After the years of intense investigations, nanomaterials have entered the phase of commercial applications in medicine as drug carriers or labels contrast agents for magnetic resonance imaging, and convenient tool for biodetection. Prominent example is the use of nanoparticles in combination with fluorescent labels for large number of biochemical tests. During last decade a new class of biological sensors emerged, which relies on the use of nanomaterials i.e. nanoparticles or nanowires, for detection of biological molecules or of products of biologically catalyzed reactions. Within this novel group of the devices, silicon nanowire based field effect transistors represent a promising route for label-free detection of biochemical species. Here we present and fully characterize the biosensor platform based on NiSi2-Si-NiSi2 nanowire heterostructures. Such devices require integration of Schottky-barriers (SB) to provide the change in contact resistance, which can be further used for sensing. We focus on the following aspects of the biosensor functioning and characterization: (i) fabrication and characterization of the SB-FET nanodevices; (ii) biochemical functionalization of the silicon nanowire sensors using aptamers, also known as "artificial antibodies"; (iii) demonstrate sensing capabilities of the developed devices.