Effect of bi-metallic structure on the performance of chitosan-graphene oxide surface plasmon resonance sensor

This paper demonstrates the effect of bi-metallic structure on the performance of a chitosan (CS)-graphene oxide (GO) surface plasmon resonance (SPR) sensor for heavy metal detection. The fabricated sensor consists of chromium, silver-gold metal layer and CS-GO at the top most surface. The sensor is used to detect Pb²⁺ ion solution with different concentration. The result shows that the structure with 40 nm silver layer gives better sensitivity than the one with 60 nm. Our proposed bimetallic structure is capable to detect Pb²⁺ ion from 0.001 ppm to 5 ppm without regeneration. The results prove that the CS-GO SPR sensor with bi-metallic structure demonstrates great performance in detecting Pb²⁺ ion.