Recently, with the development of nanotechnology, researchers are constantly expanding the applications of nanotechnology with unique properties to construct novel biosensors. For instance, quantum dots[17], carbon nanotubes[18], nanowires[19] and magnetic nanoparticles[20-22] have attracted much attention as signal transducers. Biosensors based on nanotechnology show high specificity and sensitivity after being labeled with DNA probe or antibody. The nanoparticle-based biosensor has high specificity, ease of operation, low cost, and the sensitivity needed for the rapid and reproducible detection of pathogenic microorganisms in clinical specimens. However, the covalent labeling with nanoparticles is time consuming and involves complicated synthetic procedures.