Biosensors using Surface Plasmon Resonance (SPR) have attracted a great concern of research workers in recent years. Two sensor systems have been constructed and analyzed for performance evaluations; detecting SPR angle at a monochromatic wavelength and detecting SPR wavelength at a fixed angle, respectively. The sensitivity of SPR angle shift was found to increase with both the probing wavelength and the refractive index of the underlying biochip materials. For SPR wavelength shift mode the detection sensitivity was found to increase with wavelength, but decrease with the refractive index of the overlayer materials. The white-light SPR detection system was tested for a protein array chip and this technology will play an important role in the diagnosis of the protein chips.
