A Study On The Biosensor Based On The Surface Plasmon Resonance Effect

Surface plasma is a kind of electric charge density oscillation existing in metal nanoparticles and discontinuous metal nanometer structure. Surface plasma resonance occurs when electric charges are inspired by the incident light. After surface plasma is inspired, local electric field of the metal nanometer structure is growing up thousands times and surface plasma absorption appears distinctly. Noble metal nanoparticles such as Au, Ag, and Pt with surface plasma resonance effect possess intensive absorption in the ultraviolet-visible light bands. Absorption wavelength spectra of surface plasma resonance depend on the materials' microscale structure specialities. The two dimension microstructures and the sensitive optoelectronic properties of noble metal nano-particles become a fast developing field in basic theory and application researches. Presently, surface plasma resonance effect is widely applied in as sensing platforms for chemical sensors and biological sensors. This effect has found increasing applications in bioaction detector, medicament selection, clinic diagnosis, food control, membrane biology and so on. It will become an important normal biophysics measurement both in life science and pharmacy research.A kind biosensor system based on surface plasma resonance effect is presented in this thesis in detail. The system made up of surface plasma resonance sensing system and digital acquiring system. The sensing system uses a halogen tungsten lamp its as light source, grating as the dispersive device, linear charge coupled device as detector and resonance wavelength as metrical signal. In addition, Au metal nanoparticle film fabricated by vacuum vaporize deposition method is adopted as sensing element. Finally, the computer control system monitors the surface plasma resonance spectra change in real-time.The sensing system is used to detect related physics parameters in our application experiment researches. Surface plasma resonance biosensor response is related to the micro array structure of nanoparticle film and the dielectric constant of the microenvironment. The parameters of the microenvironment can be detected through picking up eigenvalues of the surface plasma resonance spectra. Satisfactory results have been obtained in both the experiments of detecting the refractive index of sucrose and the self assembly process of thiol.