Enhanced Transmission-Surface Plasmon Resonance Signal by Propagating and Localized Plasmon Coupling

摘要

In this work, we explored an enhancement of the transmission surface plasmon resonance (T-SPR) intensity by depositing silver nanoparticles (AgNPs) on a gold grating substrate. The T-SPR spectrum of the gold grating substrate with AgNPs showed a strong and narrow SPR peak located between 650 and 800 nm. The maximum SPR excitation was observed at an incident angle of 35 degree. We controlled the distance between the gold grating surface and the AgNPs by using Layer-by-Layer (LbL) ultrathin films of poly(diallydimethylammonium chloride) (PDADMAC) and poly(sodium 4-styrenesulfonate) (PSS) to study the distance dependence of coupling effect between the AgNPs and the gold grating substrate. The maximum coupling of the surface plasmons was observed at an intermediate layer thickness of ～17 nm.