A novel refractive index detection method in voltage scanning surface plasmon resonance system

Voltage scanning surface plasmon resonance (VSSPR) detection is realized by a metal/electro-optic dielectric/metal (MEM) three-layer sensor chip used in a prism-coupled attenuated total reflection (ATR) setup. Sweeping DC voltage is applied and recorded in real time with a fixed incident angle near the resonant angle. The VSSPR curve is defined by the reflected intensity and the applied voltage. It is observed experimentally that the resonant voltage obtained by the centroid method varied linearly with the concentration of the analytes and can be used as a characteristic and quantitative parameter to describe the SPR effect. This method can be used for refractive index detection, and also have potential applications in surface plasmon resonance imaging systems.