Surface Plasmon Resonance Effect of the MoS2/Ag System

Detection of organic materials or heavy ions using the surface plasmon resonance (SPR) effect of the MoS2/Ag system was studies. We found that the reflectivity of the SPR system was sensitive to the incident angle of light, dielectric constant of the detected samples, wavelength of light, and thickness of the Ag film. It reached an extreme minimal value (EMV) at an extreme angle θ. As the dielectric constant of the samples was increased from 1.0 to 3.25, θ increased, enabling high-resolution detection. θ slightly decreased with the thickness of the Ag film changed from 300 to 700 nm for a given detected sample while the EMV of reflectivity increased. Moreover, the reflectivity curves were overlapped when the wavelength of light and the thickness, d of the Ag film both increased from 400 to 700 nm, showing synchronous effect. The results showed that MoS2 was a suitable material for the detection of a wide range of samples and could replace the prism.