Silver nanoparticle arrays enhanced spectral surface plasmon resonance optical sensor

An on-chip spectral surface plasmon resonance (SPR) optical sensor with a silver nanoparticle (Ag NP) array has been designed. Dextran (Dex)-capped Ag NP (Dex-Ag NP) arrays were initially self-assembled on the gold (Au) sensing film. The large perturbations and increased penetration depth of the evanescent field, which is caused by the use of the Dex-Ag NP array self-assembled on the Au sensing film, can effectively enhance the SPR spectral shift response. Compared with the bare Au sensing film configuration, the Au sensing film with a Dex-Ag NP array configuration improves sensitivity from 5492 to 6613 nm/RIU.