Electrically detectable surface plasmon resonance sensor by combining a gold grating and a silicon photodiode

Abstract

We propose an electrically detectable surface plasmon resonance sensor in a liquid consisting of a Au grating and a silicon p+n photodiode. The surface plasmon resonance (SPR) was excited on the Au grating, affecting the photovoltaic signal of the photodiode under the grating. The SPR signal was thus measured by obtaining the electrical signal without reflection measurements and a polarizer. The SPR conditions were clearly measured with our proposed sensor. It was verified that the SPR condition could also be measured without polarizing the incident light. The dielectric constant of water was determined using the proposed sensor.