sensitive photoluminescence based biosensor for GVA-antigens has been developed. Another part of our study is a specific control of protein anchoring by the development of multifunctional surface with large-scale array of polystyrene spheres (PSS), which produced by nanosphere lithography and further blocking the unspecific adsorption of protein on the surface of the PSS by PEG SAMs. The epifluorescence microscopy was used to confirm that after immersion of sample on target protein (avidin and anti-avidin) solution, the latter are specifically located on polystyrene sphere. These results are meaningful for exploration of devices based on large-scale nanoarray of PS spheres and can be used for detection of target proteins or simply to pattern a surface with specific proteins. Our research also includes the tuning of structural properties and the enhancement of electronic and optical properties of 1D PAN ZnO/Al2O3 nanolaminates designed by atomic layer deposition (ALD) and electrospinning. The structural and optical properties of Al2O3/ ZnO determined from the XPS, TEM, FTIR, XRD and PL analysis. The enhancement of electronic and optical properties would allow application in different fields such sensors and biosensors.
L'objectif général de ce projet est de développer des solutions de nanotechnologie efficaces pour les applications de biocapteurs optiques en combinant ALD sur mesure et des processus MLD avec de nouvelles architectures de substrat 3D. Ces nouvelles architectures de substrat comptent sur haute-rapport d'aspect topographies avec des dimensions latérales caractéristiques au niveau du sous-micron à l'échelle du nanomètre et comprennent des matériaux de substrat tels que le silicium, des oxydes, ou des polymères flexibles. Leur efficacité provient du rapport élevé de la surface au volume. Toutefois, afin d'être utilisé dans des applications de capteurs optiques, conformationnelle et homogène fonctionnalisation de surface est nécessaire au niveau atomique. ALD est une excellente technique basée sur des réactions successives, l'auto-limitation de surface contrôlée de la phase gazeuse pour produire des films minces et nanolaminates dans la gamme nanométrique avec une parfaite conformité et le contrôle de processus.
Domaines
Chimie
Origine : Fichiers produits par l'(les) auteur(s)
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