Current Detection SPR Sensor Using Discontinuous Au Grating For Compact Chemical Sensor

In this paper, we propose a current-detecting surface plasmon resonance (SPR) sensor with a discontinuous Au grating on a Si nanostep. Although it is effective to illuminate vertically the backside of the grating-type SPR sensor to realize a compact chemical sensor that eliminates the interaction between the incident light and the sample under test, the spectral sensitivity of the grating structures reported so far is not sufficiently sharp. In this study, we found that a discontinuous Au grating on Si nanosteps shows sharp spectral response to a vertical illumination of near-infrared (NIR) light on the backside, and verified the effectiveness of this structure by simulations and actual device measurements.