Graphene Oxide/Gold Coated Kretschmann Surface Plasmon Resonance Setup for Relative Humidity Detection

A Kretschmann surface plasmon resonance setup was used to detect relative humidity changes. The used prism had a gold coating of 50-nm thickness, and then, it was additionally coated with graphene oxide (GO) to increase its sensitivity to relative humidity changes. GO can adsorb moisture from air, increasing its thickness and changing its refractive index. The GO/gold coated setup had a sensitivity of 0.17°/%RH compared to the setup with gold coating only, which had a sensitivity of 0.07°/%RH. The GO/gold coated setup also had good stability and showed a standard deviation of less than 0.038 mW.