Bio-plasmonics is proposed for the research and development of novel devices, which use biomolecules as a part of the plasmon oscillation system to actively interact with nano/micro structure. We have reported a novel design of Surface Plasmon Resonance (SPR) device and system, which uses alternative dielectric layers to enhance the SPR signal quality and modulate its resonant position. The use of biomolecular thin film, such as DNAs or Proteins, in this design can result in resonant condition of wavelength changes and thus can be detected by using nano-grating in the scattering mode with ehanced feature due to resonance. According to our calculation, it can provide ultra sensitivity system (dLx/dn) of 10 8 for biosensor applications. The fundamental SPR principle and extended application of these fundamental principles and novel devices, including screening and diagnosis, will be discussed SPR-system to control is the ability. SPR-system has the ability to detect, in near real-time, the concentration of a target analyte and biosensing is viewed as a key application domain for this new technology.