Sensitivity-stability-optimized surface plasmon resonance sensing with double metal layers

A surface plasmon resonance (SPR) sensor, with a double-metal-layer (gold-silver) configuration that utilizes the sensitivity of the silver and the stability of the gold, was studied experimentally. Both theoretical simulations and experimental results are presented for this configuration. The measured FWHM of the reflectivity curve for the bimetallic-layer configuration is 4.8 times narrower than the single gold film configuration and its stability is better than that of the silver film configuration as well.