Characterization of surface plasmon resonance biosensor

In the present work we present a simple method for analyzing the surface plasmon resonance (SPR) spectra numerically. According to our calculation, we found that the shift of the resonance angle is proportional to the surface density of the adsorbed molecular layer and the value difference between the refractive index of the protein layer and that of the buffer. The variation of the thickness of the gold film may change the resonance angle but does not affect the linear correlation of the shift of the resonance angle with the surface density of the adsorbed protein. In addition, we found that the variation of the thickness of the cover slide, which is stuck to the base of the prism and which is covered by a thin gold film, is approximately not influenced by the resonance angle of SPR.