The present invention provides a diagnostic device allowing highly specific and efficient in vivo and/or in vitro detection of a bio marker in a broad range of bodily fluids or tissues. The diagnostic device is composed of a binding agent that specifically binds a bio marker present in the bodily fluid linked by a linker compound or layer to the substrate, which includes a metallic, a semiconductor, or a polymeric carrier. The present invention further provides methods using said device for the detection of bio markers, as well as kits comprising said device and suitable ingredients for the detections of bio markers in a bodily fluid. Furthermore, the invention provides suitable in vivo and in vitro applications of said binding agent for the detection of specific disease-related target structures.
