High-Performance Bimetallic SPR Sensor Based on Periodic-Multilayer-Waveguides

We propose a high-performance bimetallic surface plasmon resonance (SPR) sensor based on periodic-multilayer waveguide and analyze its performance with respect to SPR active metals, such as gold (Au) and aluminum (Al). We found that an ultra thin (similar to 3 nm) layer of gold (Au) over aluminum (Al) protects aluminum (Al) from oxidation and exhibits better sensor performance. Using couple-mode theory, we show that the sensitivity and detection accuracy could be appropriately tailored for bimetallic (Au+Al) configuration.