Functionalization of the inorganic interface in nano-bio hybrid materials is a key step for a successful combination of silicon technology at the nanoscale with the specificity of biomolecular recognition in biological systems. The aims are to provide the desired functional groups for the covalent attachment of biomolecules, to guarantee the functionality of the bound biomolecules and to prevent unspecific attachment to the surface. Monolayers on silicon wafers were prepared by covalently binding organic molecules to the surface, such as organosilanes or alkenes, respectively. Biomolecules such as single-stranded DNA are acting as receptors for target molecules. They were further linked to this functionalized surface by using wet bio-chemistry. Static contact angle measurements for the quantification of the wetting behavior indicate that different molecular layers were successfully attached to silicon surfaces. The layer thickness and quality of the film formation were studied with ellipsometry and AFM. Functional end groups like the amino group and potential biomolecules such as DNA strands were labelled with fluorescent dyes to detect the binding with fluorescence microscopy.